INHIBITION OF THE ANTICANCER TARGET GLYOXALASE I

该项目的长期目标是确定抑制剂是否 乙二醛酶系，由乙二酸酶I异构酶组成 (GLXi)和硫酯水解酶乙二醛酶II(GlxII)可以开发 在整个动物体内转化为有效的抗肿瘤药物。这一总体战略 可能很重要，因为(A)它不直接针对原子核 酸代谢，因此可能不会引起副作用 通常与大多数癌症化疗有关，以及(B)使用 可能对多种药物不太敏感的亲水性酶抑制剂 耐药性曾作为亲脂性前体药物输送到癌细胞中。在……里面 支持这一抗癌战略的可行性，我们最近 合成了四个烯二醇类似物，它们是最强的 人类GLXi已报道：GSC(O)N(OH)R，其中GS=谷胱甘肽，R= CH3(L)，C6H5(2)，C6H4Cl3(3)，C6H4Br4(4)。初步的体外研究是 与这些化合物是潜在的肿瘤的想法一致- 选择性抗癌药物作为载体进入人白血病细胞 亲脂性的[甘氨酰，伽马-谷氨酰基]二乙酯。最直接的 这项修订建议的目的是进一步检查体外和 这些化合物在小鼠模型系统中的体内抗肿瘤特性， 为了更好地理解紧密结合抑制的分子基础 通过烯二醇类似物对GLXi的影响。具体目标如下：(L) 研究烯二醇类似物的二乙酯的作用机理 (1-4)在体外被转运到小鼠白血病L1210细胞。(2)至 评价烯二醇类似物(1-4)及其乙基化合物的细胞毒性 体外对L1210细胞的酯化作用。(3)测定药代动力学。 烯二醇类似物(1-4)及其乙酯在血清中的性质 酯酶缺陷小鼠。(4)测定亚麻酚的体内药效。 类似物及其乙酯在血清酯酶缺陷小鼠生育中的作用 L1210小鼠白血病和荷人肿瘤的C.B-L7 SCID小鼠 异种移植，雄激素非依赖性人前列腺癌(PC-3)和人 结肠腺癌(HT-29)。(5)检验假设 反应过程中生成的烯二醇(ATE)中间体的稳定化 GLXi的途径是由于一种灵活的(TIM样)多肽的运动 在活动站点附近循环。(6)检验假设：在 GLXi反应活性中心谷氨酸残基催化质子 与异构化有关的转移。

The long term objective of this project is to determine whether inhibitors of the glyoxalase enzyme system, composed of the isomerase glyoxalase I (GlxI) and the thioester hydrolase glyoxalase II (GlxII), can be developed into effective antitumor agents in whole animals. This general strategy is potentially important because (a) it does not directly target nucleic acid metabolism and, therefore, might not give rise to the side effects commonly associated with most cancer chemotherapies, and (b) uses hydrophilic enzyme inhibitors that might be less susceptible to multidrug resistance once delivered into cancer cells as lipophilic prodrugs. In support of the feasibility of this anticancer strategy, we recently synthesized four enediol analogs that are the strongest inhibitors of human GlxI yet reported: GSC(O)N(OH)R, where GS = glutathionyl, R = CH3(l), C6H5(2), C6H4Cl(3), C6H4Br(4). Preliminary in vitro studies are consistent with the idea that these compounds are potential tumor- selective anticancer agents when delivered into human leukemia cells as the lipophilic [glycyl, gamma-glutamyl] diethyl esters. The immediate objective of this revised proposal is to further examine the in vitro and in vivo antitumor properties of these compounds in a murine model system, and to better understand the molecular basis of tight-binding inhibition of GlxI by the enediol analogs. The specific aims are as follows: (l) To examine the mechanism by which the diethyl esters of the enediol analogs (1-4) are transported into mouse leukemia L1210 cells in vitro. (2) To evaluate the cytotoxicities of the enediol analogs (1-4) and their ethyl esters toward L1210 cells in vitro. (3) To determine the pharmacokinetic properties of the enediol analogs (1-4) and their ethyl esters in serum esterase deficient mice. (4) To test the in vivo efficacy of the enediol analogs and their ethyl esters in serum esterase-deficient mice bearing L1210 murine leukemia and in C.B-l7 SCID mice bearing human tumor xenografts, androgen-independent human prostate cancer (PC-3), and human colon adenocarcinoma (HT-29). (5) To test the hypothesis that stabilization of the enediol(ate) intermediate, formed along the reaction pathway of GlxI, is due to the movement of a flexible (TIM-like) peptide loop near the active site. (6) To test the hypothesis that during the GlxI reaction an active site glutamic acid residue catalyzes the proton transfer associated with isomerization.