乳腺癌耐药蛋白在肝癌多药耐药中的作用及其机制探讨

目的研究乳腺癌耐药蛋白(breastcancer resistance protein,BCRP)在肝癌中的表达及其意义。方法通过培养液中ADM浓度递增诱导法筛选培养,建立HepG2/ADM肝癌多药耐药细胞株;采用荧光定量PCR及免疫组织化学技术,分别在mRNA和蛋白质水平检测BCRP在正常肝细胞系L02、肝癌细胞系HepG2及HepG2/ADM与未经化疗的癌组织、多次化疗后的癌组织、癌旁组织的表达差异。结果HepG2/ADM的BCRPmRNA表达是HepG2的9倍(P<0.01);L02和HepG2中BCRPmRNA的表达无差异(P>0.05);化疗后病人癌组织BCRPmRNA平均表达是未化疗病人癌组织的4.2倍(P<0.01);化疗病人癌组织BCRPmRNA平均表达是癌旁组织的3.4倍(P<0.01);未化疗病人癌和癌旁组织间的表达无差异(P>0.05);免疫组织化学显示BCRP在胞膜表达;BCRPmRNA和蛋白表达具有一致性。结论HepG2/ADM多药耐药细胞株是一个较好的研究肝癌多药耐药的模型。BCRP基因在正常肝细胞中表达,而在多次化疗后的病人和HepG2/ADM中表达上调,提示化疗药物诱导BCRP的表达,BCRP的高表达与肝癌多药耐药有关。

The role of BCRP in hepatocellular carcinoma multidrug resistance and mechanism

Objective To study the expression of breast cancer resistance protein(BCRP)in hepatocellular carcinoma(HCC)and its significance.Methods HepG2 cell line resistant to adriamycin(HepG2/ADM)was induced by increasing concentration of ADM step by step. The expression of BCRP protein and mRNA was detected by real-time RT-PCR and immunohistochemistry respectively in normal hepatocellular line L02,HCC lines HepG2 and HepG2/ADM,HCC tissues without chemotherapy,HCC tissues after therapies and para-tumor tissues.Results The expression of BCRP mRNA in HepG2/ADM cells was 9 times of HepG2 cells(P< 0.01);there was no difference in the BCRP mRNA expression between HepG2 cells and L02 cells(P> 0.05);the expression of BCRP in HCC tissues after chemotherapy was 4.2 times of that in HCC tissues without chemotherapy(P< 0.01);in the patients subject to chemotherapy,the expression of BCRP mRNA in tumor tissues was 3.4 times of para-tumor tissues;in patients without subject to chemotherapy,there was no difference in the BCRP mRNA expression between tumor and para-tumor tissues;immunohistochemistry revealed that BCRP was mainly expressed in the cell membrane;the expression of BCRP protein was in coincidence with the expression of MRNA.Conclusion HepG2/ADM is a good model for the study of MDR.BCRP gene was expressed in normal liver cells.The expression of BCRP was up-regulated in the patients subject to chemotherapies and HepG2/ADM cell line,suggesting anticancer agents could induce the expression of BCRP and the high expression of BCRP was related with the MDR of HCC.