骨髓基质细胞在小鼠肝脏内分化及癌变的潜能

Possibility of differentiation and malignant transformation of bone marrow stromal cells in the liver of mice

目的:探讨骨髓基质细胞(BMSCs)在诱癌小鼠模型中向肝细胞分化及癌变的可能性.方法:♂BALB/c小鼠BMSCs分离培养及经门静脉移植到♀BALB/c小鼠肝脏.二乙基亚硝胺诱导肝癌.6mo后处死小鼠,取肝脏标本.用免疫组织化学检测胎盘型谷胱苷肽转移酶、甲胎蛋白和角蛋白19的表达及用荧光原位杂交(fluorescence in situ hybridisation,FISH)检测Y染色体阳性细胞.结果:BMSCs在添加肝细胞生长因子的培养基中体外培养能分化为肝细胞样细胞.诱癌6mo后26%的小鼠存活并成功诱导肝细胞性肝癌.免疫组织化学显示肝癌细胞表达胎盘型谷胱苷肽转移酶和甲胎蛋白,而不表达角蛋白19.FISH结果显示骨髓基质细胞移植及诱癌6mo后小鼠肝脏内有Y染色体阳性的肝细胞.而无二乙基亚硝胺诱癌的小鼠,BMSCs移植6mo后肝脏内未发现Y染色体阳性的肝细胞.另外,FISH检测未发现Y染色体阳性的肝癌细胞.结论:在肝癌的小鼠诱癌模型中,移植的BMSCs能分化为肝细胞,但癌变的可能性小.

AIM： To evaluate the possibility of differentiation and malignant transformation of bone marrow stromal cells （BMSCs） in a mouse model of chemical hepatocarcinogenesis. METHODS： BMSCs were harvested from male BALB/c mice, cultured and transplanted into the liver of female syngeneic BALB/c mice via the portal vein. Diethylnitrosamine was administered to mice for six months to induce hepatocarcinogenesis. Six months later, liver samples were taken and used to evaluate the expression of placental form of glutathione-S-transferase,a-fetoprotein and cytokeratin 19 by immuno- histochemistry. Y chromosome-positive hepa- tocytes were detected by fluorescence in situ hybridization （FISH）. RESULTS： BMSCs were shown to differentiate into hepatocyte-like phenotypes after hepatocyte growth factor treatment in vitro. Twenty-six per- cent of recipient mice survived and developed multiple hepatocellular carcinomas （HCCs）. Immunohistochemically, HCCs expressed pla- cental form of glutathione-S-transferase and a-fetoprotein, but did not express cytokeratin 19. Y chromosome-positive hepatocytes were detected by FISH in the liver of mice that were treated with diethylnitrosamine after BMSC transplantation while no such hepatocytes were identified in the liver of mice that were not treated with diethylnitrosamine. No hepatocel- lular carcinoma cells positive for Y chromosome marker were detected. CONCLUSION： Transplanted BMSCs can differentiate into hepatocytes but have low malignant potential in the mouse model of chemical hepatocarcinogenesis.