Fig. 1

Upregulated expression of mettl3 was responsible for abnormal m6a modification in CRC. (a) m6A modification was detected using m6a quantification in two samples. (b) Catalytic proteins involved in m6a modification were assessed in CRC (TCGA data, blue box for normal tissues, n = 379; red box for tumor tissues, n = 51). (c) Relative increased level of METTL3 was confirmed in the CRC tumor and adjacent normal tissues by qRT-PCR (n = 60). (d) Representative image of immunohistochemical staining by METTL3 antibody in two patient tissues. Original magnification 100X; scale bar: 50 μm. (e) qRT-PCR showed the expression level of METTL3 in CACO2, HT-29, HCT116, DLD-1, LOVO and NCM460; western blot showed the protein level in cell lines above. (f) The expression of METTL3 in eight pairs CRC tissues (T) and adjacent normal tissues (N) were detected by western blot. (g) Poly(A) + RNA isolated from METTL3-knockdown cells were used in dot blot assay with m6A antibody. Methylene blue staining served as a loading control. (h) Kaplan-Meier survival curves of OS based on METTL3 mRNA expression in 174 CRC patients. All patients were divided into two groups based on the median level of METTL3. The log-rank test was used to calculate the significant level (GEO data). Data are presented as means ± standard deviation (*P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001)