Developing therapies to improve enzalutamide in CRPC

项目总结 这项建议的目标是开发一种新的基于机制的治疗方法，以提高抗肿瘤疗效。 以及苯扎鲁胺的可持续性。转移性前列腺癌是导致癌症死亡的第二大原因。 在美国的男人身上。抗去势PCa(CRPC)是该病最常见和最致命的形式。 有效和挽救生命的治疗是一种未得到满足的需求。最近，以苯扎鲁胺(ENZ)为基础的治疗已经 显示了良好的临床效果。然而，许多患者没有反应或迅速产生抵抗力。新的 迫切需要从机制上认识和制定治疗策略，以改善Enz。在CRISPR/CAS9中- 在筛选的基础上，我们确定谷丙转氨酶(GPT)是一个新的脆弱性或靶点， 使CRPC细胞对ENZ增敏。临床上，我们发现GPT在患者亚群中扩增或上调 与ENZ耐药性和不良疾病结局显著相关的样本。从生物学上讲，我们的 初步研究表明，GPT通过连接3个基团对ENZ产生适应性反应和抗性 CRPC中的重要致癌途径-I)未折叠蛋白反应(UPR)，II)谷氨酰胺代谢，以及III) 脂肪酸和脂类的合成(脂肪生成)，这是CRPC和CRPC的代谢标志 对前列腺癌细胞的存活和增殖至关重要。在治疗方面，我们筛选了一组转氨酶抑制剂 并将临床批准的抗生素D-环丝氨酸(DC)确定为GPT的特异性和选择性抑制剂， 但不包括其他转氨酶。基于这些数据，我们将开发一种新的治疗方法来改善 靶向GPT和DC的ENZ的抗肿瘤效果和可持续性。中心假设是GPT是一种 在基于ENZ的治疗中，对PCA细胞，特别是CRPC，新的分子脆弱性；因此，GPT 可用于治疗，以提高Enz的疗效和耐受性。我们将测试 三个目标中的假设。目标1是了解将GPT定义为一种新的治疗脆弱性的机制 让恩兹敏感起来。我们将揭示生物学，解释为什么抑制GPT可以改善Enz。目标2是测试 GPT-抑制剂DC在体内外改善Enz的作用。我们将测试一个工作假设，即分布式控制系统 通过抑制CRPC肿瘤的生长和阻断肿瘤的进展使PCa细胞/肿瘤对ENZ增敏 ADPC肿瘤与CRPC的关系。目的3确定GPT在急性髓细胞白血病临床进展中的相关性和意义。 PCA。我们将使用免疫组织化学和单细胞RNA测序来分析前列腺癌组织和活检 来自接受Enz治疗的患者的样本。我们将检验一个有效的假设，即GPT mRNA/蛋白质 与CRPC进展和Enz耐药有关。

PROJECT SUMMARY The goal of this proposal is to develop a new mechanism-based therapy to improve the antitumor efficacy and sustainability of enzalutamide. Metastatic prostate cancer (PCa) is the 2nd-leading cause of cancer death in men in the US. Castration resistant PCa (CRPC) is the most common and lethal form of the disease. Effective and life-saving treatment is an unmet need. Recently, the enzalutamide (Enz)-based treatment has shown promising clinical results. However, many patients do not respond or quickly develop resistance. New mechanistic understandings and treatment strategies are urgently needed to improve Enz. In CRISPR/Cas9- based screen, we identified glutamic pyruvate transaminases (GPT) as a novel vulnerability or target, sensitizing CRPC cells to Enz. Clinically, we found that GPT is amplified or upregulated in subsets of patient samples that were significantly associated with Enz-resistance and poor disease outcomes. Biologically, our preliminary studies suggest that GPT confers adaptive response and resistance to Enz by connecting 3 important oncogenic pathways in CRPC – i) unfolded protein response (UPR), ii) glutamine metabolism, and iii) synthesis of fatty acids and lipids (lipogenesis), which is known as the metabolic hallmark of CRPC and essential to PCa cell survival and proliferation. Therapeutically, we screened a panel of transaminase inhibitors and identified D-cycloserine (DCS), a clinically-approved antibiotic, as a specific and selective inhibitor to GPT, but not other transaminases. Based on these data, we will develop a new therapy approach to improve the antitumor efficacy and sustainability of Enz by targeting GPT with DCS. The central hypothesis is that GPT is a novel molecular vulnerability to PCa cells, especially CRPC, in Enz-based treatments; therefore, GPT can be therapeutically exploited by DCS to improve the efficacy and durability of Enz. We will test the hypothesis in 3 aims. Aim 1 is to understand the mechanisms defining GPT as a novel therapeutic vulnerability to sensitize Enz. We will reveal the biology, explaining why inhibiting GPT improves Enz. Aim 2 is to test the role of GPT-inhibitor DCS to improve Enz in vitro and in vivo. We will test a working hypothesis that DCS sensitizes PCa cells/tumors to Enz by arresting the growth of CRPC tumors and blocking the progression of ADPC tumors to CRPC. Aim 3 is to determine the relevance and significance of GPT in clinical progressions of PCa. We will use immunohistochemistry and single-cell RNA-sequencing to analyze PCa tissues and biopsy samples from patients undergoing Enz-treatments. We will test a working hypothesis that GPT mRNA/proteins are associated with CRPC progression and Enz-resistance.