Targeting Metabolic Vulnerabilities with Synergistic Therapeutic Agents for Treatment of Metastatic Castration-Resistant Prostate Cancer.

项目总结 广泛影响：前列腺癌(PCA)是美国男性和2022年最常见的诊断癌症 仅此一项就会导致34000多人死亡。前列腺癌死亡通常是由以下疾病引起的 进展到转移性去势抵抗阶段(MCRPC)，并已扩散到较远的部位，如 骨、脑、肝和淋巴结。目前，还没有有效或根治的治疗策略 MCRPC，部分原因是对雄激素剥夺疗法(ADT)的获得性耐药率较高 以及治疗mCRPC的标准化疗药物多西紫杉醇(DTX)。因此，有一个关键的 需要新的有效的治疗方案来治疗mCRPC。最近的研究结果表明，谷氨酰胺和 相关谷氨酸代谢是mCRPC代谢重编程的重要驱动因素 耐药机制。事实上，在ADT之后，已经在PCA中发现了代谢转换 使细胞依赖于雄激素非依赖性谷氨酰胺酶亚型(GLS1，一种将 谷氨酰胺到谷氨酸)，而不是ADT抑制的异构体，提供抗药性。努力实现 化学抑制GLS1来克服这个问题都失败了，因为有一个稳定的谷氨酸通过 当有生理相关水平的胱氨酸时，XCT转运蛋白。然而，我们的初步数据显示， 同时抑制GLS1和谷氨酸脱氢酶(GDH)，谷氨酸脱氢酶是 谷氨酸到TCA循环中间体α-酮戊二酸)可能足以克服这种抗性 包括mCRPC在内的所有PCA亚型的机制。这个项目的总体目标是找出 联合治疗mCRPC，与DTX协同作用，靶向代谢易损性并克服 抗药性，以改善治疗结果。中心假说：GLS1和GDH的同时抑制 联合应用DTX可绕过耐药机制，提高疗效 与mCRPC中的SOC相比。目的1：确定CB-839与DTX联用抑制GLS1的代谢作用 对体内PCa肿瘤生长有协同抑制作用。目标2：阐明并发GLS1和 GDH抑制加DTX对PCa生长、增殖、代谢、侵袭性和侵袭性的影响 与体外培养的SOC进行比较。目的3：评价GLS1抑制剂和GDH联合治疗是否 在体内，抑制剂+DTX能比SOC更有效地协同抑制PCa的生长。实验 包括代谢组学、使用稳定同位素示踪剂的代谢流量分析、体外和体内技术 为了实现这项研究，将进行mCRPC的建模和药物治疗效果的验证 目标。这些发现将被用来提供新的治疗策略，与多西紫杉醇一起预防 MCRPC中的癌症生长、增殖和侵袭性，以实现更有效的治疗和改善 MCRPC患者的预后。

PROJECT SUMMARY Broad Impact: Prostate cancer (PCa) is the most commonly diagnosed cancer in American men and in 2022 alone will result in the death of over 34,000 men. PCa mortality is typically caused by disease that has advanced to the metastatic castration-resistant stage (mCRPC) and has spread to distant sites such as the bone, brain, liver, and lymph nodes. Currently, there are no effective or curative therapeutic strategies for mCRPC, which is in part due to high rates of acquired drug resistance to androgen deprivation therapy (ADT) and the standard-of-care chemotherapy drug for mCRPC, docetaxel (DTX). Consequently, there is a critical need for novel and effective therapeutic options for mCRPC. Recent findings have indicated glutamine and related glutamate metabolism as significant drivers of the metabolic reprogramming of mCRPC that contributes to drug resistance mechanisms. Indeed, a metabolic switch has been identified in PCa following ADT that allows the cells to rely on the androgen-independent isoform of glutaminase (GLS1, the enzyme that converts glutamine to glutamate) rather than the isoform that is inhibited by ADT, affording drug resistance. Efforts to chemically inhibit GLS1 to overcome this issue have failed since there is a steady influx of glutamate via the xCT transporter when there are physiologically-relevant levels of cystine. However, our preliminary data shows that concurrently inhibiting GLS1 as well as glutamate dehydrogenase (GDH, the enzyme that converts glutamate to the TCA cycle intermediate alpha-ketoglutarate) may be sufficient to overcome this resistance mechanism across PCa subtypes including mCRPC. The overall goal of this project is to identify novel combinatorial treatments for mCRPC that synergize with DTX to target metabolic vulnerabilities and overcome drug resistance for improved treatment outcomes. Central hypothesis: Concurrent inhibition of GLS1 and GDH in combination with DTX can circumvent drug resistance mechanisms and increase therapeutic efficacy compared to SOC in mCRPC. Aim 1: Determine the metabolic role of GLS1 inhibition with CB-839 plus DTX for the synergistic inhibition of PCa tumor growth in vivo. Aim 2: Elucidate the impact of concurrent GLS1 and GDH inhibition plus DTX on PCa growth, proliferation, metabolism, aggressiveness, and invasiveness compared to SOC in vitro. Aim 3: Evaluate whether combination treatment with a GLS1 inhibitor and a GDH inhibitor plus DTX can synergistically inhibit PCa growth more effectively than SOC in vivo. Experimental techniques including metabolomics, metabolic flux analysis using stable isotope tracers, in vitro and in vivo modeling of mCRPC, and validation of drug treatment efficacy will be undertaken to achieve the research goals. These findings will be used to inform novel treatment strategies to accompany docetaxel to prevent cancer growth, proliferation, and aggressiveness in mCRPC for more effective treatments and improved outcomes for patients with mCRPC.