基于微环境介导谷氨酰胺代谢重编程靶点ASCT2的C118P抗三阴乳腺癌转移作用及机制研究

Nowadays, metabolic abnormality is an important feature of tumor and it is also a new hotspot in cancer research. Tumor microenvironment, as an inseparable function of tumor, has been paid more and more attention to its effect on cancer metabolism. Glutamine metabolism is crucial for the development of triple-negative breast cancer (TNBC). Although adipocytes are the main stromal cells in mammary gland, the effect of adipocytes on TNBC glutamine metabolism is unknown. Based on previous study of breast cancer microenvironment, the mechanism and cause of ASCT2 affecting glutamine metabolism in TNBC will be explored by using the co-culture mode of adipocytes with TNBC cells in vitro, and co-injected models of fat with TNBC cells in vivo. In order to explain the mechanism of ASCT2 regulating tumor metastasis, transcriptional gene sequencing will be used to analyze the signal transduction pathway of ASCT2. By reverse docking, protein eutectic and biological methods, we will confirm that ASCT2 will be the target of C118P for anti TNBC metastasis. This study will investigate the effect of microenvironment remodeling on TNBC metastasis in molecular, cellular, animals and clinical samples, which begins with tumor metabolic abnormality. Based on the theory, we will explore the anti-cancer metastasis effect and mechanism of C118P on TNBC in microenvironment. The study will provide a new idea for the treatment of TNBC, and a framework for developing of C118P.

代谢异常是肿瘤的重要特征，也是目前肿瘤研究的新热点。肿瘤微环境作为肿瘤密不可分的功能整体，对其代谢的影响日益受到重视。谷氨酰胺代谢对三阴乳腺癌发展至关重要。作为乳腺最主要的间质—脂肪对乳癌谷氨酰胺代谢的影响还未有报道。本课题拟在既往对乳癌微环境研究基础上，采用体外脂肪细胞与癌细胞共培养模式，体内脂肪与癌细胞共注射模型，探讨脂肪影响三阴乳癌谷氨酰胺代谢关键蛋白ASCT2的原因及机制；利用转录组测序分析ASCT2作用的信号传导通路，探索其调控肿瘤转移的机制；通过反向对接、蛋白共晶及生物学手段，确认ASCT2是C118P抗三阴乳癌转移的靶点。课题将在分子、细胞、整体动物及临床样本水平，从肿瘤代谢异常入手，探讨微环境重塑对乳腺癌转移的影响；基于该理论，从微环境角度研究C118P抗乳腺癌转移作用及机制。研究将为临床三阴乳腺癌治疗提供新的思路和理论依据，对C118P的开发及临床试验具有一定指导意义。

代谢异常是肿瘤的重要特征，也是目前肿瘤研究的新热点。脂肪微环境对乳腺癌的恶性进展起到重要作用。肿瘤细胞存在“谷氨酰胺成瘾”现象，而谷氨酰胺通过转运体ASCT2进入细胞后才能发挥其生物学功能。因此，ASCT2在三阴乳腺癌的发生发展中起到至关重要的作用。本课题在细胞、分子、动物和临床标本四个层次，以肿瘤微环境为研究背景，探讨脂肪与三阴乳腺癌之间的相互作用，导致三阴乳腺癌细胞氨基酸代谢重编程，进而促进肿瘤转移；并在该理论基础上从脂肪-乳腺癌微环境角度全面探讨C118P抗乳腺癌转移机制。本项目研究发现，肿瘤细胞诱导脂肪细胞去分化，分泌IL-6促进三阴乳腺癌细胞ASCT2高表达，增强三阴乳腺癌细胞氨基酸代谢，进而增强乳腺癌细胞的转移能力；机制研究发现IL-6通过激活受体gp130，抑制ASCT2蛋白泛素化降解，进而促进谷氨酰胺摄取，增强三阴乳腺癌氨基酸代谢，促进三阴乳腺癌转移。单独考察ASCT2在三阴乳腺癌中的生物学功能发现，敲低ASCT2可抑制对谷氨酰胺的摄取，导致三阴乳腺癌代谢重编程，进而抑制细胞增殖及转移。机制研究发现抑制ASCT2的抗三阴乳腺癌转移作用与细胞粘附有关。在进一步的临床数据库分析中证实了ASCT2与乳腺癌的不良预后相关。C118P可以通过直接结合ASCT2促进泛素化降解，也可以通过抑制脂肪-乳腺癌微环境中IL-6介导ASCT2表达而发挥抗乳腺癌增殖及转移作用。本项目研究阐述了脂肪-乳腺癌微环境相互作用，通过调节ASCT2发挥促乳腺癌转移作用；而C118P则通过抑制乳腺癌细胞ASCT2表达，逆转脂肪促乳腺癌转移作用；阐明C118P影响谷氨酰胺代谢的潜在作用靶点为ASCT2，对于临床上指导C118P寻找潜在的患者具有重要意义。