GLUTAMINE TRANSPORT IN HEPATOCELLULAR TRANSFORMATION

描述：本研究计划的总体目标是研究 谷氨酰胺转运系统ASC的作用和调节 肝细胞转化。 该提案包含四项具体内容 假设： 1) 通过系统 ASC 加速谷氨酰胺摄取速率是 与人类肝癌的一致特征。 2) ASC介导的谷氨酰胺转运 对于致瘤表型来说是必要的，但单独使用还不够。 3） 人类肝癌的生长是通过向肝脏输送谷氨酰胺来调节的 细胞质。 4) 系统ASC活性受细胞生长状态调节。 为了检验这四个假设，研究人员提出了四个具体目标： 1）他们将检查细胞或质膜中的谷氨酰胺转运 来自手术活检的囊泡，包括肝肿瘤和正常组织 周围薄壁组织。 2）非致瘤性永生化人类肝脏 上皮细胞系（THLE-5B）将被肝癌细胞稳定转染 ASC基因注射裸鼠评价致瘤性 潜力。 3）人肝癌和永生化人肝细胞将被 在存在生理谷氨酰胺水平和存在或 缺乏过量的系统 ASC 底物及其对增殖的影响 评价。 4) ASC 介导的谷氨酰胺摄取将在 同步化肝癌细胞和 THLE-5B 细胞中的活性和分子水平 通过营养供应或生化物质进行生长调节后。

DESCRIPTION: The overall objective of this research proposal is to study the role and regulation of the glutamine transporter system ASC in hepatocellular transformation. The proposal contains four specific hypotheses: 1) Accelerated rates of glutamine uptake via System ASC are a consistent feature of human hepatomas. 2) ASC mediated glutamine transport is necessary, but not alone sufficient for a tumorigenic phenotype. 3) Growth of human hepatomas is regulated by delivery of glutamine to the cytoplasm. 4) System ASC activity is regulated by cellular growth status. To test these four hypotheses, the investigators propose four specific aims: 1) They will examine glutamine transport in cells or plasma membrane vesicles from surgical biopsies that include hepatic tumor and normal surrounding parenchyma. 2) A nontumorigenic immortalized human liver epithelial cell line (THLE-5B) will be stably transfected with the hepatoma ASC gene and injected into nude mice for evaluation of tumorigenic potential. 3) Human hepatomas and immortalized human liver cells will be grown in the presence of physiologic glutamine levels and in the presence or absence of excess System ASC substrates and the effects on proliferation evaluated. 4) ASC mediated glutamine uptake will be evaluated at both the activity and molecular levels in synchronized hepatoma and THLE-5B cells after growth modulation by nutrient supply or biochemicals.