ESRP1 regulates alternative splicing of CARM1 to sensitize small cell lung cancer cells to chemotherapy by inhibiting TGF-β/Smad signaling.

Epithelial splicing regulatory protein 1 (ESRP1) is an RNA-binding protein that regulates alternative splicing of mRNA. ESRP1 plays an important role in chemoresistance of various cancers, including breast cancer, colon cancer and non-small cell lung cancer. However, the role of ESRP1 and its mechanism in small cell lung cancer (SCLC) chemoresistance remains unclear. In this study, we found that ESRP1 is significantly downregulated in SCLC chemo-resistant cells compared with chemo-sensitive cells. Moreover, the expression of ESRP1 was significantly lower in SCLC tissues than that in normal adjacent tissues and positively correlated with overall survival. Overexpression of ESRP1 increased SCLC chemosensitivity, and induced cell apoptosis and cell cycle arrest, whereas knockdown of ESRP1 induced the opposite effects. ESRP1 could inhibit the growth of SCLC in vivo. Through mRNA transcriptome sequencing, we found that ESRP1 regulates coactivator-associated arginine methyltransferase 1 (CARM1) to produce two different transcripts CARM1FL and CARM1ΔE15 by alternative splicing. ESRP1 affects the chemoresistance of SCLC by changing the content of different transcripts of CARM1. Furthermore, CARM1 regulates arginine methylation of Smad7, activates the TGF-β/Smad pathway and induces epithelial-to-mesenchymal transition (EMT), thereby promoting SCLC chemoresistance. Collectively, our study firstly demonstrates that ESRP1 inhibits the TGF-β/Smad signaling pathway by regulating alternative splicing of CARM1, thereby reversing chemoresistance of SCLC. The splicing factor ESRP1 may serve as a new drug resistance marker molecule and a potential therapeutic target in SCLC patients.

[1]  Mengjie Wang,et al.  SRSF1‐dependent alternative splicing attenuates BIN1 expression in non–small cell lung cancer , 2020, Journal of cellular biochemistry.

[2]  B. Hinz,et al.  TGF-β1 - A truly transforming growth factor in fibrosis and immunity. , 2019, Seminars in cell & developmental biology.

[3]  Xiao Li,et al.  Systematic profiling of alternative splicing signature reveals prognostic predictor for cervical cancer , 2019, Journal of Translational Medicine.

[4]  R. Chen,et al.  Circular RNA cESRP1 sensitises small cell lung cancer cells to chemotherapy by sponging miR-93-5p to inhibit TGF-β signalling , 2019, Cell Death and Differentiation.

[5]  Jingcheng Zhang,et al.  CARM1 is heterogeneous in mouse four-cell embryo and important to blastocyst development. , 2019, Reproduction.

[6]  Yang Zhang,et al.  The canonical TGF-β/Smad signalling pathway is involved in PD-L1-induced primary resistance to EGFR-TKIs in EGFR-mutant non-small-cell lung cancer , 2019, Respiratory Research.

[7]  M. Kumar,et al.  Functional interplay between YY1 and CARM1 promotes oral carcinogenesis , 2019, Oncotarget.

[8]  Jinn-Moon Yang,et al.  Alternative splicing in human cancer cells is modulated by the amiloride derivative 3,5‐diamino‐6‐chloro‐N‐(N‐(2,6‐dichlorobenzoyl)carbamimidoyl)pyrazine‐2‐carboxide , 2019, Molecular oncology.

[9]  Yong Wang,et al.  Curcumin reverses oxaliplatin resistance in human colorectal cancer via regulation of TGF-β/Smad2/3 signaling pathway , 2019, OncoTargets and therapy.

[10]  Wenjing Zhang,et al.  Aberrant alternative splicing in breast cancer , 2019, Journal of molecular cell biology.

[11]  Tianxin Lin,et al.  Polypyrimidine tract binding protein 1 promotes lymphatic metastasis and proliferation of bladder cancer via alternative splicing of MEIS2 and PKM. , 2019, Cancer letters.

[12]  A. Azzariti,et al.  CAFs and TGF-β Signaling Activation by Mast Cells Contribute to Resistance to Gemcitabine/Nabpaclitaxel in Pancreatic Cancer , 2019, Cancers.

[13]  Xiaoping Gu,et al.  Splicing factor ESRP1 controls ER‐positive breast cancer by altering metabolic pathways , 2019, EMBO reports.

[14]  C. Stuelten,et al.  TGF-β-induced alternative splicing of TAK1 promotes EMT and drug resistance , 2018, Oncogene.

[15]  R. Lothe,et al.  Alternative splicing expands the prognostic impact of KRAS in microsatellite stable primary colorectal cancer , 2018, International journal of cancer.

[16]  N. Lee,et al.  Role of Alternative Splicing in Prostate Cancer Aggressiveness and Drug Resistance in African Americans. , 2019, Advances in experimental medicine and biology.

[17]  Olga Anczuków,et al.  Alternative‐splicing defects in cancer: Splicing regulators and their downstream targets, guiding the way to novel cancer therapeutics , 2018, Wiley interdisciplinary reviews. RNA.

[18]  A. Burlingame,et al.  Arginine methylation of SMAD7 by PRMT1 in TGF-β–induced epithelial–mesenchymal transition and epithelial stem-cell generation , 2018, The Journal of Biological Chemistry.

[19]  S. E. Harvey,et al.  Coregulation of alternative splicing by hnRNPM and ESRP1 during EMT , 2018, bioRxiv.

[20]  Jason T. George,et al.  Interconnected feedback loops among ESRP1, HAS2, and CD44 regulate epithelial-mesenchymal plasticity in cancer , 2018, bioRxiv.

[21]  Z. Siegfried,et al.  The role of alternative splicing in cancer drug resistance. , 2018, Current opinion in genetics & development.

[22]  A. Moustakas,et al.  TGF-β Family Signaling in Epithelial Differentiation and Epithelial-Mesenchymal Transition. , 2018, Cold Spring Harbor perspectives in biology.

[23]  D. Morgensztern,et al.  Treatment advances in small cell lung cancer (SCLC) , 2017, Pharmacology & therapeutics.

[24]  S. Knapp,et al.  Alternative splicing promotes tumour aggressiveness and drug resistance in African American prostate cancer , 2017, Nature Communications.

[25]  Nicholas W. Kwiecien,et al.  Global mapping of CARM1 substrates defines enzyme specificity and substrate recognition , 2017, Nature Communications.

[26]  C. Rudin,et al.  Unravelling the biology of SCLC: implications for therapy , 2017, Nature Reviews Clinical Oncology.

[27]  Xiaohui Liang,et al.  TRA2A Promoted Paclitaxel Resistance and Tumor Progression in Triple-Negative Breast Cancers via Regulating Alternative Splicing , 2017, Molecular Cancer Therapeutics.

[28]  K. Miyazawa,et al.  Dual Roles for Epithelial Splicing Regulatory Proteins 1 (ESRP1) and 2 (ESRP2) in Cancer Progression. , 2016, Advances in experimental medicine and biology.

[29]  Darío,et al.  The RNA-binding protein ESRP 1 promotes human colorectal cancer progression , 2017 .

[30]  Wei Zhou,et al.  Arginine Methylation of MDH1 by CARM1 Inhibits Glutamine Metabolism and Suppresses Pancreatic Cancer. , 2016, Molecular cell.

[31]  Prakash Kulkarni,et al.  Phenotypic plasticity in prostate cancer: role of intrinsically disordered proteins , 2016, Asian journal of andrology.

[32]  P. Ahlquist,et al.  CARM1 Methylates Chromatin Remodeling Factor BAF155 to Enhance Tumor Progression and Metastasis. , 2016, Cancer cell.

[33]  K. Yamashita,et al.  Epigenetic regulation of ZEB1-RAB25/ESRP1 axis plays a critical role in phenylbutyrate treatment-resistant breast cancer , 2015, Oncotarget.

[34]  E. Pilozzi,et al.  Modulation of PKM alternative splicing by PTBP1 promotes gemcitabine resistance in pancreatic cancer cells , 2015, Oncogene.

[35]  Y. Liu,et al.  Alternative splicing isoform of T cell factor 4K suppresses the proliferation and metastasis of non-small cell lung cancer cells. , 2015, Genetics and molecular research : GMR.

[36]  X. Bian,et al.  MED12 methylation by CARM1 sensitizes human breast cancer cells to chemotherapy drugs , 2015, Science Advances.

[37]  Menggang Yu,et al.  Differential CARM1 Isoform Expression in Subcellular Compartments and among Malignant and Benign Breast Tumors , 2015, PloS one.

[38]  D. Kerr,et al.  Alternative splicing of TIA‐1 in human colon cancer regulates VEGF isoform expression, angiogenesis, tumour growth and bevacizumab resistance , 2014, Molecular oncology.

[39]  Wenjin Xi,et al.  MiR‐200c suppresses TGF‐β signaling and counteracts trastuzumab resistance and metastasis by targeting ZNF217 and ZEB1 in breast cancer , 2014, International journal of cancer.

[40]  Nianshuang Li,et al.  SMAD7: a timer of tumor progression targeting TGF-β signaling , 2014, Tumor Biology.

[41]  A. Burlingame,et al.  Arginine Methylation Initiates BMP-Induced Smad Signaling. , 2013, Molecular cell.

[42]  Wei Xu,et al.  CARM1 automethylation is controlled at the level of alternative splicing , 2013, Nucleic acids research.

[43]  L. Wakefield,et al.  Beyond TGFβ: roles of other TGFβ superfamily members in cancer , 2013, Nature Reviews Cancer.

[44]  Nicholas C. Flytzanis,et al.  An EMT–Driven Alternative Splicing Program Occurs in Human Breast Cancer and Modulates Cellular Phenotype , 2011, PLoS genetics.

[45]  Amy J. Hawkins,et al.  SRSF1 Regulates the Alternative Splicing of Caspase 9 Via A Novel Intronic Splicing Enhancer Affecting the Chemotherapeutic Sensitivity of Non–Small Cell Lung Cancer Cells , 2011, Molecular Cancer Research.

[46]  Claude C. Warzecha,et al.  ESRP1 and ESRP2 are epithelial cell-type-specific regulators of FGFR2 splicing. , 2009, Molecular cell.