The Molecular Mechanism Of LNC942 Promoting Breast Cancer Cell Proliferation Through METTL14-mediated M~6A Methylation

Objective:N~6-methyladenine(m~6A),as the most important modification form of messenger RNA(mRNA)in eukaryotes,mediates the occurrence and development of a variety of tumors.However,its function and regulatory mechanism in breast cancer(BRCA)have yet to be clarified.Methods:1.LINC00942(LNC942)was screened by cluster analysis of BRCA Chips expression profile.The correlation between the expression of LNC942,METTL14 and m~6A modification was verified by qPCR,m~6A dot blot,WB,in situ hybridization and immunohistochemistry.2.Cell function experimenst:The effects of LNC942 and METTL14 on BRCA cells proliferation,cell cycle and apoptosis were detected by MTT,plate clone formation experiment,Transwell and flow cytometry.3.Mechanism verification:RNA pull down experiment verified that LNC942 specifically targeted METTL14.4.In vivo experiment:The effects of LNC942 and METTL14 on the proliferation of BRCA cells were verified by nude mice.Results:1.LNC942 was highly expressed in breast cancer cells and 150 pairs of breast cancer and paracancer tissues,which was positively correlated with m6A modification expression level,and significantly positively correlated with METTL14 expression level.2.Cell level:In MCF7 and SKBR3 cell lines,silencing LNC942 significantly inhibited cell proliferation and colony formation,blocked cell cycle G0/G1 phase,and promoted apoptosis of BRCA cells,and vice versa.METTL14 rescued the effects of silenced LNC942 on BRCA cells.3.In terms of mechanism,LNC942 was found to promote the expression of METTL14 by targeting METTL14 protein to promote BRCA cancer.Meanwhile,by up-regulating the m~6A modification level,LNC942 further promoted the mRNA stability and protein expression of CXCR4/CYP1B1 and other downstream target genes,positively regulating the occurrence and development of breast cancer.4.The xenograft tumor model in nude mice further verified that LNC942 promoted tumor proliferation and growth in xenograft tumor model by targeting METTL14.Conclusion:In this study,LNC942-METTL14-CXCR4/CYP1B1 signaling regulation axis was reported for the first time in breast cancer.Meanwhile,a molecular mechanism of LNC942 regulating the METTL14-mediated epigenetic modification level of m6A was revealed,this mechanism played a key role in promoting cancer.