Cryptic gut bacterial metabolites that regulate colorectal cancer formation

调节结直肠癌形成的隐性肠道细菌代谢物

基本信息

批准号：
8568949
负责人：
Jason Michael Crawford
金额：
$ 249.75万
依托单位：
YALE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-09-30 至 2018-06-30
项目状态：
已结题

项目摘要

DESCRIPTION (provided by applicant): An orphan biosynthetic gene cluster found in select gut bacterial isolates has been directly linked to long-term persistence in the human gut, host chromosome instability, and colorectal cancer formation. Without knowing the encoded molecule's identity or how it is delivered into host cells, further experiments to evaluate its specific role(s), mode(s) of action, therapeutic potential, and potential treatment areas are severely limited. We propose to identify and structurally characterize the specific bacterial encoded molecules that control host phenotypic responses. We will employ three complementary approaches: 1) bioassay-guided fractionation to enrich bacterial molecule(s) regulating the physiologically-relevant phenotypes, including antibacterial, biofilm disassembly, DNA damage, and immunomodulatory assays~ 2) differential liquid chromatography/mass spectrometric analysis of locus positive versus locus negative cells to identify gene cluster-specific molecules~ and 3) protein mediated small molecule capture of unknown toxin ligands. Biological activity of the toxin is imparted through a highly unusual bacteria-human cell contact-dependent manner, which lacks genetic or phenotypic similarities to previously described toxin delivery strategies. We also propose to manipulate the bacterial biosynthetic pathway to engineer toxin derivatives with reactive bioorthogonal functionalities. Our probe-driven strategy could not only illuminate the unusual cell contact-dependent delivery mechanism directing molecules into mammalian cells, but also reveal potentially new cancer targets involved in regulating chromosome instability. A fundamental understanding of the toxin's unusual delivery mechanism could lead to a Nature-inspired approach for directing engineered molecules directly into mammalian cells in a spatially controlled manner with potential applications in probiotic therapies.

描述（由申请人提供）：在某些肠道细菌分离株中发现的孤儿生物合成基因簇已直接与人类肠道，宿主染色体染色体不稳定性和结直肠癌形成的长期持久性联系在一起。不知道编码分子的身份或如何将其传递到宿主细胞中，而是进一步评估其特定作用，动作模式，治疗潜力和潜在治疗区域的特定作用受到严重限制。我们建议识别和结构表征控制宿主表型反应的特定细菌编码分子。我们将采用三种互补方法：1）生物测定指导的分级来富集细菌分子（S）调节与生理相关的表型，包括抗菌，生物膜拆卸，DNA损伤，DNA损伤和免疫调节性分析〜2）识别液体质量光谱分析的差异分析量〜2）分子〜和3）蛋白介导的小分子捕获未知的毒素配体。毒素的生物学活性是通过高度不寻常的细菌 - 人类接触依赖性的方式赋予的，该方式缺乏与先前描述的毒素递送策略的遗传或表型相似性。我们还建议操纵具有反应性生物正交功能的工程毒素衍生物的细菌生物合成途径。我们的探针驱动的策略不仅可以阐明引导分子到哺乳动物细胞的异常细胞接触依赖性递送机制，而且还揭示了可能与调节染色体不稳定性的新癌症靶标有关。对毒素异常递送机制的基本了解可能会导致一种自然风格的方法，该方法以空间控制的方式将工程分子直接引导到哺乳动物细胞中，并在益生菌治疗中潜在应用。