RÉSUMÉ
【Objective】 To investigate the mechanism by which the up-regulation of miR-221-3p by tumor-associated macrophages (TAMs) may be involved in promoting the malignant metastasis of prostate cancer (PCa). 【Methods】 The microRNAs (miRNAs) expression profiles of 6 cases of metastatic PCa tissues were sequenced and analyzed.The primary TAMs were isolated.The expression of miR-221-3p was determined with qPCR.The miR-221-3p mimic or miR-221-3p inhibitor was transfected into RAW264.7 macrophages in vitro, and co-cultured with human prostate cancer PC3 cells.The proliferation, apoptosis, invasion and migration of PC3 cells were detected with CCK-8, flow cytometry (FCM), Transwell assay, respectively.Expressions of epithelial-mesenchymal transformation (EMT) related protein factors were determined with Western blot. 【Results】 In the 6 cases of metastatic PCa, hsa-miR-221-3p was significantly up-regulated in TAMs-derived from PCa tissues with positive lymph node metastasis (P<0.05).In the co-cultured system, compared with Mimic-NC group, miR-221-3p mimic group had significantly up-regulated proliferation, migration, invasion and EMT-related protein factors (except E-Cadherin) (P<0.05).Compared with Inhibitor-NC group, miR-221-3p inhibitor group had significantly up-regulated apoptosis rate, but down-regulated proliferation, migration, invasion and EMT-related protein factors (except E-Cadherin) (P<0.05). 【Conclusion】 The miR-221-3p expression up-regulate by TAMs may participate in the malignant metastasis of prostate cancer.