肿瘤研究的新焦点——外体

New focus in cancer research: exosomes

外体（exosomes）是细胞分泌的不可溶的膜性囊泡中的一种,是由脂质双层膜包绕形成的扁平半球体,直径30~100 nm,密度1.13~1.21 g/m L[1-5]。由Johnstone等[3]于1987年在网织红细胞培养液中分离并命名,后来发现多种细胞均能以胞外分泌的方式释放外体,如肥大细胞、T淋巴细胞、B淋巴细胞、血小板、肠上皮细胞、星形胶质细胞、树突状细胞、生殖细胞以及肿瘤细胞等[6-8]。

Exosomes represent a class of cell-derived bilayered membrane-bound nanovesicles defined by size,surface protein and lipid composition,and the ability to carry bio-information. Their contained mRNAs,miRNAs and proteins are important mediators of intercellular communication. Thus,exosomes participate in many normal and pathological processes. They appear to be promising new tools for the clinical diagnostics and potentially for novel therapeutic strategies. More and more studies focus on the roles of exosomes in cancer development,metastasis,drug resistance,diagnosis and cancer treatments. This article reviewed the current evidence concerning exosome-based cancer researches,as well as the biogenesis of exosomes and their molecular compositions.