DETECTION OF POLYPEPTIDE AND GENETIC ALTERATIONS DURING HEPATOCARCINOGENESIS

肝癌发生过程中多肽和基因改变的检测

• 批准号: 3853553
• 负责人: P J WIRTH
• 金额: --
• 依托单位: DIVISION OF CANCER EPIDEMIOLOGY AND GENETICS
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3853553
• 关键词: aflatoxins; athymic mouse; carcinogenesis; cellular oncology; chemical carcinogenesis; gel electrophoresis; gene expression; liver cells; liver neoplasms; molecular oncology; neoplasm /cancer genetics; neoplastic transformation; oncogenes; point mutation; tissue /cell culture; tumor suppressor genes

Rat liver epithelial (RLE) cells provide a very valuable in vitro model to study both spontaneous and chemically induced hepatocarcinogenesis. Therefore, the main objectives of this project are to characterize the early cellular biochemical events as a result of genetic alterations and subsequent changes in protein expression during spontaneous and chemically mediated hepatocarcinogenesis. RLE cells can be transformed in vitro by various agents including chemical carcinogens and specific oncogenes as well as spontaneously when the cells are maintained under certain selective growth conditions. When injected into nude mice the transformed cells produce a diverse variety of tumor types including those of a well-differentiated hepatocellular carcinoma-like tumor. Two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) was utilized to construct comprehensive computerized topographical protein database maps of protein expression in each of the major subcellular fractions (whole cell, cytosol, nuclei, mitochondria, plasma membrane). Genetic analysis of aflatoxin Bl induced RLE transformants revealed a consistent point mutation consisting of a transition from G to A within codon 173 (CGC to GAG) in the tumor suppressor p53 gene. This mutation resulted in a change of the encoded amino acid from histidine to arginine. Mutations in the p53 gene are currently being analyzed in monkey genomic DNA extracted from paraffin embedded AFB induced tumors.

大鼠肝上皮（RLE）细胞提供了非常有价值的体外模型 研究自发和化学诱导的肝癌发生。 因此，本项目的主要目标是描述 早期细胞生化事件作为遗传改变的结果， 随后在自发和自发的过程中蛋白质表达的变化， 化学介导的肝癌 RLE细胞可以转化为 在体外通过各种试剂，包括化学致癌物和特定的 癌基因以及自发地当细胞维持在 选择性生长条件。 当注射到裸鼠体内时， 转化细胞产生多种肿瘤类型， 分化良好的肝细胞癌样肿瘤。 采用双向聚丙烯酰胺凝胶电泳（2D-PAGE） 构建全面的计算机化蛋白质拓扑数据库 每个主要亚细胞组分中的蛋白质表达图 （全细胞、胞质溶胶、细胞核、线粒体、质膜）。 遗传 对黄曲霉毒素B1诱导的RLE转化体的分析揭示了一致的 密码子173内由G转变为A的点突变 (CGC在肿瘤抑制基因p53中的GAG）。 该突变导致 编码的氨基酸从组氨酸变为精氨酸。 突变 目前正在猴子基因组DNA中进行分析 从石蜡包埋的AFB诱导的肿瘤中提取。