The M6A Methyltransferase METTL3 Regulates The Malignant Proliferation Of Colorectal Cancer Cells Through The CDK4/P53/MYC Signaling Pathway

Colorectal cancer(CRC)is the second most common malignant tumor of the digestive system.However,because most patients have no obvious clinical symptoms in the early stage of the disease,and lack of early detection indicators or characteristic molecular markers,the patients are already at an advanced stage when they are diagnosed,and they have lost the opportunity for treatment such as Healing Star.Studies have found that RNA methylation is involved in various biological processes such as RNA transcription and post-transcriptional modification.As the core gene of m6 ARNA methyltransferase,METTL3 has been confirmed to be involved in the occurrence and development of a variety of cancers;however,the research on its function in colorectal cancer is still insufficient.Therefore,this study comprehensively and systematically explores its biological function in colorectal cancer,and explores the potential molecular mechanism of its biological function in colorectal cancer.Objective : This study intends to use bioinformatics to analyze the differences and possible biological functions of m6A-related genes in CRC;and to screen out the key genes in the m6 ARNA methylation process as the research object,explore their involvement in the malignant proliferation of colorectal cancer cells The biological function and potential molecular mechanism provide an important reference for the clinical diagnosis and treatment of colorectal cancer.Methods:Obtain m6 ARNA methyltransferase-related gene expression data from the Cancer Genome Atlas(TCGA)database,analyze and screen the core differential gene METTL3 as the target gene.Analyze the expression of m6 ARNA methyltransferase METL3 in colorectal cancer tissues,and further verify the differential expression of METL3 in colorectal cancer tissues through clinical samples.Synthesize a stable transduction virus that overexpresses and silences METL3,and constructs a stable transduction and silence METL3 cell line in the colorectal cancer cell line SW480,and constructs a stable transduction METL3 cell line in the colorectal cancer cell line HCT116.Then,the function of METL3 in colorectal cancer cells was comprehensively evaluated through cell function experiments(Cell proliferation,apoptosis,cell cycle,cell migration,invasion,etc.).Through(Gene Set Enrichment Analysis,GSEA)pathway enrichment analysis,the possible biological pathways of METL3 regulating the malignant proliferation of colorectal cancer cells were analyzed;then the correlation between METL3 and downstream target molecules was analyzed by Pearson correlation test to construct hypothetical molecular mechanisms;finally,real-time fluorescent quantitative PCR and Western blotting method was used to detect the effect of METTL3 on the m RNA and protein levels of key molecules in downstream pathways.Results:1)Analysis of m6 ARNA transferase data in the TCGA database shows that m6 ARNA methyltransferase METTL3 is significantly high in colorectal cancer and is related to the clinical pathological stage of patients.In addition,the analysis of METTL3 at the clinical tissue level also reached the same conclusion.2)Silencing METL3 in colorectal cancer cell line SW480 can significantly inhibit the malignant proliferation of colorectal cancer cells;on the contrary,overexpression of METL3 in colorectal cancer cell line HCT116 can significantly promote the malignant proliferation of colorectal cancer cells.3)Silencing METL3 in the colorectal cancer cell line SW480 can block the division of colorectal cancer cells in the G2/M phase;on the contrary,overexpression of METL3 in the colorectal cancer cell line HCT116 can promote colorectal cancer cells G2/M Period split.4)Silencing METL3 in the colorectal cancer cell line SW480 can significantly inhibit the migration of colorectal cancer cells;on the contrary,overexpression of METL3 in the colorectal cancer cell line HCT116 can significantly promote the migration of colorectal cancer cells.5)The GSEA pathway enrichment analysis of METL3 found that METL3 may promote the malignant proliferation of colorectal cancer cells through the P53 signal pathway.Further correlation analysis of the target molecules in the METL3 and P53 signaling pathways showed that METL3 was significantly correlated with P53,CDK4 and MYC,and there was also a significant correlation between P53,CDK4 and MYC.6)Real-time fluorescent quantitative PCR and western blotting experiments confirmed at the m RNA and protein levels that silencing METL3 can promote the expression of P53 and inhibit the expression of CDK4 and MYC;on the contrary,overexpression of METL3 can inhibit the expression of P53 and promote the expression of CDK4 and MYC.Conclusions : The expression of m6 ARNA methyltransferase METL3 is elevated in colorectal cancer,and it can participate in the occurrence and development of colorectal cancer by promoting cell proliferation and metastasis of colorectal cancer and inhibiting apoptosis.METTL3 targets CDK4 in the P53 signaling pathway to promote the malignant proliferation of colorectal cancer cells through MYC;this study provides a potential theoretical basis for the clinical diagnosis and molecular targeted therapy of colorectal cancer.