Anti-Cancer Activities of PTPase Inhibitors

PTPase 抑制剂的抗癌活​​性

• 批准号: 6745187
• 负责人: Taolin Yi
• 金额: $ 33.95万
• 依托单位: CLEVELAND CLINIC LERNER COM-CWRU
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-05-06 至 2008-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6745187
• 关键词: 3T3 cells; SDS polyacrylamide gel electrophoresis; active sites; antimony; antineoplastics; antiprotozoal agents; athymic mouse; biological products; biological signal transduction; biotherapeutic agent; enzyme activity; gluconate; interferon alpha; mass spectrometry; pharmacokinetics; phosphatase inhibitor; polymerase chain reaction; protein tyrosine phosphatase; tissue /cell culture; western blottings

DESCRIPTION (provided by applicant): Protein tyrosine phosphatases (PTPases) are key signaling molecules and potential targets for developing inhibitors as novel therapeutics. Our preliminary studies demonstrate for the first time that sodium stibogluconate (SS) and glucantime (GT), antimony (Sb) based anti-leishmania drugs of unknown mechanism, are inhibitors of selective PTPases with activity against cancer cells in vitro and in mouse models at nontoxic doses and in synergy with IFNs. We propose the following specific aims: Aim 1. To test the hypothesis that SS anti-cancer activity functions via inactivating PRLs and SHPs, we will: a), assess the role of PRLs in SS activity against cancer cell lines using SS-insensitive PRL mutants; b), assess the role of SHPs in SS synergy with IFNa in cell growth inhibition using SHP-deficient cell lines and SHP transfectants; c), define the pharmacodynamics of SS in inhibiting PRLs/SHPs in mouse models; d), determine the effects of SS on PRLs-regulated signaling molecules in cancer cells; e), determine the effects of SS on IFNa signaling molecules in WM9 melanoma cells against which SS and IFNa showed a synergistic effect. Aim 2. To test the hypothesis that SS inactivates target PTPases via covalent modification of a catalytic cysteine residue in the enzymes through the Sb in the drugs while the gluconic acid conjugated to Sb facilitates Sb/cysteine interactions and defines the drugs' PTPase specificity, we will: a), define the nature and significance of SS-induced mass increase in PRL-2 by mass spectrometry and mutational analysis; b), assess the ability of SS to modify MKP1 and PRL-1R86 mutant insensitive to SS inhibition; c), determine the effects of Sb and gluconic acid on PTPases sensitive or insensitive to SS inhibition; d), determine the PTPase inhibitory activity and anti-cancer activity of different molecular weight fractions of SS, which is mixture of polymers of Sb/gluconic acid complexes of 100-4000 Da. Aim 3. To test the hypothesis that GT has anti-cancer activity via targeting PTPases, we will: a), determine its inhibitory activity against a panel of PTPases; b), define its inhibitory mechanism by mass spectrometry and mutational analysis; c), assess its anti-cancer activity against human cancer cell lines in vitro and in mouse models; d), assess the role of its target PTPases in mediating its anti-cancer activity.

描述（由申请人提供）：蛋白酪氨酸磷酸酶（PTPases）是关键信号分子，也是开发抑制剂作为新型疗法的潜在靶标。我们的初步研究首次证明，葡萄糖酸锑钠 (SS) 和葡聚糖酸 (GT)（机制未知的基于锑 (Sb) 的抗利什曼原虫药物）是选择性 PTPase 抑制剂，在体外和小鼠模型中具有抗癌细胞活性。无毒剂量并与 IFN 协同作用。我们提出以下具体目标： 目标 1. 为了检验 SS 抗癌活性通过灭活 PRL 和 SHP 发挥作用的假设，我们将： a) 使用 SS 不敏感的 PRL 评估 PRL 在针对癌细胞系的 SS 活性中的作用突变体； b)，使用SHP缺陷细胞系和SHP转染子评估SHP在SS与IFNa协同抑制细胞生长中的作用； c)、定义SS在小鼠模型中抑制PRL/SHP的药效学； d)、确定SS对癌细胞中PRLs调节信号分子的影响； e)，确定SS对WM9黑色素瘤细胞中的IFNa信号分子的影响，SS和IFNa对其表现出协同作用。目标 2. 为了检验以下假设：SS 通过药物中的 Sb 共价修饰酶中的催化半胱氨酸残基来灭活目标 PTPase，而与 Sb 缀合的葡萄糖酸促进 Sb/半胱氨酸相互作用并定义药物的 PTPase 特异性，我们将： a) 通过质谱和突变分析确定 SS 诱导的 PRL-2 质量增加的性质和意义； b)，评估SS修饰对SS抑制不敏感的MKP1和PRL-1R86突变体的能力； c)，确定Sb和葡萄糖酸对对SS抑制敏感或不敏感的PTPases的影响； d)、测定SS的不同分子量级分的PTPase抑制活性和抗癌活性，SS是100-4000Da的Sb/葡萄糖酸复合物的聚合物的混合物。目标 3. 为了检验 GT 通过靶向 PTPase 具有抗癌活性的假设，我们将： a) 确定其对一组 PTPase 的抑制活性； b)、通过质谱和突变分析确定其抑制机制； c)、在体外和小鼠模型中评估其对人类癌细胞系的抗癌活性； d)，评估其靶点PTPases在介导其抗癌活性中的作用。