Effects Of Transfected P21^Waf1-p27^Kip1 Gene On The Duplication Of Centrosomes And The Proliferation Of Breast Breast Cancer Cell Line MCF-7

[Objective] To explore the role of transfected p21 Waf1-p27Kip1 gene on the centrosome duplication and cell proliferation of MCF-7, a breast cancer cell line.[Methods] pIRES-p21Waf1, pIRES-p27Kip1 and pIRES-p21Waf1-p27Kip1 genes were transfected into the MCF-7 cells by lipofection. The effect on proliferation was evaluated by MTT assay and cell growth curve was drawn. The cell cycle was analyzed by flow cytometry. The centrosome duplication was detected by using indirect immunofluorescen-ce microscopy.[Results] After transfected 24 hours, the p21Waf1 and p27Kip1 protein expressions were significantly increased as compared with untransfected MCF-7 cells (P<0.01), and cell growth was obviously inhibited and resulted in an accumulation of cells in G1 (P<0.01), presenting that the proportion of cells in G1 phase was obviously increased from (47.28±2.25%) to (69.52±3.21)% of p21Waf1 transfected cells, (60.83±3.02)% of p27Kip1 trans-fected cells, and (78.37±2.83)% of p21Waf1-p27Kip1 transfected cells. The proportion of cells which contained unnormal centrosomes was obviously decreased, from (13.47±0.33)% to (5.07±0.38)%, (6.28±0.35)%, (3.47±0.23)%, respectively.[Conclusion] The transfer of p21Waf1 and p27Kip1 genes could inhibit the growth of human breast carcinoma cells and the unnormal duplication of centrosomes. p21Waf1 had a really synergy with p27Kip1 in these effects, suggesting p21Waf1-p27Kip1 combined gene can inhibit the genesis and development of breast cancer and might have potential clinical significance as therapeutic agents of breast cancer.