CELL AND MATRIX BIOLOGY IN FISHLIVER CARCINOGENESIS

人们对使用硬骨鱼进行生物测试、检测 环境中的致癌物，并作为潜在的比较肿瘤学 人类癌症的模型。然而，关于发病机制的基本问题仍然存在。 以及鱼类肿瘤的生物学特性。肝是敏感的 鱼和高等脊椎动物中的致癌物质。以进一步发展鱼类 作为有用的动物模型，我们将分析肝癌发生的各个方面。 在两个有希望的物种中，Salmo Gairdneri和Oryzias laitpe。问题 关于：鱼肝的增生性病变如何符合数据 哺乳动物肝脏肿瘤.肝细胞的形态特征 鱼肿瘤中细胞内基质与肝内药物敏感性的关系 胆管上皮细胞对致癌物的作用将得到解决。体内偶联 而体外研究将集中在鱼肝细胞的种群上。 将使用敏感的免疫组织化学探针来确定 特定致癌物对有丝分裂指数、非程序DNA的诱导 细胞和基质糖蛋白的合成(UDS)和改变 糖胺聚糖。肝脏肿瘤性病变的进程和命运将是 用酶组织化学方法研究改变的细胞和长期 富含肿瘤的鱼的随访。致癌物形成特定物质的能力 用超灵敏质谱仪测定DNA加合物 学习。我们将寻求将形成与特定的DNA加合物关联起来 肝脏病变的类型。提出了三个具体目标。1. 描述正常病变进展过程中的形态学事件 青冈日本人肝脏至显性肿瘤的发病年龄关系 并确定肝细胞肿瘤的长期潜力 生长/转移。2.分离和保存原代培养的肝脏 鲑鱼细胞和开发分离非肝细胞的程序 人口。从后者出发，建立鲑鱼胆汁的长期养殖 上皮细胞。3.测定肝细胞和其他细胞的能力 不同类型鲑鱼肝脏体外激活遗传毒性致癌物的实验研究 并确定暴露的程度和特定的细胞类型 致癌物诱导的DNA修复发生了。定性地确定和 鲑鱼肝脏和细胞中DNA加合物在不同环境中的定量研究 致癌物及DNA修复对加合物数量的影响。vbl.使用 致癌物生物测定法，确定DNA加合物的化合物特异性效应 在修复和致癌潜力上形成。

Interest has heightened in use of teleosts for bioassay testing, detection of carcinogens in the environment, and as potential comparative oncology models for human cancer. However, basic questions remain on pathogenesis and biologic properties of fish tumors. The liver is sensitive to carcinogens in fish and higher vertebrates. To further development of fish as useful animal models, we will analyze aspects of hepatic carcinogenesis in two promising species, Salmo gairdneri and Oryzias latipes. Questions about: how proliferative lesions of fish liver conform to data on neoplasms in mammalian liver; morphologic characteristics of liver cells and intracellular matrix in fish neoplasms and sensitivity of intrahepatic biliary epithelial cells to carcinogens will be addressed. Coupled in vivo and in vitro studies will focus on populations of fish liver cells. Sensitive immunohistochemical probes will be used to determine effect of specific carcinogens on mitotic index, induction of unscheduled DNA synthesis (UDS) and alterations of cell and matrix glycoproteins and glycosaminoglycans. Course and fate of neoplastic liver lesions will be studied using enzyme histochemistry of altered cells and long-term follow-up of tumor laden fish. The ability of carcinogens to form specific DNA adducts will be determined by ultrasensitive mass spectrometer studies. We will seek to correlate formation to specific DNA adducts with types of liver lesions. Three specific aims are proposed. 1. Characterize morphologic events in the progression of lesions from normal liver to overt tumor in Japanese medaka as a function of age at initiation and determine long-term potential of liver cell tumors for growth/metastasis. 2. Isolate and maintain, in primary culture, liver cells of trout and develop procedures to separate nonhepatocytic cell populations. From the latter, establish long-term culture of trout biliary epithelial cells. 3. Determine capacity of hepatocytes and other cell types of trout liver to activate genotoxic carcinogens after in vitro exposure and determine extent and specific cell types in which carcinogen-induced DNA repair occurs. Determine, qualitatively and quantitatively, DNA adducts in trout liver and cells exposed to various carcinogens and follow effect of DNA repair on amount of adduct. Using carcinogen bioassay, determine compound specific effects of DNA adduct formation on repair and on carcinogenic potential.