Notch3 siRNA enhances chemosensitivity of colon cancer cells to topotecan / 中国肿瘤生物治疗杂志

ABSTRACT

Objective: To elucidate the relationship between Notch3 expression and chemosensitivity of human colon carcinoma cell line SW620 to topotecan. Methods: Notch3 siRNA was transfected into SW620 cells, and the expression of Notch3 in SW620 cells was examined by Western blotting. After transfected with Notch3 siRNA for different time peri-ods, SW620 cells were further treated with topotecan, and the proliferation of SW620 cells was detected by MTT assay; the apoptosis of SW620 cells was detected by Hoechst 33342 staining and flow cytometry. Caspase-3 activation in SW620 cells was examined by caspase-3 activation kit. Results: Notch3 siRNA transfection remarkably inhibited Notch3 protein expression in SW620 cells. The IC_(50) of topotecan in Notch3 siRNA-transfected group was significantly decreased compared with that in the Ctrl siRNA group (P <0.05). Silence of Notch3 expression in SW620 cells by Notch3 siRNA remarkably promoted apoptosis (P < 0.05) and caspase-3 activation (P < 0.05) of SW620 cells induced by topotecan. Conclusion: Notch3 down-regulation by siRNA in SW620 cells can enhance the chemosensitivity cells to topotecan.