YTHDC1 Controls The Sensitivity Of CcRCC To Sunitinib By Targeting The ANXA1-MAPK Pathway

Objective: Clear cell renal cell carcinoma(cc RCC)is the main type of renal carcinoma.Although surgical treatment is the mainstay of treatment for renal cancer,patients with unresectable advanced renal cancer or recurrent renal cancer rely on systemic treatment,typically antiangiogenic or immunotherapeutic treatment,to prolong their lives.Tyrosine kinase inhibitors(TKIs)such as sunitinib are multitarget antiangiogenic agents in cc RCC.They are widely used in the treatment of advanced or metastatic renal cancer.However,resistance to TKIs is common in the clinic,particularly after long-term treatment.The mechanism of drug resistance may be related to proangiogenic signaling pathways,changes in the tumor microenvironment,increased tumor invasion and metastasis,micro RNA-mediated drug resistance or the activation of other signaling pathways.However,the factors associated with TKI resistance in cc RCC have not been fully clarified.Thus,further study of the mechanism of TKI resistance would be helpful for the development of new antitumor strategies for cc RCC.YTHDC1(YTH N6-methyladenosine RNA binding protein C1)is the main nuclear reader protein that binds with m6 A to regulate the splicing,export and stability of m RNA.However,the specific role and corresponding mechanism of YTHDC1 in renal cancer cells are still unclear.Our study is to investigate the role of YTHDC1 in cc RCC and provide therapeutic target for treatment of cc RCC.Methods: The Cancer Genome Atlas(TCGA)dataset was used to study the expression of YTHDC1 in cc RCC.Cell counting kit-8(CCK-8),wound healing,Transwell and xenograft assays were applied to explore the biological function of YTHDC1 in cc RCC.Western blot,quantitative real time PCR(RT?q PCR),RNA immunoprecipitation PCR(RIP-q PCR),methylated RIP-q PCR(Me RIP-q PCR)and RNA sequencing(RNA-seq)analyses were applied to study the YY1/HDAC2/YTHDC1/ANXA1 axis in renal cancer cells.The CCK-8 assay and xenograft assay were used to study the role of YTHDC1 in determining the sensitivity of cc RCC to sunitinib.Results: Our results demonstrated that YTHDC1 is downregulated in cc RCC tissues compared with normal tissues.Low expression of YTHDC1 is associated with a poor prognosis in patients with cc RCC.Ectopic overexpression of YTHDC1 impeded the proliferation,migration,and invasion of both A498 and 786-O cells.The nude mouse xenograft assay also demonstrated that knockdown of YTHDC1 increased the tumor growth of renal cancer cells.Subsequently,we showed that YTHDC1 inactivates the ERK/MAPK signaling pathway to inhibit the proliferation of renal cancer cells.Moreover,we showed that YTHDC1 decreases the m RNA stability of ANXA1 in renal cancer cells.YTHDC1 inhibits activation of the MAPK signaling pathway by targeting ANXA1 in cc RCC.YTHDC1 regulates the sensitivity of renal cancer cells to sunitinib through ANXA1.We also showed that the YY1/HDAC2 complex downregulates the expression of YTHDC1 in cc RCC.HDAC2 inhibitors enhance the sensitivity of cc RCC to sunitinib.We then revealed that HDAC2 inhibitors resensitize cc RCC to tyrosine kinase inhibitors through the YY1/HDAC2 complex.Conclusion: We showed that YTHDC1 is downregulated in cc RCC.Subsequently,we demonstrated that YTHDC1 inhibits the progression of renal cancer cells via downregulation of the ANXA1/MAPK pathways.Moreover,we also showed that the YTHDC1/ANXA1 axis modulates the sensitivity of tyrosine kinase inhibitors.We also revealed that HDAC2 inhibitors resensitize cc RCC to tyrosine kinase inhibitors through the YY1/HDAC2 complex.Taken together,we identified a novel YY1/HDAC2/YTHDC1/ANXA1 axis modulating the progression and chemosensitivity of ccRCC.