髓源性抑制细胞促进循环肿瘤细胞形成转移的研究进展*

循环肿瘤细胞（circulating tumor cell ，CTC ）作为肿瘤转移的“种子”，能够逃避免疫系统的清除并有可能分泌囊泡塑造的适宜的转移前环境，最终导致转移的发生；髓源性抑制细胞（myeloid-derived suppressor cells，MDSC）是一群来源于骨髓并具有免疫抑制性特征的细胞，可诱导产生肿瘤微环境和外周免疫逃逸，在CTC 的形成及免疫逃逸等过程中起到关键作用。本文综述了MDSC对CTC 的作用机制，以期加深对转移发生的免疫机制认识并发掘免疫治疗的新靶点。 

Progress on metastasis induced by myeloid-derived suppressor cells to promote circu-lating tumor cell

Circulating tumor cells (CTCs), as the seeds of tumor metastasis, manage to escape from immune clearance both in microen-vironment and in peripheral blood. CTCs can also facilitate formation of pre-existing environment, which is the crucial step in metasta-sis. Myeloid-derived suppressor cells (MDSC), as a group of immunosuppressive cells derived from bone marrow cells, may play a key role in this process. In this review, the progress in MDSC and its role in the formation, survival, and immune escape of CTCs were exten-sively discussed to explore a new target for tumor immunotherapy.