Conjugation of anticancer drugs

描述（由申请人提供）： 结直肠癌是一种可预防但在世界范围内高度流行的疾病。患者对筛查程序的依从性差会增加结直肠癌的死亡率。目前迫切需要针对这种肿瘤类型的化学预防措施。近年来最有前途的化学预防剂之一是膳食多酚白藜芦醇（RSV）。虽然RSV在细胞和啮齿动物模型中显示出有效的抗癌特性，但其作为药物开发的一个限制是其极高的代谢和由此产生的低口服生物利用度。尽管RSV具有高代谢，但有充分的证据表明其治疗功效。RSV代谢产物的药理学作用尚未阐明。本提案的总体目标是表征RSV主要结合代谢物的药理学，并描述RSV对结合酶表达和活性的影响。这项研究将推进我们对潜在的新型化学预防药物RSV、其药理学及其药物相互作用潜力的了解。我们假设RSV结合通过灭活或产生活性代谢物在其治疗效果中起重要作用。另外还假设RSV通过抑制或诱导异生物质缀合酶来改变其自身的缀合。提出了两个具体目标：1）确定RSV结合物的药理学活性，和2）表征RSV对人尿苷葡萄糖醛酸基转移酶（UGT）和磺基转移酶（SULT）诱导/抑制的影响。我们将合成RSV的主要代谢产物，并以结肠癌细胞系（FHC对照、Caco-2、HT-29和HCT-116）作为模型，测试其在细胞增殖中的作用。我们还将评价RSV或其代谢产物处理后人肝细胞以及结肠细胞中UGT / SULT蛋白表达和酶活性的变化。蛋白质表达将用蛋白质印迹分析定量，而酶活性将用针对每种同工酶的特异性底物表征。总之，这些实验将首次评价RSV代谢物的药理学，以及RSV在调节负责其代谢的酶中的作用。

DESCRIPTION (provided by applicant): Colorectal cancer is a preventable yet highly prevalent disease worldwide. Poor patient compliance with screening procedures increases the mortality due to colorectal cancer. There is an urgent need for chemopreventive measures for this tumor type. One of the most promising chemopreventives in recent years is the dietary polyphenol resveratrol (RSV). While RSV has shown effective anticancer properties in cellular and rodent models, one limit to its development as a drug is its extremely high metabolism and resultant low oral bioavailability. There is ample evidence for therapeutic efficacy of RSV despite its high metabolism. The pharmacologic effects of RSV metabolites have never been elucidated. The overall goal of this proposal is to characterize the pharmacology of the major conjugated metabolites of RSV, and to delineate the effect of RSV on conjugating enzyme expression and activity. This research will advance our knowledge of a potential new chemopreventive drug, RSV, its pharmacology, and its potential for drug-drug interactions. We hypothesize that RSV conjugation plays an important role in its therapeutic effects via either inactivation or production of active metabolites. RSV is additionally hypothesized to alter its own conjugation by inhibition or induction of xenobiotic conjugating enzymes. Two specific aims are proposed: 1) Determine the pharmacologic activity of RSV conjugates, and 2) Characterize the effect of RSV on human uridine glucuronosyltransferase (UGT) and sulfotransferase (SULT) induction / inhibition. We will synthesize the major metabolites of RSV and test their role in cell proliferation with colon cancer cell lines (FHC controls, Caco-2, HT-29, and HCT-116) as our model. We will additionally evaluate changes in UGT / SULT protein expression and enzyme activity in human hepatocytes as well as colon cells upon treatment with RSV or its metabolites. Protein expression will be quantitated with western blot analysis, while enzyme activity will be characterized with specific substrates toward each isozyme. Taken together, these experiments will provide the first evaluation of the pharmacology of RSV metabolites, and the effect of RSV in regulation of enzymes responsible for its metabolism.