STAT3, G6PD and TrxR as underlying mechanisms for antitumor responses tohirsutinolides

多形性胶质母细胞瘤（GBM）和乳腺癌是主要的健康负担， 机械的见解，导致新的管理策略。我们建议调查信号 转录转导和激活因子（STAT）3，硫氧还蛋白还原酶（TrxR）1胞质亚型3， 和葡萄糖-6-磷酸1-脱氢酶（G6 PD）亚型a作为靶向机制， GBM和三阴性乳腺癌对毛舒替尼化合物的抗肿瘤反应。多毛的 系列化合物是斑鸠菊的主要化学成分。这种植物传统上用于 亚洲治疗特定疾病，并在临床试验中证明是有效的中度2型糖尿病， 减少吸烟。然而，尽管毛舒内酯具有治疗潜力， 药理学特性，以促进其临床开发，直到我们的研究。我们令人信服的数据 显示结构上合适的毛松内酯强烈抑制STAT 3、TrxR 1和G6 PD功能，从而 在体外和体内抑制乳腺癌和GBM表型。初始构效关系 分析表明，对于活性来说，13位酯基是关键的要求。无偏 计算建模/对接和核磁共振结构研究表明， 合适的毛松内酯通过STAT 3 DNA结合结构域（DBD）与STAT 3 DNA结合结构域之间的疏水相互作用结合STAT 3 DNA结合结构域（DBD）。 STAT 3 DBD中的13位侧链和特定氨基酸残基。选择化合物引起 有丝分裂和细胞周期停滞，并抑制人乳腺癌和GBM异种移植物的生长。符合 TrxR 1或G6 PD在细胞保护免受过度氧化损伤中的功能作用 活性氧（ROS）或戊糖磷酸途径中的NADPH生产，分别， ROS水平和糖酵解代谢产物，包括葡萄糖，G6 P和丙酮酸， 毛舒内酯处理的肿瘤细胞。我们推测，结构合适的hirsutinolides是固有的活性 针对STAT 3、TrxR 1和G6 PD功能，并改变细胞氧化还原事件和糖酵解代谢， 从而阻断乳腺癌和GBM进展。我们将测定毛松内酯相对于 抑制STAT 3活性并阐明STAT 3抑制的结构决定因素（目的1）， 研究毛舒内酯抑制STAT 3信号传导的机制细节，以及 针对GBM和乳腺癌的抗肿瘤反应（目标2），定义了 STAT 3，TrxR 1和G6 PD功能，改变细胞氧化还原循环，代谢，有丝分裂和细胞周期（目的 3），并研究选择的毛舒替尼类似物的抗肿瘤功效反应及其与STAT 3的相关性， 体内TrxR 1和G6 PD依赖性分子和代谢组学事件（目的4）。数据最终将 促进毛舒内酯作为乳腺癌和GBM的潜在治疗剂的开发。

Glioblastoma multiforme (GBM) and breast cancer are major health burdens that will benefit from new mechanistic insights that lead to novel management strategies. We propose to investigate Signal Transducer and Activator of Transcription (STAT)3, thioredoxin reductase (TrxR)1 cytoplasmic isoform 3, and glucose-6-phosphate 1-dehydrogenase (G6PD) isoform a as the targeting mechanisms underlying the antitumor responses of GBM and triple-negative breast cancer to hirsutinolide compounds. The hirsutinolide series are the major chemical constituents of Vernonia cinerea. This plant has traditionally been used in Asia to treat specific ailments and in clinical trials proofed to be effective to moderate type 2 diabetes and curtail smoking. Despite the therapeutic potential of the hirsutinolides, however, little was known of their pharmacological properties to facilitate their clinical development until our studies. Our compelling data show that structurally suitable hirsutinolides strongly inhibit STAT3, TrxR1 and G6PD functions and thereby suppress breast cancer and GBM phenotypes in vitro and in vivo. Initial structure activity relationship analysis showed a critical requirement for a position 13 ester group for the activities. Unbiased computational modeling/docking and nuclear magnetic resonance structural studies show that structurally suitable hirsutinolides bind the STAT3 DNA-binding domain (DBD) via hydrophobic interactions between the position 13 side chain and specific amino acid residues in the STAT3 DBD. Select compounds caused mitotic and cell cycle arrests and inhibited growth of human breast cancer and GBM xenografts. In line with the TrxR1 or G6PD functional roles in the cellular protection against the oxidative damage from excessive reactive oxygen species (ROS) or in the pentose phosphate pathway for NADPH production, respectively, ROS levels and glycolytic metabolites, including glucose, G6P and pyruvate are significantly altered in hirsutinolide-treated tumor cells. We hypothesize that structurally suitable hirsutinolides are inherently active against STAT3, TrxR1 and G6PD functions, and alter cellular redox events and glycolytic metabolism, and thereby block breast cancer and GBM progression. We will determine the SAR of the hirsutinolides relative to inhibition of STAT3 activity and elucidate the structural determinants for STAT3 inhibition (Aim 1), investigate the mechanistic details of the STAT3 signaling inhibition by hirsutinolides and the significance to the antitumor responses against GBM and breast cancer (Aim 2), define the mechanistic link between STAT3, TrxR1 and G6PD functions, altered cellular redox recycle, metabolism, mitosis and cell cycle (Aim 3), and study the antitumor efficacy responses of select hirsutinolide analogs and their correlation to STAT3, TrxR1 and G6PD-dependent molecular and metabolomic events in vivo (Aim 4). Data will ultimately facilitate the development of the hirsutinolides as potential therapeutics for breast cancer and GBM.