M2 macrophages contribute to cell proliferation and migration of breast cancer

Abstract Background: Breast cancer is a kind of malignant tumor that severely threatens women’s health and life worldwide. Macrophages have been reported to mediate tumor progression, while the potential mechanism still needs further identification. Methods: Human monocytic cell line THP-1 was used to induce M2-macrophage. Real-time PCR and western blot were performed to determine gene expression in mRNA and protein level, respectively. Cell proliferation was determined using MTT assays, while cell migration was detected based on the scratch wound healing assays. Results: The supernatant medium of M2-macrophages incubated breast cancer cells showed increased cell proliferation and reduced expression of IRF-7. Overexpression of IRF-7 reversed the increased level of M2-macrophage induced cell proliferation and migration. The supernatant medium of M2-macrophages incubation promoted miR-1587 expression in breast cancer cells. miR-1587 overexpression promoted cell proliferation and migration of breast cancer. In addition, miR-1587 knockdown suppressed cell proliferation and migration that induced by M2-macrophages. miR-1587 targets IRF-7 to regulate its expression. Knockdown of IRF-7 reversed the effects of miR-1587 knockdown on cell proliferation and migration. Conclusion: Collectively, this study revealed that miR-1587/IRF-7 mediated the mechanism of M2-macrophages-induced breast cancer progression, and this would shed light on the further clinical therapy of breast cancer.