M3 knockdown represses cell proliferation, invasion and migration in vitro. (A) Protein levels (right, quantitative analysis) of M3 in HCT-116 and SW480 cells upon transfection with a scrambled shRNA or with one of three different M3-silencing shRNAs. (B) mRNA levels of M3 in HCT-116 and SW480 cells infected with lentivirus carrying the indicated shRNA. (C) Protein levels of M3 in HCT-116 and SW480 cells infected with lentivirus carrying the indicated shRNA (right, quantitative analysis). (D) The proliferation rate of stable scrambled shRNA (shNC) and stable METTL3 knockdown (shM3) cells was evaluated by Cell Counting Kit-8 assay in HCT-116 and SW480 cells. (E) Transwell assay (right, quantitative analysis) was employed to analyze the difference in the invasion ability of shNC and shM3 cells. (F) Wound healing assay (magnification, ×200; right, quantitative analysis) revealed differences in the migration ability of shNC and shM3 cells. Each experiment was repeated three times independently. Error bars represent standard deviation. *P<0.05, **P<0.01, ***P<0.001. M3, methyltransferase-like 3; sh, small hairpin RNA; NC, negative control; ns, not significant.