外泌体在白血病中的重要调控作用

目前,白血病复发是患者死亡的主要原因之一。肿瘤细胞和微环境的相互作用，以及隐匿在骨髓中的肿瘤干细胞，促进了白血病的复发和向淋巴组织的转移，因此白血病的治疗、转移和复发问题受到广泛关注。外泌体是由绝大多数细胞分泌的双层脂质膜囊泡，可以调控细胞间的交流和信息传递。在白血病细胞、基质细胞和内皮细胞之间的相互联系中都涉及到外泌体，白血病细胞来源的外泌体存在于白血病患者的血浆中，能把其携带的白血病相关抗原及微小RNA呈递给靶细胞，促进白血病肿瘤细胞的增殖，有助于肿瘤细胞实现免疫逃避，保护白血病细胞抵抗化疗药物导致的细胞毒性作用，促进血管生成及肿瘤细胞的迁移。因此，外泌体与白血病的转移、治疗及预后密切相关，可以用来检测和监测白血病的进展。本文综述了外泌体的来源、形成与分泌机制，以及外泌体在白血病发生前、发展中、预后和免疫治疗中所扮演的重要角色。

The Regulatory Roles of Exosomes in Leukemia

Most of the leukemia patients died of the recurrence nowadays. The interaction between cancer cells and microenvironment as well as the existence of cancer stem cells in marrow cause the high possibility of leukemia recurrence and tumor metastasis to lymphoid tissues. This is why the therapy, metastasis and recurrence of leukemia are seriously concerned. Exosomes are extracellular vesicles secreted by most cell types. They play crucial roles in regulating cell-to-cell communication and message delivery. Exosomes are widely involved in the interaction among leukemia cells, stroma cells and endothelial cells. Leukemia cell-derived exosomes exist in the plasma and can deliver miRNA and leukemia related antigens to target cells to assist tumor cells to perform proliferation, immune escape, drug resistance, angiogenesis and metastasis. Therefore, exosome can be used as a biomarker to detect and monitor leukemia tumor progression. This review summarizes the origin, biogenesis and secretion regulations of exosomes as well as the important roles which exosomes play in leukemia detection, progression, prognosis and immunotherapy.