Abstract：
BACKGROUND: Metastasis driven by epithelial-mesenchymal transition (EMT) remains a significant contributor to the poor prognosis of colorectal cancer (CRC), and requires more effective interventions. GPR81 signaling has been linked to tumor metastasis, while lacks an efficient specific inhibitor.
OBJECTIVE: Our study aimed to investigate the effect and mechanism of Gentisic acid on colorectal cancer (CRC) metastasis.
METHODS: A lung metastasis mouse model induced by tail vein injection and a subcutaneous graft tumor model were used. Gentisic acid (GA) was administered by an intraperitoneal injection. HCT116 was treated with lactate to establish an in vitro model.
METHODS: MC38 cells with mCherry fluorescent protein were injected into tail vein to investigate lung metastasis ability in vivo. GA was administered by intraperitoneal injection for 3 weeks. The therapeutic effect was evaluated by survival rates, histochemical analysis, RT-qPCR and live imaging. The mechanism was explored using small interfering RNA (siRNA), Western blotting, RT-qPCR and immunofluorescence.
RESULTS: GA had a therapeutic effect on CRC metastasis and improved survival rates and pathological changes in dose-dependent manner. GA emerged as an GPR81 inhibitor, effectively suppressed EMT and mTOR signaling in CRC induced by lactate both in vivo and in vitro. Mechanistically, GA halted lactate-induce degradation of DEPDC5 through impeding the activation of Chaperone-mediated autophagy (CMA).
CONCLUSIONS: CMA-mediated DEPDC5 degradation is crucial for lactate/GPR81-induced CRC metastasis, and GA may be a promising candidate for metastasis by inhibiting GPR81 signaling.
OBJECTIVE: Our study aimed to investigate the effect and mechanism of Gentisic acid on colorectal cancer (CRC) metastasis.
METHODS: A lung metastasis mouse model induced by tail vein injection and a subcutaneous graft tumor model were used. Gentisic acid (GA) was administered by an intraperitoneal injection. HCT116 was treated with lactate to establish an in vitro model.
METHODS: MC38 cells with mCherry fluorescent protein were injected into tail vein to investigate lung metastasis ability in vivo. GA was administered by intraperitoneal injection for 3 weeks. The therapeutic effect was evaluated by survival rates, histochemical analysis, RT-qPCR and live imaging. The mechanism was explored using small interfering RNA (siRNA), Western blotting, RT-qPCR and immunofluorescence.
RESULTS: GA had a therapeutic effect on CRC metastasis and improved survival rates and pathological changes in dose-dependent manner. GA emerged as an GPR81 inhibitor, effectively suppressed EMT and mTOR signaling in CRC induced by lactate both in vivo and in vitro. Mechanistically, GA halted lactate-induce degradation of DEPDC5 through impeding the activation of Chaperone-mediated autophagy (CMA).
CONCLUSIONS: CMA-mediated DEPDC5 degradation is crucial for lactate/GPR81-induced CRC metastasis, and GA may be a promising candidate for metastasis by inhibiting GPR81 signaling.
摘要：
背景：由上皮间质转化（EMT）驱动的转移仍然是结直肠癌（CRC）预后不良的重要因素，需要更有效的干预措施。GPR81信号与肿瘤转移有关，而缺乏有效的特异性抑制剂。
目的：本研究旨在探讨龙胆酸对大肠癌(CRC)转移的影响及其机制。
方法:采用尾静脉注射诱导的肺转移小鼠模型和皮下移植瘤模型。通过腹膜内注射施用龙胆酸(GA)。用乳酸处理HCT116以建立体外模型。
方法：尾静脉注射含mCherry荧光蛋白的MC38细胞，观察其体内肺转移能力。GA通过腹膜内注射给药3周。通过生存率评估治疗效果，组织化学分析,RT-qPCR和活成像。使用小干扰RNA(siRNA)探索机制，西方印迹,RT-qPCR和免疫荧光。
结果：GA对CRC转移有治疗作用，并以剂量依赖性方式改善生存率和病理变化。GA作为GPR81抑制剂出现，在体内和体外均有效抑制乳酸诱导的CRC中的EMT和mTOR信号传导。机械上,GA通过阻止伴侣介导的自噬（CMA）的激活来阻止乳酸诱导DEPDC5的降解。
结论：CMA介导的DEPDC5降解对于乳酸/GPR81诱导的CRC转移至关重要，和GA可能通过抑制GPR81信号传导而成为转移的有希望的候选者。
目的：本研究旨在探讨龙胆酸对大肠癌(CRC)转移的影响及其机制。
方法:采用尾静脉注射诱导的肺转移小鼠模型和皮下移植瘤模型。通过腹膜内注射施用龙胆酸(GA)。用乳酸处理HCT116以建立体外模型。
方法：尾静脉注射含mCherry荧光蛋白的MC38细胞，观察其体内肺转移能力。GA通过腹膜内注射给药3周。通过生存率评估治疗效果，组织化学分析,RT-qPCR和活成像。使用小干扰RNA(siRNA)探索机制，西方印迹,RT-qPCR和免疫荧光。
结果：GA对CRC转移有治疗作用，并以剂量依赖性方式改善生存率和病理变化。GA作为GPR81抑制剂出现，在体内和体外均有效抑制乳酸诱导的CRC中的EMT和mTOR信号传导。机械上,GA通过阻止伴侣介导的自噬（CMA）的激活来阻止乳酸诱导DEPDC5的降解。
结论：CMA介导的DEPDC5降解对于乳酸/GPR81诱导的CRC转移至关重要，和GA可能通过抑制GPR81信号传导而成为转移的有希望的候选者。
