三苯氧胺在肝癌化疗中作用机制的实验研究

The effect of tamoxifen (TAM) in the chemotherapy of hepatocellular carcinoma(HCC) and its mechanism

目的研究三苯氧胺在肝癌化疗中的作用效果,并对其作用机制进行初步探讨。方法通过阿霉素(ADM)浓度梯度递增诱导法,建立人肝癌多药耐药细胞株Hep-3B/ADM。MTT法检测细胞对化学疗法药物的敏感性;流式细胞仪检测细胞表面多药耐药基因(MDR1)表达产物P-170及分析细胞内Rhdaming123(Rh123)相对荧光强度;流式细胞仪及电镜观察TAM对ADM诱导Hep-3B/ADM细胞凋亡的影响。结果TAM预处理组ADM对Hep-3B/ADM细胞的IC50下降为非预处理组的1/7;TAM(2.5μmol/L)处理前后,Hep-3B/ADM细胞表面P-170表达及细胞内Rh123相对荧光强度均无明显变化;TAM(2.5μmol/L)可明显增强ADM诱导Hep-3B/ADM细胞凋亡的效果。结论TAM(2.5μmol/L)具有增强ADM对Hep-3B/ADM细胞的毒性作用,其作用机制与逆转MDR无关,而是增强了ADM诱导耐药细胞凋亡的作用。

Objective To investigate the effect of TAM（2.5μmol/L） in the chemotherapy of HCC and its mechanism. Methods An adriamycin-resistant human HCC cell subline （Hep-3B/ADM） was established, through exposure to gradually increased concentration of ADM. Drug sensitivity was measured by MTT. Flow cytometry（FCM） was performed to assess the expression of P-170 and the fluorescene intensity of Rh123 in the cells. Modulation of ADM-induced apoptosis of Hep-3B/ADM cells was assessed by cell morphology and FCM. Results TAM （2.5μmol/L） decreased the IC50 of ADM from 1.64μg/ml to 0.23μg/ml in the Hep-3B/ADM cells. With or without TAM, the expression of P-170 and the fluorescene intensity of Rh123 in the cells were not altered significantly. TAM exhibited a 2-fold potentiation on apoptosis caused by ADM in Hep-3B/ADM cells. Conclusion TAM（2.5μmol/L） significantly enhanced ADM-induced cytotoxicity. The mechanism is not mediated by inhibiting multidrug-resistant （MDR1）, it may be that TAM potentiate the apoptosis induced by ADM.