Astragaloside IV antagonizes M2 phenotype macrophage polarization-evoked ovarian cancer cell malignant progression by suppressing the HMGB1-TLR4 axis.

Macrophages are the most abundant cells in tumor stroma and their polarization within tumor microenvironment exert the key roles in tumorigenesis. Astragaloside IV is a natural extract from traditional Chinese herbal Radix Astragali, and fulfills pleiotropic function in several cancers. Nevertheless, its function in ovarian cancer microenvironment remains elusive. In the present research, astragaloside IV exhibited little cytotoxicity within a certain dose range in THP-1 cells. Moreover, astragaloside IV suppressed the ratio of CD14+CD206+ cells in IL-4/IL-13-treated THP-1 macrophages and transcripts of M2 macrophage markers (including CD206, CCL24, PPARγ, Arg-1, IL-10), indicating the inhibitory effects of astragaloside IV on IL-4/IL-13-induced macrophage M2 polarization. Intriguingly, astragaloside IV antagonized M2 macrophages coculture-evoked cell proliferation, invasion and migration in ovarian cancer cells. During this process, administration with astragaloside IV restrained the high expression of high-mobility group box1 (HMGB1) and TLR4 in macrophages co-cultured with ovarian cancer cells, concomitant with decreases in release of M2 marker TGF-β, MMP-9 and IL-10. Moreover, targeting the HMGB1 signaling reversed M2 macrophages-induced ovarian cancer cell proliferation, invasion and migration. Noticeably, exogenous HMGB1 overturned the inhibitory efficacy of astragaloside IV against macrophage M2 polarization-evoked malignant potential in ovarian cancer cells. Together, these findings suggest that astragaloside IV may protect against M2 macrophages-evoked malignancy in ovarian cancer cells by suppressing the HMGB1-TLR4 signaling. Therefore, astragaloside may alleviate the progression of ovarian cancer by regulating macrophage M2 polarization within tumor microenvironment, implying a promising therapeutic strategy against ovarian cancer.

Wang X ，Gao S ，Song L ，Liu M ，Sun Z ，Liu J ... -  《-》

Astragaloside IV inhibits lung cancer progression and metastasis by modulating macrophage polarization through AMPK signaling.

Xu F ，Cui WQ ，Wei Y ，Cui J ，Qiu J ，Hu LL ，Gong WY ，Dong JC ，Liu BJ ... -  《JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH》

Ligustilide counteracts carcinogenesis and hepatocellular carcinoma cell-evoked macrophage M2 polarization by regulating yes-associated protein-mediated interleukin-6 secretion.

Yang J ，Xing Z 《-》

MiR-217 Inhibits M2-Like Macrophage Polarization by Suppressing Secretion of Interleukin-6 in Ovarian Cancer.

Jiang B ，Zhu SJ ，Xiao SS ，Xue M ... -  《-》

Astragaloside IV inhibits the progression of liver cancer by modulating macrophage polarization through the TLR4/NF-κB/STAT3 signaling pathway.

The purpose of the present research was to investigate the effect and mechanism of Astragaloside IV (AS-IV) on liver cancer progression in vivo and in vitro. Since M1 macrophages play an essential role in suppressing tumors, while M2 macrophages can accelerate the incidence and progression of tumors by promoting angiogenesis, increasing tumor cell invasion and inhibiting tumor immune response, the effect and mechanism of AS-IV on macrophage polarization and their role in the development of HCC was explored. The effects of different concentrations of AS-IV (0, 50, 80, 100, 120, and 150 μM) on the capacity of hepatocellular carcinoma (HCC) cells to proliferate, migrate, and invade were detected. THP-1 cells were subjected to incubation in PMA for the purpose of stimulating differentiation into M0 macrophages. These macrophages were treated using LPS, IFN-γ, and PMA to produce M1 macrophages or treated using PMA, IL-13, and IL-4 to produce M2 macrophages. HCC cells and M1 or M2 macrophages were co-cultured for 48 hours, then the cell proliferation and migration were measured. The MTT assay was employed to determine cell viability. The capability of the cells to migrate and invade was investigated utilizing the Transwell assay and the wound healing assay. The expression of the M2 macrophage CD206 in macrophages treated with AS-IV was evaluated by flow cytometry. The expression of p-signal transducer and activator of transcription 3 (STAT3), phosphorylated (p)-NF-κB, and toll-like receptor 4 (TLR4) in macrophages was measured after treatment with AS-IV and M2 induction. To verify the function of the TLR4/NF-κB/STAT3 signaling pathway, TLR4 expression was knocked down in M2 macrophages, then the proliferation and migration and the M2 macrophage markers of HCC cells were measured. The effect of AS-IV on HCC in vivo was confirmed by a subcutaneous tumor mouse model. AS-IV was 2 was administered by gavage (0, 40, 80, and 100 mg/kg) for every 3 days. The tumor volume and weight were recorded. AS-IV suppressed the capacities of HCC cells to proliferate, migrate, and invade in a dose-dependent way. M2 macrophages could promote the proliferative, migratory, and invasive ability of Huh-7 cells, which were suppressed by AS-IV. AS-IV directly attenuated the expression of M2 macrophage markers, indicating that AS-IV can inhibit macrophage M2 polarization. M2 macrophages stimulated the expression of p-STAT3, p-NF-κB, and TLR4, while AS-IV decreased the expression compared to the M2 group, indicating that AS-IV can regulate the TLR4/NF-κB/STAT3 signaling pathway. TLR4 small interfering RNA (siRNA/si) inhibited the proliferation of Huh-7 cells. The tumor volume, as well as weight of mice, was significantly reduced by AS-IV, indicating the antitumor impact of AS-IV in vivo. AS-IV can inhibit the proliferative, invasive, and migratory ability of liver cancer through the suppression of the M2 polarization of macrophages, and the mechanism may involve the TLR4/NF-κB/STAT3 signaling pathway. The present study indicates that AS-IV could be an alternative drug to treat liver cancer, and the polarization of macrophages may be a novel treatment target for HCC.

Min L ，Wang H ，Qi H 《American Journal of Translational Research》