Genesis of Liver Carcinomas with Oval Cell Traits

描述：(申请人提供)卵圆形细胞，导管的双能细胞 起源，在人类肝脏中被肝毒素、致癌物、病毒制剂激活 或慢性疾病状态，所有这些都极大地增加了患肝癌的风险。 对卵圆细胞作为肝细胞癌前体细胞的认识 (肝细胞癌)可以带来有价值的见解，特别是如果卵圆形细胞来源的肝细胞癌 在行为上不同于他们的二倍体肝细胞衍生的同龄人。这个 拟议的研究是围绕肝癌起源这一假设构建的，在 至少部分来自从启动的卵圆形细胞衍生的肝细胞。 这些发起的卵圆细胞已经获得了新的遗传变化(S)，即停滞 分化并产生卵圆细胞抗原阳性的肝细胞 进展为肝细胞癌。这一假设将通过评估 致癌物诱导的Fischer大鼠卵圆细胞经脾移植入 同基因宿主的肝脏含有突变的、失活的二肽基肽酶IV(DPPIV)。 供体细胞将根据其活性的表达在组织化学上加以区分 DPPIV或外源性β-半乳糖苷酶(B-GAL)。特定目标的实验I 将确定已建立的由乙硫氨酸诱导的卵圆细胞培养 在胆碱缺乏(CD)饮食中(CDE)可以整合、分化和 镉饮食促进肝细胞癌的进展。为了鼓励供体细胞的扩增， 宿主大鼠将接受逆皮质醇/部分肝切除(PH)治疗，然后 移植。整合后基因表达的变化将是 通过在不同的时间点对供体细胞进行表型监测 移植。在具体目标2中，将进行一系列类似的实验 使用CDE维持的DPPIV+大鼠的原代卵圆细胞分离物进行手术 饮食或用二乙基亚硝胺、2-AAF和PH(抗性肝细胞)治疗 养生法)。用抗Thy-1抗体用高速流式细胞仪分离卵圆细胞 抗体和一组独特的定义表面谱系的单抗 记号笔。肝细胞癌将通过测量血清DPPIV活性，DPPIV/B-GAL来定量 肝提取液中的活性或直接定量肝细胞癌切片的活性 DPPIV、B-GAL或已知肿瘤标志物染色。在具体目标3中， 重点将放在确定卵圆形细胞和高传代BDEC是否失败 在G1/S被捕后培养上调BDEC抗原BD.1代表 一次肿瘤前事件。比较研究将考察生长特征， 导管形态发生、黏附表型、细胞凋亡和基因表达 在胆管癌变的早期阶段(c-neu、COX-2、c-Met)被激活。 通过阐明卵圆细胞在肝癌发生中的作用，结果显示 这些研究将提供有价值的信息，这些信息可以转化为新的 肝细胞癌的诊断、治疗和预后策略。

DESCRIPTION:(PROVIDED BY APPLICANT) Oval cells, bipotent cells of ductal origin, are activated in human liver by hepatotoxins, carcinogens, viral agents or chronic disease states, all which greatly increase the risk of liver cancer. A better understanding of oval cells as progenitors of hepatocellular carcinoma (HCC) could lead to valuable insights, particularly if oval cell-derived HCC differ in behavior from their diploid hepatocyte-derived counterparts. The proposed research is structured around the hypothesis that HCC originate, at least in part, from hepatocytes derived de novo from initiated oval cells. These initiated oval cells have newly acquired genetic change(s) that arrest differentiation and produce oval-cell-antigen positive hepatocytes capable of progression to HCC. This hypothesis will be tested by assessing the fate of carcinogen-induced Fischer rat oval cells transplanted via the spleen into the liver of syngeneic hosts with mutated, inactive dipeptidylpeptidase IV (DPPIV). Donor cells will be distinguished histochemically by their expression of active DPPIV or exogenous beta-galactosidase (B-gal). Experiments in Specific Aim I will determine whether established cultures of oval cells induced by ethionine in a choline deficient (CD) diet (CDE) can integrate, differentiate and progress to HCC when promoted by CD diet. To encourage donor cell expansion, host rats will be treated with retrorsine/partial hepatectomy (PH) prior to transplantation. Changes in gene expression following integration will be monitored by phenotyping donor cells at various timepoints after transplantation. In Specific Aim 2, a similar series of experiments will be performed using primary oval cell isolates from DPPIV+ rats maintained on CDE diet or treated with diethylnitrosamine, 2-AAF and PH (resistant hepatocyte regimen). Oval cells will be isolated by high speed FACS using anti Thy-1 antibodies and a unique panel of monoclonal antibodies defining surface lineage markers. HCC will be quantitated by measuring serum DPPIV activity, DPPIV/B-gal activity in liver extracts or by direct quantitation of HCC transections stained for DPPIV, B-gal or known neoplastic markers. In Specific Aim 3, the focus will be on determining if the failure of oval cell and high passage BDEC cultures to upregulate the BDEC antigen, BD.1, following G1/S arrest represents a preneoplastic event. Comparative studies will examine growth characteristics, ductal morphogenesis, adhesion phenotypes, apoptosis and expression of genes activated in the early stages of cholangiocarcinogenesis (c-neu, COX-2, c-met). By elucidating the role of oval cells in liver carcinogenesis, the results from these studies will provide valuable information that can be translated into new strategies for the diagnosis, treatment and prognosis of HCC.