SASS6基因敲除对三阴性乳腺癌MDA-MB-231细胞周期和凋亡的影响

The effect of lentivirus-mediated SASS6 on cell cycle and cell apoptosis of MDA-MB-231 breast cancer cells

目的研究慢病毒转染沉默SASS6基因对人乳腺癌细胞MDA-MB-231生长、周期及凋亡的影响,探讨SASS6基因在三阴性乳腺癌发生发展中的作用,为乳腺癌的治疗寻找新的靶点。方法采用噻唑蓝比色法检测SASS6基因表达下调后肿瘤细胞生长的影响,流式细胞术分析细胞周期的变化,Annexin V-FITC/PI染色法检测细胞凋亡。结果慢病毒转染72 h后,显微镜下荧光观察,结果显示细胞感染效率达到80%以上,细胞状态正常。MTT法检测细胞增殖,结果显示,与对照组相比,实验组在培养的5天里均有统计学差异,P值分别为0.001、0.004、<0.001、<0.001、<0.001,但4~5d实验组与对照组相比测定值差异分别为36.8%和44.3%,呈强阳性结果。相比对照组,shSASS6组处于G 1期的细胞明显减少(P<0.05),处于S期的细胞两组无显著差异,处于G 2/M期的细胞shSASS6组明显增多(P<0.05),差异有显著性。培养4d后,与对照组相比,shSASS6组细胞凋亡率显著增加(P<0.05)。结论SASS6基因具有促进乳腺癌细胞增殖、抑制凋亡、增强肿瘤细胞活力的作用。

Objective To investigate the role of SASS6 gene on the cell proliferation,apoptosis and cell cycle of the MDA-MB-231 breast cancer cell line and to explore the new therapeutic target of breast cancer.Methods First we knockdown the SASS6 gene on the MDA-MB-231 breast cancer cell and we observed the cell cycle of the shSASS6 cell line which was examined by flow cytometry and apoptosis was detected by Annexin V-FITC/PI stain method.Results shSASS6 cell line adhered to the cell wall by single layer culture,irregular shape,and cell amounts increased over time.MTT was used to measure the cell proliferation,and the results showed that all five days had significantly differences between two groups,P values were 0.001,0.004,<0.001,<0.001,<0.001,but only 4 and 5 days had the very positive results,the inhibition ratio of the tumor cells were 36.8%and 44.3%.The results showed that compared with the control group,shSASS6 group in the G 1 phase of the cell is less than the control group(P<0.05),no significant difference in S phase but G 2/M stage cells were increased significantly(P<0.05).The apoptosis rate shSASS6 cells was significantly higher than the control group(P<0.05).Conclusions The down-regulated expression of SASS6 gene may regulate the distribution of cell cycle.It may induce G1 phase arrest of MDA-MB-231 cells and reduce the DNA synthesis and increase the apoptosis of the breast cancer cells.