Takahashi K, Viviano C J, Elwell M R, Bakewell W E, Kuwahara M, Nakashima N, Blackwell B N, Maronpot R R
National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA.
Lab Invest. 1995 Sep;73(3):424-32.
It is well established that alterations in the expression of cell surface glycoproteins occur during the course of tumorigenesis and can be detected immunohistochemically. However, no consistent markers of malignancy in mouse hepatocellular tumors have yet been identified.
Lectin histochemistry, using three bile duct-specific lectins, Dolichos biflorus agglutinin (DBA), peanut agglutinin (PNA) and soybean agglutinin (SBA), and anti-epidermal keratin immunohistochemistry, was conducted on formalin-fixed, paraffin-embedded tissues of a spectrum of benign and malignant hepatocellular proliferative lesions of mice, including hepatocholangiocarcinomas. DBA- and PNA-binding glycoproteins in normal livers and in bile and liver tumors of mice were verified by SDS-PAGE and Western blot analysis.
Normal bile duct cells stained strongly with DBA but minimally to moderately with PNA and SBA. DBA-positive tumor cells were present in 96% of hepatocholangiocarcinomas, 89% of hepatocellular carcinomas, and 35% of hepatocellular adenomas. In comparison, 43% of hepatocholangiocarcinomas, 37% of hepatocellular carcinomas, and 24% of hepatocellular adenomas exhibited PNA staining. SBA did not specifically stain tumor cells. Normal hepatocytes and those in altered foci were consistently negative for these three lectins. Keratin-positive staining was found only in normal bile ductular cells and ductal elements in 70% of hepatocholangiocarcinomas. Electrophoresis and Western blot analysis demonstrated that, in normal livers, DBA and PNA bound to the 13- to 16-kDa and 27- to 30-kDa glycoproteins believed to be of bile duct cell origin and commonly present in hepatocellular adenomas, hepatocellular carcinomas, and hepatocholangiocarcinomas, with strongest expression in the last. In addition, hepatocholangiocarcinomas had the same high molecular mass glycoprotein (> 200 kDa) labeled with DBA as detected in bile.
Our results suggest that some malignant hepatocytes, especially in mouse hepatocholangiocarcinomas, have the potential of biliary differentiation. DBA is a sensitive marker for malignant hepatocytes in mice.
细胞表面糖蛋白表达的改变在肿瘤发生过程中会出现，并且可以通过免疫组织化学检测到，这一点已得到充分证实。然而，小鼠肝细胞肿瘤中尚未确定一致的恶性标志物。
使用三种胆管特异性凝集素，即双花扁豆凝集素（DBA）、花生凝集素（PNA）和大豆凝集素（SBA）进行凝集素组织化学，以及对福尔马林固定、石蜡包埋的小鼠一系列良性和恶性肝细胞增殖性病变组织（包括肝内胆管癌）进行抗表皮角蛋白免疫组织化学。通过SDS-PAGE和蛋白质印迹分析验证正常肝脏以及小鼠胆汁和肝脏肿瘤中DBA和PNA结合的糖蛋白。
正常胆管细胞DBA染色强，但PNA和SBA染色轻微至中度。96%的肝内胆管癌、89%的肝细胞癌和35%的肝细胞腺瘤存在DBA阳性肿瘤细胞。相比之下，43%的肝内胆管癌、37%的肝细胞癌和24%的肝细胞腺瘤呈现PNA染色。SBA未特异性染色肿瘤细胞。正常肝细胞以及灶性改变中的肝细胞对这三种凝集素始终呈阴性。仅在70%的肝内胆管癌的正常胆管细胞和胆管成分中发现角蛋白阳性染色。电泳和蛋白质印迹分析表明，在正常肝脏中，DBA和PNA与据信源自胆管细胞且通常存在于肝细胞腺瘤、肝细胞癌和肝内胆管癌中的13至16 kDa和27至30 kDa糖蛋白结合，在肝内胆管癌中表达最强。此外，肝内胆管癌具有与胆汁中检测到的相同的被DBA标记的高分子量糖蛋白（> 200 kDa）。
我们的结果表明，一些恶性肝细胞，尤其是小鼠肝内胆管癌中的恶性肝细胞，具有胆管分化的潜能。DBA是小鼠恶性肝细胞的敏感标志物。
