Novel Mechanisms of ROS/RNS Signaling Underlying Castration-Resistant Prostate Cancer Emergence and Progression

摘要 去势抵抗性前列腺癌（CRPC）是一种致命的疾病， 对它的出现和发展背后的分子因素的了解有限。通过无偏 转录组学分析的早期CRPC模型在我们的实验室和患者数据集分析，我们有 发现刺激一氧化氮受体复合物，可溶性鸟苷酸环化酶（sGC）， 标准治疗雄激素剥夺（AD）可能对CRPC有治疗益处。基于我们 初步结果，我们的假设是，降低sGC活性促进CRPC生长，增加sGC活性促进CRPC生长。 sGC活性将限制CRPC的出现和进展。我们研究的基本原理，得到我们发现的支持， 和来自心肺领域的充分表征的sGC调节机制，是sGC被氧化， CRPC对刺激难治，但通过AD诱导的氧化还原保护反应功能性再生。 因此，sGC激动剂和AD的组合使用被预测为对抗CRPC的有效策略。 sGC激动剂利奥西呱是FDA批准的肺动脉高压治疗中的血管扩张剂。我们 初步数据显示利奥西呱可降低异种移植CRPC生长。这种抗肿瘤反应伴随着 PSA水平降低以及全身和肿瘤内cGMP（cGMP）水平升高，表明 靶向刺激sGC生物活性。与增强sGC活性的生理功能一致，我们发现 利奥西呱治疗导致显著的肿瘤氧合和CD 44（一种关键PC干细胞）水平降低 标记。因此，利奥西呱的疗效可能来自于消除缺氧小生境和残留的雄激素- 难治性干细胞群被认为是CRPC的基础。缺氧还通过以下方式改变肿瘤的氧化还原状态： 血管生成的ROS，调节血管生成信号。通过其假定的癌症干细胞靶向 细胞和氧化还原脆弱性，利奥西呱在PC治疗中是新颖的，并且是安全的，长期耐受性良好。我们 目的是全面建立如何以及为什么刺激sGC通路的机制 限制CRPC的生长和进展。因此，在这些研究中，我们将评估1）控制机制如何 sGC表达和再生的氧化失活sGC在去势敏感性与去势抵抗性中改变 细胞，2）sGC生物活性的增强如何通过考虑缺氧诱导抗CRPC结果- 相关的代谢和氧化还原应激，包括AD下雄激素受体再激活诱导的应激， 和3）使用稳健的临床前和患者来源的 包括出现、生长、进展和转移性骨定植的模型。我们将验证密钥 去识别PC患者标本中的分子结果。我们的研究具有很强的潜力， PC进展的潜在机制，以及通过将利奥西呱重新用于治疗CRPC的临床转化。

Abstract Castration-resistant prostate cancer (CRPC), a fatal disease, remains therapeutically underserved due to limited understanding of molecular factors underlying its emergence and progression. Through unbiased transcriptomics analysis of an early CRPC model developed in our lab and patient dataset analyses, we have discovered that stimulation of the nitric oxide receptor complex, soluble guanylate cyclase (sGC), in conjunction with standard-of-care androgen deprivation (AD) is likely to be therapeutically beneficial in CRPC. Based on our preliminary results, our hypothesis is that decreased sGC activity promotes CRPC growth and that increasing sGC activity will limit CRPC emergence and progression. The rationale of our studies, supported by our findings and well-characterized sGC regulatory mechanisms from the cardiopulmonary field, is that sGC is oxidized and refractory to stimulation in CRPC but is functionally regenerated by AD-induced redox-protective responses. Thus, the combinatorial use of sGC agonists and AD is predicted to be an effective strategy to combat CRPC. The sGC agonist, riociguat, is FDA-approved as a vasodilator in pulmonary hypertension treatment. Our preliminary data show riociguat reduces xenograft CRPC growth. This anti-tumor response is accompanied by lowered PSA levels as well as increased systemic and intratumoral cyclic GMP (cGMP) levels, indicating on- target stimulation of sGC bioactivity. Consistent with the physiologic function of enhanced sGC activity, we find riociguat treatment leads to marked tumor oxygenation and decreased levels of CD44, a key PC stem cell marker. Thus, riociguat efficacy may derive from eradication of hypoxic niches and the residing androgen- refractory stem cell populations thought to underlie CRPC. Hypoxia also alters the tumor redox state through mitochondrially-generated ROS that regulate angiogenic signaling. Through its putative targeting of cancer stem cells and redox vulnerabilities, riociguat is novel in PC therapy, and is safe and well-tolerated longterm. Our objective is to comprehensively establish mechanisms underlying how and why stimulating the sGC pathway limits CRPC growth and progression. Therefore, in these studies, we will assess 1) how mechanisms that control sGC expression and regenerate oxidized inactive sGC are altered in hormone-sensitive vs. castration-resistant cells, 2) how enhancement of sGC bioactivity induces anti-CRPC outcomes through consideration of hypoxia- associated metabolic and redox stresses, including those induced by androgen receptor re-activation under AD, and 3) test riociguat efficacy in the spectrum of CRPC disease, using robust preclinical and patient-derived models encompassing emergence, growth, progression and metastatic bone colonization. We will validate key molecular findings in de-identified PC patient specimens. Our studies possess strong potential to uncover novel mechanisms underlying PC progression, and for clinical translation via repurposing riociguat to treat CRPC.