Transfer of miRNA in tumor-derived exosomes suppresses breast tumor cell invasion and migration by inducing M1 polarization in macrophages.

Macrophage repolarization from M1 to M2 phenotype is one of the hallmarks of malignancy. M2 macrophages are the most represented population in the tumor microenvironment and play an active role in tumor progression. In recent years, microRNAs (miRNAs) have been identified as a regulator of macrophage polarization. In this study, miR-130 was delivered to M2 macrophages using tumor-derived exosomes. Then, we evaluated the macrophage polarization status by assessment of specific markers and cytokines for M1 and M2 phenotype. The phagocytosis ability of macrophages was also investigated. Additionally, we performed migration and invasion assays to detect the effect of macrophage reprogramming on breast cancer cells migration and invasion. The findings of the current study indicated that exosomes efficiently delivered miR-130 into macrophages. Delivery of miR-130 into macrophages resulted in upregulation of M1 specific markers and cytokines, including CD86, Irf5, Nos2, TNF-α, and IL-1β and downregulation of M2 specific markers and cytokines, including CD206, Ym1, Arg, TGF-β, and IL-10. The phagocytosis ability of macrophages also enhanced after treatment with miRNA-loaded exosomes. Furthermore, migration and invasion assays demonstrated reduced ability of 4T1 breast cancer cells for migration and invasion after macrophages reprogramming. These observations suggest that repolarization of M2 macrophages to M1 phenotype using miRNA-containing exosomes can be a therapeutic strategy against tumor invasion and metastasis in breast cancer.

Moradi-Chaleshtori M ，Shojaei S ，Mohammadi-Yeganeh S ，Hashemi SM ... -  《-》

Exosome-mediated miR-33 transfer induces M1 polarization in mouse macrophages and exerts antitumor effect in 4T1 breast cancer cell line.

Macrophages are the most abundant tumor-infiltrating immune cells. Macrophages are conventionally classified as M1 or M2 types. M2 type is the dominant phenotype of macrophages in the tumor microenvironment. M2 macrophages support different aspects of tumor development, including tumor formation, growth, and metastasis. MicroRNAs (miRNAs) have been demonstrated to regulate numerous cellular processes, including macrophage polarization. To determine whether miR-33 containing exosomes can alter macrophage polarization, we used the exosomes isolated from 4T1 breast cancer cells to deliver miR-33 mimic into IL-4 induced M2 macrophages and treated macrophages with 4T1-conditioned media. Then, we assayed the expression of M1 specific markers and the production of cytokines using real-time PCR and ELISA, respectively. Additionally, we performed MTT, migration, and invasion assays to detect the effect of miRNA-mediated macrophage repolarization on cancer cell proliferation, migration, and invasion. The results of this study showed that miR-33 containing exosomes could convert M2 to M1 phenotype as indicated by an increase in expression of M1 markers, including Irf5, Nos2, and CD86, and a decrease in M2 markers including Arg, Ym1, and CD206. Furthermore, the secretion of TNF-α and IL-1β as M1 specific cytokines increased, while the secretion of IL-10 and TGF-β as M2 specific cytokines decreased. Incubation of 4T1 cells with conditioned media of treated macrophages showed reduced proliferation, invasion, and migration of these cells. So, our data suggests that exosomes can be used as an efficient nanocarrier for miR-33 delivery into macrophages. Also, miR-33 is capable of inducing M1 polarization in macrophages, which is essential for suppressing tumor growth and metastasis.

Moradi-Chaleshtori M ，Bandehpour M ，Heidari N ，Mohammadi-Yeganeh S ，Mahmoud Hashemi S ... -  《-》

In vitro and in vivo evaluation of anti-tumoral effect of M1 phenotype induction in macrophages by miR-130 and miR-33 containing exosomes.

Moradi-Chaleshtori M ，Bandehpour M ，Soudi S ，Mohammadi-Yeganeh S ，Hashemi SM ... -  《-》

Exosomes derived from rapamycin-treated 4T1 breast cancer cells induced polarization of macrophages to M1 phenotype.

M2 macrophages are the most prevalent type in the tumor microenvironment and their polarization to M1 type can be used as a potential cancer immunotherapy. Here, we investigated the role of tumor microenvironment and particularly purified exosomes in M2 to M1 macrophage polarization. Rapamycin treatment on triple-negative breast cancer cells (TNBC) was performed. Tumor cells-derived exosomes (called texosomes) were isolated and characterized using scanning electron microscopy, transmission electron microscopy, dynamic light scattering, high-performance liquid chromatography, Fourier transform infrared, and Western blot assays. M2 mouse peritoneal macrophages were treated with rapamycin or rapamycin-texosome. Then, M1/M2 phenotype-specific marker genes and proteins were measured to assess the degree of M2 to M1 polarization. Finally, nitric oxide (NO) production, phagocytosis, and efferocytosis assays were assessed to verify the functionality of the polarized macrophages. Purified rapamycin-texosomes significantly increased the expression of the M1 markers (Irf5, Nos2, and CD86) and decreased M2 markers (Arg, Ym1, and CD206). In addition, the levels of M1-specific cytokines tumor necrosis factor alpha and interleukin 1β (IL-1β) were increased, whereas the levels of M2 specific cytokines IL-10 and transforming growth factor beta were declined. Furthermore, texosome treatment increased NO concentration and phagocytosis and decreased efferocytosis indicating M1 polarization. These findings suggest rapamycin-texosomes can induce M2 to M1 macrophages polarization as a potential immunotherapy for TNBC.

Ghalavand M ，Moradi-Chaleshtori M ，Dorostkar R ，Mohammadi-Yeganeh S ，Hashemi SM ... -  《-》

Exosome derived from epigallocatechin gallate treated breast cancer cells suppresses tumor growth by inhibiting tumor-associated macrophage infiltration and M2 polarization.

Jang JY ，Lee JK ，Jeon YK ，Kim CW ... -  《BMC CANCER》