The Roles And Mechanisms Of M6A Binding Protein YTHDF2 In Head And Neck Cancer

Background: Head and neck squamous cell carcinoma（HNSCC）is a common malignant tumor with high invasiveness,and its incidence rate ranks sixth in all human cancers.More than 50% of patients were in advanced stage at the time of treatment,and the 5-year overall survival rate was about 50%.Although we have made some progress in cancer prevention,early diagnosis and multimodal treatment in recent decades,the improvement of the overall prognosis of patients with HNSCC is very limited.Therefore,exploring the potential molecular mechanism of HNSCC initiation and malignant progression is very important to improve the overall survival rate of patients.Epigenetic modification plays an important role in tumor initiation and progression.N6methyladenine（m6A）,as the most common way of RNA epigenetic regulation in eukaryotes,has attracted more and more attention.m6 A methylation modification is a dynamic and reversible process,which is mainly regulated by "writer"（methyltransferase）,"reader"（m6A binding protein）and "eraser"（demethylase）.As a major reader,YTHDF2 serves as a tumor development accelerator or suppressor through regulates the stability of the downstream target genes in an m6A-dependent manner.However,few studies have explored the role and regulatory mechanism of YTHDF2 in the occurrence and malignant progression of HNSCC.Methods: 1.Firstly,the expression of m6 A binding protein YTHDF2 in HNSCC was revealed by analyzing the data of TCGA and the GEO database,and the expression level of YTHDF2 in HNSCC and adjacent non tumor tissues was detected by immunohistochemistry.2.Lentivirus was used to infect Cal-27 and FD-LSC-1 cells to stably reduce the expression of target gene YTHDF2 in HNSCC cells,and the infection efficiency was verified by Western blot and RT-q PCR.3.CCK-8 cell proliferation test,clone formation experiment,cell apoptosis assay,Transwell migration and invasion experiment were used to research the role of YTHDF2 on the proliferation,clone formation,apoptosis,migration and invasion of HNSCC cells.4.Establish a subcutaneous transplanted tumor model in nude mice to verify the effect of YTHDF2 on the growth of HNSCC cells in vivo.5.The possible downstream target genes of YTHDF2 were screened by m6 A sequencing,RNA immunoprecipitation sequencing and RNA expression profile sequencing.Results: 1.TCGA and GEO database showed that YTHDF2 was highly expressed in HNSCC.2.The results of CCK-8,clone formation test and Transwell experiment confirmed that knockdown of YTHDF2 could significantly inhibit the proliferation,migration and invasion of Cal-27 and FD-LSC-1 cells.Analysis of cells apoptosis by flow cytometry showed that knockdown of YTHDF2 promoted apoptosis in Cal-27 and FD-LSC-1 cells compared with the control group.3.The subcutaneous transplanted tumor model in nude mice confirmed that YTHDF2 inhibited the tumorigenesis and growth of HNSCC cells in mice.4.Through the intersection of Me RIP,RIP and RNA transcription group sequencing results,it was found that there were 26 overlapping genes,which prepared for the further study of the mechanism of YTHDF2 regulating the occurrence and development of HNSCC in an m6 A dependent manner.