miR-15a and miR-16-1 exert tumor suppressor function in GAC. (A) MTT proliferation results of ectopic miR-15a and miR-16-1 expression in AGS, MKN1 and MGC-803 cells (**, P < 0.001). The P-Value was calculated by the 575 nm absorbance readings in Day 5. (B) Ectopic expression of miR-15a and miR-16-1 inhibited monolayer colony formation in AGS, MKN1 and MGC-803 cells (**, P < 0.001). The experiment was performed in triplicate wells to get SDs. (C) Flow cytometry analysis of miR-15a and miR-16-1 transfectants compared with scramble miRNA transfectants. Two independent experiments were performed and the representative one was shown. (D) miR-15a and miR-16-1 suppressed cell invasion through matrigel (**, P < 0.001). Representative images of cell invasion were also shown. The invaded cells in 3 random vision fields were counted and calculated to get SDs. (E) miR-15a-MGC-803 and miR-16-1-MGC-803 formed smaller tumors than scramble-miRNA-MGC-803 (**, P < 0.001). The tumor sizes in the Day 24 were calculated for the P-Value. (F) Western blot analysis of CCND3, CCNE1, CDK6, p21, p27, p-Rb and cleaved-PARP after miR-15a and miR-16-1 transfection.