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Jiang T, Xu L, Qu X, Li R, Cheng Y, He H. Hsa_circ_0014606 Derived from Exosomes Promotes Gastric Carcinoma Tumorigenesis and Proliferation by Sponging miR-514b-3p to Upregulate HNRNPC. Dig Dis Sci 2024; 69:811-820. [PMID: 38217675 DOI: 10.1007/s10620-023-08254-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 12/14/2023] [Indexed: 01/15/2024]
Abstract
Gastric cancer is a common malignant tumor, and due to its insidious onset and limited screening methods, most patients are diagnosed with advanced disease and have a poor prognosis. The circRNA in exosomes has an essential role in cancer diagnosis and treatment. However, the part of hsa_circ_0014606 within exosomes in gastric cancer progression is unclear. Firstly, we extracted exosomes from the serum of gastric cancer patients and healthy individuals by ultracentrifugation and analyzed the expression of hsa_circ_0014606 in both exosomes; then knocked down hsa_circ_0014606 in vivo and in vitro, respectively, to observe its effect on the physiological function of gastric cancer cells; finally, we used bioinformatics to screen hsa_circ_0014606 targeting miRNAs and mRNAs, and experiments were performed to verify the interrelationship between the three. The results showed that the level of hsa_circ_0014606 in the serum exosomes of gastric cancer patients was significantly higher than that of the healthy population. The knockdown of hsa_circ_0014606 slowed the proliferation of gastric cancer cells, significantly reduced migration and invasion ability, accelerated apoptosis, and reduced tumor size in mice. In addition, the expression of hsa_circ_0014606 was negatively correlated with the expression of miR-514b-3p and positively correlated with the expression of heterogeneous nuclear ribonucleoprotein C (HNRNPC). In conclusion, hsa_circ_0014606 exerted a pro-cancer effect indirectly through miR-514b-3p targeting gene HNRNPC, and this study provides a new potential target for treating gastric cancer.
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Affiliation(s)
- Tao Jiang
- Department of Otolaryngology, Affiliated Zhongshan Hospital of Dalian University, Dalian, Liaoning, China
| | - Lingling Xu
- Department of Medical Oncology, The Second Hospital of Dalian Medical University, Dalian, Liaoning, China
| | - Xiaona Qu
- Department of Medical Oncology, The Second Hospital of Dalian Medical University, Dalian, Liaoning, China
| | - Rui Li
- Department of Otolaryngology, Affiliated Zhongshan Hospital of Dalian University, Dalian, Liaoning, China
| | - Ye Cheng
- Department of Medical Oncology, The Second Hospital of Dalian Medical University, Dalian, Liaoning, China
| | - Hongmei He
- Department of Medical Oncology, The Second Hospital of Dalian Medical University, Dalian, Liaoning, China.
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Huang L, Sharma D, Feng X, Pan Z, Wu S, Munoz D, Bekker A, Hu H, Tao YX. RALY participates in nerve trauma-induced nociceptive hypersensitivity through triggering Eif4g2 gene expression in primary sensory neurons. Br J Pharmacol 2024; 181:735-751. [PMID: 37782223 PMCID: PMC10873045 DOI: 10.1111/bph.16259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 08/29/2023] [Accepted: 09/13/2023] [Indexed: 10/03/2023] Open
Abstract
BACKGROUND AND PURPOSE Peripheral nerve trauma-induced dysregulation of pain-associated genes in the primary sensory neurons of dorsal root ganglion (DRG) contributes to neuropathic pain genesis. RNA-binding proteins participate in gene transcription. We hypothesized that RALY, an RNA-binding protein, participated in nerve trauma-induced dysregulation of DRG pain-associated genes and nociceptive hypersensitivity. METHODS AND RESULTS Immunohistochemistry staining showed that RALY was expressed exclusively in the nuclei of DRG neurons. Peripheral nerve trauma caused by chronic constriction injury (CCI) of unilateral sciatic nerve produced time-dependent increases in the levels of Raly mRNA and RALY protein in injured DRG. Blocking this increase through DRG microinjection of adeno-associated virus 5 (AAV5)-expressing Raly shRNA reduced the CCI-induced elevation in the amount of eukaryotic initiation factor 4 gamma 2 (Eif4g2) mRNA and Eif4g2 protein in injured DRG and mitigated the development and maintenance of CCI-induced nociceptive hypersensitivity, without altering basal (acute) response to noxious stimuli and locomotor activity. Mimicking DRG increased RALY through DRG microinjection of AAV5 expressing Raly mRNA up-regulated the expression of Eif4g2 mRNA and Eif4g2 protein in the DRG and led to hypersensitive responses to noxious stimuli in the absence of nerve trauma. Mechanistically, CCI promoted the binding of RALY to the promoter of Eif4g2 gene and triggered its transcriptional activity. CONCLUSION AND IMPLICATIONS Our findings indicate that RALY participates in nerve trauma-induced nociceptive hypersensitivity likely through transcriptionally triggering Eif4g2 expression in the DRG. RALY may be a potential target in neuropathic pain management.
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Affiliation(s)
- Lina Huang
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
| | - Dilip Sharma
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
| | - Xiaozhou Feng
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
| | - Zhiqiang Pan
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
| | - Shaogen Wu
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
| | - Daisy Munoz
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
| | - Alex Bekker
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
| | - Huijuan Hu
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
- Department of Physiology, Pharmacology & Neuroscience, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ07103, USA
| | - Yuan-Xiang Tao
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
- Department of Physiology, Pharmacology & Neuroscience, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ07103, USA
- Department of Cell Biology & Molecular Medicine, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ07103, USA
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Wu N, Zhu Y. HNRNPC Regulates GLUT1/LDHA Pathway by Stabilizing FOXM1 mRNA to Promote the Progression and Aerobic Glycolysis of Multiple Myeloma. Ann Clin Lab Sci 2024; 54:56-65. [PMID: 38514068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/23/2024]
Abstract
OBJECTIVE Multiple Myeloma (MM) is a malignant hematological disease. Heterogeneous nuclear ribonucleoprotein C1/C2 (HNRNPC) acts as an oncogene in a variety of cancers. However, the role of HNRNPC in MM has not been reported so far. METHODS The mRNA and protein expressions of HNRN-PC and FOXM1 were detected by qRT-PCR and western blot. CCK8, EDU staining, flow cytometry and western blot were used to detect cell viability and cell cycle. The extracellular flux analyzer XF96 was used to detect the production of oxygen consumption rate (OCR) and extracellular acidification rate (ECAR). Lactic acid and glucose levels in culture medium were detected by lactic acid assay kits and glucose assay kits, respectively. Then, the binding ability of HNRNPC with FOXM1 was detected by RIP and the stability of FOXM1 mRNA was appraised with qRT-PCR. With the application of qRT-PCR and western blot, the transfection efficacy of si-HNRNPC and Oe-FOXM1 was examined. Western blot was applied for the estimation of GLUT1/LDHA signaling pathway-related proteins. RESULTS The expression of HNRNPC in MM cell line was abnormally elevated. HNRNPC silence significantly inhibited the proliferation, facilitated the apoptosis, induced cycle arrest, and suppressed aerobic glycolysis in MM cells, which were all reversed by FOXM1 overexpression. It was also found that the regulatory effect of HNRNPC is realized by stabilizing FOXM1 mRNA and regulating GLUT1/LDHA pathway. CONCLUSION HNRNPC regulated GLUT1/LDHA pathway by stabilizing FOXM1 mRNA to promote the progression and aerobic glycolysis of MM.
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Affiliation(s)
- Ningning Wu
- Department of Geriatrics, Ningbo No.2 Hospital, Ningbo, Zhejiang, China
| | - Yao Zhu
- Department of Geriatrics, Ningbo No.2 Hospital, Ningbo, Zhejiang, China
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Yu YM, Hu Y. The m6A reader HNRNPC predicts adverse prognosis and promotes the progression of colorectal cancer. Technol Health Care 2024; 32:1445-1453. [PMID: 37661903 DOI: 10.3233/thc-230429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
BACKGROUND As a critical m6A RNA methylation regulator, HNRNPC has been revealed to serve as potential biomarkers in various human cancers. The specific expression and significance of HNRNPC in colorectal cancer remain unknown. OBJECTIVE This study aimed to confirm HNRNPC expression level and evaluate its function in colorectal cancer progression. METHODS 101 paired tissue samples were collected from colorectal cancer patients. HNRNPC levels in colorectal cancer were detected using PCR. CCK8 and transwell assays were conducted to estimate the effect of HNRNPC on cell growth and metastasis with the regulation of HNRNPC by cell transfection. RESULTS Upregulated HNRNPC was observed in colorectal cancer compared with normal tissues and cells. The higher HNRNPC levels in tumor tissues were associated with the advanced TNM stage and positive lymph node metastasis. Meanwhile, HNRNPC upregulation could indicate adverse outcomes of colorectal cancer patients. In vitro, the knockdown of HNRNPC significantly suppressed the proliferation, migration, and invasion of colorectal cancer cells. CONCLUSIONS Upregulated HNRNPC served as a biomarker for the prognosis and development of colorectal cancer, which provides a novel therapeutic target for colorectal cancer.
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Affiliation(s)
- Yong Ming Yu
- Department of Gastroenterology, Jiangxi Province Hospital of Integrated Chinese and Western Medicine, Nanchang, Jiangxi, China
| | - Yang Hu
- Department of Gastroenterology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China
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Guo M, He M, Zhang Y, Liu W, Qi M, Liu Z, Yi G, Deng S, Li Y, Sun X, Zhao L, Chen T, Liu Y. Nucleo-cytoplasmic shuttling of 14-3-3 epsilon carrying hnRNP C promotes autophagy. Cancer Biol Ther 2023; 24:2246203. [PMID: 37599448 PMCID: PMC10443976 DOI: 10.1080/15384047.2023.2246203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 08/03/2023] [Accepted: 08/04/2023] [Indexed: 08/22/2023] Open
Abstract
Translocation of 14-3-3 protein epsilon (14-3-3ε) was found to be involved in Triptolide (Tp)-induced inhibition of colorectal cancer (CRC) cell proliferation. However, the form of cell death induced by 14-3-3ε translocation and mechanisms underlying this effect remain unclear. This study employed label-free LC-MS/MS to identify 14-3-3ε-associated proteins in CRC cells treated with or without Tp. Our results confirmed that heterogeneous nuclear ribonucleoproteins C1/C2 (hnRNP C) were exported out of the nucleus by 14-3-3ε and degraded by ubiquitination. The nucleo-cytoplasmic shuttling of 14-3-3ε carrying hnRNP C mediated Tp-induced proliferation inhibition, cell cycle arrest and autophagic processes. These findings have broad implications for our understanding of 14-3-3ε function, provide an explanation for the mechanism of nucleo-cytoplasmic shuttling of hnRNP C and provide new insights into the complex regulation of autophagy.
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Affiliation(s)
- Manlan Guo
- Department of Neurosurgery & Medical Research Center, Shunde Hospital, Southern Medical University (The First People’s Hospital of Shunde Foshan), Foshan, China
- Transformation Engineering Research Center of Chronic Disease Diagnosis and Treatment, Department of Physiology, School of Basic Medical Sciences, Guizhou Medical University, Guiyang, Guizhou, China
| | - Minyi He
- Center for Clinical Medical Education, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Yi Zhang
- Transformation Engineering Research Center of Chronic Disease Diagnosis and Treatment, Department of Physiology, School of Basic Medical Sciences, Guizhou Medical University, Guiyang, Guizhou, China
- Department of Oncology, Guizhou Cancer Hospital, Guiyang, Guizhou, China
| | - Weiwen Liu
- Department of Neurosurgery & Medical Research Center, Shunde Hospital, Southern Medical University (The First People’s Hospital of Shunde Foshan), Foshan, China
| | - Min Qi
- Department of Neurosurgery & Medical Research Center, Shunde Hospital, Southern Medical University (The First People’s Hospital of Shunde Foshan), Foshan, China
| | - Zhifeng Liu
- Guangdong Provincial Key Laboratory of Molecular Oncologic Pathology, Southern Medical University, Guangzhou, China
| | - Guozhong Yi
- Department of Neurosurgery & Medical Research Center, Shunde Hospital, Southern Medical University (The First People’s Hospital of Shunde Foshan), Foshan, China
| | - Shengze Deng
- Department of Neurosurgery & Medical Research Center, Shunde Hospital, Southern Medical University (The First People’s Hospital of Shunde Foshan), Foshan, China
| | - Yaomin Li
- Department of Neurosurgery & Medical Research Center, Shunde Hospital, Southern Medical University (The First People’s Hospital of Shunde Foshan), Foshan, China
| | - Xuegang Sun
- School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, China
| | - Liang Zhao
- Guangdong Provincial Key Laboratory of Molecular Oncologic Pathology, Southern Medical University, Guangzhou, China
| | - Tengxiang Chen
- Transformation Engineering Research Center of Chronic Disease Diagnosis and Treatment, Department of Physiology, School of Basic Medical Sciences, Guizhou Medical University, Guiyang, Guizhou, China
| | - Yawei Liu
- Department of Neurosurgery & Medical Research Center, Shunde Hospital, Southern Medical University (The First People’s Hospital of Shunde Foshan), Foshan, China
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Zhang M, Huang N, Gao Y, Feng Z, Kang B, Guo H, Jiang J, Liao S, Wang H. HNRNPC mediated m 6A methylation of 5-methyltetrahydrofolate-homocysteine methyltransferase and involved in the occurrence of RSA. J Reprod Immunol 2023; 160:104160. [PMID: 37857158 DOI: 10.1016/j.jri.2023.104160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 08/16/2023] [Accepted: 10/02/2023] [Indexed: 10/21/2023]
Abstract
N6-methyladenosine methylated modification has been shown to play roles in recurrent spontaneous abortion. We aimed to explore role of heterogeneous nuclear ribonucleoprotein C in the occurrence of recurrent spontaneous abortion. We collected embryonic villous tissues from 3 patients with recurrent spontaneous abortion (RSA group) and 3 normal control pregnancy patients. Methylated RNA immunoprecipitation sequencing, RNA sequencing, methylated RNA immunoprecipitation quantitative PCR were conducted to detect the differentially expressed m6A methylation modification gene and regulatory gene in patients with recurrent spontaneous abortion. Methylated RNA immunoprecipitation sequencing and RNA sequencing results showed that the mRNA expression level of heterogeneous nuclear ribonucleoprotein C significantly decreased in RSA group and mRNA expression level of 5-methyltetrahydrofolate-homocysteine methyltransferase increased. Real-time quantitative PCR confirmed the differential expression of heterogeneous nuclear ribonucleoprotein C and 5-methyltetrahydrofolate-homocysteine methyltransferase. Methylated RNA immunoprecipitation quantitative PCR result showed that mRNA m6A modification level of 5-methyltetrahydrofolate-homocysteine methyltransferase decreased in RSA group. The results of western blotting, real-time quantitative PCR, immunofluorescence, matrigel invasion and wound healing assays indicated that heterogeneous nuclear ribonucleoprotein C might regulate the expression of 5-methyltetrahydrofolate-homocysteine methyltransferase by mediating m6A modification, thereby reducing the proliferation and migration of trophoblast cell line, ultimately leading to the occurrence of recurrent spontaneous abortion.
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Affiliation(s)
- Mengting Zhang
- Medical Genetic Institute of Henan Province, Henan Provincial People's Hospital, Zhengzhou University People's Hospital, Zhengzhou, China
| | - Nana Huang
- Medical Genetic Institute of Henan Province, Henan Provincial People's Hospital, Zhengzhou University People's Hospital, Zhengzhou, China
| | - Yue Gao
- Medical Genetic Institute of Henan Province, Henan Provincial People's Hospital, Zhengzhou University People's Hospital, Zhengzhou, China
| | - Zhanqi Feng
- Department of Urology, The First People's Hospital of Zhengzhou, Zhengzhou, China
| | - Bing Kang
- Medical Genetic Institute of Henan Province, Henan Provincial People's Hospital, Zhengzhou University People's Hospital, Zhengzhou, China
| | - Han Guo
- Department of Pharmacology, Huadong Hospital, Fudan University, Shanghai, China
| | - Jincheng Jiang
- Medical Genetic Institute of Henan Province, Henan Provincial People's Hospital, Zhengzhou University People's Hospital, Zhengzhou, China
| | - Shixiu Liao
- Medical Genetic Institute of Henan Province, Henan Provincial People's Hospital, Zhengzhou University People's Hospital, Zhengzhou, China.
| | - Hongdan Wang
- Medical Genetic Institute of Henan Province, Henan Provincial People's Hospital, Zhengzhou University People's Hospital, Zhengzhou, China; National Health Commission Key Laboratory of Birth Defects Prevention, Henan Key Laboratory of Population Defects Prevention, Zhengzhou, China.
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7
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Cao S, Wang D, Wang P, Liu Y, Dong W, Ruan X, Liu L, Xue Y, E T, Lin H, Liu X. SUMOylation of RALY promotes vasculogenic mimicry in glioma cells via the FOXD1/DKK1 pathway. Cell Biol Toxicol 2023; 39:3323-3340. [PMID: 37906341 PMCID: PMC10693529 DOI: 10.1007/s10565-023-09836-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2023] [Accepted: 10/11/2023] [Indexed: 11/02/2023]
Abstract
Human malignant gliomas are the most common and aggressive primary malignant tumors of the human central nervous system. Vasculogenic mimicry (VM), which refers to the formation of a tumor blood supply system independently of endothelial cells, contributes to the malignant progression of glioma. Therefore, VM is considered a potential target for glioma therapy. Accumulated evidence indicates that alterations in SUMOylation, a reversible post-translational modification, are involved in tumorigenesis and progression. In the present study, we found that UBA2 and RALY were upregulated in glioma tissues and cell lines. Downregulation of UBA2 and RALY inhibited the migration, invasion, and VM of glioma cells. RALY can be SUMOylated by conjugation with SUMO1, which is facilitated by the overexpression of UBA2. The SUMOylation of RALY increases its stability, which in turn increases its expression as well as its promoting effect on FOXD1 mRNA. The overexpression of FOXD1 promotes DKK1 transcription by activating its promoter, thereby promoting glioma cell migration, invasion, and VM. Remarkably, the combined knockdown of UBA2, RALY, and FOXD1 resulted in the smallest tumor volumes and the longest survivals of nude mice in vivo. UBA2/RALY/FOXD1/DKK1 axis may play crucial roles in regulating VM in glioma, which may contribute to the development of potential strategies for the treatment of gliomas.
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Affiliation(s)
- Shuo Cao
- Key Laboratory of Neuro-Oncology in Liaoning Province, Shenyang, 110004, China
- Department of Oncology, Shengjing Hospital of China Medical University, Shenyang, 110004, Liaoning Province, China
| | - Di Wang
- Key Laboratory of Neuro-Oncology in Liaoning Province, Shenyang, 110004, China
- Department of Neurosurgery, Shengjing Hospital of China Medical University, Shenyang, 110004, China
- Liaoning Medical Surgery and Rehabilitation Robot Technology Engineering Research Center, Shenyang, 110004, China
| | - Ping Wang
- Key Laboratory of Neuro-Oncology in Liaoning Province, Shenyang, 110004, China
- Department of Neurobiology, School of Life Sciences, China Medical University, Shenyang, 110122, China
| | - Yunhui Liu
- Key Laboratory of Neuro-Oncology in Liaoning Province, Shenyang, 110004, China
- Department of Neurosurgery, Shengjing Hospital of China Medical University, Shenyang, 110004, China
- Liaoning Medical Surgery and Rehabilitation Robot Technology Engineering Research Center, Shenyang, 110004, China
| | - Weiwei Dong
- Key Laboratory of Neuro-Oncology in Liaoning Province, Shenyang, 110004, China
- Department of Neurosurgery, Shengjing Hospital of China Medical University, Shenyang, 110004, China
- Liaoning Medical Surgery and Rehabilitation Robot Technology Engineering Research Center, Shenyang, 110004, China
| | - Xuelei Ruan
- Key Laboratory of Neuro-Oncology in Liaoning Province, Shenyang, 110004, China
- Department of Neurobiology, School of Life Sciences, China Medical University, Shenyang, 110122, China
| | - Libo Liu
- Key Laboratory of Neuro-Oncology in Liaoning Province, Shenyang, 110004, China
- Department of Neurobiology, School of Life Sciences, China Medical University, Shenyang, 110122, China
| | - Yixue Xue
- Key Laboratory of Neuro-Oncology in Liaoning Province, Shenyang, 110004, China
- Department of Neurobiology, School of Life Sciences, China Medical University, Shenyang, 110122, China
| | - Tiange E
- Key Laboratory of Neuro-Oncology in Liaoning Province, Shenyang, 110004, China
- Department of Neurosurgery, Shengjing Hospital of China Medical University, Shenyang, 110004, China
- Liaoning Medical Surgery and Rehabilitation Robot Technology Engineering Research Center, Shenyang, 110004, China
| | - Hongda Lin
- Key Laboratory of Neuro-Oncology in Liaoning Province, Shenyang, 110004, China
- Department of Neurosurgery, Shengjing Hospital of China Medical University, Shenyang, 110004, China
- Liaoning Medical Surgery and Rehabilitation Robot Technology Engineering Research Center, Shenyang, 110004, China
| | - Xiaobai Liu
- Key Laboratory of Neuro-Oncology in Liaoning Province, Shenyang, 110004, China.
- Department of Neurosurgery, Shengjing Hospital of China Medical University, Shenyang, 110004, China.
- Liaoning Medical Surgery and Rehabilitation Robot Technology Engineering Research Center, Shenyang, 110004, China.
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Wu Z, Zuo X, Zhang W, Li Y, Gui R, Leng J, Shen H, Pan B, Fan L, Li J, Jin H. m6A-Modified circTET2 Interacting with HNRNPC Regulates Fatty Acid Oxidation to Promote the Proliferation of Chronic Lymphocytic Leukemia. Adv Sci (Weinh) 2023; 10:e2304895. [PMID: 37821382 PMCID: PMC10700176 DOI: 10.1002/advs.202304895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 09/01/2023] [Indexed: 10/13/2023]
Abstract
Chronic lymphocytic leukemia (CLL) is a hematological malignancy with high metabolic heterogeneity. N6-methyladenosine (m6A) modification plays an important role in metabolism through regulating circular RNAs (circRNAs). However, the underlying mechanism is not yet fully understood in CLL. Herein, an m6A scoring system and an m6A-related circRNA prognostic signature are established, and circTET2 as a potential prognostic biomarker for CLL is identified. The level of m6A modification is found to affect the transport of circTET2 out of the nucleus. By interacting with the RNA-binding protein (RBP) heterogeneous nuclear ribonucleoprotein C (HNRNPC), circTET2 regulates the stability of CPT1A and participates in the lipid metabolism and proliferation of CLL cells through mTORC1 signaling pathway. The mTOR inhibitor dactolisib and FAO inhibitor perhexiline exert a synergistic effect on CLL cells. In addition, the biogenesis of circTET2 can be affected by the splicing process and the RBPs RBMX and YTHDC1. CP028, a splicing inhibitor, modulates the expression of circTET2 and shows pronounced inhibitory effects. In summary, circTET2 plays an important role in the modulation of lipid metabolism and cell proliferation in CLL. This study demonstrates the clinical value of circTET2 as a prognostic indicator as well as provides novel insights in targeting treatment for CLL.
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Affiliation(s)
- Zijuan Wu
- Department of Hematologythe First Affiliated Hospital of Nanjing Medical UniversityJiangsu Province HospitalNanjing Medical UniversityNanjing210029China
- Key Laboratory of Hematology of Nanjing Medical UniversityNanjing210029China
- Jiangsu Key Lab of Cancer Biomarkers, Prevention and TreatmentCollaborative Innovation Center for Personalized Cancer MedicineNanjing Medical UniversityNanjing210029China
| | - Xiaoling Zuo
- Jiangsu Key Lab of Cancer Biomarkers, Prevention and TreatmentCollaborative Innovation Center for Personalized Cancer MedicineNanjing Medical UniversityNanjing210029China
- Anqing First People's Hospital of Anhui Medical UniversityAnqing First People's Hospital of Anhui ProvinceAnqing246004China
| | - Wei Zhang
- Department of Hematologythe First Affiliated Hospital of Nanjing Medical UniversityJiangsu Province HospitalNanjing Medical UniversityNanjing210029China
- Key Laboratory of Hematology of Nanjing Medical UniversityNanjing210029China
- Jiangsu Key Lab of Cancer Biomarkers, Prevention and TreatmentCollaborative Innovation Center for Personalized Cancer MedicineNanjing Medical UniversityNanjing210029China
| | - Yongle Li
- Department of Hematologythe First Affiliated Hospital of Nanjing Medical UniversityJiangsu Province HospitalNanjing Medical UniversityNanjing210029China
- Key Laboratory of Hematology of Nanjing Medical UniversityNanjing210029China
- Jiangsu Key Lab of Cancer Biomarkers, Prevention and TreatmentCollaborative Innovation Center for Personalized Cancer MedicineNanjing Medical UniversityNanjing210029China
| | - Renfu Gui
- Department of Hematologythe First Affiliated Hospital of Nanjing Medical UniversityJiangsu Province HospitalNanjing Medical UniversityNanjing210029China
- Key Laboratory of Hematology of Nanjing Medical UniversityNanjing210029China
- Jiangsu Key Lab of Cancer Biomarkers, Prevention and TreatmentCollaborative Innovation Center for Personalized Cancer MedicineNanjing Medical UniversityNanjing210029China
| | - Jiayan Leng
- Department of HematologyAffiliated People's Hospital of Jiangsu UniversityZhenjiang212002China
| | - Haorui Shen
- Department of Hematologythe First Affiliated Hospital of Nanjing Medical UniversityJiangsu Province HospitalNanjing Medical UniversityNanjing210029China
- Key Laboratory of Hematology of Nanjing Medical UniversityNanjing210029China
- Jiangsu Key Lab of Cancer Biomarkers, Prevention and TreatmentCollaborative Innovation Center for Personalized Cancer MedicineNanjing Medical UniversityNanjing210029China
| | - Bihui Pan
- Department of Hematologythe First Affiliated Hospital of Nanjing Medical UniversityJiangsu Province HospitalNanjing Medical UniversityNanjing210029China
- Key Laboratory of Hematology of Nanjing Medical UniversityNanjing210029China
- Jiangsu Key Lab of Cancer Biomarkers, Prevention and TreatmentCollaborative Innovation Center for Personalized Cancer MedicineNanjing Medical UniversityNanjing210029China
| | - Lei Fan
- Department of Hematologythe First Affiliated Hospital of Nanjing Medical UniversityJiangsu Province HospitalNanjing Medical UniversityNanjing210029China
- Key Laboratory of Hematology of Nanjing Medical UniversityNanjing210029China
- Jiangsu Key Lab of Cancer Biomarkers, Prevention and TreatmentCollaborative Innovation Center for Personalized Cancer MedicineNanjing Medical UniversityNanjing210029China
| | - Jianyong Li
- Department of Hematologythe First Affiliated Hospital of Nanjing Medical UniversityJiangsu Province HospitalNanjing Medical UniversityNanjing210029China
- Key Laboratory of Hematology of Nanjing Medical UniversityNanjing210029China
- Jiangsu Key Lab of Cancer Biomarkers, Prevention and TreatmentCollaborative Innovation Center for Personalized Cancer MedicineNanjing Medical UniversityNanjing210029China
- National Clinical Research Center for Hematologic Diseasesthe First Affiliated Hospital of Soochow UniversitySuzhou215000China
| | - Hui Jin
- Department of Hematologythe First Affiliated Hospital of Nanjing Medical UniversityJiangsu Province HospitalNanjing Medical UniversityNanjing210029China
- Key Laboratory of Hematology of Nanjing Medical UniversityNanjing210029China
- Jiangsu Key Lab of Cancer Biomarkers, Prevention and TreatmentCollaborative Innovation Center for Personalized Cancer MedicineNanjing Medical UniversityNanjing210029China
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Zheng J, Wu S, Tang M, Xi S, Wang Y, Ren J, Luo H, Hu P, Sun L, Du Y, Yang H, Wang F, Gao H, Dai Z, Ou X, Li Y. USP39 promotes hepatocellular carcinogenesis through regulating alternative splicing in cooperation with SRSF6/HNRNPC. Cell Death Dis 2023; 14:670. [PMID: 37821439 PMCID: PMC10567755 DOI: 10.1038/s41419-023-06210-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 09/20/2023] [Accepted: 10/02/2023] [Indexed: 10/13/2023]
Abstract
Abnormal alternative splicing (AS) caused by alterations in spliceosomal factors is implicated in cancers. Standard models posit that splice site selection is mainly determined by early spliceosomal U1 and U2 snRNPs. Whether and how other mid/late-acting spliceosome components such as USP39 modulate tumorigenic splice site choice remains largely elusive. We observed that hepatocyte-specific overexpression of USP39 promoted hepatocarcinogenesis and potently regulated splice site selection in transgenic mice. In human liver cancer cells, USP39 promoted tumor proliferation in a spliceosome-dependent manner. USP39 depletion deregulated hundreds of AS events, including the oncogenic splice-switching of KANK2. Mechanistically, we developed a novel RBP-motif enrichment analysis and found that USP39 modulated exon inclusion/exclusion by interacting with SRSF6/HNRNPC in both humans and mice. Our data represented a paradigm for the control of splice site selection by mid/late-acting spliceosome proteins and their interacting RBPs. USP39 and possibly other mid/late-acting spliceosome proteins may represent potential prognostic biomarkers and targets for cancer therapy.
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Affiliation(s)
- Jingyi Zheng
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Shasha Wu
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Mao Tang
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Shaoyan Xi
- Department of Pathology, Sun Yat-Sen University Cancer Center, Guangzhou, China
- State Key Laboratory of Oncology in South China and Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Yanchen Wang
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Jun Ren
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Hao Luo
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Pengchao Hu
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Liangzhan Sun
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Yuyang Du
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Hui Yang
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Fenfen Wang
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Han Gao
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Ziwei Dai
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Xijun Ou
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Yan Li
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China.
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10
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Jia R, Che X, Jia J, Guo J. FOXM1a Isoform of Oncogene FOXM1 Is a Tumor Suppressor Suppressed by hnRNP C in Oral Squamous Cell Carcinoma. Biomolecules 2023; 13:1331. [PMID: 37759731 PMCID: PMC10526205 DOI: 10.3390/biom13091331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 08/24/2023] [Accepted: 08/29/2023] [Indexed: 09/29/2023] Open
Abstract
FOXM1 is an oncogenic transcriptional factor and includes several isoforms generated by alternative splicing. Inclusion of alternative exon 9 produces FOXM1a, a transcriptionally inactive isoform. However, the role of FOXM1a in tumorigenesis remains unknown. In addition, the regulatory mechanisms of exon 9 splicing are also unclear. In the present study, we found that overexpression of FOXM1a significantly reduced cell proliferation and colony formation of oral squamous cell carcinoma (OSCC) cell proliferation in vitro. Importantly, OSCC cells with FOXM1a overexpression showed significantly slower tumor formation in nude mice. Moreover, we identified a U-rich exonic splicing suppressor (ESS) which is responsible for exon 9 skipping. Splicing factor heterogeneous nuclear ribonucleoprotein C (hnRNP C) can bind to the ESS and suppress exon 9 inclusion and FOXM1a expression. Silence of hnRNP C also significantly suppresses OSCC cell proliferation. HnRNP C is significantly co-expressed with FOXM1 in cancers. Our study uncovered a novel regulatory mechanism of oncogene FOXM1 expression in OSCC.
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Affiliation(s)
- Rong Jia
- State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, Key Laboratory of Oral Biomedicine Ministry of Education, Hubei Key Laboratory of Stomatology, School & Hospital of Stomatology, Wuhan University, Wuhan 430072, China; (R.J.); (X.C.)
| | - Xiaoxuan Che
- State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, Key Laboratory of Oral Biomedicine Ministry of Education, Hubei Key Laboratory of Stomatology, School & Hospital of Stomatology, Wuhan University, Wuhan 430072, China; (R.J.); (X.C.)
| | - Jun Jia
- State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, Key Laboratory of Oral Biomedicine Ministry of Education, Hubei Key Laboratory of Stomatology, School & Hospital of Stomatology, Wuhan University, Wuhan 430072, China; (R.J.); (X.C.)
- Department of Oral and Maxillofacial Surgery, School & Hospital of Stomatology, Wuhan University, Wuhan 430072, China
| | - Jihua Guo
- State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, Key Laboratory of Oral Biomedicine Ministry of Education, Hubei Key Laboratory of Stomatology, School & Hospital of Stomatology, Wuhan University, Wuhan 430072, China; (R.J.); (X.C.)
- Department of Endodontics, School & Hospital of Stomatology, Wuhan University, Wuhan 430072, China
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11
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Hu H, Zhao K, Fang D, Wang Z, Yu N, Yao B, Liu K, Wang F, Mei Y. The RNA binding protein RALY suppresses p53 activity and promotes lung tumorigenesis. Cell Rep 2023; 42:112288. [PMID: 36952348 DOI: 10.1016/j.celrep.2023.112288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 02/10/2023] [Accepted: 03/03/2023] [Indexed: 03/24/2023] Open
Abstract
The tumor suppressor p53 plays a pivotal role in tumor prevention. The activity of p53 is mainly restrained by the ubiquitin E3 ligase Mdm2. However, it is not well understood how the Mdm2-p53 pathway is intricately regulated. Here we report that the RNA binding protein RALY functions as an oncogenic factor in lung cancer. RALY simultaneously binds to Mdm2 and the deubiquitinating enzyme USP7. Via these interactions, RALY not only stabilizes Mdm2 by stimulating the deubiquitinating activity of USP7 toward Mdm2 but also increases the trans-E3 ligase activity of Mdm2 toward p53. Consequently, RALY enhances Mdm2-mediated ubiquitination and degradation of p53. Functionally, RALY promotes lung tumorigenesis, at least partially, via negative regulation of p53. These findings suggest that RALY destabilizes p53 by modulating the function of Mdm2 at multiple levels. Our study also indicates a critical role for RALY in promoting lung tumorigenesis via p53 inhibition.
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Affiliation(s)
- Hao Hu
- Hefei National Laboratory for Physical Sciences at Microscale, School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, Anhui, China
| | - Kailiang Zhao
- Hefei National Laboratory for Physical Sciences at Microscale, School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, Anhui, China
| | - Debao Fang
- Hefei National Laboratory for Physical Sciences at Microscale, School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, Anhui, China
| | - Zhongyu Wang
- Hefei National Laboratory for Physical Sciences at Microscale, School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, Anhui, China
| | - Ning Yu
- Hefei National Laboratory for Physical Sciences at Microscale, School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, Anhui, China
| | - Bo Yao
- Hefei National Laboratory for Physical Sciences at Microscale, School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, Anhui, China
| | - Kaiyue Liu
- Hefei National Laboratory for Physical Sciences at Microscale, School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, Anhui, China
| | - Fang Wang
- Hefei National Laboratory for Physical Sciences at Microscale, School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, Anhui, China
| | - Yide Mei
- Hefei National Laboratory for Physical Sciences at Microscale, School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, Anhui, China; The CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, Anhui, China; Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, Anhui, China.
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12
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Cai Y, Chen T, Wang M, Deng L, Li C, Fu S, Xie K. N6-methylation of RNA-bound adenosine regulator HNRNPC promotes vascular endothelial dysfunction in type 2 diabetes mellitus by activating the PSEN1-mediated Notch pathway. Diabetes Res Clin Pract 2023; 197:110261. [PMID: 36681355 DOI: 10.1016/j.diabres.2023.110261] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 12/26/2022] [Accepted: 01/16/2023] [Indexed: 01/20/2023]
Abstract
AIM The regulatory mechanism of m6A regulators in vascular endothelial function of type 2 diabetes mellitus (T2DM) remains largely unknown. We addressed this issue based on the data retrieved Gene Expression Omnibus (GEO) database and experimental validations. METHODS Expression of m6A methylation regulators was evaluated in T2DM samples of GSE76894 dataset and GSE156341 dataset. Further analysis of candidate m6A methylation regulators was conducted in the thoracic aorta of db/db mice and high glucose (HG)-induced human umbilical vein endothelial cells (HUVECs). Ectopic expression and depletion experiments were conducted to detect effects of m6A methylation regulators on vascular endothelial function in T2DM. RESULTS It emerged that three m6A methylation regulators (HNRNPC, RBM15B, and ZC3H13) were highly expressed in T2DM, which were related to vascular EC function, showing diagnostic values for T2DM. HNRNPC expression in the thoracic aorta of db/db mice was higher than that in heterozygous db mice, and HNRNPC expression in HG-induced HUVECs was upregulated when compared with normal glucose-exposed HUVECs. Furthermore, HNRNPC activated PSEN1-dependent Notch pathway to induce eNOS inactivation and NO production decrease, thereby causing vascular endothelial dysfunction in T2DM. CONCLUSIONS HNRNPC impaired vascular endothelial function to enhance the development of vascular complications in T2DM through PSEN1-mediated Notch signaling pathway.
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Affiliation(s)
- Ying Cai
- Department of Rehabilitation Medicine, Xiangya Hospital Central South University, Changsha 410008, PR China; National Clinical Research Center for Geriatric Disorders, Xiangya Hospital Central South University, Changsha 410008, PR China
| | - Tao Chen
- The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou 510120, PR China
| | - Mingzhu Wang
- Department of Rehabilitation Medicine, Xiangya Hospital Central South University, Changsha 410008, PR China; National Clinical Research Center for Geriatric Disorders, Xiangya Hospital Central South University, Changsha 410008, PR China
| | - Lihua Deng
- Department of Rehabilitation Medicine, Xiangya Hospital Central South University, Changsha 410008, PR China; National Clinical Research Center for Geriatric Disorders, Xiangya Hospital Central South University, Changsha 410008, PR China
| | - Cui Li
- Department of Rehabilitation Medicine, Xiangya Hospital Central South University, Changsha 410008, PR China; National Clinical Research Center for Geriatric Disorders, Xiangya Hospital Central South University, Changsha 410008, PR China
| | - Siqian Fu
- Department of Rehabilitation Medicine, Xiangya Hospital Central South University, Changsha 410008, PR China; National Clinical Research Center for Geriatric Disorders, Xiangya Hospital Central South University, Changsha 410008, PR China
| | - Kangling Xie
- Department of Rehabilitation Medicine, Xiangya Hospital Central South University, Changsha 410008, PR China; National Clinical Research Center for Geriatric Disorders, Xiangya Hospital Central South University, Changsha 410008, PR China.
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13
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Qiao Y, Shi Q, Yuan X, Ding J, Li X, Shen M, Huang S, Chen Z, Wang L, Zhao Y, He X. RNA binding protein RALY activates the cholesterol synthesis pathway through an MTA1 splicing switch in hepatocellular carcinoma. Cancer Lett 2022; 538:215711. [PMID: 35490918 DOI: 10.1016/j.canlet.2022.215711] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 04/21/2022] [Accepted: 04/22/2022] [Indexed: 12/15/2022]
Abstract
Alternative splicing is an important RNA processing event that contributes to RNA complexity and protein diversity in cancer. Accumulating evidence demonstrates the essential roles of some alternatively spliced genes in carcinogenesis. However, the potential roles of alternatively spliced genes in hepatocellular carcinoma (HCC) are still largely unknown. Here we showed that the HnRNP Associated with Lethal Yellow Protein Homolog (RALY) gene is upregulated and associated with poor outcomes in HCC patients. RALY acts as a tumor-promoting factor by cooperating with splicing factor 3b subunit 3 (SF3B3) and modulating the splicing switch of Metastasis Associated 1 (MTA1) from MTA-S to MTA1-L. Normally, MTA1-S inhibits cell proliferation by reducing the transcription of cholesterol synthesis genes. In HCC, RALY and SF3B3 cooperate to regulate the MTA1 splicing switch, leading to a reduction in the MTA1-S level, and alleviating the inhibitory effect of MTA1-S on cholesterol synthesis genes, thus promoting HCC cell proliferation. In conclusion, our results revealed that the RALY-SF3B3/MTA1/cholesterol synthesis pathway contributes essentially to hepatic carcinogenesis and could serve as a promising therapeutic target for HCC.
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Affiliation(s)
- Yejun Qiao
- Fudan University Shanghai Cancer Center and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, 200032, China
| | - Qili Shi
- Fudan University Shanghai Cancer Center and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, 200032, China
| | - Xu Yuan
- Fudan University Shanghai Cancer Center and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, 200032, China
| | - Jie Ding
- Fudan University Shanghai Cancer Center and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, 200032, China
| | - Xinrong Li
- Fudan University Shanghai Cancer Center and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, 200032, China
| | - Mengting Shen
- Fudan University Shanghai Cancer Center and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, 200032, China
| | - Shenglin Huang
- Fudan University Shanghai Cancer Center and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, 200032, China; Key Laboratory of Breast Cancer in Shanghai, Fudan University Shanghai Cancer Center, Fudan University, Shanghai, 200032, China; Shanghai Key Laboratory of Radiation Oncology, Fudan University Shanghai Cancer Center, Fudan University, Shanghai, 200032, China
| | - Zhiao Chen
- Fudan University Shanghai Cancer Center and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, 200032, China; Key Laboratory of Breast Cancer in Shanghai, Fudan University Shanghai Cancer Center, Fudan University, Shanghai, 200032, China; Shanghai Key Laboratory of Radiation Oncology, Fudan University Shanghai Cancer Center, Fudan University, Shanghai, 200032, China
| | - Lu Wang
- Department of Hepatic Surgery, Fudan University Shanghai Cancer Center, Fudan University, Shanghai, 200032, China.
| | - Yingjun Zhao
- Fudan University Shanghai Cancer Center and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, 200032, China; Key Laboratory of Breast Cancer in Shanghai, Fudan University Shanghai Cancer Center, Fudan University, Shanghai, 200032, China; Shanghai Key Laboratory of Radiation Oncology, Fudan University Shanghai Cancer Center, Fudan University, Shanghai, 200032, China.
| | - Xianghuo He
- Fudan University Shanghai Cancer Center and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, 200032, China; Key Laboratory of Breast Cancer in Shanghai, Fudan University Shanghai Cancer Center, Fudan University, Shanghai, 200032, China; Shanghai Key Laboratory of Radiation Oncology, Fudan University Shanghai Cancer Center, Fudan University, Shanghai, 200032, China; Collaborative Innovation Center for Cancer Personalized Medicine, Nanjing Medical University, Nanjing, 211166, China.
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14
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Xia N, Yang N, Shan Q, Wang Z, Liu X, Chen Y, Lu J, Huang W, Wang Z. HNRNPC regulates RhoA to induce DNA damage repair and cancer-associated fibroblast activation causing radiation resistance in pancreatic cancer. J Cell Mol Med 2022; 26:2322-2336. [PMID: 35277915 PMCID: PMC8995438 DOI: 10.1111/jcmm.17254] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 01/29/2022] [Accepted: 02/17/2022] [Indexed: 12/24/2022] Open
Abstract
Pancreatic cancer (PC) is one of the most lethal types of cancer due to its asymptomatic nature in the early stages and consequent late diagnosis. Its mortality rate remains high despite advances in treatment strategies, which include a combination of surgical resection and adjuvant therapy. Although these approaches may have a positive effect on prognosis, the development of chemo- and radioresistance still poses a significant challenge for successful PC treatment. Heterogeneous nuclear ribonucleoprotein C1/C2 (HNRNPC) and RhoA have been implicated in the regulation of tumour cell proliferation and chemo- and radioresistance. Our study aims to investigate the mechanism for HNRNPC regulation of PC radiation resistance via the RhoA pathway. We found that HNRNPC and RhoA mRNA and protein expression levels were significantly higher in PC tissues compared to adjacent non-tumour tissue. Furthermore, high HNRNPC expression was associated with poor patient prognosis. Using HNRNPC overexpression and siRNA interference, we demonstrated that HNRNPC overexpression promoted radiation resistance in PC cells, while HNRNPC knockdown increased radiosensitivity. However, silencing of RhoA expression was shown to attenuate radiation resistance caused by HNRNPC overexpression. Next, we identified RhoA as a downstream target of HNRNPC and showed that inhibition of the RhoA/ROCK2-YAP/TAZ pathway led to a reduction in DNA damage repair and radiation resistance. Finally, using both in vitro assays and an in vivo subcutaneous tumour xenograft model, we demonstrated that RhoA inhibition can hinder the activity of cancer-related fibroblasts and weaken PC radiation resistance. Our study describes a role for HNRNPC and the RhoA/ROCK2-YAP/TAZ signalling pathways in mediating radiation resistance and provides a potential therapeutic target for improving the treatment of PC.
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Affiliation(s)
- Ning Xia
- Department of RadiologyRuijin Hospital Luwan BranchShanghai Jiao Tong University School of MedicineShanghaiChina
| | - Nannan Yang
- Department of RadiologyRuijin Hospital Luwan BranchShanghai Jiao Tong University School of MedicineShanghaiChina
| | - Qungang Shan
- Department of Interventional RadiologyRuijin HospitalShanghai Jiao Tong University School of MedicineShanghaiChina
| | - Ziyin Wang
- Department of Interventional RadiologyRuijin HospitalShanghai Jiao Tong University School of MedicineShanghaiChina
| | - Xiaoyu Liu
- Department of Interventional RadiologyRuijin HospitalShanghai Jiao Tong University School of MedicineShanghaiChina
| | - Yingjie Chen
- Department of Interventional RadiologyRuijin HospitalShanghai Jiao Tong University School of MedicineShanghaiChina
| | - Jian Lu
- Department of RadiologyRuijin Hospital Luwan BranchShanghai Jiao Tong University School of MedicineShanghaiChina
| | - Wei Huang
- Department of Interventional RadiologyRuijin HospitalShanghai Jiao Tong University School of MedicineShanghaiChina
| | - Zhongmin Wang
- Department of RadiologyRuijin Hospital Luwan BranchShanghai Jiao Tong University School of MedicineShanghaiChina
- Department of Interventional RadiologyRuijin HospitalShanghai Jiao Tong University School of MedicineShanghaiChina
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15
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González‐Arzola K, Guerra‐Castellano A, Rivero‐Rodríguez F, Casado‐Combreras MÁ, Pérez‐Mejías G, Díaz‐Quintana A, Díaz‐Moreno I, De la Rosa MA. Mitochondrial cytochrome c shot towards histone chaperone condensates in the nucleus. FEBS Open Bio 2021; 11:2418-2440. [PMID: 33938164 PMCID: PMC8409293 DOI: 10.1002/2211-5463.13176] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 04/26/2021] [Indexed: 12/15/2022] Open
Abstract
Despite mitochondria being key for the control of cell homeostasis and fate, their role in DNA damage response is usually just regarded as an apoptotic trigger. However, growing evidence points to mitochondrial factors modulating nuclear functions. Remarkably, after DNA damage, cytochrome c (Cc) interacts in the cell nucleus with a variety of well-known histone chaperones, whose activity is competitively inhibited by the haem protein. As nuclear Cc inhibits the nucleosome assembly/disassembly activity of histone chaperones, it might indeed affect chromatin dynamics and histone deposition on DNA. Several histone chaperones actually interact with Cc Lys residues through their acidic regions, which are also involved in heterotypic interactions leading to liquid-liquid phase transitions responsible for the assembly of nuclear condensates, including heterochromatin. This relies on dynamic histone-DNA interactions that can be modulated by acetylation of specific histone Lys residues. Thus, Cc may have a major regulatory role in DNA repair by fine-tuning nucleosome assembly activity and likely nuclear condensate formation.
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Affiliation(s)
- Katiuska González‐Arzola
- Institute for Chemical Research (IIQ)Scientific Research Centre Isla de la Cartuja (cicCartuja)University of Seville – CSICSpain
| | - Alejandra Guerra‐Castellano
- Institute for Chemical Research (IIQ)Scientific Research Centre Isla de la Cartuja (cicCartuja)University of Seville – CSICSpain
| | - Francisco Rivero‐Rodríguez
- Institute for Chemical Research (IIQ)Scientific Research Centre Isla de la Cartuja (cicCartuja)University of Seville – CSICSpain
| | - Miguel Á. Casado‐Combreras
- Institute for Chemical Research (IIQ)Scientific Research Centre Isla de la Cartuja (cicCartuja)University of Seville – CSICSpain
| | - Gonzalo Pérez‐Mejías
- Institute for Chemical Research (IIQ)Scientific Research Centre Isla de la Cartuja (cicCartuja)University of Seville – CSICSpain
| | - Antonio Díaz‐Quintana
- Institute for Chemical Research (IIQ)Scientific Research Centre Isla de la Cartuja (cicCartuja)University of Seville – CSICSpain
| | - Irene Díaz‐Moreno
- Institute for Chemical Research (IIQ)Scientific Research Centre Isla de la Cartuja (cicCartuja)University of Seville – CSICSpain
| | - Miguel A. De la Rosa
- Institute for Chemical Research (IIQ)Scientific Research Centre Isla de la Cartuja (cicCartuja)University of Seville – CSICSpain
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16
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Martin SE, Gan H, Toomer G, Sridhar N, Sztuba-Solinska J. The m 6A landscape of polyadenylated nuclear (PAN) RNA and its related methylome in the context of KSHV replication. RNA 2021; 27:1102-1125. [PMID: 34187903 PMCID: PMC8370742 DOI: 10.1261/rna.078777.121] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 06/25/2021] [Indexed: 05/10/2023]
Abstract
Polyadenylated nuclear (PAN) RNA is a long noncoding transcript involved in Kaposi's sarcoma-associated herpesvirus (KSHV) lytic reactivation and regulation of cellular and viral gene expression. We have previously shown that PAN RNA has dynamic secondary structure and protein binding profiles that can be influenced by epitranscriptomic modifications. N6-methyladenosine (m6A) is one of the most abundant chemical signatures found in viral RNA genomes and virus-encoded RNAs. Here, we combined antibody-independent next-generation mapping with direct RNA sequencing to address the epitranscriptomic status of PAN RNA in KSHV infected cells. We showed that PAN m6A status is dynamic, reaching the highest number of modifications at the late lytic stages of KSHV infection. Using a newly developed method, termed selenium-modified deoxythymidine triphosphate (SedTTP)-reverse transcription (RT) and ligation assisted PCR analysis of m6A (SLAP), we gained insight into the fraction of modification at identified sites. By applying comprehensive proteomic approaches, we identified writers and erasers that regulate the m6A status of PAN, and readers that can convey PAN m6A phenotypic effects. We verified the temporal and spatial subcellular availability of the methylome components for PAN modification by performing confocal microscopy analysis. Additionally, the RNA biochemical probing (SHAPE-MaP) outlined local and global structural alterations invoked by m6A in the context of full-length PAN RNA. This work represents the first comprehensive overview of the dynamic interplay that takes place between the cellular epitranscriptomic machinery and a specific viral RNA in the context of KSHV infected cells.
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MESH Headings
- Adenosine/analogs & derivatives
- Adenosine/genetics
- Adenosine/metabolism
- Alpha-Ketoglutarate-Dependent Dioxygenase FTO/genetics
- Alpha-Ketoglutarate-Dependent Dioxygenase FTO/metabolism
- Base Pairing
- Base Sequence
- Cell Line, Tumor
- Endonucleases/genetics
- Endonucleases/metabolism
- Epigenesis, Genetic
- Herpesvirus 8, Human/genetics
- Herpesvirus 8, Human/metabolism
- Heterogeneous-Nuclear Ribonucleoprotein Group C/genetics
- Heterogeneous-Nuclear Ribonucleoprotein Group C/metabolism
- Host-Pathogen Interactions/genetics
- Humans
- Lymphocytes/metabolism
- Lymphocytes/virology
- Methylation
- Methyltransferases/genetics
- Methyltransferases/metabolism
- Nucleic Acid Conformation
- RNA, Long Noncoding/genetics
- RNA, Long Noncoding/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA, Nuclear/genetics
- RNA, Nuclear/metabolism
- RNA-Binding Proteins/genetics
- RNA-Binding Proteins/metabolism
- Reverse Transcription
- Sequence Analysis, RNA
- Transcriptome
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Affiliation(s)
| | - Huachen Gan
- Department of Biological Sciences, Auburn University, Auburn, Alabama 36849, USA
| | - Gabriela Toomer
- Department of Biological Sciences, Auburn University, Auburn, Alabama 36849, USA
| | - Nikitha Sridhar
- Department of Biological Sciences, Auburn University, Auburn, Alabama 36849, USA
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17
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Pan Z, Du S, Wang K, Guo X, Mao Q, Feng X, Huang L, Wu S, Hou B, Chang Y, Liu T, Chen T, Li H, Bachmann T, Bekker A, Hu H, Tao Y. Downregulation of a Dorsal Root Ganglion-Specifically Enriched Long Noncoding RNA is Required for Neuropathic Pain by Negatively Regulating RALY-Triggered Ehmt2 Expression. Adv Sci (Weinh) 2021; 8:e2004515. [PMID: 34383386 PMCID: PMC8356248 DOI: 10.1002/advs.202004515] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 03/19/2021] [Indexed: 05/07/2023]
Abstract
Nerve injury-induced maladaptive changes of gene expression in dorsal root ganglion (DRG) neurons contribute to neuropathic pain. Long non-coding RNAs (lncRNAs) are emerging as key regulators of gene expression. Here, a conserved lncRNA is reported, named DRG-specifically enriched lncRNA (DS-lncRNA) for its high expression in DRG neurons. Peripheral nerve injury downregulates DS-lncRNA in injured DRG due, in part, to silencing of POU domain, class 4, transcription factor 3, a transcription factor that interacts with the DS-lncRNA gene promoter. Rescuing DS-lncRNA downregulation blocks nerve injury-induced increases in the transcriptional cofactor RALY-triggered DRG Ehmt2 mRNA and its encoding G9a protein, reverses the G9a-controlled downregulation of opioid receptors and Kcna2 in injured DRG, and attenuates nerve injury-induced pain hypersensitivities in male mice. Conversely, DS-lncRNA downregulation increases RALY-triggered Ehmt2/G9a expression and correspondingly decreases opioid receptor and Kcna2 expression in DRG, leading to neuropathic pain symptoms in male mice in the absence of nerve injury. Mechanistically, downregulated DS-lncRNA promotes more binding of increased RALY to RNA polymerase II and the Ehmt2 gene promoter and enhances Ehmt2 transcription in injured DRG. Thus, downregulation of DS-lncRNA likely contributes to neuropathic pain by negatively regulating the expression of RALY-triggered Ehmt2/G9a, a key neuropathic pain player, in DRG neurons.
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Affiliation(s)
- Zhiqiang Pan
- Department of AnesthesiologyNew Jersey Medical School, RutgersThe State University of New JerseyNewarkNJ07103USA
| | - Shibin Du
- Department of AnesthesiologyNew Jersey Medical School, RutgersThe State University of New JerseyNewarkNJ07103USA
| | - Kun Wang
- Department of AnesthesiologyNew Jersey Medical School, RutgersThe State University of New JerseyNewarkNJ07103USA
| | - Xinying Guo
- Department of AnesthesiologyNew Jersey Medical School, RutgersThe State University of New JerseyNewarkNJ07103USA
| | - Qingxiang Mao
- Department of AnesthesiologyNew Jersey Medical School, RutgersThe State University of New JerseyNewarkNJ07103USA
| | - Xiaozhou Feng
- Department of AnesthesiologyNew Jersey Medical School, RutgersThe State University of New JerseyNewarkNJ07103USA
| | - Lina Huang
- Department of AnesthesiologyNew Jersey Medical School, RutgersThe State University of New JerseyNewarkNJ07103USA
| | - Shaogen Wu
- Department of AnesthesiologyNew Jersey Medical School, RutgersThe State University of New JerseyNewarkNJ07103USA
| | - Bailing Hou
- Department of AnesthesiologyNew Jersey Medical School, RutgersThe State University of New JerseyNewarkNJ07103USA
| | - Yun‐Juan Chang
- The Office of Advanced Research ComputingRutgersThe State University of New JerseyNewarkNJ07103USA
| | - Tong Liu
- Center for Advanced Proteomics ResearchDepartments of Biochemistry, Microbiology & Molecular GeneticsNew Jersey Medical School, RutgersThe State University of New JerseyNewarkNJ07103USA
| | - Tong Chen
- Center for Advanced Proteomics ResearchDepartments of Biochemistry, Microbiology & Molecular GeneticsNew Jersey Medical School, RutgersThe State University of New JerseyNewarkNJ07103USA
| | - Hong Li
- Center for Advanced Proteomics ResearchDepartments of Biochemistry, Microbiology & Molecular GeneticsNew Jersey Medical School, RutgersThe State University of New JerseyNewarkNJ07103USA
| | - Thomas Bachmann
- Department of AnesthesiologyNew Jersey Medical School, RutgersThe State University of New JerseyNewarkNJ07103USA
| | - Alex Bekker
- Department of AnesthesiologyNew Jersey Medical School, RutgersThe State University of New JerseyNewarkNJ07103USA
| | - Huijuan Hu
- Department of AnesthesiologyNew Jersey Medical School, RutgersThe State University of New JerseyNewarkNJ07103USA
- Department of Physiology, Pharmacology & NeuroscienceNew Jersey Medical SchoolRutgersThe State University of New JerseyNewarkNJ07103USA
| | - Yuan‐Xiang Tao
- Department of AnesthesiologyNew Jersey Medical School, RutgersThe State University of New JerseyNewarkNJ07103USA
- Department of Physiology, Pharmacology & NeuroscienceNew Jersey Medical SchoolRutgersThe State University of New JerseyNewarkNJ07103USA
- Department of Cell Biology & Molecular MedicineNew Jersey Medical SchoolRutgersThe State University of New JerseyNewarkNJ07103USA
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18
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Xu F, Guan Y, Ma Y, Xue L, Zhang P, Yang X, Chong T. Bioinformatic analyses and experimental validation of the role of m6A RNA methylation regulators in progression and prognosis of adrenocortical carcinoma. Aging (Albany NY) 2021; 13:11919-11941. [PMID: 33952721 PMCID: PMC8109058 DOI: 10.18632/aging.202896] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 03/14/2021] [Indexed: 04/11/2023]
Abstract
M6A-related genes have been proven to play an important role in many cancers. However, the role of that in adrenocortical carcinoma (ACC) has not been fully elucidated. In the present study, 77 ACC samples from TCGA database were divided into localized (n = 46) and metastatic (n = 31) groups. Three differential expression genes (DEGs) and five prognostic m6A genes were screened out. M6A-related risk signature (RBM15 and HNRNPC) was constructed by the Lasso regression analysis. In TCGA cohort (training cohort), the risk signature was identified as an ACC-independent prognostic factor and can distinguish the prognostic difference of ACC patients with clinical stage I-II, T3-4 and N0 stages. A nomogram combining T stage and m6A risk score was constructed to predict the overall survival rate (OSR) of individual at 1,2,3 year. Meanwhile, its prognostic value was also confirmed in the validation cohort (GSE33371 dataset). The potential associations between m6A risk level and immune checkpoint inhibitors (ICIs) therapy were also investigated via the TISIDB online tool. High m6A risk not only can suppress immunotherapy-related biological processes, but also repress the expressions of immune-checkpoint markers. Moreover, five pairs of clinical specimens were collected to confirm the overexpression of HNRNPC and non-ectopic expression of RBM15 in tumor tissues. HNRNPC was proven to promote the proliferation, migration and invasion of H295R and SW13 cells through MTT and Transwell assays. In conclusion, the m6A-related risk signature was beneficial for prognostic analysis and can affect immune microenvironment in ACC. HNRNPC played a pro-cancer role in ACC progression.
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Affiliation(s)
- Fangshi Xu
- Department of Medicine, Xi’an Jiaotong University, Xi’an, Shaanxi 710061, China
| | - Yibing Guan
- Department of Medicine, Xi’an Jiaotong University, Xi’an, Shaanxi 710061, China
| | - Yubo Ma
- Department of Medicine, Xi’an Jiaotong University, Xi’an, Shaanxi 710061, China
| | - Li Xue
- Department of Urology, The Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi 710000, China
| | - Peng Zhang
- Department of Urology, The Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi 710000, China
| | - Xiaojie Yang
- Department of Urology, The Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi 710000, China
| | - Tie Chong
- Department of Urology, The Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi 710000, China
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19
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Hou J, Shan H, Zhang Y, Fan Y, Wu B. m 6A RNA methylation regulators have prognostic value in papillary thyroid carcinoma. Am J Otolaryngol 2020; 41:102547. [PMID: 32474328 DOI: 10.1016/j.amjoto.2020.102547] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 05/12/2020] [Indexed: 01/09/2023]
Abstract
BACKGROUND N6-Methyladenosine (m6A) is a ubiquitous RNA modification with vital roles in various cancers, but little is known about its role in papillary thyroid carcinoma (PTC), a common endocrine malignancy. METHODS In this study, an m6A RNA methylation regulator-based biomarker signature was developed for the effective prediction of prognosis in patients with PTC. The gene expression profiles of m6A RNA methylation regulators and the corresponding clinical information was downloaded from The Cancer Genome Atlas (TCGA). Differentially expressed m6A RNA methylation regulators between tumor and normal control samples, and correlation expression levels, clinical parameters, and outcomes were evaluated. And a prognostic signature was built using a PTC cohort from TCGA. RESULTS The expression level of HNRNPC was remarkably upregulated in tumor samples, while WTAP, RBM15, YTHDC2, YTHDC1, FTO, METTL14, METTL3, ALKBH5, KIAA1429, YTHDF1, and ZC3H13 were significantly downregulated in the cancer specimens compared with those in control samples. A three-gene prognostic signature comprising RBM15, KIAA1429, and FTO could predict overall survival in patients with PTC. In addition, the prognostic signature-based risk score was identified as an independent prognostic indicator for PTC. CONCLUSIONS We established a robust m6A RNA methylation regulator-based molecular signature for predicting prognosis in patients with PTC with high accuracy; this signature might provide important guidance for therapeutic strategies.
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Affiliation(s)
- Jianzhong Hou
- Department of General Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, China
| | - Haojie Shan
- Department of Orthopaedic Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, China.
| | - Yingchao Zhang
- Department of General Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, China
| | - Youben Fan
- Department of General Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, China
| | - Bo Wu
- Department of General Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, China.
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20
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Seo J, Singh NN, Ottesen EW, Lee BM, Singh RN. A novel human-specific splice isoform alters the critical C-terminus of Survival Motor Neuron protein. Sci Rep 2016; 6:30778. [PMID: 27481219 PMCID: PMC4969610 DOI: 10.1038/srep30778] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Accepted: 06/22/2016] [Indexed: 12/30/2022] Open
Abstract
Spinal muscular atrophy (SMA), a leading genetic disease of children and infants, is caused by mutations or deletions of Survival Motor Neuron 1 (SMN1) gene. SMN2, a nearly identical copy of SMN1, fails to compensate for the loss of SMN1 due to skipping of exon 7. SMN2 predominantly produces SMNΔ7, an unstable protein. Here we report exon 6B, a novel exon, generated by exonization of an intronic Alu-like sequence of SMN. We validate the expression of exon 6B-containing transcripts SMN6B and SMN6BΔ7 in human tissues and cell lines. We confirm generation of SMN6B transcripts from both SMN1 and SMN2. We detect expression of SMN6B protein using antibodies raised against a unique polypeptide encoded by exon 6B. We analyze RNA-Seq data to show that hnRNP C is a potential regulator of SMN6B expression and demonstrate that SMN6B is a substrate of nonsense-mediated decay. We show interaction of SMN6B with Gemin2, a critical SMN-interacting protein. We demonstrate that SMN6B is more stable than SMNΔ7 and localizes to both the nucleus and the cytoplasm. Our finding expands the diversity of transcripts generated from human SMN genes and reveals a novel protein isoform predicted to be stably expressed during conditions of stress.
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Affiliation(s)
- Joonbae Seo
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa 50011, USA
| | - Natalia N. Singh
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa 50011, USA
| | - Eric W. Ottesen
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa 50011, USA
| | - Brian M. Lee
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa 50011, USA
- Center for Advanced Host Defenses, Immunobiotics & Translational Comparative Medicine (CAHDIT), Iowa State University, Ames, IA 50011, USA
| | - Ravindra N. Singh
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa 50011, USA
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21
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Tajnik M, Vigilante A, Braun S, Hänel H, Luscombe NM, Ule J, Zarnack K, König J. Intergenic Alu exonisation facilitates the evolution of tissue-specific transcript ends. Nucleic Acids Res 2015; 43:10492-505. [PMID: 26400176 PMCID: PMC4666398 DOI: 10.1093/nar/gkv956] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2015] [Revised: 09/09/2015] [Accepted: 09/10/2015] [Indexed: 11/14/2022] Open
Abstract
The 3' untranslated regions (3' UTRs) of transcripts serve as important hubs for posttranscriptional gene expression regulation. Here, we find that the exonisation of intergenic Alu elements introduced new terminal exons and polyadenylation sites during human genome evolution. While Alu exonisation from introns has been described previously, we shed light on a novel mechanism to create alternative 3' UTRs, thereby opening opportunities for differential posttranscriptional regulation. On the mechanistic level, we show that intergenic Alu exonisation can compete both with alternative splicing and polyadenylation in the upstream gene. Notably, the Alu-derived isoforms are often expressed in a tissue-specific manner, and the Alu-derived 3' UTRs can alter mRNA stability. In summary, we demonstrate that intergenic elements can affect processing of preceding genes, and elucidate how intergenic Alu exonisation can contribute to tissue-specific posttranscriptional regulation by expanding the repertoire of 3' UTRs.
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Affiliation(s)
- Mojca Tajnik
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH, UK International Centre for Genetic Engineering and Biotechnology, Padriciano 99, 34149 Trieste, Italy
| | - Alessandra Vigilante
- UCL Genetics Institute, Department of Genetics, Evolution & Environment, University College London, Gower Street, London WC1E 6BT, UK Cancer Research UK London Research Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK
| | - Simon Braun
- Institute of Molecular Biology (IMB) gGmbH, Ackermannweg 4, 55128 Mainz, Germany
| | - Heike Hänel
- Institute of Molecular Biology (IMB) gGmbH, Ackermannweg 4, 55128 Mainz, Germany
| | - Nicholas M Luscombe
- UCL Genetics Institute, Department of Genetics, Evolution & Environment, University College London, Gower Street, London WC1E 6BT, UK Cancer Research UK London Research Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK Okinawa Institute of Science & Technology, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa 904-0495, Japan
| | - Jernej Ule
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH, UK Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Kathi Zarnack
- Cancer Research UK London Research Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK Buchmann Institute for Molecular Life Sciences (BMLS), Max-von-Laue-Str. 15, 60438 Frankfurt, Germany
| | - Julian König
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH, UK Institute of Molecular Biology (IMB) gGmbH, Ackermannweg 4, 55128 Mainz, Germany Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK
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22
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Cieniková Z, Jayne S, Damberger FF, Allain FHT, Maris C. Evidence for cooperative tandem binding of hnRNP C RRMs in mRNA processing. RNA 2015; 21:1931-42. [PMID: 26370582 PMCID: PMC4604433 DOI: 10.1261/rna.052373.115] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Accepted: 07/21/2015] [Indexed: 05/20/2023]
Abstract
The human hnRNP C is a ubiquitous cellular protein involved in mRNA maturation. Recently, we have shown that this protein specifically recognizes uridine (U) pentamers through its single RNA recognition motif (RRM). However, a large fraction of natural RNA targets of hnRNP C consists of much longer contiguous uridine stretches. To understand how these extended sites are recognized, we studied the binding of the RRM to U-tracts of 8-11 bases. In vivo investigation of internal translation activation of unr (upstream of N-ras) mRNA indicates that the conservation of the entire hnRNP C binding site, UC(U)8, is required for hnRNP C-dependent IRES activation. The assays further suggest a synergistic interplay between hnRNP C monomers, dependent on the protein's ability to oligomerize. In vitro spectroscopic and thermodynamic analyses show that isolated RRMs bind to (U)11 oligomers as dimers. Structural modeling of a ternary double-RRM/RNA complex indicates additionally that two RRM copies can be accommodated on the canonical sequence UC(U)8. The proposed tandem RRM binding is in very good agreement with the transcriptome-wide recognition of extended U-tracts by full-length hnRNP C, which displays a cross-linking pattern consistent with a positively cooperative RRM dimer binding model.
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Affiliation(s)
- Zuzana Cieniková
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zürich, 8093 Zürich, Switzerland
| | - Sandrine Jayne
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zürich, 8093 Zürich, Switzerland
| | - Fred Franz Damberger
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zürich, 8093 Zürich, Switzerland
| | - Frédéric Hai-Trieu Allain
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zürich, 8093 Zürich, Switzerland
| | - Christophe Maris
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zürich, 8093 Zürich, Switzerland
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23
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Hamada T, Miyakawa K, Kushige H, Shibata S, Kurachi S. Age-related expression analysis of mouse liver nuclear protein binding to 3'-untranslated region of Period2 gene. J Physiol Sci 2015; 65:349-57. [PMID: 25846207 PMCID: PMC10717453 DOI: 10.1007/s12576-015-0373-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Accepted: 03/07/2015] [Indexed: 10/23/2022]
Abstract
In mammals, both circadian rhythm and aging play important roles in regulating time-dependent homeostasis. We previously discovered an age-related increase element binding protein, hnRNP A3, which binds to the 3'-untranslated region (UTR) of blood coagulation factor IX (FIX). Here, we describe other members of this protein family, hnRNP C and hnRNP H, which bind to the 3'-UTR of the mouse circadian clock gene Period 2 (mPer2). RNA electrophoretic mobility shift assays using a (32)P-labeled Per2 RNA probe coupled with two-dimensional gel electrophoresis followed by MALDI-TOF/MS peptide mass fingerprint analysis was used to analyze these proteins. Western blotting suggested that the total expression of these proteins in mouse liver cell nuclei does not increase with age. Two-dimensional gel electrophoresis analysis of age-related protein expression showed that many isoforms of these proteins exist in the liver and that each protein exhibits a complex age-related expression pattern. These results suggest that many isoforms of proteins are regulated by different aging systems and that many age regulation systems function in the liver.
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Affiliation(s)
- Toshiyuki Hamada
- Applied Molecular-Imaging Physics, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido, 060-8638, Japan,
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24
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Rivera D, Fedele E, Marinari UM, Pronzato MA, Ricciarelli R. Evaluating the role of hnRNP-C and FMRP in the cAMP-induced APP metabolism. Biofactors 2015; 41:121-6. [PMID: 25809670 DOI: 10.1002/biof.1207] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Accepted: 02/27/2015] [Indexed: 11/09/2022]
Abstract
Cyclic adenosine monophosphate (cAMP) modulates synaptic plasticity and memory and manipulation of the cAMP/protein kinase A/cAMP responsive element binding protein pathway significantly affects cognitive functions. Notably, cAMP can increase the expression of the amyloid precursor protein (APP), whose proteolytic processing gives rise to amyloid beta (Aβ) peptides. Despite playing a pathogenic role in Alzheimer's disease, physiological concentrations of Aβ are necessary for the cAMP-mediated regulation of long-term potentiation, supporting the existence of a novel cAMP/APP/Aβ cascade with a crucial role in memory formation. However, the molecular mechanisms by which cAMP stimulates APP expression and Aβ production remain unclear. Here, we investigated whether hnRNP-C and FMRP, two RNA-binding proteins largely involved in the expression of APP, are the cAMP effectors inducing the protein synthesis of APP. Using RNA immunoprecipitation and RNA-silencing approaches, we found that neither hnRNP-C nor FMRP is required for cAMP to stimulate APP and Aβ production.
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Affiliation(s)
- D Rivera
- Department of Experimental Medicine, University of Genoa, Genoa, Italy
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25
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Dechtawewat T, Songprakhon P, Limjindaporn T, Puttikhunt C, Kasinrerk W, Saitornuang S, Yenchitsomanus PT, Noisakran S. Role of human heterogeneous nuclear ribonucleoprotein C1/C2 in dengue virus replication. Virol J 2015; 12:14. [PMID: 25890165 PMCID: PMC4351676 DOI: 10.1186/s12985-014-0219-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Accepted: 11/27/2014] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Host and viral proteins are involved in dengue virus (DENV) replication. Heterogeneous ribonucleoprotein (hnRNP) C1/C2 are abundant host cellular proteins that exhibit RNA binding activity and play important roles in the replication of positive-strand RNA viruses such as poliovirus and hepatitis C virus. hnRNP C1/C2 have previously been shown to interact with vimentin and viral NS1 in DENV-infected cells; however, their functional role in DENV replication is not clearly understood. In the present study, we investigated the role of hnRNP C1/C2 in DENV replication by using an in vitro model of DENV infection in a hepatocyte cell line (Huh7) and siRNA-mediated knockdown of hnRNP C1/C2. METHODS Huh7 cells were transfected with hnRNP C1/C2-specific siRNA or irrelevant siRNA (control) followed by infection with DENV. Mock and DENV-infected knockdown cells were processed for immunoprecipitation using hnRNP C1/C2-specific antibody or their isotype-matched control antibody. The immunoprecipitated samples were subjected to RNA extraction and reverse transcriptase polymerase chain reaction (RT-PCR) for detection of DENV RNA. In addition, the knockdown cells harvested at varying time points after the infection were assessed for cell viability, cell proliferation, percentage of DENV infection, amount of viral RNA, and viral E and NS1 expression. Culture supernatants were subjected to focus forming unit assays to determine titers of infectious DENV. DENV luciferase reporter assay was also set up to determine viral translation. RESULTS Immunoprecipitation with the anti-hnRNP C1/C2 antibody and subsequent RT-PCR revealed the presence of DENV RNA in the immunoprecipitated complex containing hnRNP C1/C2 proteins. Transfection with hnRNP C1/C2-specific siRNA resulted in a significant reduction of hnRNP C1/C2 mRNA and protein levels but did not induce cell death during DENV infection. The reduced hnRNP C1/C2 expression decreased the percentage of DENV antigen-positive cells as well as the amount of DENV RNA and the relative levels of DENV E and NS1 proteins; however, it had no direct effect on DENV translation. In addition, a significant reduction of DENV titers was observed in the supernatant from DENV-infected cells following the knockdown of hnRNP C1/C2. CONCLUSIONS Our findings suggest that hnRNP C1/C2 is involved in DENV replication at the stage of viral RNA synthesis.
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Affiliation(s)
- Thanyaporn Dechtawewat
- Division of Molecular Medicine, Office of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, 10700, Thailand.
- Graduate Program in Immunology, Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, 10700, Thailand.
| | - Pucharee Songprakhon
- Division of Molecular Medicine, Office of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, 10700, Thailand.
| | - Thawornchai Limjindaporn
- Department of Anatomy, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, 10700, Thailand.
| | - Chunya Puttikhunt
- Medical Biotechnology Research Unit, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Bangkok, 10700, Thailand.
- Division of Dengue Hemorrhagic Fever Research Unit, Office of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, 10700, Thailand.
| | - Watchara Kasinrerk
- Division of Clinical Immunology, Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, 50200, Thailand.
- Biomedical Technology Research Center, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Chiang Mai, 50200, Thailand.
| | - Sawanan Saitornuang
- Medical Biotechnology Research Unit, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Bangkok, 10700, Thailand.
- Division of Dengue Hemorrhagic Fever Research Unit, Office of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, 10700, Thailand.
| | - Pa-Thai Yenchitsomanus
- Division of Molecular Medicine, Office of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, 10700, Thailand.
| | - Sansanee Noisakran
- Medical Biotechnology Research Unit, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Bangkok, 10700, Thailand.
- Division of Dengue Hemorrhagic Fever Research Unit, Office of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, 10700, Thailand.
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26
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Cholewa B, Pellitteri-Hahn MC, Scarlett CO, Ahmad N. Large-scale label-free comparative proteomics analysis of polo-like kinase 1 inhibition via the small-molecule inhibitor BI 6727 (Volasertib) in BRAF(V600E) mutant melanoma cells. J Proteome Res 2014; 13:5041-50. [PMID: 24884503 PMCID: PMC4227549 DOI: 10.1021/pr5002516] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Indexed: 12/11/2022]
Abstract
Polo-like kinase 1 (Plk1) is a serine/threonine kinase that plays a key role during the cell cycle by regulating mitotic entry, progression, and exit. Plk1 is overexpressed in a variety of human cancers and is essential to sustained oncogenic proliferation, thus making Plk1 an attractive therapeutic target. However, the clinical efficacy of Plk1 inhibition has not emulated the preclinical success, stressing an urgent need for a better understanding of Plk1 signaling. This study addresses that need by utilizing a quantitative proteomics strategy to compare the proteome of BRAF(V600E) mutant melanoma cells following treatment with the Plk1-specific inhibitor BI 6727. Employing label-free nano-LC-MS/MS technology on a Q-exactive followed by SIEVE processing, we identified more than 20 proteins of interest, many of which have not been previously associated with Plk1 signaling. Here we report the down-regulation of multiple metabolic proteins with an associated decrease in cellular metabolism, as assessed by lactate and NAD levels. Furthermore, we have also identified the down-regulation of multiple proteasomal subunits, resulting in a significant decrease in 20S proteasome activity. Additionally, we have identified a novel association between Plk1 and p53 through heterogeneous ribonucleoprotein C1/C2 (hnRNPC), thus providing valuable insight into Plk1's role in cancer cell survival.
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Affiliation(s)
- Brian
D. Cholewa
- Department of Dermatology, Molecular and Environmental Toxicology
Center, and School of Pharmacy, University of Wisconsin, 1300 University Avenue, Madison, Wisconsin 53706, United States
| | - Molly C. Pellitteri-Hahn
- Department of Dermatology, Molecular and Environmental Toxicology
Center, and School of Pharmacy, University of Wisconsin, 1300 University Avenue, Madison, Wisconsin 53706, United States
| | - Cameron O. Scarlett
- Department of Dermatology, Molecular and Environmental Toxicology
Center, and School of Pharmacy, University of Wisconsin, 1300 University Avenue, Madison, Wisconsin 53706, United States
| | - Nihal Ahmad
- Department of Dermatology, Molecular and Environmental Toxicology
Center, and School of Pharmacy, University of Wisconsin, 1300 University Avenue, Madison, Wisconsin 53706, United States
- William
S. Middleton Memorial VA Hospital, 2500 Overlook Terrace, Madison, Wisconsin 53705, United States
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Juan WC, Roca X, Ong ST. Identification of cis-acting elements and splicing factors involved in the regulation of BIM Pre-mRNA splicing. PLoS One 2014; 9:e95210. [PMID: 24743263 PMCID: PMC3990581 DOI: 10.1371/journal.pone.0095210] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Accepted: 03/25/2014] [Indexed: 11/25/2022] Open
Abstract
Aberrant changes in the expression of the pro-apoptotic protein, BCL-2-like 11 (BIM), can result in either impaired or excessive apoptosis, which can contribute to tumorigenesis and degenerative disorders, respectively. Altering BIM pre-mRNA splicing is an attractive approach to modulate apoptosis because BIM activity is partly determined by the alternative splicing of exons 3 or 4, whereby exon 3-containing transcripts are not apoptotic. Here we identified several cis-acting elements and splicing factors involved in BIM alternative splicing, as a step to better understand the regulation of BIM expression. We analyzed a recently discovered 2,903-bp deletion polymorphism within BIM intron 2 that biased splicing towards exon 3, and which also impaired BIM-dependent apoptosis. We found that this region harbors multiple redundant cis-acting elements that repress exon 3 inclusion. Furthermore, we have isolated a 23-nt intronic splicing silencer at the 3′ end of the deletion that is important for excluding exon 3. We also show that PTBP1 and hnRNP C repress exon 3 inclusion, and that downregulation of PTBP1 inhibited BIM-mediated apoptosis. Collectively, these findings start building our understanding of the cis-acting elements and splicing factors that regulate BIM alternative splicing, and also suggest potential approaches to alter BIM splicing for therapeutic purposes.
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Affiliation(s)
- Wen Chun Juan
- Cancer and Stem Cell Biology Signature Research Programme, Duke-NUS Graduate Medical School, Singapore, Singapore
| | - Xavier Roca
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
- * E-mail: (XR); (STO)
| | - S. Tiong Ong
- Cancer and Stem Cell Biology Signature Research Programme, Duke-NUS Graduate Medical School, Singapore, Singapore
- Department of Haematology, Singapore General Hospital, Singapore, Singapore
- Department of Medical Oncology, National Cancer Centre, Singapore, Singapore
- Division of Medical Oncology, Department of Medicine, Duke University Medical Center, Chapel Hill, North Carolina, United States of America
- * E-mail: (XR); (STO)
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28
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Abstract
DUSP3 (or Vaccinia virus phosphatase VH1-related; VHR) is a small dual-specificity phosphatase known to dephosphorylate c-Jun N-terminal kinases and extracellular signal-regulated kinases. In human cervical cancer cells, DUSP3 is overexpressed, localizes preferentially to the nucleus, and plays a key role in cellular proliferation and senescence triggering. Other DUSP3 functions are still unknown, as illustrated by recent and unpublished results from our group showing that this enzyme mediates DNA damage response or repair processes. In this study, we sought to identify new interactions between DUSP3 and proteins directly or indirectly involved in or correlated with its biological roles in HeLa cells exposed to gamma or UV radiation. By using GST-DUSP as bait, we pulled down interacting proteins and identified them by LC-MS/MS. Of the 46 proteins obtained, six hits were extensively validated by immune techniques; the proteins Nucleophosmin, HnRNP C1/C2, and Nucleolin were the most promising targets found to directly interact with DUSP3. We then analyzed the DUSP3 interactomes using physical protein-protein interaction networks using our hits as the seed list. The validated hits as well as unvalidated hits fluctuated on the DUSP3 interactomes of HeLa cells, independent of the time post radiation, which confirmed our proteomic and experimental data and clearly showed the proximity of DUSP3 to proteins involved in processes intimately related to DNA repair and senescence, such as Ku70 and Tert, via interactions with nucleolar proteins, which were identified in this study, that regulate DNA/RNA structure and functions.
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Affiliation(s)
- Karine Panico
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC , Rua Santa Adélia, 166, Bairro Bangu, Santo Andre-SP 09210-170, Brazil
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29
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Wang H, Albadawi H, Siddiquee Z, Stone JM, Panchenko MP, Watkins MT, Stone JR. Altered vascular activation due to deficiency of the NADPH oxidase component p22phox. Cardiovasc Pathol 2013; 23:35-42. [PMID: 24035466 DOI: 10.1016/j.carpath.2013.08.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Revised: 08/04/2013] [Accepted: 08/05/2013] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Reactive oxygen species generated by nicotinamide adenine dinucleotide phosphate (NADPH) oxidase play important roles in vascular activation. The p22(phox) subunit is necessary for the activity of NADPH oxidase complexes utilizing Nox1, Nox2, Nox3, and Nox4 catalytic subunits. METHODS We assessed p22(phox)-deficient mice and human tissue for altered vascular activation. RESULTS Mice deficient in p22(phox) were smaller than their wild-type littermates but showed no alteration in basal blood pressure. The wild-type littermates were relatively resistant to forming intimal hyperplasia following carotid ligation, and the intimal hyperplasia that developed was not altered by p22(phox) deficiency. However, at the site of carotid artery ligation, the p22(phox)-deficient mice showed significantly less vascular elastic fiber loss compared with their wild-type littermates. This preservation of elastic fibers was associated with a reduced matrix metallopeptidase (MMP) 12/tissue inhibitor of metalloproteinase (TIMP) 1 expression ratio. A similar decrease in the relative MMP12/TIMP1 expression ratio occurred in human coronary artery smooth muscle cells upon knockdown of the hydrogen peroxide responsive kinase CK1αLS. In the ligated carotid arteries, the p22(phox)-deficient mice showed reduced expression of heterogeneous nuclear ribonucleoprotein C (hnRNP-C), suggesting reduced activity of CK1αLS. In a lung biopsy from a human patient with p22(phox) deficiency, there was also reduced vascular hnRNP-C expression. CONCLUSIONS These findings indicate that NADPH oxidase complexes modulate aspects of vascular activation including vascular elastic fiber loss, the MMP12/TIMP1 expression ratio, and the expression of hnRNP-C. Furthermore, these findings suggest that the effects of NADPH oxidase on vascular activation are mediated in part by protein kinase CK1αLS.
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MESH Headings
- Animals
- Carotid Artery Injuries/enzymology
- Carotid Artery Injuries/pathology
- Carotid Artery, Common/enzymology
- Carotid Artery, Common/pathology
- Case-Control Studies
- Casein Kinase Ialpha/genetics
- Casein Kinase Ialpha/metabolism
- Cells, Cultured
- Coronary Vessels/enzymology
- Coronary Vessels/pathology
- Cytochrome b Group/deficiency
- Cytochrome b Group/genetics
- Elastic Tissue/enzymology
- Elastic Tissue/pathology
- Female
- Granulomatous Disease, Chronic/enzymology
- Granulomatous Disease, Chronic/genetics
- Granulomatous Disease, Chronic/pathology
- Heterogeneous-Nuclear Ribonucleoprotein Group C/metabolism
- Humans
- Hyperplasia
- Infant
- Male
- Matrix Metalloproteinase 12/metabolism
- Mice
- Mice, Knockout
- Muscle, Smooth, Vascular/enzymology
- Muscle, Smooth, Vascular/pathology
- NADPH Oxidases/deficiency
- NADPH Oxidases/genetics
- Neointima
- RNA Interference
- Reactive Oxygen Species/metabolism
- Tissue Inhibitor of Metalloproteinase-1/metabolism
- Transfection
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Affiliation(s)
- He Wang
- Center for Systems Biology, Massachusetts General Hospital and Department of Pathology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
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30
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Anantha RW, Alcivar AL, Ma J, Cai H, Simhadri S, Ule J, König J, Xia B. Requirement of heterogeneous nuclear ribonucleoprotein C for BRCA gene expression and homologous recombination. PLoS One 2013; 8:e61368. [PMID: 23585894 PMCID: PMC3621867 DOI: 10.1371/journal.pone.0061368] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2012] [Accepted: 03/12/2013] [Indexed: 12/01/2022] Open
Abstract
Background Heterogeneous nuclear ribonucleoprotein C1/C2 (hnRNP C) is a core component of 40S ribonucleoprotein particles that bind pre-mRNAs and influence their processing, stability and export. Breast cancer tumor suppressors BRCA1, BRCA2 and PALB2 form a complex and play key roles in homologous recombination (HR), DNA double strand break (DSB) repair and cell cycle regulation following DNA damage. Methods PALB2 nucleoprotein complexes were isolated using tandem affinity purification from nuclease-solubilized nuclear fraction. Immunofluorescence was used for localization studies of proteins. siRNA-mediated gene silencing and flow cytometry were used for studying DNA repair efficiency and cell cycle distribution/checkpoints. The effect of hnRNP C on mRNA abundance was assayed using quantitative reverse transcriptase PCR. Results and Significance We identified hnRNP C as a component of a nucleoprotein complex containing breast cancer suppressor proteins PALB2, BRCA2 and BRCA1. Notably, other components of the 40S ribonucleoprotein particle were not present in the complex. hnRNP C was found to undergo significant changes of sub-nuclear localization after ionizing radiation (IR) and to partially localize to DNA damage sites. Depletion of hnRNP C substantially altered the normal balance of repair mechanisms following DSB induction, reducing HR usage in particular, and impaired S phase progression after IR. Moreover, loss of hnRNP C strongly reduced the abundance of key HR proteins BRCA1, BRCA2, RAD51 and BRIP1, which can be attributed, at least in part, to the downregulation of their mRNAs due to aberrant splicing. Our results establish hnRNP C as a key regulator of BRCA gene expression and HR-based DNA repair. They also suggest the existence of an RNA regulatory program at sites of DNA damage, which involves a unique function of hnRNP C that is independent of the 40S ribonucleoprotein particles and most other hnRNP proteins.
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Affiliation(s)
- Rachel W. Anantha
- Department of Radiation Oncology, The Cancer Institute of New Jersey and Robert Wood Johnson Medical School, New Brunswick, New Jersey, United States of America
| | - Allen L. Alcivar
- Department of Radiation Oncology, The Cancer Institute of New Jersey and Robert Wood Johnson Medical School, New Brunswick, New Jersey, United States of America
| | - Jianglin Ma
- Department of Radiation Oncology, The Cancer Institute of New Jersey and Robert Wood Johnson Medical School, New Brunswick, New Jersey, United States of America
| | - Hong Cai
- Department of Radiation Oncology, The Cancer Institute of New Jersey and Robert Wood Johnson Medical School, New Brunswick, New Jersey, United States of America
| | - Srilatha Simhadri
- Department of Radiation Oncology, The Cancer Institute of New Jersey and Robert Wood Johnson Medical School, New Brunswick, New Jersey, United States of America
| | - Jernej Ule
- MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Julian König
- MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Bing Xia
- Department of Radiation Oncology, The Cancer Institute of New Jersey and Robert Wood Johnson Medical School, New Brunswick, New Jersey, United States of America
- * E-mail:
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31
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Zarnack K, König J, Tajnik M, Martincorena I, Eustermann S, Stévant I, Reyes A, Anders S, Luscombe N, Ule J. Direct competition between hnRNP C and U2AF65 protects the transcriptome from the exonization of Alu elements. Cell 2013; 152:453-66. [PMID: 23374342 PMCID: PMC3629564 DOI: 10.1016/j.cell.2012.12.023] [Citation(s) in RCA: 334] [Impact Index Per Article: 30.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Revised: 09/22/2012] [Accepted: 12/12/2012] [Indexed: 11/26/2022]
Abstract
There are ~650,000 Alu elements in transcribed regions of the human genome. These elements contain cryptic splice sites, so they are in constant danger of aberrant incorporation into mature transcripts. Despite posing a major threat to transcriptome integrity, little is known about the molecular mechanisms preventing their inclusion. Here, we present a mechanism for protecting the human transcriptome from the aberrant exonization of transposable elements. Quantitative iCLIP data show that the RNA-binding protein hnRNP C competes with the splicing factor U2AF65 at many genuine and cryptic splice sites. Loss of hnRNP C leads to formation of previously suppressed Alu exons, which severely disrupt transcript function. Minigene experiments explain disease-associated mutations in Alu elements that hamper hnRNP C binding. Thus, by preventing U2AF65 binding to Alu elements, hnRNP C plays a critical role as a genome-wide sentinel protecting the transcriptome. The findings have important implications for human evolution and disease.
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Affiliation(s)
- Kathi Zarnack
- European Molecular Biology Laboratory (EMBL) European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK
| | - Julian König
- MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 0QH, UK
| | - Mojca Tajnik
- MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 0QH, UK
- Faculty of Medicine, University of Ljubljana, Vrazov trg 2, SI-1104 Ljubljana, Slovenia
| | - Iñigo Martincorena
- European Molecular Biology Laboratory (EMBL) European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK
| | | | - Isabelle Stévant
- European Molecular Biology Laboratory (EMBL) European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK
| | - Alejandro Reyes
- EMBL, Genome Biology Unit, Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Simon Anders
- EMBL, Genome Biology Unit, Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Nicholas M. Luscombe
- European Molecular Biology Laboratory (EMBL) European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK
- UCL Genetics Institute, Department of Genetics, Environment and Evolution, University College London, Gower Street, London WC1E 6BT, UK
- Cancer Research UK London Research Institute, 44 Lincoln’s Inn Fields, London WC2A 3LY, UK
- Okinawa Institute for Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa 904-0495, Japan
| | - Jernej Ule
- MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 0QH, UK
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Sun S, Zhang Z, Fregoso O, Krainer AR. Mechanisms of activation and repression by the alternative splicing factors RBFOX1/2. RNA 2012; 18:274-83. [PMID: 22184459 PMCID: PMC3264914 DOI: 10.1261/rna.030486.111] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2011] [Accepted: 11/09/2011] [Indexed: 05/20/2023]
Abstract
RBFOX1 and RBFOX2 are alternative splicing factors that are predominantly expressed in the brain and skeletal muscle. They specifically bind the RNA element UGCAUG, and regulate alternative splicing positively or negatively in a position-dependent manner. The molecular basis for the position dependence of these and other splicing factors on alternative splicing of their targets is not known. We explored the mechanisms of RBFOX splicing activation and repression using an MS2-tethering assay. We found that the Ala/Tyr/Gly-rich C-terminal domain is sufficient for exon activation when tethered to the downstream intron, whereas both the C-terminal domain and the central RRM are required for exon repression when tethered to the upstream intron. Using immunoprecipitation and mass spectrometry, we identified hnRNP H1, RALY, and TFG as proteins that specifically interact with the C-terminal domain of RBFOX1 and RBFOX2. RNA interference experiments showed that hnRNP H1 and TFG modulate the splicing activity of RBFOX1/2, whereas RALY had no effect. However, TFG is localized in the cytoplasm, and likely modulates alternative splicing indirectly.
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Affiliation(s)
- Shuying Sun
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA
| | - Zuo Zhang
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA
| | - Oliver Fregoso
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA
- Watson School of Biological Sciences, Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA
| | - Adrian R. Krainer
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA
- Corresponding author.E-mail .
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Irimura S, Kitamura K, Kato N, Saiki K, Takeuchi A, Matsuo M, Nishio H, Lee MJ. HnRNP C1/C2 may regulate exon 7 splicing in the spinal muscular atrophy gene SMN1. Kobe J Med Sci 2009; 54:E227-E236. [PMID: 19628962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Spinal muscular atrophy (SMA) is caused by loss of SMN1. A nearly identical gene, SMN2, fails to compensate for the loss of SMN1 because SMN2 produces mainly an exon 7-skipped product. The +6C in SMN1 exon 7 proceeds to include exon 7 into mRNA, while the +6U in SMN2 causes skipping of exon 7. Here, approximately 45kD proteins bound to the SMN exon 7 RNA probe was found, and identified as hnRNP C1/C2. In gel-shift assay, hnRNP C1/C2 had a greater affinity for the RNA probe with +6C than for the RNA probe with +6U. In vitro splicing assay showed that anti-hnRNP C1/C2 antibody hampered splicing of SMN1 exon 7, but did not affect splicing of SMN2 exon 7. In conclusion, we showed the possibility that hnRNP C1/C2 enhanced SMN1 exon 7 splicing specifically.
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Affiliation(s)
- Sanae Irimura
- Department of Genetic Epidemiology, Kobe University Graduate School of Medicine, Kobe, Japan
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34
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Bedri S, Cizek SM, Rastarhuyeva I, Stone JR. Regulation of protein kinase CK1alphaLS by dephosphorylation in response to hydrogen peroxide. Arch Biochem Biophys 2007; 466:242-9. [PMID: 17626781 PMCID: PMC2131699 DOI: 10.1016/j.abb.2007.06.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2007] [Revised: 06/12/2007] [Accepted: 06/14/2007] [Indexed: 12/19/2022]
Abstract
Low levels of hydrogen peroxide (H(2)O(2)) are mitogenic to mammalian cells and stimulate the hyperphosphorylation of heterogeneous nuclear ribonucleoprotein C (hnRNP-C) by protein kinase CK1alpha. However, the mechanisms by which CK1alpha is regulated have been unclear. Here it is demonstrated that low levels of H(2)O(2) stimulate the rapid dephosphorylation of CK1alphaLS, a nuclear splice form of CK1alpha. Furthermore, it is demonstrated that either treatment of endothelial cells with H(2)O(2), or dephosphorylation of CK1alphaLS in vitro enhances the association of CK1alphaLS with hnRNP-C. In addition, dephosphorylation of CK1alphaLS in vitro enhances the kinase's ability to phosphorylate hnRNP-C. While CK1alpha appears to be present in all metazoans, analysis of CK1alpha genomic sequences from several species reveals that the alternatively spliced nuclear localizing L-insert is unique to vertebrates, as is the case for hnRNP-C. These observations indicate that CK1alphaLS and hnRNP-C represent conserved components of a vertebrate-specific H(2)O(2)-responsive nuclear signaling pathway.
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Affiliation(s)
| | | | | | - James R. Stone
- Correspondence: James R. Stone, MD, PhD, Massachusetts General Hospital, Simches Research Building, Room 8236, 185 Cambridge Street CPZN, Boston, MA 02114. Tel: 617 726-8303; Fax: 617 643-3566; E-mail:
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Abstract
Clinically apparent hereditary vitamin D-resistant rickets (HVDRR) usually results from a loss of function mutation in the vitamin D receptor (VDR). We recently described a human with the classical HVDRR phenotype but normal VDR function. Hormone resistance resulted from constitutive overexpression of heterogeneous nuclear ribonucleoprotein (hnRNP) that competed with a normally functioning VDR-retinoid X receptor (RXR) dimer for binding to the vitamin D response element (VDRE). Here we describe the purification, molecular cloning, and expression of this vitamin D resistance-causing, competitive response element-binding protein (REBiP) hnRNP C1/C2. When overexpressed in vitamin D-responsive cells, cDNAs for both hnRNPC1 and hnRNPC2 inhibited VDR-VDRE-directed transactivation (28 and 43%, respectively; both p < 0.005). By contrast, transient expression of an hnRNP C1/C2 small interfering RNA increased VDR transactivation by 39% (p < 0.005). Chromatin immunoprecipitation of nucleoproteins bound to the transcriptionally active 1,25-dihydroxy vitamin D-driven CYP24 promoter revealed the presence of REBiP in vitamin D-responsive human cells and indicated that the normal pattern of 1,25-dihydroxy vitamin D-initiated cyclical movement of the VDR on and off the VDRE is legislated by competitive, reciprocal occupancy of the VDRE by hnRNP C1/C2. The temporal and reciprocal pattern of VDR and hnRNPC1/C2 interaction with the VDRE was lost in HVDRR cells overexpressing the hnRNP C1/C2 REBiP. These observations provide further evidence for the functional importance of REBiP as a component of the multiprotein complex involved in the regulation of vitamin D-mediated transcription. In particular, chromatin immunoprecipitation data suggest that, in addition to its RNA-processing functions, hnRNP C1/C2 may be a key determinant of the temporal patterns of VDRE occupancy.
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Affiliation(s)
- Hong Chen
- Division of Endocrinology, Diabetes and Metabolism, Burns and Allen Research Institute, Cedars-Sinai Medical Center, UCLA School of Medicine, Los Angeles, California 90048, USA
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36
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Hossain MN, Fuji M, Miki K, Endoh M, Ayusawa D. Downregulation of hnRNP C1/C2 by siRNA sensitizes HeLa cells to various stresses. Mol Cell Biochem 2006; 296:151-7. [PMID: 16960656 DOI: 10.1007/s11010-006-9308-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2005] [Accepted: 12/23/2005] [Indexed: 10/24/2022]
Abstract
The heterogeneous nuclear ribonucleoprotein C1/C2 is one of the most abundant proteins in the nucleus, and shown to have roles in cellular differentiation and proliferation through post-transcriptional regulations of certain mRNA species. We studied its role in stress response using siRNA mediated knockdown approach in HeLa cells. Upon transient transfection with plasmid encoding siRNA, the cells showed increased sensitivities to various chemical agents, namely H(2)O(2, )paraquat, camptothecin, ICRF-193 and halogenated deoxyuridines. These results demonstrate that hnRNP C1/C2 is involved in maintenance of cellular homeostasis besides cellular differentiation and proliferation.
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Affiliation(s)
- Mohammad Nazir Hossain
- Kihara Institute for Biological research, Yokohama City University, Maioka-cho 641-12, Totsuka-ku, Yokohama 244-0813, Japan
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Abstract
Deleted in Azoospermia Associated Protein 1 (DAZAP1) is a ubiquitous RNA-binding protein highly expressed in the human and the mouse testes. It shows a dynamic subcellular localization during spermatogenesis, present predominantly in the nuclei of late-stage spermatocytes and round spermatids and translocated to the cytoplasm during spermatid elongation. To test the hypothesis that DAZAP1 shuttles between the nucleus and the cytoplasm, we studied the nuclear transport of DAZAP1 in somatic cells using immunostaining, heterokaryon formation, and mutagenesis. DAZAP1 is detected exclusively in the nucleus and has the ability to shuttle between the nucleus and the cytoplasm using a highly conserved 25 amino acid segment, designated ZNS, at its C terminus. ZNS shares no sequence homology with other known nuclear localization or export signals. Attachment of ZNS to a red fluorescent protein DsRed2 confers the nucleocytoplasmic shuttling ability to that protein. The nuclear localization of DAZAP1 depends on active transcription. In the presence of an RNA polymerase II inhibitor, DAZAP1 is retained in the cytoplasm. DAZAP1 colocalizes with hnRNP A1 and hnRNP C1 in the nucleus and is a component of the heterogeneous nuclear ribonucleoprotein particles. Our results suggest that DAZAP1 plays a key role in mRNA transport during spermatogenesis.
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Affiliation(s)
- Yi-Tzu Lin
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
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Lee EJ, Kim SH, Kwark YE, Kim J. Heterogeneous nuclear ribonuclear protein C is increased in the celecoxib-induced growth inhibition of human oral squamous cell carcinoma. Exp Mol Med 2006; 38:203-9. [PMID: 16819278 DOI: 10.1038/emm.2006.25] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Celecoxib is a selective inhibitor of cyclooxygenase-2 (COX-2) that is a critical factor in carcinogenesis, but precise mechanism of its action remains to be elucidated. Here we evaluated the inhibitory effect of celecoxib on cell growth of human oral squamous cell carcinoma (OSCC) YD-10(B), which was established to be used as in vitro OSCC model, and identified celecoxib-regulated protein by proteomics techniques. Celecoxib (IC(50)=37 microM) inhibited the growth of YD-10(B) cells with the decrease of COX-2 protein expression. Its inhibition could be linked in the arrest of G(1) phase with increased levels of p(27) protein, a specific CDK inhibitor. Using proteomics, the 10- to 20-fold increase of heterogeneous nuclear ribonuclear protein C (hnRNP C), which has been suggested to be related with the translation of p(27) mRNA, was observed in celecoxib-treated YD-10(B) cells. In summary, celecoxib has a potential to induce the protein expression of hnRNP C and its increase subsequently induce the translation of p(27) mRNA, which trigger the inhibition of cell growth via p(27)-regulated cell cycle arrest in YD-10(B) cells. In addition, YD-10(B) cells could be useful to study the pathological mechanism of OSCC.
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Affiliation(s)
- Eun Ju Lee
- Department of Oral Pathology, Oral Cancer Research Institute, Yonsei University College of Dentistry, Seoul 120-752, Korea
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39
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Abstract
Increased urokinase receptor (uPAR) expression as well as stabilisation of uPAR mRNA contribute to the pathogenesis of lung inflammation and neoplasia. Post-transcriptional regulation of uPAR mRNA involves interaction of both coding and 3'-UTR sequences with regulatory uPAR mRNA binding proteins (Bps). In order to identify novel regulatory interactions, we performed gel mobility shift and UV cross-linking assays and found two distinct uPAR mRNA-protein complexes. We identified a rapidly migrating 40 kDa uPAR mRNABp that selectively bound a 110 nucleotide (nt) fragment of the uPAR mRNA 3'UTR. Chimeric beta-globin/uPAR mRNA containing the 110 nt 40 kDa protein binding fragment destabilised stable beta-globin mRNA with a rate of decay identical to that of chimeric beta-globin/uPAR containing the full uPAR 3'UTR. The 40 kDa uPAR 3'UTR Bp was purified using poly (U) sepharose and identified as heterogeneous nuclear ribonucleoprotein C (hnRNPC). Finally, we confirmed its interaction with the uPAR mRNA 3' UTR by gel mobility supershift assay using an anti-hnRNPC antibody. Direct in vivo interaction of hnRNPC with the uPAR mRNA 3'UTR was demonstrated by immunoprecipitation and combined RT PCR-Southern blotting assay. Co-transfection of hnRNPC cDNA in Beas2B cells reversed destabilisation of chimeric beta-globin/uPAR 3'UTR mRNA and its over-expression also induced uPAR protein and mRNA expression through stabilisation of uPAR mRNA. These observations indicate a novel mechanism of uPAR gene regulation in lung epithelial cells in which cis elements within a 110 nt uPAR mRNA 3'UTR sequence interact with hnRNPC to regulate uPAR mRNA stability.
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Affiliation(s)
- Sreerama Shetty
- Department of Specialty Care Services, The University of Texas Health Center at Tyler, Tyler, TX 75708, USA.
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Mahajan MC, Narlikar GJ, Boyapaty G, Kingston RE, Weissman SM. Heterogeneous nuclear ribonucleoprotein C1/C2, MeCP1, and SWI/SNF form a chromatin remodeling complex at the beta-globin locus control region. Proc Natl Acad Sci U S A 2005; 102:15012-7. [PMID: 16217013 PMCID: PMC1257739 DOI: 10.1073/pnas.0507596102] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Locus control regions (LCRs) are regulatory DNA sequences that are situated many kilobases away from their cognate promoters. LCRs protect transgenes from position effect variegation and heterochromatinization and also promote copy-number dependence of the levels of transgene expression. In this work, we describe the biochemical purification of a previously undescribed LCR-associated remodeling complex (LARC) that consists of heterogeneous nuclear ribonucleoprotein C1/C2, nucleosome remodeling SWI/SNF, and nucleosome remodeling and deacetylating (NuRD)/MeCP1 as a single homogeneous complex. LARC binds to the hypersensitive 2 (HS2)-Maf recognition element (MARE) DNA in a sequence-specific manner and remodels nucleosomes. Heterogeneous nuclear ribonucleoprotein C1/C2, previously known as a general RNA binding protein, provides a sequence-specific DNA recognition element for LARC, and the LARC DNA-recognition sequence is essential for the enhancement of transcription by HS2. Independently of the initiation of transcription, LARC becomes associated with beta-like globin promoters.
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Affiliation(s)
- Milind C Mahajan
- Department of Genetics, The Anlyan Center, Yale University School of Medicine, New Haven, CT 06511, USA
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41
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Whitson SR, LeStourgeon WM, Krezel AM. Solution structure of the symmetric coiled coil tetramer formed by the oligomerization domain of hnRNP C: implications for biological function. J Mol Biol 2005; 350:319-37. [PMID: 15936032 DOI: 10.1016/j.jmb.2005.05.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2005] [Revised: 04/28/2005] [Accepted: 05/03/2005] [Indexed: 11/16/2022]
Abstract
During active cell division, heterogeneous nuclear ribonucleoprotein (hnRNP) C is one of the most abundant proteins in the nucleus. hnRNP C exists as a stable tetramer that binds about 230 nucleotides of pre-mRNA and functions in vivo to package nascent transcripts and nucleate assembly of the 40 S hnRNP complex. Previous studies have shown that monomers lacking or possessing mutant oligomerization domains bind RNA with low affinity, strongly suggesting a cooperative protomer-RNA binding mode. In order to understand the role of the oligomerization domain in defining the biological functions and structure of hnRNP C tetramers, we have determined the high-resolution NMR structure of the oligomerization interface that is formed at the core of the complex, examining specific molecular interactions that drive assembly and contribute to the structural integrity of the tetramer. The determined structure reveals an antiparallel four-helix coiled coil, where classically described knobs-into-holes packing interactions at interhelical contact surfaces are optimized so that side-chains interdigitate to create an even distribution of hydrophobic surfaces along the core. While the stoichiometry of the complex appears to be primarily specified by occlusion of hydrophobic surfaces, particularly the interfacial residue L198, from solvent, helix orientation is primarily determined by electrostatic attractions across helix interfaces. The creation of potential interaction surfaces for other hnRNP C domains along the coiled coil exterior and the assembly of oligomerization interfaces in an antiparallel orientation shape the tertiary fold of full-length monomers and juxtapose RNA-binding elements at distal surfaces of the tetrameric complex in the quaternary assembly. In addition, we discuss the specific challenges encountered in structure determination of this symmetric oligomer by NMR methods, specifically in sorting ambiguous interatomic distance constraints into classes that define different elements of the coiled coil structure.
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Affiliation(s)
- Stefanie R Whitson
- Department of Biological Sciences, 465 21st Ave. South, Vanderbilt University, Nashville, TN 37232, USA
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42
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Zhao X, Oberg D, Rush M, Fay J, Lambkin H, Schwartz S. A 57-nucleotide upstream early polyadenylation element in human papillomavirus type 16 interacts with hFip1, CstF-64, hnRNP C1/C2, and polypyrimidine tract binding protein. J Virol 2005; 79:4270-88. [PMID: 15767428 PMCID: PMC1061554 DOI: 10.1128/jvi.79.7.4270-4288.2005] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
We have investigated the role of the human papillomavirus type 16 (HPV-16) early untranslated region (3' UTR) in HPV-16 gene expression. We found that deletion of the early 3' UTR reduced the utilization of the early polyadenylation signal and, as a consequence, resulted in read-through into the late region and production of late L1 and L2 mRNAs. Deletion of the U-rich 3' half of the early 3' UTR had a similar effect, demonstrating that the 57-nucleotide U-rich region acted as an enhancing upstream element on the early polyadenylation signal. In accordance with this, the newly identified hFip1 protein, which has been shown to enhance polyadenylation through U-rich upstream elements, interacted specifically with the HPV-16 upstream element. This upstream element also interacted specifically with CstF-64, hnRNP C1/C2, and polypyrimidine tract binding protein, suggesting that these factors were either enhancing or regulating polyadenylation at the HPV-16 early polyadenylation signal. Mutational inactivation of the early polyadenylation signal also resulted in increased late mRNA production. However, the effect was reduced by the activation of upstream cryptic polyadenylation signals, demonstrating the presence of additional strong RNA elements downstream of the early polyadenylation signal that direct cleavage and polyadenylation to this region of the HPV-16 genome. In addition, we identified a 3' splice site at genomic position 742 in the early region with the potential to produce E1 and E4 mRNAs on which the E1 and E4 open reading frames are preceded only by the suboptimal E6 AUG. These mRNAs would therefore be more efficiently translated into E1 and E4 than previously described HPV-16 E1 and E4 mRNAs on which E1 and E4 are preceded by both E6 and E7 AUGs.
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Affiliation(s)
- Xiaomin Zhao
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
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43
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Brunner JE, Nguyen JHC, Roehl HH, Ho TV, Swiderek KM, Semler BL. Functional interaction of heterogeneous nuclear ribonucleoprotein C with poliovirus RNA synthesis initiation complexes. J Virol 2005; 79:3254-66. [PMID: 15731220 PMCID: PMC1075716 DOI: 10.1128/jvi.79.6.3254-3266.2005] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2004] [Accepted: 10/23/2004] [Indexed: 12/20/2022] Open
Abstract
We had previously demonstrated that a cellular protein specifically interacts with the 3' end of poliovirus negative-strand RNA. We now report the identity of this protein as heterogeneous nuclear ribonucleoprotein (hnRNP) C1/C2. Formation of an RNP complex with poliovirus RNA was severely impaired by substitution of a lysine, highly conserved among vertebrates, with glutamine in the RNA recognition motif (RRM) of recombinant hnRNP C1, suggesting that the binding is mediated by the RRM in the protein. We have also shown that in a glutathione S-transferase (GST) pull-down assay, GST/hnRNP C1 binds to poliovirus polypeptide 3CD, a precursor to the viral RNA-dependent RNA polymerase, 3D(pol), as well as to P2 and P3, precursors to the nonstructural proteins. Truncation of the auxiliary domain in hnRNP C1 (C1DeltaC) diminished these protein-protein interactions. When GST/hnRNP C1DeltaC was added to in vitro replication reactions, a significant reduction in RNA synthesis was observed in contrast to reactions supplemented with wild-type fusion protein. Indirect functional depletion of hnRNP C from in vitro replication reactions, using poliovirus negative-strand cloverleaf RNA, led to a decrease in RNA synthesis. The addition of GST/hnRNP C1 to the reactions rescued RNA synthesis to near mock-depleted levels. Furthermore, we demonstrated that poliovirus positive-strand and negative-strand RNA present in cytoplasmic extracts prepared from infected HeLa cells coimmunoprecipitated with hnRNP C1/C2. Our findings suggest that hnRNP C1 has a role in positive-strand RNA synthesis in poliovirus-infected cells, possibly at the level of initiation.
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Affiliation(s)
- Jo Ellen Brunner
- Department of Microbiology and Molecular Genetics, College of Medicine, University of California, Med. Sci. B240, Irvine, CA 92697, USA
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44
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Abstract
Expression of the urokinase-type plasminogen activator (uPA) is under tight regulation by hormones, cytokines and growth factors under physiological conditions. Treatment of lung epithelial (Beas2B) cells with translation inhibitors induces uPA mRNA expression, as well as early response genes. To understand the specific expression and regulation of uPA mRNA, we treated Beas2B cells with cycloheximide (CycD), anisomycin, emitine and puromycin in a time-dependent manner and measured uPA mRNA expression by Northern blotting. All these agents induced uPA mRNA by two- to seven-fold within 3 h after treatment in Beas2B cells. CycD, emitine, puromycin and anisomycin also enhanced uPA mRNA half-life by three- to five-fold in Beas2B cells treated with DRB, an inhibitor of transcription. However, run-on-transcription experiments indicated that these agents failed to induce uPA mRNA transcription indicating that they augment uPA mRNA mainly due to increased stability. Using gel mobility shift, we identified an uPA mRNA binding protein (uPA mRNABp) that selectively binds to uPA mRNA [Gyetko MR, Todd III RF, Wilkinson CC, Sitrin RG: The urokinase receptor is required for human monocyte chemotaxis in vitro. J Clin Invest 93: 1380-1387, 1994]. Binding of both cytoplasmic and nuclear uPA mRNABp to uPA mRNA was abolished after treatment with translation inhibitors, which coincides with the maximal expression of uPA mRNA. We also found a similar decline in HuR and heterogeneous nuclear ribonucleoprotein C (hnRNPC) which are known to stabilize uPA mRNA both in the nuclear and cytosolic compartments. These results strongly suggest that increased uPA mRNA stability induced by translational inhibitors involves the interaction of uPA mRNA with a degrading protein factor rather than increased interaction of proteins that are known to stabilize uPA mRNA. These data also strongly suggests that down-regulation of the uPA-uPA mRNABp interaction by translational inhibitors rather than the translocation of uPA mRNABp contributes to increased uPA mRNA stability. This pathway may regulate uPA-mediated functions of the lung epithelium in the context of inflammation or neoplasia.
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Affiliation(s)
- Sreerama Shetty
- Department of Specialty Care Services, The University of Texas Health Center at Tyler, 11937 U.S. Highway 271, Tyler, TX 75708, USA.
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45
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Kattapuram T, Yang S, Maki JL, Stone JR. Protein kinase CK1alpha regulates mRNA binding by heterogeneous nuclear ribonucleoprotein C in response to physiologic levels of hydrogen peroxide. J Biol Chem 2005; 280:15340-7. [PMID: 15687492 DOI: 10.1074/jbc.m500214200] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
At low concentrations, hydrogen peroxide (H(2)O(2)) is a positive endogenous regulator of mammalian cell proliferation and survival; however, the signal transduction pathways involved in these processes are poorly understood. In primary human endothelial cells, low concentrations of H(2)O(2) stimulated the rapid phosphorylation of the acidic C-terminal domain (ACD) of heterogeneous nuclear ribonucleoprotein C (hnRNP-C), a nuclear restricted pre-mRNA-binding protein, at Ser(240) and at Ser(225)-Ser(228). A kinase activity was identified in mouse liver that phosphorylates the ACD of hnRNP-C at Ser(240) and at two sites at Ser(225)-Ser(228). The kinase was purified and identified by tandem mass spectrometry as protein kinase CK1alpha (formerly casein kinase 1alpha). Protein kinase CK1alpha immunoprecipitated from primary human endothelial cell nuclei also phosphorylated the ACD of hnRNP-C at these positions. Pretreatment of endothelial cells with the protein kinase CK1-specific inhibitor IC261 prevented the H(2)O(2)-stimulated phosphorylation of hnRNP-C. Utilizing phosphoserine-mimicking Ser-to-Glu point mutations, the effects of phosphorylation on hnRNP-C function were investigated by quantitative equilibrium fluorescence RNA binding analyses. Wild-type hnRNP-C1 and hnRNP-C1 modified at the basal sites of phosphorylation (S247E and S286E) both avidly bound RNA with similar binding constants. In contrast, hnRNP-C1 that was also modified at the CK1alpha phosphorylation sites exhibited a 14-500-fold decrease in binding affinity, demonstrating that CK1alpha-mediated phosphorylation modulates the mRNA binding ability of hnRNP-C.
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MESH Headings
- Amino Acid Sequence
- Animals
- Casein Kinase Ialpha/metabolism
- Casein Kinase Ialpha/physiology
- Cells, Cultured
- Chromatography, High Pressure Liquid
- Chromatography, Ion Exchange
- Electrophoresis, Gel, Two-Dimensional
- Endothelium, Vascular/cytology
- Escherichia coli/metabolism
- Evolution, Molecular
- Heterogeneous-Nuclear Ribonucleoprotein Group C/metabolism
- Humans
- Hydrogen Peroxide/pharmacology
- Immunoprecipitation
- Indoles/pharmacology
- Kinetics
- Liver/metabolism
- Mice
- Molecular Sequence Data
- Phloroglucinol/analogs & derivatives
- Phloroglucinol/pharmacology
- Phosphorylation
- Protein Binding
- Protein Structure, Tertiary
- RNA/metabolism
- RNA, Messenger/metabolism
- Sequence Homology, Amino Acid
- Serine/chemistry
- Spectrometry, Fluorescence
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Affiliation(s)
- Taj Kattapuram
- Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, USA
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46
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Lee HH, Chien CL, Liao HK, Chen YJ, Chang ZF. Nuclear efflux of heterogeneous nuclear ribonucleoprotein C1/C2 in apoptotic cells: a novel nuclear export dependent on Rho-associated kinase activation. J Cell Sci 2004; 117:5579-89. [PMID: 15494373 DOI: 10.1242/jcs.01482] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Using a proteomic approach, we searched for protein changes dependent on Rho-associated kinase (ROCK) during phorbol-12-myristate-13-acetate (PMA)-induced apoptosis. We found that heterogeneous nuclear ribonucleoprotein C1 and C2 (hnRNP C1/C2), two nuclear restricted pre-mRNA binding proteins, are translocated to the cytosolic compartment in a ROCK-dependent manner in PMA-induced pro-apoptotic cells, where nuclear envelopes remain intact. The subcellular localization change of hnRNP C1/C2 appears to be dependent on ROCK-mediated cytoskeletal change and independent of caspase execution and new protein synthesis. Such a ROCK-dependent translocation is also seen in TNFalpha-induced apoptotic NIH3T3 cells. By overexpressing the dominant active form of ROCK, we showed that a ROCK-mediated signal is sufficient to induce translocation of hnRNP C1/C2. Deletion experiments indicated that the C-terminal 40-amino-acid region of hnRNP C1/C2 is required for ROCK-responsive translocation. By using nuclear yellow fluorescent protein (YFP) fusion, we determined that the C-terminal 40-amino-acid region of hnRNP C1/C2 is a novel nuclear export signal responsive to ROCK-activation. We conclude that a novel nuclear export is activated by the ROCK signaling pathway to exclude hnRNP C1/C2 from nucleus, by which the compartmentalization of specific hnRNP components is disturbed in apoptotic cells.
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Affiliation(s)
- Hsiao-Hui Lee
- Institute of Biochemistry and Molecular Biology, College of Medicine, National Taiwan University, No.1 Jen Ai Road Sec.1, Taipei, 100, Taiwan, Republic of China
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47
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Osipovich AB, White-Grindley EK, Hicks GG, Roshon MJ, Shaffer C, Moore JH, Ruley HE. Activation of cryptic 3' splice sites within introns of cellular genes following gene entrapment. Nucleic Acids Res 2004; 32:2912-24. [PMID: 15155860 PMCID: PMC419606 DOI: 10.1093/nar/gkh604] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Gene trap vectors developed for genome-wide mutagenesis can be used to study factors governing the expression of exons inserted throughout the genome. For example, entrapment vectors consisting of a partial 3'-terminal exon [i.e. a neomycin resistance gene (Neo), a poly(A) site, but no 3' splice site] were typically expressed following insertion into introns, from cellular transcripts that spliced to cryptic 3' splice sites present either within the targeting vector or in the adjacent intron. A vector (U3NeoSV1) containing the wild-type Neo sequence preferentially disrupted genes that spliced in-frame to a cryptic 3' splice site in the Neo coding sequence and expressed functional neomycin phosphotransferase fusion proteins. Removal of the cryptic Neo 3' splice site did not reduce the proportion of clones with inserts in introns; rather, the fusion transcripts utilized cryptic 3' splice sites present in the adjacent intron or generated by virus integration. However, gene entrapment with U3NeoSV2 was considerably more random than with U3NeoSV1, consistent with the widespread occurrence of potential 3' splice site sequences in the introns of cellular genes. These results clarify the mechanisms of gene entrapment by U3 gene trap vectors and illustrate features of exon definition required for 3' processing and polyadenylation of cellular transcripts.
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Affiliation(s)
- Anna B Osipovich
- Department of Microbiology and Immunology, Vanderbilt University School of Medicine, 1161 21st Avenue South, Nashville, TN 37232-2363, USA
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48
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Lee CG, Hague LK, Li H, Donnelly R. Identification of toposome, a novel multisubunit complex containing topoisomerase IIalpha. Cell Cycle 2004; 3:638-47. [PMID: 15034300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023] Open
Abstract
Topoisomerase IIalpha plays essential roles in chromosome segregation. However, it is not well understood how topoisomerase IIalpha exerts its function during mitosis. In this report, we find that topoisomerase IIalpha forms a multisubunit complex, named toposome, containing two ATPase/helicase proteins (RNA helicase A and RHII/Gu), one serine/threonine protein kinase (SRPK1), one HMG protein (SSRP1), and two pre-mRNA splicing factors (PRP8 and hnRNP C). Toposome separates entangled circular chromatin DNA about fourfold more efficiently than topoisomerase IIalpha. Interestingly, this decatenation reaction yields knotted circles, which are not seen in reactions provided with monomeric circular DNA. Our results also show that interaction among toposome-associated proteins is highest in G2/M phase but drastically diminishes in G1/S phase. These results suggest that toposome is a dynamic complex whose assembly or activation is subject to cell cycle regulation.
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Affiliation(s)
- Chee-Gun Lee
- Department of Biochemistry and Molecular Biology, Graduate School of Biomedical Sciences, University of Medicine and Dentistry of New Jersey, Newark 07013, USA.
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49
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Esnault S, Malter JS. Hyaluronic acid or TNF-alpha plus fibronectin triggers granulocyte macrophage-colony-stimulating factor mRNA stabilization in eosinophils yet engages differential intracellular pathways and mRNA binding proteins. J Immunol 2004; 171:6780-7. [PMID: 14662883 DOI: 10.4049/jimmunol.171.12.6780] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Eosinophils (Eos) accumulate in airways and lung parenchyma of active asthmatics. GM-CSF is a potent inhibitor of Eos apoptosis both in vitro and in vivo and is produced by activated fibroblasts, mast cells, T lymphocytes as well as Eos. Cytokine release by Eos is preceded by GM-CSF mRNA stabilization induced by TNF-alpha plus fibronectin. Hyaluronic acid (HA) is a major extracellular matrix proteoglycan, which also accumulates in the lung during asthma exacerbations. In this study we have analyzed the effects of HA on Eos survival and GM-CSF expression. We demonstrate that like TNF-alpha plus fibronectin, HA stabilizes GM-CSF mRNA, increases GM-CSF secretion, and prolongs in vitro Eos survival. GM-CSF mRNA stabilization accounts for most of the observed GM-CSF mRNA accumulation and protein production. Unlike TNF-alpha plus fibronectin, GM-CSF mRNA stabilization induction by HA requires continuous extracellular signal-regulated kinase phosphorylation. Finally, to identify potential protein regulators responsible for GM-CSF mRNA stabilization, immunoprecipitation-RT-PCR studies revealed increased GM-CSF mRNA associated with YB-1, HuR, and heterogeneous nuclear ribonucleoprotein (hnRNP) C after TNF-alpha plus fibronectin but only hnRNP C after HA. Thus, our data suggest that both TNF-alpha plus fibronectin and HA, which are relevant physiological effectors in asthma, contributes to long-term Eos survival in vivo by enhancing GM-CSF production through two different posttranscriptional regulatory pathways involving extracellular signal-regulated kinase phosphorylation and RNA binding proteins YB-1, HuR, and hnRNP C.
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Affiliation(s)
- Stéphane Esnault
- Department of Pathology and Laboratory Medicine, University of Wisconsin Medical School, Madison, WI 53792, USA
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50
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Abstract
Hydrogen peroxide (H2O2) is a recently recognized second messenger, which regulates mammalian cell proliferation and migration. The biochemical mechanisms by which mammalian cells sense and respond to low concentrations of H2O2 are poorly understood. Recently, heterogeneous nuclear ribonucleoprotein C1/C2 (hnRNP-C1/C2) was found to be rapidly phosphorylated in response to the application of low concentrations of H2O2 to human endothelial cells. Here, using tandem mass spectrometry, four sites of phosphorylation are identified in hnRNP-C1/C2, all of which are in the acidic C-terminal domain of the protein. Under resting conditions, the protein is phosphorylated at S247 and S286. In response to low concentrations of H2O2, there is increased phosphorylation at S240 and at one of the four contiguous serine residues from S225-S228. Studies using a recombinant acidic C-terminal domain of hnRNP-C overexpressed in Escherichia coli demonstrate that protein kinase CK2 phosphorylates hnRNP-C1/C2 at S247, while protein kinase A and several protein kinase C isoforms fail to phosphorylate the isolated domain. These findings demonstrate that the acidic C-terminal domain of hnRNP-C1/C2 serves as the site for both basal and stimulated phosphorylation, indicating that this domain may play an important role in the regulation of mRNA binding by hnRNP-C1/C2.
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Affiliation(s)
- James R Stone
- Department of Pathology, Children's Hospital and Brigham & Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115,USA.
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