Improving CPT-11 Efficacy Using Structural and Chemical Biology

描述（由申请人提供）：我们正在通过调节胃肠道微生物组的成分来减轻抗癌药物CPT-11的毒性。CPT-11在治疗结直肠癌和胰腺癌中是必不可少的，但剂量限制性毒性严重降低了其疗效。这种毒性是由肠道微生物共生体中的细菌酶引起的。这种酶，葡萄糖醛酸酶，从CPT-11的关键代谢物中去除失活的葡萄糖醛酸糖，使胃肠道中的药物重新激活，产生上皮细胞死亡和急性腹泻。我们假设，选择性的、非致死性的微生物β -葡萄糖醛酸酶抑制可以减轻这种副作用。在上一个项目期间进行的概念验证分子到动物的研究中，这一假设得到了验证。我们现在将从三个关键方面推进这个项目。首先，我们将对活动范围进行定性？-葡萄糖醛酸酶存在于胃肠道微生物组使用结构生物学和生物化学。其次，我们将通过结构和化学生物学创造差异性优化的细菌β -葡萄糖醛酸酶抑制剂。第三，利用深度测序和宏基因组学，我们将揭示这种方法如何影响胃肠道微生物组的组成和活性。总之，我们寻求一种新的模式-抑制特定的微生物酶，以获得治疗效果，而不损害对人类健康至关重要的细菌共生体。

DESCRIPTION (provided by applicant): We are alleviating the toxicity of the anticancer drug CPT-11 by modulating components of the GI microbiome. CPT-11 is essential in treating colorectal and pancreatic cancer, but dose-limiting toxicity severely reduces its efficacy. This toxicity is caused by a bacterial enzyme in enteric microbial symbiotes. The enzyme, beta glucuronidase, removes the inactivating glucuronic acid sugar from CPT-11's key metabolite, which reactivates the drug in the GI and produces epithelial cell death and acute diarrhea. We hypothesized that the selective, non-lethal inhibition of microbial beta glucuronidases would alleviate this side effect. This hypothesis tested true in proof-of-concept molecular-to-animal studies conducted in the previous project period. We will now advance the project in three crucial ways. First, we will characterize the range of active ?-glucuronidases present in the GI microbiome using structural biology and biochemistry. Second, we will create differentially optimized bacterial beta glucuronidase inhibitors via structural and chemical biology. Third, using deep-sequencing and metagenomics, we will unravel how this approach impacts the composition and activity of the GI microbiome. In summary, we seek to advance a novel paradigm - inhibiting specific microbial enzymes for therapeutic gain without harming the bacterial symbiotes essential for human health.