关键词: PRTN3, 肿瘤相关巨噬细胞, M1/M2极化, 吞噬作用, 抗肿瘤功能

Abstract: Objective To investigate the effect of knockdown PRTN3 on polarization phenotype and anti-tumor function of macrophages in breast cancer. Methods A mouse monocyte/macrophage cell line(RAW264.7) with knockdown of PRTN3 was constructed. The mRNA and protein levels of PRTN3 were detected by RT-qPCR and flow cytometry. Macrophages were co-cultured with tumor cells, and the polarization phenotypes of macrophages were detected by flow cytometry, and the mRNA levels of polarization and cytokines related genes were detected by RT-qPCR. The tumor phagocytosis and tumor killing ability of macrophages were determined by in vitro phagocytosis assay and tumor killing assay. The effect of macrophages with PRTN3 knockdown on tumor progression and metastasis was compared in an orthotopic transplantation model of mouse breast cancer. Results The mRNA and protein levels of PRTN3 in the RAW264.7 cell line with stable knockdown of PRTN3 were significantly decreased(P＜0.01). Knockdown of PRTN3 in RAW264.7 cells upregulated the expression of M1 phenotype-related genes(CD80, CD86, iNOS, IL-1β, IL-6 and TNF-α)(P＜0.05). After macrophages co-culture with tumor cells, macrophages with knockdown of PRTN3 upregulated the expression of M1 phenotype-related genes(CD80, CD86, iNOS, IL-1β, IL-6 and TNF-α)(P＜0.01). Knockdown of PRTN3 enhanced the phagocytosis(P＜0.05) and tumor killing ability(P＜0.05) of macrophages in vitro. Adoptive transfusion of PRTN3-knockdown macrophages into tumor-bearing mice inhibited the growth of in situ breast cancer and reduced lung metastasis(P＜0.05). Conclusions PRTN3 regulates phenotypic polarization of macrophages, and knockdown of PRTN3 enhances the anti-tumor function of macrophages.

Key words: PRTN3, tumor-associated macrophages, M1/M2 polarization, phagocytosis, anti-tumor function