Inhibition of SW620 human colon cancer cells by upregulating miRNA-145

AIM: To investigate the targeted inhibition of proliferation and migration of SW620 human colon cancer cells by upregulating miRNA-145 (miR-145). METHODS: Forty-five samples of colon cancer tissues and 45 normal control samples were obtained from the biological database of the First Affiliated Hospital of Liaoning Medical University. We performed quantitative analysis of miR-145 and N-ras expression in tissues; reverse transcriptase polymerase chain reaction analysis of miR-145 expression in SW620 colon cancer cells and normal colonic epithelial cells; construction of miR-145 lentiviral vector and determination of miR-145 expression in SW620 cells transduced with miR-145 vector; analysis of the effect of miR-145 overexpression on SW620 cell proliferation; analysis of the effect of miR-145 overexpression on SW620 cell migration using a wound healing assay; and analysis of the effect of miR-145 on N-ras expression using Western blotting. RESULTS: miR-145 expression was significantly downregulated in colon cancer tissues, with its expression in normal colonic tissues being 4-5-fold higher (two sample t test, P < 0.05), whereas N-ras expression showed the opposite trend. miR-145 expression in SW620 cells was downregulated, which was significantly lower compared to that in colonic epithelial cells (two sample t test, P < 0.05). miR-145 vector and control were successfully packaged; expression of miR-145 in SW620 cells transduced with miR-145 was 8.2-fold of that in control cells (two sample t test, P < 0.05). The proliferation of miR-145-transduced SW620 cells was significantly decreased compared to control cells (two sample t test, P < 0.05). At 48 h in the wound healing experiment, the migration indexes and controls were (97.27% +/- 9.25%) and (70.22% +/- 6.53%), respectively (two sample t test, P < 0.05). N-ras expression in miR-145-tranduced SW620 cells was significantly lower than others (one-way analysis of variance, P < 0.05). CONCLUSION: miR-145 is important in inhibiting colon cancer cell proliferation and migration. This is a good foundation for development of colon cancer therapy by targeting tumor suppressor miR-145.