Regulation of macrophage plasticity by circCCDC719-13 through HSP90 inhibition suppresses prostate cancer progression and metastasis: a translational study

Background: Macrophages play a crucial role in cancer development by differentiating into M1 or M2 phenotypes with opposing functions.The conversion of M2 to M1 macrophages has significant implications in cancer treatment. Non-coding RNA, such as circRNA and lncRNA, have been shown to regulate macrophage polarization by specific pathways.However, the molecular mechanism of this conversion process is still not fully understood. Method: In this study, we investigated the role of circCCDC7 19-13 in regulating macrophage polarization in prostate cancer (PCA). We examined the expression level of circCCDC7 19-13 in tumor-associated macrophages (TAMs) and M2 macrophages in PCA.We used in vitro experiments to investigate the effects of transfection of circCCDC7 19-13 overexpression Lentivirus on M2 polarization and the expression level of M2 cytokines.We also assessed the ability of TAM to promote malignant behavior in PCA cells.Furthermore,we explored the downstream target of circCCDC7 19-13 and its role in macrophage polarization. Results: We found that circCCDC7 19-13 was significantly lower in TAMs and M2 macrophages in PCA. Overexpression of circCCDC7 19-13 inhibited M2 polarization and downregulated the expression level of M2 cytokines.Overexpression of circCCDC7 19-13 also reduced the ability of TAM to promote malignant behavior in PCA cells.Our study demonstrated that HSP90 was a downstream target of circCCDC7 19-13 , which could regulate macrophage polarization based on inhibition of ferroptosis. Overexpression of HSP90 restored the phenotype of circCCDC7 19-13 overexpressing macrophages. CircCCD7 19-13 overexpression of TAMs inhibited the growth and metastasis of PC3M cells. Conclusions: Our findings suggest that circCCDC7 19-13 may alter macrophage polarization by inducing ferroptosis and targeting HSP90, which can decrease the ratio of M2 phenotype TAMs and inhibit the progression and metastasis of PCA. The results of this study provide new insights for clarifying the molecular mechanism of macrophage polarization and have reference value for targeted treatment of PCA.