CD244 < sup > + < /sup > polymorphonuclear myeloid ‑derived suppressor cells reflect the status of peritoneal dissemination in a colon cancer mouse model

Oncol Rep. 2021 Jun;45(6):106. doi: 10.3892/or.2021.8057. Epub 2021 Apr 28.ABSTRACTDespite the recent development of chemotherapeutic agents, the prognosis of colorectal cancer (CRC) patients with peritoneal dissemination (PD) remains poor. The tumor immune microenvironment (TIME) has drawn attention as a key contributing factor of tumor progression. Of TIME components, myeloid‑derived suppressor cells (MDSCs) are considered to play a responsible role in the immunosuppressive characteristics of the TIME. MDSCs are classified into two major subsets: Monocytic MDSCs (M‑MDSCs) and polymorphonuclear MDSCs (PMN‑MDSCs). Therefore, we hypothesize that MDSCs would play important roles in the PD‑relevant TIME and PD progression. To address this hypothesis, we established PD mouse models. As the PD nodules consisted scarcely of immune cells, we focused on the peritoneal cavity, but not PD nodule, to evaluate the PD‑relevant TIME. As a result, intraperitoneal PMN‑MDSCs were found to be substantially increased in association with PD progression. Based on these results, we phenotypically and functionally verified the usefulness of CD244 for identifying PMN‑MDSCs. In addition, the concentrations of interleukin (IL)‑6 and granulocyte‑colony stimulating factor (G‑CSF) were significantly increased in the peritoneal cavity, both of which were produced by the tumors and thought to contribute to the increases in the PMN‑MDSCs. In vivo depletion of the PMN‑MDSCs by anti‑...
Source: Oncology Reports - Category: Cancer & Oncology Authors: Source Type: research