胚胎肝干细胞癌变潜能的研究

Investigation into the canceration of hepatic stem cell derived from the fetal liver in a mouse model of chemical hepatocarcinogenesis

目的研究肝干细胞癌变的可能性。方法取孕14d的小鼠胚胎肝细胞作为肝干细胞移植到雌性小鼠肝脏,二乙基亚硝胺诱导肝癌。6个月后取肝癌结节做连续切片,免疫组化或免疫荧光分析Y染色体性别决定区域蛋白(SRY)、AFP、胎盘型谷胱苷肽转移酶(GST-P)或角蛋白19的表达,以研究肝癌的细胞来源和特征。结果6个月后诱导多发性肝癌结节。实验组17.1%的肝细胞癌结节SRY染色阳性,胆管细胞癌结节SRY染色均为阴性。肝细胞癌结节表达AFP和GST-P,而不表达角蛋白19。胆管细胞癌结节不表达AFP和GST-P,而表达角蛋白19。结论移植的肝干细胞转变为肝癌,并且保持了胚胎肝干细胞未成熟的特征,仍表达GST-P和AFP。提示在诱导肝癌过程中移植的肝干细胞有直接癌变形成肝细胞癌潜能。

Objective To investigate the canceration of mature hepatocytes or maturation arrest of hepatic stem cells in a mouse model of chemical hepatocarcinogenesis.Methods Hepatic stem cells were obtained from 14-day embryo mice and transplanted into female recipients.Hepatocarcinogenesis was induced by diethylnitrosamine（DEN）.Six months later,the expression of SRY protein,GST-P,AFP or cytokeratin 19 was determined with immunohistochemistry or immunofluorescence after DEN treatment in the serial liver sections in tumor nodules.Immunohistochemistry was performed for the SRY protein to identify the origin of cells in the tumor nodules.Immunohistochemistry or immunofluorescence for GST-P,AFP,or cytokeratin 19 was performed to determine tumor characteristics.Results DEN treatment resulted in the appearance of multiple tumors in the liver.Six（17.1%） of HCCs stained positively for SRY and all of CCCs were negative for SRY in experiment group.These SRY positive hepatocellular carcinoma expressed GST-P and AFP in the cytoplasm,but negative for cytokeratin 19.All CCCs expressed cytokeratin 19,but negative for GST-P and AFP.These results showed that the transplanted hepatic stem cells were converted into HCCs directly.Conclusion There is potential of canceration in hepatic stem cells in the DEN model of hepatocarcinogenesis.