体内微环境对肝卵圆细胞分化的影响

Study of the role of microenvironment on the hepatic oval cell differentiation in vivo

目的 研究体内微环境对肝卵圆细胞分化的影响,探讨肝卵圆细胞是否可在体内分化为肝癌.方法 在使用黄曲霉素作为诱癌剂的情况下,将转染乙肝病毒X基因（HBx）的大鼠卵圆细胞种植于裸鼠皮下,形成肿瘤后再移植至同一裸鼠肝实质内,使其继续生长.收集皮下肿瘤和肝内肿瘤,用苏木素-伊红（HE）、免疫组织化学染色和透射电镜对其进行检查,明确其性质.结果 10周时,实验组中10只（10/15）裸鼠形成皮下肿瘤,对照组中8只（8/15）裸鼠形成皮下肿瘤,两组在肿瘤大小和生长速度方面差异无统计学意义（P＞0.05）;两组均在皮下分化成间质肿瘤,表达间质性标志物波形蛋白（Vimentin）和平滑肌肌动蛋白（SMA）.皮下间质肿瘤移植至肝内8周后,在肝内种植处长成肝内肿瘤;经病理确诊实验组肿瘤为肝癌肉瘤（由恶性间质细胞和肝癌细胞组成）,表达HepPar1、细胞角蛋白8（CK8）和甲胎蛋白（AFP）抗原,说明肝卵圆细胞在HBx和黄曲霉素的共同作用下可部分分化成肝细胞癌.结论 肝卵圆细胞具有可塑性,局部微环境对其分化方向起关键作用;肝癌可能来源于卵圆细胞的异常分化.

Objective To study the role of microenvironment on the differentiation of hepatic oval cells and explore whether hepatic oval cells can differentiate into liver cancer.Methods The transfected hepatitis B virus X oncogene （HBx） rat hepatic oval cells were implanted into the subcutaneous tissue of nude mice to develop tumor for 10 weeks,then the subcutaneous tumors were collected and divided to transplant into liver parenchyma,at the same time treating with aflatoxin B1 （AFB1） for 18 weeks.The subcutaneous tumors and intrahepatic tumors were collected and stained by haematoxylin and eosin （HE） and immunohistochemistry staining,as well as observed by transmission electron microscopy.Results About 10 weeks,10 （10/15） subcutaneous tumor formation in group A and 8 （8/15） subcutaneous tumor formation in control group.The subcutaneous tumors were composited by the mesenchymal cells with expression of mesenchymal marker Vimentin and smooth muscle actin （SMA）.8 weeks after transplantation,the intrahepatic tumors were found at the site of inoculated.The HBx intrahepatic tumor included components of mesenchymal cells,which expressing Vimentin and SMA,and cancer cells,which accounting for about 10％-20％ of cells and expressed HepParl,cytokeratin 8 （CK8）,and alpha fetal protein （AFP） antigen.These results indicate that the intrahepatic tumor was liver carcinosarcoma and oval cells can be abnormal differentiated into hepatocellular carcinoma on the cooperation of the HBx gene and AFB1.Conclusion Hepatic oval cells have the plasticity and local microenvironment play a key role on its differentiation ; hepatocellular carcinoma is likely to come from the abnormal differentiation of oval cells.