ABCG2在肝细胞性肝癌组织和肝癌细胞株中的表达及意义

Expression of stem cell marker ABCG2 and its signifi cance in hepatocellular carcinoma tissue and cell lines

目的:探讨干细胞标志物ABCG2在肝细胞性肝癌组织和肝癌细胞株中表达的意义.方法:应用免疫组化SP方法检测ABCG2在30例肝细胞性肝癌组织和8例癌旁肝硬化组织中的表达、分布,并采用细胞免疫荧光技术检测ABCG2在两种肝癌细胞株HepG2、PLC/PRF/5中的表达,采用流式细胞技术测试出两种细胞株中ABCG2阳性细胞的比例.结果:免疫组化中,ABCG2阳性染色定位于癌细胞胞膜,部分病例胞质也有分布.免疫组化显示ABCG2在肝细胞性肝癌组织和癌旁肝硬化组织中的表达阳性率分别为63.33%(19/30)和25%(2/8).ABCG2蛋白在HepG2、PLC/PRF/5这两个肝癌细胞株中均有表达,HepG2中,ABCG2阳性染色定位于细胞胞质中,而在PLC/PRF/5中,ABCG2阳性染色定位于细胞胞质和细胞膜上.PLC/PRF/5细胞株中,通过流式细胞仪能检测出表达ABCG2的细胞(P<0.05),而在HepG2细胞株中,通过流式细胞仪不能检测出表达ABCG2的细胞.结论:ABCG2在肝细胞性肝癌的发生发展过程中可能起着非常重要的作用,有可能成为临床治疗肝细胞性肝癌的分子靶标.

AIM： To investigate ABCG2 expression and its significance in hepatocellular carcinoma （HCC） tissue and HCC cell lines. METHODS： The expression of ABCG2 and the distribution of ABCG2-positive cells of 30 HCC cases and 8 cases of paraneoplastic liver cirrhosis were examined using immunohistochemistry SP methods. Dual-fluorescent immunostaining was used to detect ABCG2 positive cells in two HCC cell lines, and flow cytometry was used to figure out the percentages of ABCG2-positive cells in the two HCC cell lines. RESULTS： The present study confirmed the predominant localization of ABCG2 transporter in plasma membrane. Some of ABCG2-positive tumors showed mixed membranous and cytoplasmic staining. ABCG2 expression was detected in 63.33% （19/30） of HCC and 25% （2/8） of paraneoplastic liver cirrhosis. ABCG2 expression was observed both in the two HCC cell lines,ABCG2 expression in HepG2 was only observed in the cytoplasm, whereas ABCG2 expression was observed on the cell membrane in addition to the cytoplasm in PLC/PRF/5; ABCG2-positive ceils can be detected by flow cytometry in PLC/PRF/5 （P 〈 0.05）, but not in HepG2. CONCLUSION： The expression of ABCG2 found in HCC tissue and HCC cell lines may be closely related to oncogenesis and progress of HCC, and the ABCG2 may be regarded as a potential maker for liver cancer stem cells.