Fig. 3

miR-21 overexpression enhances stem cell-like properties of gastric cancer cells. a miR-21 is overexpressed in cancer stem-like cells of gastric cancer. Fold change of miR-21 in spheroid cells (SC) and parental cells (PC) of SGC7901 was analyzed by QRT-PCR. b miR-21 overexpression increases microsphere formation rate in gastric cancer cells. Microsphere formation rate was detected by serum-free culture (upper panel) and quantified (lower panel) in miR-21 overexpressing cells (miR-21) and control cells (Con). c miR-21 overexpression increases drug resistance in SGC7901 cells. Cell viability in miR-21 overexpressing cells (miR-21) and control cells (Con) treated with different doses of EPI for 48 h was determinated with CCK-8. d miR-21 overexpression promotes migration potential in SGC7901 cells. Migration ability of cells was detected by Transwell Assay and then photographed (upper pane) and quantified (lower panel). e miR-21 overexpression was confirmed in SGC7901 cells after infected by lentivirus with miR-21 overexpression. Fold change of miR-21 in miR-21 overexpressing cells (miR-21) and control cells (Con) was analyzed by QRT-PCR. f miR-21 overexpression upregulates the expression of stem cell markers in SGC7901 cells. The expression of stem cell markers and known miR-21 target and downstream genes (PTEN-AKT, P53) in the cell lysis was analyzed by Western blot. Error bars in all panels represent the mean ± SD (*P < 0.05, **P < 0.01 as compared with control)