Colorectal cancer-associated anaerobic bacteria proliferate in tumor spheroids and alter the microenvironment
Colorectal cancer-associated anaerobic bacteria proliferate in tumor spheroids and alter the microenvironment
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DOI：
10.1038/s41598-020-62139-z
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发表时间：
2020-03-24
影响因子：
4.6
通讯作者：
Hett, Erik C.
中科院分区：
文献类型：
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作者：
Kasper, Stephen H.;Morell-Perez, Carolina;Hett, Erik C.
最近的报告显示，结直肠肿瘤中含有的微生物群与“正常”结肠环境中的微生物群不同，这些微生物群可以促进癌症的进展。核梭杆菌是结直肠肿瘤微环境中最常见的物种，据报道，它通过多种机制影响疾病进展。然而，对这种生物在癌症进展中的作用的详细了解是有限的，部分原因是在标准有氧细胞培养条件下维持具核梭菌的活力存在挑战。在这里，我们描述了一个三维（3D）肿瘤球体模型的发展，可以庇护和促进厌氧菌的生长。通过测量细菌生长动力学、细胞形态和裂解、癌症相关基因表达和代谢组学，广泛研究了细菌-肿瘤细胞相互作用和代谢串扰。我们观察到活的核梭菌在肿瘤球体微环境中组装生物膜样结构，而热杀灭的核梭菌则内化并隔离在癌细胞中。最后，我们使用该模型对28株临床分离的梭杆菌进行了共培养，并证明该模型成功地支持了多种梭杆菌物种的共培养。这种细菌-球体共培养模型使厌氧细菌在肿瘤微环境中的作用的机制研究成为可能。
Recent reports show that colorectal tumors contain microbiota that are distinct from those that reside in a 'normal' colon environment, and that these microbiota can contribute to cancer progression. Fusobacterium nucleatum is the most commonly observed species in the colorectal tumor microenvironment and reportedly influences disease progression through numerous mechanisms. However, a detailed understanding of the role of this organism in cancer progression is limited, in part due to challenges in maintaining F. nucleatum viability under standard aerobic cell culture conditions. Herein we describe the development of a 3-dimensional (3D) tumor spheroid model that can harbor and promote the growth of anaerobic bacteria. Bacteria-tumor cell interactions and metabolic crosstalk were extensively studied by measuring the kinetics of bacterial growth, cell morphology and lysis, cancer-related gene expression, and metabolomics. We observed that viable F. nucleatum assembles biofilm-like structures in the tumor spheroid microenvironment, whereas heat-killed F. nucleatum is internalized and sequestered in the cancer cells. Lastly, we use the model to co-culture 28 Fusobacterium clinical isolates and demonstrate that the model successfully supports co-culture with diverse fusobacterial species. This bacteria-spheroid co-culture model enables mechanistic investigation of the role of anaerobic bacteria in the tumor microenvironment.