阿霉素对人乳腺癌细胞凋亡及去磷酸化RB蛋白表达的影响

Effects of adriamycin on cell apoptosis and expression of dephosphorylated RB protein in human breast cancer

目的 :探讨阿霉素 (ADR)体外诱导人乳腺癌化疗敏感细胞 (MCF 7 S)凋亡与去磷酸化RB蛋白表达之间的关系。方法 :应用MTT比色法检测ADR对体外培养的MCF 7 S细胞增殖抑制作用 ,同时应用末端标记 (TUNEL)法观测ADR对MCF 7 S细胞凋亡程度的影响。采用免疫细胞化学法检测去磷酸化RB蛋白的表达水平。结果 :ADR抑制MCF 7 S细胞增殖呈剂量依赖性 ,半数抑制浓度 (IC50 )为0 .12 8mg·L-1;ADR作用组MCF 7 S细胞的凋亡率(apoptoticrate ,AR)为 0 .2 6 1,较对照组 (0 .0 4 5 )明显增高 (P <0 .0 1) ;ADR作用组MCF 7 S细胞的去磷酸化RB蛋白表达量MOD(阳性细胞平均光密度 )×area(阳性面积相对比 )均数是 987± 2 0 7,较对照组132± 32显著增高 (P <0 .0 1) ;ADR能促进MCF 7 S细胞内去磷酸化RB蛋白的表达。在ADR作用组 ,MCF 7 S细胞的凋亡率与去磷酸化RB蛋白表达量呈正相关 (P <0 .0 5 )。结论 :ADR抑制MCF 7 S细胞增殖和诱导MCF 7 S细胞凋亡可能与细胞内去磷酸化RB蛋白表达水平有关。

AIM: To investigate the roles that adriamycin (ADR) plays in the expression of dephosphorylated RB protein and inducing apoptosis of human breast cancer cells (MCF-7/S) cultured in vitro. METHODS: MTT colorimetric assay was applied to examine the growth inhibition,and apoptosis rates (AR) were determined by terminal-deoxynucleotidyl transferase mediated d-UTP nick end labeling (TUNEL);the expressive levels of dephosphorylated RB protein were detected with immunocytochemistry. RESULTS: ADR inhibited proliferation of MCF-7/S cells in a dose dependent manner,and the 50% inhibition concentration (IC_ 50 ) was 0.128 mg·L -1 . Tumor cell AR in ADR group (x= 0.261 ) was significantly higher than that in control group (x= 0.045 ,P< 0.01 ). The expressive levels of dephosphorylated RB protein in ADR group (MOD×area=987±207) was significantly higher than that in control group (MOD×area=132±32,P< 0.01 ). The dephosphorylated RB was enhanced by ADR in breast cancer cells. There was significant positive correlation between AR and the expressive levels of dephosphorylated RB protein in ADR group (P< 0.05 ). CONCLUSION: ADR inhibits the growth proliferation and induces apoptosis in MCF-7/S cell line,which is possibly related to enhancing dephosphorylated RB protein expression.