Effect of Bak gene overexpression on proliferation of breast cancer MCF-7 cells and sensitivity to paclitaxel / 解剖学报

ABSTRACT

Objective: To investigate the effect of Bak gene overexpression on proliferation of breast cancer MCF-7 cells and sensitivity to paclitaxel. Methods: Western blotting and Real-time PCR were used to detect the expression of Bak protein in breast cancer MCF-7 cells before and after transfection. The effects of Bak gene overexpression and paclitaxel treatment for 24 hours, 48 hours and 72 hours on MCF-7 cell proliferation and cell cycle were detected by cell counting kit-8(CCK-8) and flow cytometry. Results: The results of Western blotting and Real-time PCR showed that the expression of Bak protein increased significantly after transfection. The results of Western blotting and Real-time PCR showed that the expression of Bak protein increased significantly after transfection, and the mRNA expression of MCF-7-Bak group was 2.15±0.07, which was significantly higher than that of MCF-7-NC group, which was 1.03±0.04(r= 13.412, P <0.05). After 48 hours, 72 hours and 96 hours of transfection, the proliferation rates of MCF-7-Bak cells were (0.31 ± 0.03)%, (0.37±0.03)%, (0.47±0.04)%, respectively, which were lower than that of MCF-7 NC group (0.40± 0.03)%, (0.48±0.04)%, (0.61±0.06)%, and the difference was statistically significant (t48 = 2.145, t72 = 3.164, t96 = 5.487, P<0.05). The number of G2 phase cells in MCF-7 Bak group were (26.84±2.69)% significantly higher than that in MCF-7 NC group (16.02±1.61)% ({=12.887, P<0.05). After 24 hours, 48 hours, and 72 hours of paclitaxel treatment, the cell inhibition rate of MCF-7-Bak group was (35.98±4.00)%, (54.66±5.50) %, (80.11 ± 8.00) %, respectively, which were higher than that of MCF-7 NC group (24.12±2.40)%, (40.12±4.00)%, (61.09±6.09)%. And the difference was statistically significant (t24 = 8.456, t48 = 10.547, t72 = 13.442, P<0.05). After 24 hours of paclitaxel treatment, the number of G2 phase cells in MCF-7 Bak group was (73.01 ±7.02)% higher than that in MCF-7 NC group (63.84±6.68) %(t = 9.736, P<0.05). Conclusion: Up-regulate of Bak gene expression can inhibit the proliferation of breast cancer MCF-7 cells, up-regulating the proportion of G0/G1 phase, and enhance the sensitivity of paclitaxel.