1
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Yang ZY, Zhang WL, Jiang CW, Sun G. PCBP1-mediated regulation of WNT signaling is critical for breast tumorigenesis. Cell Biol Toxicol 2023; 39:2331-2343. [PMID: 35639300 DOI: 10.1007/s10565-022-09722-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Accepted: 05/11/2022] [Indexed: 11/28/2022]
Abstract
Loss of expression or protein kinase B (Akt1)-mediated post-translational modification of the RNA binding protein Poly r(C) binding protein 1 (PCBP1) is closely related to metastatic advancement of breast cancer. However, the role of PCBP1 in tumorigenesis is not completely defined. Using a xenograft orthotopic model of breast tumorigenesis (4T1-Pcbp1-/-), we show here that PCBP1 knockdown-induced tumorigenesis is inhibited by activation of the WNT signaling via treating with the glycogen synthase kinase 3 beta inhibitor TWS119, but not the Akt2/Akt3 inhibitor GSK690693. Mass cytometry-based evaluation of the tumor microenvironment (TME) revealed significantly more regulatory T cells (Tregs) and significantly less cytotoxic T cells in 4T1-Pcbp1-/-mice treated with saline control in comparison to mice treated with TWS119. Infiltrating cytotoxic T cells were phenotypically and functionally exhausted. Treatment with TWS119 resulted in rescue of cytotoxic T cell function and inhibition of suppressor activity of Tregs. Using cytotoxic T cells isolated from healthy donors, we show that TWS119-induced WNT signaling-mediated inhibition of cytotoxic T cell expansion is reliant on expression of PCBP1. In conclusion, decreased PCBP1 expression favors breast tumorigenesis by potentiating skewing of tumor infiltrating T cells towards Tregs, thereby effectively suppressing anti-tumor immunity.
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Affiliation(s)
- Zhao-Ying Yang
- Department of Breast Surgery, China-Japan Union Hospital of Jilin University, No.126, Xiantai Street, Changchun, Jilin, 130033, China
| | - Wen-Long Zhang
- Department of Hematology and Oncology, China-Japan Union Hospital of Jilin University, Changchun, Jilin, 130033, China
| | - Cheng-Wei Jiang
- Department of Pathology, China-Japan Union Hospital of Jilin University, Changchun, Jilin, 130033, China
| | - Guang Sun
- Department of Breast Surgery, China-Japan Union Hospital of Jilin University, No.126, Xiantai Street, Changchun, Jilin, 130033, China.
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2
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Lu N, Zhang M, Lu L, Liu YZ, Zhang HH, Liu XD. miRNA‑490‑3p promotes the metastatic progression of invasive ductal carcinoma. Oncol Rep 2021; 45:706-716. [PMID: 33416185 PMCID: PMC7757091 DOI: 10.3892/or.2020.7880] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 11/10/2020] [Indexed: 11/06/2022] Open
Abstract
MicroRNA (miRNA/mir)‑490‑3p has been defined as a tumor suppressor in different types of cancer, including breast cancer. However, miR‑490‑3p has been shown to function as a tumor suppressor and promoter in a context‑dependent manner in hepatocellular and lung cancer. Contrary to previous studies, the present study revealed that miR‑490‑3p expression was significantly higher in invasive ductal carcinoma (IDC) tissue specimens, the most common form of breast cancer, compared to tumor‑adjacent normal tissue specimens (n=20). Its expression was also higher in the more metastatic breast cancer cell line, MDA‑MB‑231, compared to the non‑metastatic breast cancer cell line, MCF7, and the moderately metastatic breast cancer cell line, MDA‑MB‑468. The expression of miR‑490‑3p was induced following transforming growth factor (TGF)‑β‑induced epithelial‑to‑mesenchymal transition (EMT) in MCF10A cells. Gain‑and loss‑of‑function assays revealed that the expression of miR‑490‑3p regulated the proliferation, colony formation, EMT, migration and invasion in vitro, but not the apoptosis of MDA‑MB‑468 and MDA‑MB‑231 cells. The knockdown of miR‑490‑3p expression in MDA‑MB‑231 cells inhibited experimental metastasis in a tumor xenograft assay. As in lung cancer, miR‑490‑3p was found to target and downregulate the expression of the tumor suppressor RNA binding protein poly r(C) binding protein 1 (PCBP1). PCBP1 protein and miR‑490‑3p expression inversely correlated in patients with ductal carcinoma in situ (DCIS; n=10; no nodal involvement) and IDC (n=10; different stages of metastatic progression) with a significantly higher miR‑490‑3p expression in patients with IDC compared to those with DCIS. The expression of miR‑490‑3p was negatively associated with both overall and disease‑free survival in the patients with breast cancer included in the present study. On the whole, the results confirm a pro‑metastatic role of miR‑490‑3p in IDC, establishing it as a biomarker for disease progression in these patients.
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MESH Headings
- Animals
- Breast/pathology
- Breast/surgery
- Breast Neoplasms/genetics
- Breast Neoplasms/mortality
- Breast Neoplasms/pathology
- Breast Neoplasms/surgery
- Carcinoma, Ductal, Breast/genetics
- Carcinoma, Ductal, Breast/mortality
- Carcinoma, Ductal, Breast/secondary
- Carcinoma, Ductal, Breast/surgery
- Cell Line, Tumor
- DNA-Binding Proteins/genetics
- Disease Progression
- Disease-Free Survival
- Epithelial-Mesenchymal Transition/genetics
- Female
- Follow-Up Studies
- Gene Expression Regulation, Neoplastic
- Gene Knockdown Techniques
- Humans
- Mastectomy
- Mice
- MicroRNAs/genetics
- MicroRNAs/metabolism
- Neoplasm Recurrence, Local/epidemiology
- Neoplasm Recurrence, Local/genetics
- RNA-Binding Proteins/genetics
- Xenograft Model Antitumor Assays
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Affiliation(s)
- Ning Lu
- Department of Breast Medical Oncology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin 300060, P.R. China
| | - Mei Zhang
- Department of Rheumatology and Immunology, Tianjin Medical University General Hospital, Tianjin 300052, P.R. China
| | - Lu Lu
- Department of Pharmacy, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Tianjin 300060, P.R. China
| | - Yan-Zhao Liu
- Department of Medicine, Tianjin Medical University General Hospital, Tianjin 300052, P.R. China
| | - Hai-Hong Zhang
- Department of Human Resources, Tianjin Hospital, Tianjin 300211, P.R. China
| | - Xiao-Dong Liu
- Department of Breast Medical Oncology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin 300060, P.R. China
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3
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Guo J, Jia R. Splicing factor poly(rC)-binding protein 1 is a novel and distinctive tumor suppressor. J Cell Physiol 2018; 234:33-41. [PMID: 30132844 DOI: 10.1002/jcp.26873] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Accepted: 05/23/2018] [Indexed: 12/20/2022]
Abstract
A lot of evidence has been found on the link between tumorigenesis and the aberrant expression of splicing factors. A number of splicing factors have been reported to be either oncogenic or overexpressed in cancer cells. However, splicing factors can also play negative roles in tumorigenesis. In the current review, we focus on splicing factor poly(rC)-binding protein 1 (PCBP1), a novel tumor suppressor that is characterized by downregulation in many cancer types and shows inhibition of tumor formation and metastasis. Notably, the messenger RNA levels of PCBP1 are not significantly decreased in most cancer types. In fact, PCBP1 protein is often degraded or shows a loss-of-function through phosphorylation in cancer cells. PCBP1 is highly homologous to its family member, PCBP2. Interestingly, PCBP2 appears to be an oncogenic splicing factor. A growing body of evidence has shown that PCBP1 regulates alternative splicing, translation, and RNA stability of many cancer-related genes. Taking together, PCBP1 has distinctive tumor suppressive functions, and increasing PCBP1 expression may represent a new approach for cancer treatment.
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Affiliation(s)
- Jihua Guo
- State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory for Oral Biomedicine of Ministry of Education (KLOBM), School and Hospital of Stomatology, Wuhan University, Wuhan, China
| | - Rong Jia
- State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory for Oral Biomedicine of Ministry of Education (KLOBM), School and Hospital of Stomatology, Wuhan University, Wuhan, China
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4
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Hunkele A, Sultan H, Ikalina FA, Liu AH, Nahar-Gohad P, Ko JL. Identification of gamma-synuclein as a new PCBP1-interacting protein. Neurol Res 2016; 38:1064-1078. [PMID: 26344801 DOI: 10.1179/1743132815y.0000000091] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
OBJECTIVES PolyC binding protein 1 (PCBP1) is a transcriptional regulator of human mu-opioid receptor (hMOR) gene in the CNS and is also related to cancer/diseases. It possesses multi-roles that can be mediated by protein-protein interactions. To understand the mechanism controlling PCBP1 functions, PCBP1-interacting protein was investigated. METHODS Using PCBP1 as the bait, a human brain cDNA library was screened via two-hybrid system. DNA sequence of candidate protein was confirmed using NCBI/SNP databases. Candidate protein in various cell lines was examined by RT-PCR. Glutathione-S-transferase (GST) pull-down and co-immunoprecipitation were used to validate the physical interaction. Its effects on hMOR gene regulation were examined. RESULTS One clone was identified as gamma-synuclein110E, an SNP of gamma-synuclein110V. The interaction between PCBP1 and gamma-synuclein110E was confirmed by further validation and GST pull-down assay. Confocal analysis showed gamma-synuclein110E mainly expressing in the cytosol of human neuronal NMB cells. This interaction was confirmed by co-immunoprecipitation with NMB lysates, containing both proteins endogenously. Ectopic expression of gamma-synuclein110E or 110V did not alter hMOR mRNA level or promoter activity, suggesting no involvement of gamma-synuclein in modulating hMOR expression. Co-immunoprecipitation using gamma-synuclein110E or 110V overexpressed NMB cells with anti-PCBP1 antibody revealed a stronger intensity of co-immunoprecipitated gamma-synuclein band using gamma-synuclein110E-overexpressed cells as compared to that using gamma-synuclein110V-overexpressed cells. Synuclein110E was also identified in H292 (lung), HT29 (colon) and T47D (breast) cells, and this physical interaction was confirmed. CONCLUSION We report a newly identified PCBP1-interacting protein, gamma-synuclein110E, and provide some insight into its complex role as well as discuss potential roles of this interaction.
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Affiliation(s)
- Amanda Hunkele
- a Department of Biological Sciences ; Seton Hall University , USA
| | - Hamidah Sultan
- a Department of Biological Sciences ; Seton Hall University , USA
| | - Faith A Ikalina
- a Department of Biological Sciences ; Seton Hall University , USA
| | - Alexander H Liu
- a Department of Biological Sciences ; Seton Hall University , USA
| | | | - Jane L Ko
- a Department of Biological Sciences ; Seton Hall University , USA
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5
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MicroRNA-490 regulates lung cancer metastasis by targeting poly r(C)-binding protein 1. Tumour Biol 2016; 37:15221-15228. [PMID: 27683057 DOI: 10.1007/s13277-016-5347-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2016] [Accepted: 09/06/2016] [Indexed: 12/17/2022] Open
Abstract
Lung cancer remains a leading cause of cancer-related mortality, with metastatic progression remaining the single largest cause of lung cancer mortality. Hence, it is imperative to determine reliable biomarkers of lung cancer prognosis. MicroRNA-490-3p has been previously reported to be a positive prognostic biomarker for hepatocellular cancer. However, its role in human lung cancer has not yet been elucidated. Here, we report that hsa-miR-490-3p expression is significantly higher in human lung cancer tissue specimens and cell line. Gain- and loss-of-function studies of hsa-miR-490-3p showed that it regulates cell proliferation and is required for induction of in vitro migration and invasion-the latter being a hallmark of epithelial to mesenchymal transition. In situ analysis revealed that hsa-miR-490-3p targets poly r(C)-binding protein 1 (PCBP1), which has been previously shown to be a negative regulator of lung cancer metastasis. Reporter assays confirmed PCBP1 as a bona fide target of miR-490-3p, and metagenomic analysis revealed an inverse relation between expression of miR-490-3p and PCBP1 in metastatic lung cancer patients. In fact, PCBP1 expression, as detected by immunohistochemistry, was undetectable in advanced stages of lung cancer patients' brain and lymph node tissues. Xenograft tail vein colonization assays proved that high expression of miR-490-3p is a prerequisite for metastatic progression of lung cancer. Our results suggest that hsa-miR-490-3p might be a potential biomarker for lung cancer prognosis. In addition, we can also conclude that the lung cancer cells have evolved refractory mechanisms to downregulate the expression of the metastatic inhibitor, PCBP1.
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6
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Poly r(C) binding protein is post-transcriptionally repressed by MiR-490-3p to potentiate squamous cell carcinoma. Tumour Biol 2016; 37:14773-14778. [DOI: 10.1007/s13277-016-5234-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 07/15/2016] [Indexed: 10/21/2022] Open
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7
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Ding X, Lu J, Yu R, Wang X, Wang T, Dong F, Peng B, Wu W, Liu H, Geng Y, Zhang R, Ma H, Cheng J, Yu M, Fang S. Preliminary Proteomic Analysis of A549 Cells Infected with Avian Influenza Virus H7N9 and Influenza A Virus H1N1. PLoS One 2016; 11:e0156017. [PMID: 27223893 PMCID: PMC4880285 DOI: 10.1371/journal.pone.0156017] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2016] [Accepted: 05/09/2016] [Indexed: 11/18/2022] Open
Abstract
A newly emerged H7N9 influenza virus poses high risk to human beings. However, the pathogenic mechanism of the virus remains unclear. The temporal response of primary human alveolar adenocarcinoma epithelial cells (A549) infected with H7N9 influenza virus and H1N1 influenza A virus (H1N1, pdm09) were evaluated using the proteomics approaches (2D-DIGE combined with MALDI-TOF-MS/MS) at 24, 48 and 72 hours post of the infection (hpi). There were 11, 12 and 33 proteins with significant different expressions (P<0.05) at 24, 48 and 72hpi, especially F-actin-capping protein subunit alpha-1 (CAPZA1), Ornithine aminotransferase (OAT), Poly(rC)-binding protein 1 (PCBP1), Eukaryotic translation initiation factor 5A-1 (EIF5A) and Platelet-activating factor acetylhydrolaseⅠb subunit beta (PAFAH1B2) were validated by western-blot analysis. The functional analysis revealed that the differential proteins in A549 cells involved in regulating cytopathic effect. Among them, the down-regulation of CAPZA1, OAT, PCBP1, EIF5A are related to the death of cells infected by H7N9 influenza virus. This is the first time show that the down-regulation of PAFAH1B2 is related to the later clinical symptoms of patients infected by H7N9 influenza virus. These findings may improve our understanding of pathogenic mechanism of H7N9 influenza virus in proteomics.
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Affiliation(s)
- Xiaoman Ding
- School of Public Health, Sun Yat-sen University, Guangzhou, China
| | - Jiahai Lu
- School of Public Health, Sun Yat-sen University, Guangzhou, China
| | - Ruoxi Yu
- Southern Medical University, Guangzhou, China
| | - Xin Wang
- Major Infectious Disease Control Key Laboratory, Key Reference Laboratory of Pathogen and Biosafety, Shenzhen Center for Disease Control and Prevention, Shenzhen, China
| | - Ting Wang
- Nanshan Center for Disease Control and Prevention, Shenzhen, China
| | - Fangyuan Dong
- Major Infectious Disease Control Key Laboratory, Key Reference Laboratory of Pathogen and Biosafety, Shenzhen Center for Disease Control and Prevention, Shenzhen, China
| | - Bo Peng
- Major Infectious Disease Control Key Laboratory, Key Reference Laboratory of Pathogen and Biosafety, Shenzhen Center for Disease Control and Prevention, Shenzhen, China
| | - Weihua Wu
- Major Infectious Disease Control Key Laboratory, Key Reference Laboratory of Pathogen and Biosafety, Shenzhen Center for Disease Control and Prevention, Shenzhen, China
| | - Hui Liu
- Major Infectious Disease Control Key Laboratory, Key Reference Laboratory of Pathogen and Biosafety, Shenzhen Center for Disease Control and Prevention, Shenzhen, China
| | - Yijie Geng
- Major Infectious Disease Control Key Laboratory, Key Reference Laboratory of Pathogen and Biosafety, Shenzhen Center for Disease Control and Prevention, Shenzhen, China
| | - Renli Zhang
- Major Infectious Disease Control Key Laboratory, Key Reference Laboratory of Pathogen and Biosafety, Shenzhen Center for Disease Control and Prevention, Shenzhen, China
| | - Hanwu Ma
- Major Infectious Disease Control Key Laboratory, Key Reference Laboratory of Pathogen and Biosafety, Shenzhen Center for Disease Control and Prevention, Shenzhen, China
| | - Jinquan Cheng
- Major Infectious Disease Control Key Laboratory, Key Reference Laboratory of Pathogen and Biosafety, Shenzhen Center for Disease Control and Prevention, Shenzhen, China
| | - Muhua Yu
- Nanshan Center for Disease Control and Prevention, Shenzhen, China
- * E-mail: (MHY); (SSF)
| | - Shisong Fang
- Major Infectious Disease Control Key Laboratory, Key Reference Laboratory of Pathogen and Biosafety, Shenzhen Center for Disease Control and Prevention, Shenzhen, China
- * E-mail: (MHY); (SSF)
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8
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Ji X, Park JW, Bahrami-Samani E, Lin L, Duncan-Lewis C, Pherribo G, Xing Y, Liebhaber SA. αCP binding to a cytosine-rich subset of polypyrimidine tracts drives a novel pathway of cassette exon splicing in the mammalian transcriptome. Nucleic Acids Res 2016; 44:2283-97. [PMID: 26896798 PMCID: PMC4797308 DOI: 10.1093/nar/gkw088] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 02/03/2016] [Indexed: 12/17/2022] Open
Abstract
Alternative splicing (AS) is a robust generator of mammalian transcriptome complexity. Splice site specification is controlled by interactions of cis-acting determinants on a transcript with specific RNA binding proteins. These interactions are frequently localized to the intronic U-rich polypyrimidine tracts (PPT) located 5′ to the majority of splice acceptor junctions. αCPs (also referred to as polyC-binding proteins (PCBPs) and hnRNPEs) comprise a subset of KH-domain proteins with high affinity and specificity for C-rich polypyrimidine motifs. Here, we demonstrate that αCPs promote the splicing of a defined subset of cassette exons via binding to a C-rich subset of polypyrimidine tracts located 5′ to the αCP-enhanced exonic segments. This enhancement of splice acceptor activity is linked to interactions of αCPs with the U2 snRNP complex and may be mediated by cooperative interactions with the canonical polypyrimidine tract binding protein, U2AF65. Analysis of αCP-targeted exons predicts a substantial impact on fundamental cell functions. These findings lead us to conclude that the αCPs play a direct and global role in modulating the splicing activity and inclusion of an array of cassette exons, thus driving a novel pathway of splice site regulation within the mammalian transcriptome.
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Affiliation(s)
- Xinjun Ji
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Juw Won Park
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA Department of Computer Engineering and Computer Science, University of Louisville, Louisville, KY 40292, USA KBRIN Bioinformatics Core, University of Louisville, Louisville, KY 40202, USA
| | - Emad Bahrami-Samani
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Lan Lin
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Christopher Duncan-Lewis
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Gordon Pherribo
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Yi Xing
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Stephen A Liebhaber
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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Computational Identification of Post Translational Modification Regulated RNA Binding Protein Motifs. PLoS One 2015; 10:e0137696. [PMID: 26368004 PMCID: PMC4569568 DOI: 10.1371/journal.pone.0137696] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2015] [Accepted: 08/19/2015] [Indexed: 11/19/2022] Open
Abstract
RNA and its associated RNA binding proteins (RBPs) mitigate a diverse array of cellular functions and phenotypes. The interactions between RNA and RBPs are implicated in many roles of biochemical processing by the cell such as localization, protein translation, and RNA stability. Recent discoveries of novel mechanisms that are of significant evolutionary advantage between RBPs and RNA include the interaction of the RBP with the 3’ and 5’ untranslated region (UTR) of target mRNA. These mechanisms are shown to function through interaction of a trans-factor (RBP) and a cis-regulatory element (3’ or 5’ UTR) by the binding of a RBP to a regulatory-consensus nucleic acid motif region that is conserved throughout evolution. Through signal transduction, regulatory RBPs are able to temporarily dissociate from their target sites on mRNAs and induce translation, typically through a post-translational modification (PTM). These small, regulatory motifs located in the UTR of mRNAs are subject to a loss-of-function due to single polymorphisms or other mutations that disrupt the motif and inhibit the ability to associate into the complex with RBPs. The identification of a consensus motif for a given RBP is difficult, time consuming, and requires a significant degree of experimentation to identify each motif-containing gene on a genomic scale. We have developed a computational algorithm to analyze high-throughput genomic arrays that contain differential binding induced by a PTM for a RBP of interest–RBP-PTM Target Scan (RPTS). We demonstrate the ability of this application to accurately predict a PTM-specific binding motif to an RBP that has no antibody capable of distinguishing the PTM of interest, negating the use of in-vitro exonuclease digestion techniques.
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10
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Zhou M, Tong X. Downregulated Poly-C binding protein-1 is a novel predictor associated with poor prognosis in Acute Myeloid Leukemia. Diagn Pathol 2015; 10:147. [PMID: 26293996 PMCID: PMC4546103 DOI: 10.1186/s13000-015-0377-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2015] [Accepted: 07/29/2015] [Indexed: 01/09/2023] Open
Abstract
Background Depletion of Poly-C binding protein-1(PCBP1) is implicated in various human malignancies. However, the underlying biological effect of PCBP1 in cancers, including acute myeloid leukemia (AML), still remains elusive. The purpose of this study was to examine the expression and clinical outcome of PCBP1in acute myeloid leukemia. Methods Bone marrow fluids of 88 newly diagnosed AML patients were sampled, and the PCBP1 mRNA expression level was evaluated using quantitative RT-PCR. The association between PCBP1 expression and clinicopathological features or the survival status of the patients was assessed by Chi-square test and Kaplan-Meier method. Results Comparing newly diagnosed AML patients to normal healthy donors, PCBP1 expression was significantly decreased in AML patients (P < 0.001). Conversely, PCBP1 expression had accordingly recovered back to normal in patients with complete remission (P < 0.001). Clinical feature analyses showed that PCBP1 expression was negatively correlated with white blood cell count (P = 0.024). In addition, patients with low PCBP1 expression had poor disease-free survival (11.8 % vs. 45.3 %; P = 0.01) and overall survival (18.2 % vs. 42.4 %; P = 0.032), respectively. Conclusions Taken together, our results showed for the first time that expression of PCBP1 was down-regulated in newly diagnosed AML patients and might be an independent prognostic marker in AML and should to be further investigated.
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Affiliation(s)
- Meifeng Zhou
- Department of Hematology, the First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, 510080, China.
| | - Xiuzhen Tong
- Department of Hematology, the First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, 510080, China.
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11
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van Dijk M, Visser A, Buabeng KML, Poutsma A, van der Schors RC, Oudejans CBM. Mutations within the LINC-HELLP non-coding RNA differentially bind ribosomal and RNA splicing complexes and negatively affect trophoblast differentiation. Hum Mol Genet 2015; 24:5475-85. [PMID: 26173455 DOI: 10.1093/hmg/ddv274] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 07/09/2015] [Indexed: 11/14/2022] Open
Abstract
LINC-HELLP, showing chromosomal linkage with the pregnancy-specific HELLP syndrome in Dutch families, reduces differentiation from a proliferative to an invasive phenotype of first-trimester extravillous trophoblasts. Here we show that mutations in LINC-HELLP identified in HELLP families negatively affect this trophoblast differentiation either by inducing proliferation rate or by causing cell cycle exit as shown by a decrease in both proliferation and invasion. As LincRNAs predominantly function through interactions with proteins, we identified the directly interacting proteins using chromatin isolation by RNA purification followed by protein mass spectrometry. We found 22 proteins predominantly clustering in two functional networks, i.e. RNA splicing and the ribosome. YBX1, PCBP1, PCBP2, RPS6 and RPL7 were validated, and binding to these proteins was influenced by the HELLP mutations carried. Finally, we show that the LINC-HELLP transcript levels are significantly upregulated in plasma of women in their first trimester of pregnancy compared with non-pregnant women, whereas this upregulation seems absent in a pilot set of patients later developing pregnancy complications, indicative of its functional significance in vivo.
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Affiliation(s)
- Marie van Dijk
- Department of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands and
| | - Allerdien Visser
- Department of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands and
| | - Kwadwo M L Buabeng
- Department of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands and
| | - Ankie Poutsma
- Department of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands and
| | - Roel C van der Schors
- Center for Neurogenomics and Cognitive Research, VU University, Amsterdam, The Netherlands
| | - Cees B M Oudejans
- Department of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands and
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12
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Abstract
POLH (DNA polymerase η), a target of p53 tumour suppressor, plays a key role in TLS (translesion DNA synthesis). Loss of POLH is responsible for the human cancer-prone syndrome XPV (xeroderma pigmentosum variant). Owing to its critical role in DNA repair and genome stability, POLH expression and activity are regulated by multiple pathways. In the present study, we found that the levels of both POLH transcript and protein were decreased upon knockdown of the transcript encoding PCBP1 [poly(rC)-binding protein 1]. We also found that the half-life of POLH mRNA was markedly decreased upon knockdown of PCBP1. Moreover, we found that PCBP1 directly bound to the POLH 3'-UTR and the PCBP1-binding site in POLH mRNA is an atypical AU-rich element. Finally, we showed that the AU-rich element in POLH 3'-UTR was responsive to PCBP1 and sufficient for PCBP1 to regulate POLH expression. Taken together, we uncovered a novel mechanism by which POLH expression is controlled by PCBP1 via mRNA stability.
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