犬尿氨酸代谢通路调控透明肾细胞癌机制研究

Clear renal cell carcinoma accounts for about 75% of kidney malignancies, and is a hot spot in kidney cancer research. Defining the molecular mechanism of clear renal cell carcinoma has important guiding significance for early diagnosis and targeted intervention. Our previous researches have shown that kynurenine pathway is significantly activated in tissues and urines of patients with renal cancer. Kynurenine-3-monooxygenase (KMO) could activate the proliferation and migration of cancer cells through interaction with other functional molecules. Our preliminary study suggested kynurenine pathway plays an important role in clear renal cell carcinoma. However, the specific molecular mechanism needs further in-depth study. This project will firstly identify key functional molecules interacting with kynurenine pathway in renal cancer cell model using co-immunoprecipitation - proteomics technology. Then causal networks will be constructed to elucidate the mechanism of clear renal cell carcinoma regulated by kynurenine pathway. Finally, based on the results of mechanism research, targeted detection of functional molecules in urine samples of clear renal cell carcinoma will be performed to discover early screening markers of renal cell carcinoma, which will assist renal cancer diagnosis.

透明肾细胞癌约占肾癌恶性肿瘤的75%，是肾癌研究的热点。明确透明肾细胞癌的分子机制对于进行早期诊断及靶向干预具有重要的指导意义。我们前期研究基础显示，肾癌患者组织和尿液中，犬尿氨酸通路被显著激活，犬尿氨酸-3-单加氧酶（KMO）可通过分子互作网络激活癌细胞的增殖活性和迁移能力。以上结果提示该通路在透明肾细胞癌中起着重要的调控作用，然而具体的分子机制有待进一步深入研究。基于以上基础，本项目将首先应用细胞模型，采用免疫共沉淀-蛋白组学技术，通过抑制犬尿氨酸通路活性，明确与该通路相互作用的关键功能分子，进而通过构建因果网络，阐述犬尿氨酸通路调控肾癌的分子机制。最后以机制结果为导向，在尿液样本中对重要功能分子进行靶向验证，以期从发病机制角度发现透明肾细胞癌早期筛查标志物，辅助早期诊断。

芳香犬尿甲氨酶(AFMID)是一种参与色氨酸途径的代谢酶，可将n -甲酰犬尿氨酸代谢为犬尿氨酸。AFMID在透明细胞肾细胞癌(ccRCC)组织和尿液样本中均显著下调。虽然ccRCC具有典型的warburg样表型、线粒体功能障碍和脂肪沉积升高，但目前尚不清楚AFMID是否在肿瘤发生和发展中发挥作用。在本研究中，我们发现AFMID过表达对ccRCC细胞有显著抑制作用，能够降低细胞增殖速率。细胞定量蛋白质组学研究表明，AFMID过表达改变了细胞生长的信号通路和细胞代谢通路，包括脂质代谢和肌醇磷酸盐代谢。进一步的尿液蛋白质组学研究表明，AFMID过表达后细胞功能变化可反映在尿液中。上游因子预测分析显示DDX58、TREX1、TGFB1、SMARCA4和TNF在细胞和尿液中的活性变化趋势相反。根据以上功能研究，初步发现了潜在的尿液生物标志物，并使用独立队列进行验证。APOC3、 UMOD 和 CILP蛋白组在训练队列的AUC值为0.938，验证队列的AUC值为0.883。本研究深入探讨了与AFMID酶相关的肾癌肿瘤细胞中各个功能途径的变化，在发现潜在的诊断和治疗靶标，潜在特异性生物标志物方面具有重要意义。