GLUTAMINE TRANSPORT IN HEPATOCELLULAR TRANSFORMATION

描述：这项研究提案的总体目标是研究 谷氨酰胺转运体系统在心肌梗死中的作用及调控 肝细胞转化。该提案包含四个具体内容 假设：1)通过ASC系统摄取谷氨酰胺的加速速率是 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，但不是单独足够的。3) 人肝癌的生长是通过将谷氨酰胺输送到 细胞质。4)系统ASC活性受细胞生长状态的调节。 为了检验这四个假设，研究人员提出了四个具体目标： 1)他们将检查谷氨酰胺在细胞或质膜中的转运 来自手术活检的囊泡，包括肝肿瘤和正常 围绕着薄壁组织。2)无致瘤性的永生化人肝 人肝癌细胞系(THLE-5B)稳定转染人肝癌 Asc基因和裸鼠体内注射评价其致瘤性 潜力。3)人肝癌和永生化人肝细胞 在生理谷氨酰胺水平下生长，在或 无过量系统ASC底物及其对增殖的影响 已评估。4)ASC介导的谷氨酰胺摄取将在两个 同步化肝癌和THLE-5B细胞的活性和分子水平 在营养供应或生物化学物质调节生长后。

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.