2016 年 26 巻 2 号 p. 27-31
Myeloid derived suppressor cells (MDSCs), a major player for tumor-induced immunosuppression, especially induce antigen-specific CD8-Tcell tolerance and contribute to tumor growth and progression. MDSCs represent a heterogeneous group of cells originated from the myeloid cells. MDSCs accumulate in tumor-bearing mice and cancer patients. Various drugs that directly target MDSCs can improve antitumor immune response. Recent studies have demonstrated MDSCs can be suppressed by certain chemotherapeutic agents, such as 5-Fluorouracil (5-FU), gemcitabin and docetaxel. We hypothesized that treatment by 5-FU or surgical resection of primary tumors would prevent lung metastasis formation by inhibiting MDSCs. These results indicate that early-phase administration of 5-FU and early-phase resection of the primary tumor may provide therapeutic values to prevent MDSC-mediated lung metastases in tumor-bearing host. The results of our study may give a clue to develop a new strategy to control malignant tumors by regulating tumorassociated immune responses. Furthermore, we reviewed current research on the MDSC-targeted therapy.