钙离子浓度对人乳腺癌MCF-7细胞Caspase-3,Bax及Bcl-2表达的影响

目的 研究细胞内Ca^2 浓度[Ca^2 ]i的升高对人乳腺癌MCF—7细胞株中Caspase-3,Bax及Bcl—2表达的影响。方法 在体外培养下，经不同浓度thapsigargin(TG)处理的MCF—7细胞株用荧光指示剂Fura-2/AM于单波长荧光分光光度仪上测定细胞内钙离子浓度。用免疫组织化学方法检测Caspase-3，Bax及Bcl—2的表达。结果 随着细胞内钙离子浓度的提高，Bax表达逐渐增强，Bcl-2表达逐渐减弱，而Caspase-3始终呈阴性表达。结论 细胞内钙离子浓度的升高对MCF—7细胞株可诱发不通过Caspase-3途径的细胞凋亡。

Effect of raised intracellular free calcium on the expression of Caspase-3,Bax and Bcl-2 in human breast cancer MCF-7 cell lines

Objective To study the effect of rising [Ca 2+ ]i on the expression of Caspase 3, Bax and Bcl 2 in human breast cancer MCF 7 cell lines. Methods After the MCF 7 cells treated with different dose of thapsigargin(TG), intracellular calcium concentrations in MCF 7 cells were measured by calcium sensitive fluorescence indicator Fura 2/AM technique; and immunohistochemical method was used to detected the expressions of Caspase 3, Bax and Bcl 2. Results Bax was over expressed and Bcl 2 was down expressed in a [Ca 2+ ]i concentration dependent way;nevertheless, the expression of Caspase 3 was negative in all the TG treated cells. Conclusions The increase of intracellular calcium concentration may have an inductive effect of apoptosis on MCF 7 cells, which is independent to Caspase 3.