Dai Guoyu, Chen Xiang, He Yao
Department of Urology, Xiangya Hospital, Central South University, Changsha, China.
Front Nutr. 2021 Aug 11;8:712327. doi: 10.3389/fnut.2021.712327. eCollection 2021.
The incidence of renal cell carcinoma (RCC) is increasing year by year. It is difficult to have complete treatment so far. Studies have shown that tryptophan metabolite Kynurenine (Kyn) affects cell proliferation, migration, apoptosis, adhesion, and differentiation. Our aim is to explore whether Kyn activates aromatic hydrocarbon receptor (AhR) to mediate RCC metastasis. We collected RCC tissues and feces from RCC patients. 16S rRNA technology was performed to analyze the gut microbial composition of RCC patients. LC-MS/MS was used to analyze the gut microbial metabolites. The AhR was inhibited and treated with Kyn. Immunofluorescence was used to measure the degree of AhR activation. The migration and invasion ability of 786-O cells was tested by Transwell assay. Flow cytometry and cell cycle assay were utilized to observe the apoptosis and cycle of 786-O cells. CCK-8 assay was used to detect 786-O cells proliferation. qRT-PCR and Western blot were used to detect AhR and EMT-related genes expression level. AhR expression was up-regulated in RCC tissues. RCC gut microbiota was disordered. The proportion of Kyn was increased in RCC. After being treated with Kyn, the migration, invasion, and proliferation ability of 786-O cells were decreased. Furthermore, the expression of EMT-related protein E-cadherin decreased, and the expression of N-cadherin and Vimentin increased. The proportion of 786-O cells in the S phase increased. The apoptosis rate of 786-O cells was inhibited. The tryptophan metabolite Kyn could activate AhR. Kyn could promote 786-O cells migration and invasion. Gut microbiota could activate AhR through its tryptophan metabolite Kyn to mediate RCC metastasis.
肾细胞癌（RCC）的发病率逐年上升。迄今为止，其完整治疗仍存在困难。研究表明，色氨酸代谢产物犬尿氨酸（Kyn）会影响细胞增殖、迁移、凋亡、黏附和分化。我们的目的是探究Kyn是否通过激活芳烃受体（AhR）来介导RCC转移。我们收集了RCC患者的RCC组织和粪便。采用16S rRNA技术分析RCC患者的肠道微生物组成。利用液相色谱-串联质谱（LC-MS/MS）分析肠道微生物代谢产物。抑制AhR并用Kyn进行处理。采用免疫荧光法检测AhR的激活程度。通过Transwell实验检测786-O细胞的迁移和侵袭能力。利用流式细胞术和细胞周期实验观察786-O细胞的凋亡和周期。采用CCK-8实验检测786-O细胞的增殖情况。运用qRT-PCR和蛋白质免疫印迹法检测AhR及上皮-间质转化（EMT）相关基因的表达水平。RCC组织中AhR表达上调。RCC患者的肠道微生物群紊乱。RCC中Kyn的比例增加。用Kyn处理后，786-O细胞的迁移、侵袭和增殖能力下降。此外，EMT相关蛋白E-钙黏蛋白的表达降低，N-钙黏蛋白和波形蛋白的表达增加。786-O细胞处于S期的比例增加。786-O细胞的凋亡率受到抑制。色氨酸代谢产物Kyn可激活AhR。Kyn可促进786-O细胞的迁移和侵袭。肠道微生物群可通过其色氨酸代谢产物Kyn激活AhR来介导RCC转移。
