外泌体是从细胞释放的细胞外微泡，参与许多生物和病理过程，主要是由于它们在细胞间通讯中的重要作用。来自结直肠癌（CRC）细胞的外泌体与肿瘤发生、肿瘤细胞存活、化疗药物抗性和肿瘤转移密切相关。外泌体在这些过程中的作用涉及将蛋白质、RNA或突变的癌基因转移到靶细胞中。近年来，研究人员在CRC外泌体中鉴定出许多有用的生物标志物，并在用于诊断、预测预后和治疗反应方面作出了巨大努力。来自格拉纳达大学的研究人员探讨了目前关于CRC外泌体的研究，对外泌体的分离、内容物、生物标志物、外泌体对CRC的发展和进展的影响，以及对抗肿瘤治疗等方面进行了综述。
图：外泌体对结直肠癌细胞转移的影响。由CRC细胞产生的外泌体（1）可能影响远端正常细胞的功能，从而促进转移前微环境的形成（2）。肿瘤转移细胞能够破坏内皮间隙连接，进入循环系统并达到转移前的微环境。此外，CRC外泌体可被其他肿瘤细胞内化摄取（3），从而获得可能加速肿瘤进展和通过上皮间充质转化获得促转移表型的分子组分（癌蛋白、miRNA等）。
表：CRC分泌的miRNA种类
附表中参考文献：
miR-21： Exosomes secreted from human colorectal cancer cell lines contain mRNAs, microRNAs and natural antisense RNAs, that can transfer into the human hepatoma HepG2 and lung cancer A549 cell lines. Oncol. Rep. 2012; 28: 1551–8.
MicroRNA-21 (miR-21) post-transcriptionally downregulates tumor suppressor Pdcd4 and stimulates invasion, intravasation and metastasis in colorectal cancer. Oncogene 2008; 27: 2128–36.
miR-145 miR-34a： Extracellular disposal of tumor-suppressor miRs-145 and -34a via microvesicles and 5-FU resistance of human colon cancer cells. Int. J. Mol. Sci. 2014; 15: 1392–401.
miR-200：Loss of miR-200 family in 5-fluorouracil resistant colon cancer drives lymphendothelial invasiveness in vitro. Hum. Mol. Genet. 2015; 24: 3689–98.
miR-210：Exosomes secreted from human colon cancer cells influence the adhesion of neighboring metastatic cells: Role of microRNA-210. Cancer Biol. Ther. 2016; 17: 1062-9. miR-100：KRAS- dependent sorting of miRNA to exosomes. eLife 2015; 4: e07197.
miR-192 miR-215：Implications of miRNAs in Colorectal Cancer Chemoresistance. Int. Drug. Discov. 2011; 2011: 2063.
miR-1229, miR-1224-5p, miR-223, let-7a, miR-150, miR-21 and miR18a：Circulating exosomal microRNAs as biomarkers of colon cancer. PloS One 2014; 9: e92921.
Circulating miR-18a: a sensitive cancer screening biomarker in human cancer. In Vivo 2014; 28: 293–7.
miR-19a：Exosomal microRNA in serum is a novel biomarker of recurrence in human colorectal cancer. Br. J. Cancer. 2015; 113: 275–81.
参考文献：Ruiz-López L, Blancas I, Garrido JM, Mut-Salud N, Moya-Jódar M, Osuna A, Rodríguez-Serrano F. (2017) The Role of Exosomes on Colorectal Cancer: a Review. J Gastroenterol Hepatol [Epub ahead of print].
http://www.exosome.com.cn/thread-1837-1-1.html
外泌体资讯网 【综述】结直肠癌细胞的外泌体的功能
