Table 1_Gut microbiota derived metabolite trimethylamine N-oxide influences prostate cancer progression via the p38/HMOX1 pathway.xlsx

BackgroundProstate cancer was the fourth most diagnosed cancer worldwide in 2022. Radical treatments and androgen deprivation therapy benefit newly diagnosed patients but impact quality of life, often leading to castration-resistant prostate cancer. Short-term dietary changes significantly affect the gut microbiota, which differs markedly between prostate cancer patients and healthy individuals, impacting both cancer progression and treatment response. A high-choline diet increases the risk of fatal prostate cancer, potentially mediated by the conversion of choline to the trimethylamine N-oxide (TMAO) by the gut microbiota.
MethodsThe CCK8 assay was employed to investigate whether TMAO affects the proliferation ability of prostate cancer cells and to determine the appropriate drug concentration. Subsequently, CCK8 time gradients, colony formation assays, and EdU assays measured TMAO’s influence on cell proliferation. Wound healing and transwell migration assays evaluated TMAO’s effect on cell migration. RNA-seq analysis was performed to explore the mechanisms by which TMAO influences the proliferation and migration of prostate cancer cells. qPCR and Western blotting were utilized to validate the expression of related mRNA or proteins. Finally, we performed in vivo experiments to evaluate the effect of a high choline diet on the growth of subcutaneous tumors and lung metastases in mice.
ResultsOur study found that TMAO enhances the proliferation and migration of prostate cancer cells by upregulating HMOX1 via activation of the MAPK signaling pathway, specifically p38 MAPK. In mouse subcutaneous tumor and lung metastatic tumor experiments, the high-choline diet increased prostate cancer cell proliferation and migration, resulting in significantly greater tumor volume and number of metastases than controls.
ConclusionThis study is the first to demonstrate the role of the gut microbiota-derived metabolite TMAO in prostate cancer. TMAO promotes the proliferation and migration of prostate cancer cells by activating the p38 pathway and increasing HMOX1 expression. Reducing choline intake through dietary intervention may delay the onset and progression of prostate cancer, presenting significant clinical application value.

背景：2022年，前列腺癌是全球第四大确诊癌症。根治性治疗与雄激素剥夺疗法可使初诊患者获益，但会降低患者生活质量，且常引发去势抵抗性前列腺癌。短期饮食结构改变可显著影响肠道菌群，而前列腺癌患者与健康人群的肠道菌群存在显著差异，这会对癌症进展与治疗应答产生影响。高胆碱饮食会增加致死性前列腺癌的发病风险，该过程可能由肠道菌群将胆碱转化为氧化三甲胺（trimethylamine N-oxide, TMAO）所介导。
方法：本研究采用CCK8实验，探究TMAO对前列腺癌细胞增殖能力的影响，并确定适宜的药物浓度。随后，通过CCK8时间梯度实验、集落形成实验以及EdU实验，检测TMAO对细胞增殖的作用。采用划痕愈合实验与Transwell迁移实验，评估TMAO对细胞迁移能力的影响。通过RNA测序（RNA-seq）分析，探索TMAO调控前列腺癌细胞增殖与迁移的分子机制。利用实时荧光定量PCR（qPCR）与蛋白质印迹（Western blotting）技术，验证相关mRNA或蛋白的表达水平。最后，开展体内实验，评估高胆碱饮食对小鼠皮下肿瘤生长与肺转移的影响。
结果：本研究发现，TMAO可通过激活丝裂原活化蛋白激酶（mitogen-activated protein kinase, MAPK）信号通路（尤其是p38 MAPK亚型）上调血红素加氧酶1（HMOX1）的表达，从而增强前列腺癌细胞的增殖与迁移能力。在小鼠皮下肿瘤与肺转移瘤实验中，高胆碱饮食可促进前列腺癌细胞的增殖与迁移，使肿瘤体积与转移灶数量均显著高于对照组。
结论：本研究首次证实了肠道菌群代谢产物TMAO在前列腺癌发生发展中的作用。TMAO可通过激活p38通路、上调HMOX1表达，促进前列腺癌细胞的增殖与迁移。通过饮食干预降低胆碱摄入，或可延缓前列腺癌的发生与进展，具有重要的临床应用价值。