Deciphering microbial contribution to androgen bioavailability in castration resistant prostate cancer patients

项目总结 微生物组在癌症中的一个新兴作用是微生物影响治疗、药物疗效的能力 和新陈代谢。例如，我们最近发现肠道微生物群在去势中起着重要作用。 通过微生物衍生的雄激素合成耐药前列腺癌(CRPC)(Pernigoni等人。科学。 2021年；374(6564)：216-224)。在那项研究中，我们发现，在小鼠和人类中，雄激素的剥夺都会促进 能够将睾酮前体转化为活性睾酮的特定肠道细菌的扩张， 通过细菌类细胞色素P17A1酶(瘤胃球菌、瘤胃球菌、瘤胃球菌sp.和类杆菌 酸性物质)，从而提高CRPC患者和小鼠的水平，并防止完全抑制 雄激素剥夺疗法中的睾酮。除了生物合成途径外，睾酮 生物利用度可能是调节治疗反应的另一种手段。雄激素是 糖醛酸化的雄激素在肝脏中排出，其中一部分到达肠道 通过胆汁，并被细菌β-葡萄糖醛酸苷酶(GUS)(瘤胃球菌，瘤胃球菌 Sp.、类杆菌酸化杆菌和scindens梭状芽孢杆菌)，用于“重新激活”和可能的重吸收。事实上, 男性肠道中的雄激素浓度高于血清。另一条路，肠子 微生物区系通过皮质醇向11β-羟基雄烯二酮促进雄激素的生物利用度 细菌类固醇-17，20-脱解酶(Clostridium scindens desABCD操纵子)的转化。反过来，11个β- 羟基雄烯二酮被转化为11-氧雄激素，这对肿瘤雄激素池有贡献。它是 不清楚这些不同的途径中的每一条对循环中的雄激素池有多大贡献。我们的中央 假说是肠道微生物群通过一种途径促进雄激素的产生和生物利用 生物合成途径和生物利用度途径的结合。该项目的目标是通过计算识别 慢性前列腺癌患者肠道菌群中雄激素相关细菌酶(类细胞色素P17A1、GUS、DesA和DesB)的研究 并分离出含有这些酶的细菌种类，用于功能分析。建议的理由是 研究结果将为CRPC未来的发展和干预措施的评估提供目标 将雄激素的生物利用度降至最低或阻止的患者。我们的假设将通过两个方面进行检验 目的：1)鉴定前列腺癌肠道微生物群中与雄激素相关的细菌酶 病人。目的2)具有雄激素相关酶的细菌种类的功能特征。在… 该项目完成后，将确定参与雄激素生物转化和生物合成的细菌酶。 并获得含有这些酶的细菌种类。这一知识将成为未来的跳板。 应用CRPC临床前模型和针对细菌雄激素生物转化的抑制剂进行功能研究 和合成酶和/或含有它们的物种来缓解CRPC，从而提供一种创新的 减缓或预防前列腺癌进展的方法。

PROJECT SUMMARY An emerging role of microbiome in cancer is the capacity of microorganisms to impact treatment, drug efficacy and metabolism. For example, we recently showed that the gut microbiome plays an important role in castration resistant prostate cancer (CRPC) through microbial-derived androgen synthesis (Pernigoni et al. Science. 2021;374(6564):216-224). In that study, we found that androgen deprivation in both mice and humans promotes the expansion of specific gut bacteria capable of converting testosterone precursors into active testosterone, through bacterial CYP17A1-like enzymes (Ruminococcus gnavus, Ruminococcus sp. and Bacteroides acidifaciens), thus increasing its levels in patients and mice with CRPC and preventing complete suppression of testosterone during androgen deprivation therapy. In addition to the biosynthetic route, testosterone bioavailability could represent an additional means to regulate therapeutic responses. Androgens are glucuronidated in the liver for elimination and a fraction of these glucuronidated androgens reaches the gut through the bile and are targeted by bacterial β-glucuronidases (GUS) (Ruminococcus gnavus, Ruminococcus sp., Bacteroides acidifaciens and Clostridium scindens) for “reactivation” and potentially reabsorption. In fact, androgen concentration is higher in the intestine than in serum of human males. Another route by which gut microbiota contribute to the bioavailability of androgens is through cortisol to 11β-Hydroxyandrostenedione conversion by bacterial steroid-17,20-desmolases (Clostridium scindens desABCD operon). In turn, 11β- Hydroxyandrostenedione is converted to 11-oxyandrogen, which contribute to the tumor androgen pool. It is unclear how much each of these different routes contribute to the pool of circulating androgens. Our central hypothesis is that gut microbiome contributes to the production and bioavailability of androgens through a combination of biosynthetic and bioavailability routes. The objective of this project is to computationally identify androgen-related bacterial enzymes (CYP17A1-like, GUS, desA and desB) in CRPC patients gut microbiome and to isolate bacterial species harboring those enzymes for functional analysis. The rationale for the proposed research is that the outcomes will provide targets for future development and evaluation of interventions in CRPC patients that minimize or prevent the bioavailability of androgens. Our hypothesis will be tested through two specific aims: Aim 1) Identify androgen-related bacterial enzymes in the gut microbiome of prostate cancer patients. Aim 2) Functional characterization of bacterial species possessing androgen-related enzymes. At completion, this project will identify bacterial enzymes involved in androgen biotransformation and biosynthesis and obtain bacterial species harboring these enzymes. This knowledge will serve as a springboard for future functional studies using preclinical models of CRPC and inhibitors targeting bacterial androgen biotransformation and synthesis enzymes and/or species that harbor them to alleviate CRPC, thus providing an innovative approach to slow or prevent prostate cancer progression.