miR-21-5p inhibits the growth of lung cancer cells by targeting methyl transferase METTL3

Bingqiang Xu, Minggang Huang, Mingqing Kou^*

Shaanxi Provincial People’s Hospital, China

Objective: This study explores the specific role and mechanism of METTL3 in non-small cell lung cancer (NSCLC).

Methods: Data on the expression of METTL3 in NSCLC patients and healthy human lung tissues were obtained from the UALCAN database. The expression of METTL3 protein and mRNA in normal human bronchial epithelial cells BEAS-2B and NSCLC cell lines A549 and H1299 were measured by western blot and qRT-PCR. The RNA methylation quantitative kit was used to analyze the m6A content in normal human bronchial epithelial cells BEAS-2B and NSCLC cell lines A549 and H1299. The effect of METTL3 on the migration and invasion ability of NSCLC cells was determined by CCK-8 and Transwell tests. The TargetScan database was used to predict the direct target protein of miR-21-5p, simultaneously predict the possible binding sequence, and then detect the co-transfected miR-21-5p and METTL3 3`UTR plasmid NSCLC cells by using dual luciferase experiments. NSCLC cells were transfected with the miR-21-5p plasmid to further explore the relationship between miR-21-5p and METTL3 and the effect on the migration and invasion ability of NSCLC cells.

Results: Analysis of the UALCAN database showed that METTL3 was significantly overexpressed in various cancer patients, including those with NSCLC. The results of in vitro experiments showed that m6A methyltransferase METTL3 was overexpressed in NSCLC cell lines, and the content of m6A RNA in NSCLC cells increased. Functionally, silencing METTL3 by siRNA can cause the m6A content of NSCLC cells to decrease, while inhibiting the proliferation and invasion ability of NSCLC cells. The TargetScan database predicts that METTL3 may be a direct target protein of miR-21-5p. Dual luciferase experiments verify that miR-21-5p can directly act on METTL3, and miR-21-5p is negatively regulated at the transcriptional and protein levels. METTL3 level. Additional mechanism analysis showed that miR-21-5p could inhibit the expression of METTL3 in NSCLC cells, resulting in a decrease in m6A RNA content in NSCLC cells, and thereby inhibiting the promotion of METTL3 on the proliferation and invasion ability of NSCLC cells.

Conclusion: In summary, our results indicate that METTL3 promotes the proliferation and migration of NSCLC cells by promoting m6A of RNA in NSCLC cells, while miR-21-5p inhibits its promotion of NSCLC cells by directly targeting METTL3.