遗传信息传递是结肠癌转移前"微巢"形成到种植转移的关键环节，外泌体作为细胞分泌的膜性结构在癌转移微环境中的作用尚未阐明。我们前期发现低氧微环境下结肠癌细胞释放的外泌体促进细胞迁移，miR-4257等miRNA在癌细胞外泌体聚集；低氧诱导ADM分泌蛋白合成和肿瘤新生血管形成。我们推测低氧下结肠癌细胞释放外泌体，将miRNA、蛋白质等信息传递给受体细胞，促进肿瘤血管形成和转移。课题将利用三维培养技术和动物模型，评价低氧释放外泌体在结肠癌细胞与血管内皮细胞信息传递、转移微环境中的作用；利用分子影像技术追踪外泌体中miR-4257在血管内皮细胞与肿瘤组织的定位；阐明外泌体中miR-4257对候选靶基因IL-10的转录调控机制和血管生成的影响。鉴定结肠癌细胞低氧释放外泌体中的重要物质和功能，将为揭示结肠癌转移机制提供重要实验依据。

enetic information communication is a critical step during the premetastatic niche formation and cancer metastasis. Exosome is a kind of membranous structure, and its role in the microenvironment of metastasis has not yet been fully clarified. We have previously identified that exosomes released from hypoxic colon cancer cells promote the migration and miR-4257 was enriched in vast collections inside those exosomes. Morever, hypoxia induced the synthesis of secretory proteins such as ADM, which was involved in tumor angiogenesis. Hereby, we propose that exosomes released from hypoxic colon cancer cells could act as a vector during the transfer of miRNA and proteins to receiptant cells, which drive the tumor angiogenesis and metastasis. In this proposal, we aim to evaluate the role of hypoxic released exosomes on the genetic information cross-talk between the colon cancer cells and endothelial cells by using 3-D culture and animal models to simulate the metastatic microenvironment. In addition, we trace the location miR-4257 released by exosome in venous endothelial cells and tumor tissues by using the molecular imaging technique, and clarify the trancriptional regulatory mechanisms of exosomal miR-4257 on the target gene IL-10 and the effect on angiogensis. In summary, this study will discover and validate the important genetic information in exosomes released from hypoxic colon cancer cells, which will provide experimental basis on revealing the mechanisms of colon cancer metastasis.