Department of Microbiology and Immunology, Brown Cancer Center, Center for Microbiomics, Inflammation and Pathogenicity, University of Louisville, Louisville, KY, USA.
Department of Radiology, Center for Predictive Medicine, University of Louisville, Louisville, KY, USA.
Theranostics. 2022 Jul 18;12(12):5574-5595. doi: 10.7150/thno.70754. eCollection 2022.
The survival rate of colorectal cancer patients is adversely affected by the selection of tumors resistant to conventional anti-cancer drugs such as 5-fluorouracil (5FU). Although there is mounting evidence that commensal gut microbiota is essential for effective colon cancer treatment, the detailed molecular mechanisms and the role of gut microbial metabolites remain elusive. The goal of this study is to decipher the impact and mechanisms of gut microbial metabolite, urolithin A (UroA) and its structural analogue, UAS03 on reversal of 5FU-resistant (5FUR) colon cancers. We have utilized the SW480 and HCT-116 parental (5FU-sensitive) and 5FUR colon cancer cells to examine the chemosensitization effects of UroA or UAS03 by using both and models. The effects of mono (UroA/UAS03/5FU) and combinatorial therapy (UroA/UAS03 + 5FU) on cell proliferation, apoptosis, cell migration and invasion, regulation of epithelial mesenchymal transition (EMT) mediators, expression and activities of drug transporters, and their regulatory transcription factors were examined using molecular, cellular, immunological and flowcytometric methods. Further, the anti-tumor effects of mono/combination therapy (UroA or UAS03 or 5FU or UroA/UAS03 + 5FU) were examined using pre-clinical models of 5FUR-tumor xenografts in NRGS mice and azoxymethane (AOM)-dextran sodium sulfate (DSS)-induced colon tumors. Our data showed that UroA or UAS03 in combination with 5FU significantly inhibited cell viability, proliferation, invasiveness as well as induced apoptosis of the 5FUR colon cancer cells compared to mono treatments. Mechanistically, UroA or UAS03 chemosensitized the 5FUR cancer cells by downregulating the expression and activities of drug transporters (MDR1, BCRP, MRP2 and MRP7) leading to a decrease in the efflux of 5FU. Further, our data suggested the UroA or UAS03 chemosensitized 5FUR cancer cells to 5FU treatment through regulating FOXO3-FOXM1 axis. Oral treatment with UroA or UAS03 in combination with low dose i.p. 5FU significantly reduced the growth of 5FUR-tumor xenografts in NRGS mice. Further, combination therapy significantly abrogated colonic tumors in AOM-DSS-induced colon tumors in mice. In summary, gut microbial metabolite UroA and its structural analogue UAS03 chemosensitized the 5FUR colon cancers for effective 5FU chemotherapy. This study provided the novel characteristics of gut microbial metabolites to have significant translational implications in drug-resistant cancer therapeutics.
结直肠癌患者的存活率受到肿瘤对常规抗癌药物（如 5-氟尿嘧啶（5FU））耐药性选择的不利影响。尽管越来越多的证据表明共生肠道微生物群对有效的结肠癌治疗至关重要，但详细的分子机制和肠道微生物代谢物的作用仍不清楚。本研究的目的是破译肠道微生物代谢物尿石素 A（UroA）及其结构类似物 UAS03 对逆转 5FU 耐药（5FUR）结肠癌的影响和机制。我们利用 SW480 和 HCT-116 亲本（5FU 敏感）和 5FUR 结肠癌细胞，通过和模型检查 UroA 或 UAS03 的化疗增敏作用。使用分子、细胞、免疫和流式细胞术方法检查单药（UroA/UAS03/5FU）和联合治疗（UroA/UAS03+5FU）对细胞增殖、凋亡、细胞迁移和侵袭、上皮间充质转化（EMT）调节剂的调节、药物转运蛋白的表达和活性及其调节转录因子的影响。此外，使用 NRGS 小鼠 5FUR 肿瘤异种移植物和氧化偶氮甲烷（AOM）-葡聚糖硫酸钠（DSS）诱导的结肠肿瘤的临床前模型检查单药/联合治疗（UroA 或 UAS03 或 5FU 或 UroA/UAS03+5FU）的抗肿瘤作用。我们的数据表明，与单药治疗相比，UroA 或 UAS03 与 5FU 联合使用可显著抑制 5FUR 结肠癌细胞的活力、增殖、侵袭能力并诱导其凋亡。在机制上，UroA 或 UAS03 通过下调药物转运蛋白（MDR1、BCRP、MRP2 和 MRP7）的表达和活性使 5FUR 癌细胞对 5FU 增敏，从而减少 5FU 的外排。此外，我们的数据表明 UroA 或 UAS03 通过调节 FOXO3-FOXM1 轴使 5FUR 癌细胞对 5FU 治疗增敏。口服 UroA 或 UAS03 与低剂量腹腔内 5FU 联合治疗可显著减少 NRGS 小鼠 5FUR 肿瘤异种移植物的生长。此外，联合治疗可显著阻断 AOM-DSS 诱导的小鼠结肠肿瘤。总之，肠道微生物代谢物 UroA 及其结构类似物 UAS03 使 5FUR 结肠癌细胞对有效的 5FU 化疗增敏。本研究为肠道微生物代谢物在耐药性癌症治疗中的转化应用提供了新的特征。
