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Tokuda N, Watanabe D, Naito A, Yamauchi N, Ashida Y, Cheng AJ, Yamada T. Intrinsic contractile dysfunction due to impaired sarcoplasmic reticulum Ca 2+ release in compensatory hypertrophied muscle fibers following synergist ablation. Am J Physiol Cell Physiol 2023; 325:C599-C612. [PMID: 37486068 DOI: 10.1152/ajpcell.00127.2023] [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: 04/04/2023] [Revised: 07/12/2023] [Accepted: 07/12/2023] [Indexed: 07/25/2023]
Abstract
Synergist ablation (SA) is an experimental procedure for the induction of hypertrophy. However, SA causes a decrease in specific force (i.e., force per cross-sectional area), likely due to excessive muscle use. Here, we investigated the mechanisms behind the SA-induced intrinsic contractile dysfunction, especially focusing on the excitation-contraction (EC) coupling. Male Wistar rats had unilateral surgical ablation of gastrocnemius and soleus muscles to induce compensatory hypertrophy in the plantaris muscles. Two weeks after SA, plantaris muscle was dissected from each animal and used for later analyses. SA significantly increased the mean fiber cross-sectional area (+18%). On the other hand, the ratio of depolarization-induced force to the maximum Ca2+-activated specific force, an indicator of sarcoplasmic reticulum (SR) Ca2+ release, was markedly reduced in mechanically skinned fibers from the SA group (-51%). These functional defects were accompanied by an extensive fragmentation of the SR Ca2+ release channel, the ryanodine receptor 1 (RyR1), and a decrease in the amount of other triad proteins (i.e., DHPR, STAC3, and junctophilin1). SA treatment also caused activation of calpain-1 and increased the amount of NADPH oxidase 2, endoplasmic reticulum (ER) stress proteins (i.e., Grp78, Grp94, PDI, and Ero1), and lipid peroxidation [i.e., 4-hydroxynonenal (4-HNE)] in SA-treated muscles. Our findings show that SA causes skeletal muscle weakness due to impaired EC coupling. This is likely to be induced by Ca2+-dependent degradation of triad proteins, which may result from Ca2+ leak from fragmented RyR1 triggered by increased oxidative stress.NEW & NOTEWORTHY Synergist ablation (SA) has widely been used to understand the mechanisms behind skeletal muscle hypertrophy. However, compensatory hypertrophied muscles display intrinsic contractile dysfunction, i.e., a hallmark of overuse. Here, we demonstrate that SA-induced compensatory hypertrophy is accompanied by muscle weakness due to impaired sarcoplasmic reticulum Ca2+ release. This dysfunction may be caused by the degradation of triad proteins due to the reciprocal amplification of reactive oxygen species and Ca2+ signaling at the junctional space microdomain.
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Affiliation(s)
- Nao Tokuda
- Graduate School of Health Sciences, Sapporo Medical University, Sapporo, Japan
| | - Daiki Watanabe
- Graduate School of Sport and Health Sciences, Osaka University of Health and Sport Sciences, Osaka, Japan
| | - Azuma Naito
- Graduate School of Health Sciences, Sapporo Medical University, Sapporo, Japan
| | - Nao Yamauchi
- Graduate School of Health Sciences, Sapporo Medical University, Sapporo, Japan
| | - Yuki Ashida
- Graduate School of Health Sciences, Sapporo Medical University, Sapporo, Japan
- The Japan Society for the Promotion of Science (JSPS), Tokyo, Japan
| | - Arthur J Cheng
- School of Kinesiology and Health Sciences, York University, Toronto, Ontario, Canada
| | - Takashi Yamada
- Graduate School of Health Sciences, Sapporo Medical University, Sapporo, Japan
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Giraud JS, Bièche I, Pasmant É, Tlemsani C. NF1 alterations in cancers: therapeutic implications in precision medicine. Expert Opin Investig Drugs 2023; 32:941-957. [PMID: 37747491 DOI: 10.1080/13543784.2023.2263836] [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: 05/06/2023] [Accepted: 09/24/2023] [Indexed: 09/26/2023]
Abstract
INTRODUCTION NF1 is a tumor suppressor gene encoding neurofibromin, an inhibitor of the RAS/MAPK and PI3K-AKT-mTOR signaling pathways. NF1 germline pathogenic variants cause the tumor predisposition syndrome neurofibromatosis type 1. Targeted therapies (MEK inhibitors) have been approved for benign nerve sheath tumors in neurofibromatosis type 1 patients. NF1 somatic alterations are present in ~5% of all human sporadic cancers. In melanomas, acute myeloid leukemias and lung adenocarcinomas, the NF1 somatic alteration frequency is higher (~15%). However, to date, the therapeutic impact of NF1 somatic alterations is poorly investigated. AREAS COVERED This review presents a comprehensive overview of targeted therapies and immunotherapies currently developed and evaluated in vitro and in vivo for NF1-altered cancer treatment. A PubMed database literature review was performed to select relevant original articles. Active clinical trials were researched in ClinicalTrials.gov database in August 2022. TCGA and HGMD® databases were consulted. EXPERT OPINION This review highlights the need to better understand the molecular mechanisms of NF1-altered tumors and the development of innovative strategies to effectively target NF1-loss in human cancers. One of the current major challenges in cancer management is the targeting of tumor suppressor genes such as NF1 gene. Currently, most studies are focusing on inhibitors of the RAS/MAPK and PI3K-AKT-mTOR pathways and immunotherapies.
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Affiliation(s)
- Jean-Stéphane Giraud
- Institut Cochin, Inserm U1016, CNRS UMR8104, Université Paris Cité, CARPEM, Paris, France
| | - Ivan Bièche
- Institut Cochin, Inserm U1016, CNRS UMR8104, Université Paris Cité, CARPEM, Paris, France
- Genetic Department, Curie Institute, Paris, France
| | - Éric Pasmant
- Institut Cochin, Inserm U1016, CNRS UMR8104, Université Paris Cité, CARPEM, Paris, France
- Genetic Department, Hôpital Cochin, AP-HP.Centre-Université Paris Cité, Paris, France
| | - Camille Tlemsani
- Institut Cochin, Inserm U1016, CNRS UMR8104, Université Paris Cité, CARPEM, Paris, France
- Oncology Department, Hôpital Cochin, AP-HP.Centre-Université Paris Cité, Paris, France
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Yakovian O, Sajman J, Alon M, Arafeh R, Samuels Y, Sherman E. NRas activity is regulated by dynamic interactions with nanoscale signaling clusters at the plasma membrane. iScience 2022; 25:105282. [PMID: 36304112 PMCID: PMC9593252 DOI: 10.1016/j.isci.2022.105282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 06/07/2022] [Accepted: 10/04/2022] [Indexed: 11/28/2022] Open
Abstract
NRas is a key mediator of the mitogenic pathway in normal cells and in cancer cells. Its dynamics and nanoscale organization at the plasma membrane (PM) facilitate its signaling. Here, we used two-color photoactivated localization microscopy to resolve the organization of individual NRas and associated signaling proteins in live melanoma cells, with resolution down to ∼20 nm. Upon EGF activation, a fraction of NRas and BRAF (dis)assembled synchronously at the PM in co-clusters. NRas and BRAF clusters associated with GPI-enriched domains, serving as possible nucleation sites for these clusters. NRas and BRAF association in mutual clusters was reduced by the NRas farnesylation inhibitor lonafarnib, yet enhanced by the BRAF inhibitor vemurafenib. Surprisingly, dispersed NRas molecules associated with the periphery of self-clusters of either Grb2 or NF1. Thus, NRas-mediated signaling, which is critical in health and disease, is regulated by dynamic interactions with functional clusters of BRAF or other related proteins at the PM.
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Affiliation(s)
- Oren Yakovian
- Racah Institute of Physics, The Hebrew University, Jerusalem 91904, Israel
| | - Julia Sajman
- Racah Institute of Physics, The Hebrew University, Jerusalem 91904, Israel
| | - Michal Alon
- Department of Molecular Cell Biology, Weizmann Institute of Science, 7610001 Rehovot, Israel
| | - Rand Arafeh
- Department of Molecular Cell Biology, Weizmann Institute of Science, 7610001 Rehovot, Israel,Department of Molecular Oncology, Dana Farber Cancer Institute, Boston, MA, USA
| | - Yardena Samuels
- Department of Molecular Cell Biology, Weizmann Institute of Science, 7610001 Rehovot, Israel
| | - Eilon Sherman
- Racah Institute of Physics, The Hebrew University, Jerusalem 91904, Israel,Corresponding author
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Ashida Y, Himori K, Tokuda N, Naito A, Yamauchi N, Takenaka-Ninagawa N, Aoki Y, Sakurai H, Yamada T. Dissociation of SH3 and cysteine rich domain 3 and junctophilin 1 from dihydropyridine receptor in dystrophin-deficient muscles. Am J Physiol Cell Physiol 2022; 323:C885-C895. [PMID: 35912995 DOI: 10.1152/ajpcell.00163.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The disruption of excitation-contraction (EC) coupling and subsequent reduction in Ca2+ release from the sarcoplasmic reticulum (SR) have been shown to account for muscle weakness seen in patients with Duchenne muscular dystrophy (DMD). Here, we examined the mechanisms underlying EC uncoupling in skeletal muscles from mdx52 and DMD-null/NSG mice, animal models for DMD, focusing on the SH3 and cysteine rich domain 3 (STAC3) and junctophilin 1 (JP1), which link the dihydropyridine receptor (DHPR) in the transverse tubule and the ryanodine receptor 1 in the SR. The isometric plantarflexion torque normalized to muscle weight of whole plantar flexor muscles was depressed in mdx52 and DMD-null/NSG mice compared to their control mice. This was accompanied by increased autolysis of calpain-1, decreased levels of STAC3 and JP1 content, and dissociation of STAC3 and JP1 from DHPR-α1s in gastrocnemius muscles. Moreover, in vitro mechanistic experiments demonstrated that STAC3 and JP1 underwent Ca2+-dependent proteolysis which was less pronounced in dystrophin-deficient muscles where calpastatin, the endogenous calpain inhibitor, was upregulated. Eccentric contractions further enhanced autolysis of calpain-1 and proteolysis of STAC3 and JP1 that were associated with severe torque depression in gastrocnemius muscles from DMD-null/NSG mice. These data suggest that Ca2+-dependent proteolysis of STAC3 and JP1 may be an essential factor causing muscle weakness due to EC coupling failure in dystrophin-deficient muscles.
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Affiliation(s)
- Yuki Ashida
- Graduate School of Health Sciences, Sapporo Medical University, Sapporo, Japan.,Research Fellow of Japan Society for the Promotion of Science, Tokyo, Japan
| | - Koichi Himori
- Graduate School of Health Sciences, Sapporo Medical University, Sapporo, Japan.,Research Fellow of Japan Society for the Promotion of Science, Tokyo, Japan
| | - Nao Tokuda
- Graduate School of Health Sciences, Sapporo Medical University, Sapporo, Japan
| | - Azuma Naito
- Graduate School of Health Sciences, Sapporo Medical University, Sapporo, Japan
| | - Nao Yamauchi
- Graduate School of Health Sciences, Sapporo Medical University, Sapporo, Japan
| | | | - Yoshitsugu Aoki
- Department of Molecular Therapy, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan
| | - Hidetoshi Sakurai
- Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto, Japan
| | - Takashi Yamada
- Graduate School of Health Sciences, Sapporo Medical University, Sapporo, Japan
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Shi ZD, Hao L, Han XX, Wu ZX, Pang K, Dong Y, Qin JX, Wang GY, Zhang XM, Xia T, Liang Q, Zhao Y, Li R, Zhang SQ, Zhang JH, Chen JG, Wang GC, Chen ZS, Han CH. Targeting HNRNPU to overcome cisplatin resistance in bladder cancer. Mol Cancer 2022; 21:37. [PMID: 35130920 PMCID: PMC8819945 DOI: 10.1186/s12943-022-01517-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Accepted: 01/21/2022] [Indexed: 01/01/2023] Open
Abstract
Purpose The overall response of cisplatin-based chemotherapy in bladder urothelial carcinoma (BUC) remains unsatisfactory due to the complex pathological subtypes, genomic difference, and drug resistance. The genes that associated with cisplatin resistance remain unclear. Herein, we aimed to identify the cisplatin resistance associated genes in BUC. Experimental design The cytotoxicity of cisplatin was evaluated in six bladder cancer cell lines to compare their responses to cisplatin. The T24 cancer cells exhibited the lowest sensitivity to cisplatin and was therefore selected to explore the mechanisms of drug resistance. We performed genome-wide CRISPR screening in T24 cancer cells in vitro, and identified that the gene heterogeneous nuclear ribonucleoprotein U (HNRNPU) was the top candidate gene related to cisplatin resistance. Epigenetic and transcriptional profiles of HNRNPU-depleted cells after cisplatin treatment were analyzed to investigate the relationship between HNRNPU and cisplatin resistance. In vivo experiments were also performed to demonstrate the function of HNRNPU depletion in cisplatin sensitivity. Results Significant correlation was found between HNRNPU expression level and sensitivity to cisplatin in bladder cancer cell lines. In the high HNRNPU expressing T24 cancer cells, knockout of HNRNPU inhibited cell proliferation, invasion, and migration. In addition, loss of HNRNPU promoted apoptosis and S-phase arrest in the T24 cells treated with cisplatin. Data from The Cancer Genome Atlas (TCGA) demonstrated that HNRNPU expression was significantly higher in tumor tissues than in normal tissues. High HNRNPU level was negatively correlated with patient survival. Transcriptomic profiling analysis showed that knockout of HNRNPU enhanced cisplatin sensitivity by regulating DNA damage repair genes. Furthermore, it was found that HNRNPU regulates chemosensitivity by affecting the expression of neurofibromin 1 (NF1). Conclusions Our study demonstrated that HNRNPU expression is associated with cisplatin sensitivity in bladder urothelial carcinoma cells. Inhibition of HNRNPU could be a potential therapy for cisplatin-resistant bladder cancer. Supplementary Information The online version contains supplementary material available at 10.1186/s12943-022-01517-9.
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Khaddour K, Maahs L, Avila-Rodriguez AM, Maamar Y, Samaan S, Ansstas G. Melanoma Targeted Therapies beyond BRAF-Mutant Melanoma: Potential Druggable Mutations and Novel Treatment Approaches. Cancers (Basel) 2021; 13:5847. [PMID: 34831002 PMCID: PMC8616477 DOI: 10.3390/cancers13225847] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 11/17/2021] [Accepted: 11/18/2021] [Indexed: 12/24/2022] Open
Abstract
Melanomas exhibit the highest rate of somatic mutations among all different types of cancers (with the exception of BCC and SCC). The accumulation of a multimode of mutations in the driver oncogenes are responsible for the proliferative, invasive, and aggressive nature of melanomas. High-resolution and high-throughput technology has led to the identification of distinct mutational signatures and their downstream alterations in several key pathways that contribute to melanomagenesis. This has enabled the development of individualized treatments by targeting specific molecular alterations that are vital for cancer cell survival, which has resulted in improved outcomes in several cancers, including melanomas. To date, BRAF and MEK inhibitors remain the only approved targeted therapy with a high level of evidence in BRAFV600E/K mutant melanomas. The lack of approved precision drugs in melanomas, relative to other cancers, despite harboring one of the highest rates of somatic mutations, advocates for further research to unveil effective therapeutics. In this review, we will discuss potential druggable mutations and the ongoing research of novel individualized treatment approaches targeting non-BRAF mutations in melanomas.
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Affiliation(s)
- Karam Khaddour
- Division of Medical Oncology, Department of Medicine, Washington University in Saint Louis, Saint Louis, MO 63130, USA
- Division of Hematology and Oncology, Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA; (L.M.); (A.M.A.-R.)
| | - Lucas Maahs
- Division of Hematology and Oncology, Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA; (L.M.); (A.M.A.-R.)
| | - Ana Maria Avila-Rodriguez
- Division of Hematology and Oncology, Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA; (L.M.); (A.M.A.-R.)
| | - Yazan Maamar
- Division of Hematology and Oncology, Department of Medicine, University of Tishreen Lattakia, Lattakia 2217, Syria;
| | - Sami Samaan
- Department of Medicine, American University of Beirut, Beirut 1107, Lebanon;
| | - George Ansstas
- Division of Medical Oncology, Department of Medicine, Washington University in Saint Louis, Saint Louis, MO 63130, USA
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Garcia-Alvarez A, Ortiz C, Muñoz-Couselo E. Current Perspectives and Novel Strategies of NRAS-Mutant Melanoma. Onco Targets Ther 2021; 14:3709-3719. [PMID: 34135599 PMCID: PMC8202735 DOI: 10.2147/ott.s278095] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 05/28/2021] [Indexed: 12/15/2022] Open
Abstract
Melanoma is the deadliest cutaneous cancer. Activating mutations in NRAS are found in 20% of melanomas. NRAS-mutant melanoma is more aggressive and, therefore, has poorer outcomes, compared to non-NRAS-mutant melanoma. Despite promising preclinical data, to date immune checkpoint inhibitors remain the standard of care for locally advanced unresectable or metastatic NRAS melanoma. Data for efficacy of immunotherapy for NRAS melanoma mainly come from retrospective cohorts with divergent conclusions. MEK inhibitors have been the most developed targeted therapy approach. Although associated with an increase in progression-free survival, MEK inhibitors do not provide any benefit in terms of overall survival. Combination strategies with PI3K-AKT-mTOR pathway and CDK4/6 inhibitors seem to increase MEK inhibitors' benefit. Nevertheless, results from clinical trials are still prelaminar. A greater comprehension of the biology and intracellular interactions of NRAS-mutant melanoma will outline novel impactful strategies which could improve prognosis of these subgroup of patients.
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Affiliation(s)
- Alejandro Garcia-Alvarez
- Vall d’Hebron University Hospital, Medical Oncology Department, Melanoma and Other Skin Tumors Unit, Vall Hebron Institute of Oncology (VHIO), Barcelona, 08035, Spain
| | - Carolina Ortiz
- Vall d’Hebron University Hospital, Medical Oncology Department, Melanoma and Other Skin Tumors Unit, Vall Hebron Institute of Oncology (VHIO), Barcelona, 08035, Spain
| | - Eva Muñoz-Couselo
- Vall d’Hebron University Hospital, Medical Oncology Department, Melanoma and Other Skin Tumors Unit, Vall Hebron Institute of Oncology (VHIO), Barcelona, 08035, Spain
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Yakovian O, Sajman J, Arafeh R, Neve-Oz Y, Alon M, Samuels Y, Sherman E. MEK Inhibition Reverses Aberrant Signaling in Melanoma Cells through Reorganization of NRas and BRAF in Self Nanoclusters. Cancer Res 2021; 81:1279-1292. [PMID: 33355187 DOI: 10.1158/0008-5472.can-20-1205] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Revised: 07/29/2020] [Accepted: 12/14/2020] [Indexed: 11/16/2022]
Abstract
Hotspot mutations of the oncogenes BRAF and NRas are the most common genetic alterations in cutaneous melanoma. Still, the nanoscale organization and signal coupling of these proteins remain incompletely understood, particularly upon expression of oncogenic NRas mutants. Here we employed single-molecule localization microscopy to study the nanoscale organization of NRas and BRAF at the plasma membrane (PM) of melanoma cells. NRas and BRAF resided in self-clusters that did not associate well in resting cells. In EGF-activated cells, NRas clusters became more diffused while overall protein levels at the PM increased; thus allowing enhanced association of NRas and BRAF and downstream signaling. In multiple melanoma cell lines, mutant NRas resided in more pronounced self-clusters relative to wild-type (WT) NRas yet associated more with the clustered and more abundant BRAF. In cells resistant to trametinib, a clinical MEK inhibitor (MEKi), a similar coclustering of NRas and BRAF was observed upon EGF activation. Strikingly, treatment of cells expressing mutant NRas with trametinib reversed the effect of mutant NRas expression by restoring the nonoverlapping self-clusters of NRas and BRAF and by reducing their PM levels and elevated pERK levels caused by mutant NRas. Our results indicate a new mechanism for signal regulation of NRas in melanoma through its nanoscale dynamic organization and a new mechanism for MEKi function in melanoma cells carrying NRas mutations but lacking MEK mutations. SIGNIFICANCE: Nanoscale dynamic organization of WT and mutant NRas relative to BRAF serves as a regulatory mechanism for NRas signaling and may be a viable therapeutic target for its sensitivity to MEKi.
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Affiliation(s)
- Oren Yakovian
- Racah Institute of Physics, The Hebrew University, Jerusalem, Israel
| | - Julia Sajman
- Racah Institute of Physics, The Hebrew University, Jerusalem, Israel
| | - Rand Arafeh
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Yair Neve-Oz
- Racah Institute of Physics, The Hebrew University, Jerusalem, Israel
| | - Michal Alon
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Yardena Samuels
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Eilon Sherman
- Racah Institute of Physics, The Hebrew University, Jerusalem, Israel.
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Chen Y, Tang J, Lu T, Liu F. CAPN1 promotes malignant behavior and erlotinib resistance mediated by phosphorylation of c-Met and PIK3R2 via degrading PTPN1 in lung adenocarcinoma. Thorac Cancer 2020; 11:1848-1860. [PMID: 32395869 PMCID: PMC7327690 DOI: 10.1111/1759-7714.13465] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 04/14/2020] [Accepted: 04/17/2020] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Calpain 1 (CAPN1) has been found to be a promoter of cancer progression. PTPN1 as a physiological target molecule of CAPN1 plays a dephosphorylated role on multiple receptor tyrosine kinases. This study aimed to reveal the effects of CAPN1/PTPN1 on malignant phenotype and EGFR-TKI resistance of lung adenocarcinoma (LUAD) cells. METHODS A total of 84 primary LUAD tissues and paired paracancerous normal tissues were collected. Quantitative real-time PCR (qRT-PCR) and immunohistochemical (IHC) methods were used to measure the expression of CAPN1 and PTPN1 in tissues. qRT-PCR and western blot were used to detect the expressions of CAPN1, PTPN1, c-Met and PIK3R2 in cell lines. Cell counting kit-8 (CCK-8), colony formation and transwell assay were carried out to evaluate cell erlotinib resistance, proliferation, migration and invasion. Co-IP assay was used to verify the interaction between proteins. Cycloheximide (CHX) was applied to block protein synthesis. RESULTS CAPN1, c-Met and PIK3R2 were significantly upregulated and the correlation was positive in LUAD, while PTPN1 was decreased. EGFR-sensitive mutation was related to CAPN1/PTPN1. in vitro studies showed that PTPN1 can mediate dephosphorylation of c-Met and PIK3R2 by binding with both, thereby weakening cell proliferation, metastasis and erlotinib resistance, while CAPN1 could enhance the degradation of PTPN1 protein as a cancer promoter. CONCLUSIONS CAPN1 enhances the malignant behavior and erlotinib resistance of LUAD cells via degrading PTPN1 and then activating c-Met/PIK3R2, which suggests CAPN1/PTPN1 may serve as tumor markers or potential targets for diagnosis and treatment of LUAD. KEY POINTS Significant findings of the study Superior CAPN1 and inferior PTPN1 were related to activation of c-Met/PIK3R2 in lung adenocarcinoma. Moreover, regulations of CAPN1 and PTPN1 induced the changes of malignant behavior and erlotinib resistance. What this study adds Our findings confirmed that CAPN1/PTPN1 play crucial roles on proliferation, metastasis and erlotinib resistance of LUAD cells as c-Met/PIK3R2 regulators, and validated the regulatory mechanism of CAPN1 on PTPN1 in tumor model for the first time.
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Affiliation(s)
- Yichuan Chen
- Department of Cardiovascular Surgery, The Second Xiangya HospitalCentral South UniversityChangshaChina
| | - Jingqun Tang
- Department of Thoracic Surgery, The Second Xiangya HospitalCentral South UniversityChangshaChina
| | - Ting Lu
- Department of Cardiovascular Surgery, The Second Xiangya HospitalCentral South UniversityChangshaChina
| | - Fang Liu
- Clinic Nursing Teaching and Research Section, The Second Xiangya HospitalCentral South UniversityChangshaChina
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