·After the gastric cancer cell lines (MGC-803 and AGS) were exposed to different concentrations of SAG (0, 10, 20 μmol/L) for 48 h, quantitative PCR and Western blotting analysis were used to detect the effect of SAG on the expression of METTL14. Then, MGC-803 and AGS cells transfected with lentiviruses-mediated small interfering RNA of METTL14 (si-METTL14) or control (si-NC) were treated with 10 μmol/L SAG or PBS for 48 h, and thus the two cell lines were divided into si-METTL14+SAG group, si-NC+SAG group and si-NC+PBS group, respectively. Quantitative PCR and Western blotting were used to verify the expression levels of METTL14 after it was transfected with si-METTL14 in gastric cancer cells. The proliferation level, number of clones formed and invasion potential of the 3 groups in both MGC-803 cells and AGS cells were observed by MTT proliferation assay, cell clone formation test and Transwell invasion assay, respectively. Independent samples t test was used for comparison between two groups of data, and one-way ANOVA was used for comparison between more than two groups of data.

·Compared with the control group (0 μmol/L), 10 μmol/L SAG and 20 μmol/L SAG up-regulated METTL14 mRNA and protein expression levels (P<0.05), showing a certain concentration dependence. Quantitative PCR and Western blotting results confirmed that the expression levels of METTL14 in gastric cancer cells were significantly reduced after transfection of si-METTL14 in both MGC-803 cells and AGS cells. MTT cell proliferation assay showed that the cell proliferation rate of the si-NC+SAG group was significantly lower than that of the si-NC+PBS group in each cell line (P=0.000). The cell clone formation test showed that the number of cell clones of the si-NC+SAG group was significantly smaller than that of the si-NC+PBS group in each cell line (P<0.01). The Transwell invasion assay showed that the cells crossing Matrigel gel in the si-NC+SAG group was significantly less than that in the si-NC+PBS group in each cell line (P<0.01). si-METTL14 could partially reverse the inhibitory effects of SAG on gastric cancer cells.

·SAG can inhibit the proliferation activity, clonal formation and invasion potential of gastric cancer cells, which may be realized by upregulating METTL14 expression level.