IGF2BP1调控外泌体促进结直肠癌转移的作用及分子机制研究

Colorectal carcinoma (CRC) is one of the leading causes of cancer death in China. Liver metastasis is the most common site of colorectal metastases and are usually responsible for the deaths of colorectal cancer patients. To learn the genes might be involved in this process, we performed transcriptome sequencing of three early CRC primary tumor and three advanced CRC primary tumor. We found and valided that IGF2BP1 is one of the potential vital genes involved in CRC metastasis. Recently, we found IGF2BP1 overexpression enhances CRC cell metastisis by regulating exosome induced microenvironment. However, the mechanisms of IGF2BP1 regulated exosome in metastasis process of CRC have not been evaluated. In this project, gene silencing, overexpression, miRNA array, luciferase gene reporter assay, mice metastasis model and co-culture will be applied to verify and identify the function and mechnism of IGF2BP1 enhancing CRC cell metastasis by regulating exosome. Exosomal miRNA regulated by IGF2BP1 in CRC plasma will be tested to explore whether the exosomal miRNA could be a molecular marker predicting CRC metastasis. This project will provide expriment base and new clues to clarify the metastatic mechnisms of CRC.

结直肠癌（CRC）是我国最常见的恶性肿瘤之一，而CRC肝转移是造成患者死亡的最主要原因。最近我们通过二代测序比较早期与晚期CRC原发肿瘤的转录组差异，筛选到IGF2BP1是与CRC转移密切相关的重要基因，并且发现IGF2BP1过表达与CRC淋巴结及远处转移密切相关。我们的体内外功能预实验显示：IGF2BP1过表达可通过外泌体诱导肝成纤维细胞转化调控肝脏微环境进而促进CRC细胞肝转移。但IGF2BP1调控外泌体增强CRC细胞转移的机制仍不清楚。本项目将进一步通过基因沉默及回复、miRNA芯片、双荧光素酶报告基因、动物转移模型、共培养、体循环注射miRNA抑制剂或激动剂等技术确证IGF2BP1调控外泌体促进CRC转移的作用及分子机制。并通过检测血清中IGF2BP1调控的exosomal miRNA表达水平，探讨其是否可作为预测CRC转移的分子标记物。本研究将为揭示CRC转移机制提供新线索。

我们通过二代测序比较早期与晚期CRC原发肿瘤的转录组差异，筛选到IGF2BP1是与CRC转移密切相关的重要基因，并且发现IGF2BP1过表达与CRC淋巴结及远处转移密切相关。我们的体内外功能实验显示：IGF2BP1过表达可通过外泌体诱导肝成纤维细胞转化调控远处器官微环境进而促进CRC细胞肝转移，进一步机制实验发现IGF2BP1通过与LIN28A、ELAVL1结合协同调控Rab5b mRNA的m6A修饰促进其mRNA稳定性，增加CRC细胞的外泌体分泌从而促进CRC的恶性进展。该研究为进展期CRC的治疗提供新的靶点和重要研究基础。