TNF-α derived from M2 tumor-associated macrophages promotes epithelial-mesenchymal transition and cancer stemness through the Wnt/β-catenin pathway in SMMC-7721 hepatocellular carcinoma cells.

M2-polarized tumor-associated macrophages (M2-TAMs) infiltrating the tumor microenvironment contribute to hepatocellular carcinoma (HCC) progression. It was reported that cancer cells undergoing EMT will acquire stemness characteristics. Here, the HCC SMMC-7721 cell line was co-cultured with M2-TAMs polarized from THP-1 cells in vitro. In in vivo studies, we used nude mice subcutaneous tumor model to test whether the growth of the tumor was affected by M2-TAMs. Subsequently, EMT, stemness and Wnt/β-catenin pathway related markers were detected in cells and subcutaneous tumor tissues. TNF-α was also assessed in both the co-culture system supernatants and in nude mice serum. We found that SMMC-7721 underwent EMT and acquired stemness after co-culture with M2-TAMs, and resulted in larger tumor size following subcutaneous injection of SMMC-7721 suspended in M2-TAMs supernatants compared with SMMC-7721 alone. Enzyme linked immunosorbent assay showed that TNF-α expression was elevated in supernatants of M2-TAMs and positively correlated with tumor size in the serum of nude mice. Furthermore, we found that the Wnt/β-catenin pathway was a downstream target of TNF-α and that the Wnt/β-catenin inhibitor ICG-001 partially reversed EMT and attenuated cancer stemness. Our results indicate that TNF-α derived from M2-TAMs promote EMT and cancer stemness cells via the Wnt/β-catenin pathway.

Chen Y ，Wen H ，Zhou C ，Su Q ，Lin Y ，Xie Y ，Huang Y ，Qiu Q ，Lin J ，Huang X ，Tan W ，Min C ，Wang C ... -  《-》

Zoledronic acid inhibits thyroid cancer stemness and metastasis by repressing M2-like tumor-associated macrophages induced Wnt/β-catenin pathway.

This study aims to explore the effect and underlying mechanism of zoledronic acid (ZA) on the incidence of thyroid cancer (TC) tumorigenesis. Human mononuclear cells THP-1 were differentiated into M2-like tumor associated macrophages (TAMs) by incubation with PMA followed by additional incubation of IL-4 and IL-13. TC cells TPC-1 and IHH4 were co-cultured with M2-like TAMs. Identification of M2-like TAMs markers were determined by immunohistochemistry or flow cytometry. Cell proliferation, stemness and migration/invasion ability were measured by colony, sphere formation assay and transwell assay, respectively. The expression levels of cell stemness, EMT and Wnt/β-catenin pathway-related factors were verified by qRT-PCR, Western blotting, and immunofluorescence. A subcutaneous tumor model was established in nude mice to examine the in vivo effects of ZA. M2-like TAMs were enriched in TC tissues, and they promoted the colony/sphere formation, accompanied with a down-regulated expression in E-cadherin and an up-regulated expression in N-cadherin, Vimentin and other stemness-associated markers (CD133, Oct4, c-Myc) in TC cells. The effects were suppressed when ZA co-treatment was given, because ZA inhibited the polarization of M2-like TAMs and β-catenin entry into the nucleus. Moreover, in agreement with in vitro data, ZA also limited subcutaneous tumor formation and macrophage enrichment in nude mice. ZA suppressed M2-like TAMs induced TC cell proliferation, stemness and metastasis through inhibiting M2-like TAMs polarization and Wnt/β-catenin pathway, which sheds light on the mechanisms of TC and provides avenues for the development of clinical therapy to TC.

Lv J ，Chen FK ，Liu C ，Liu PJ ，Feng ZP ，Jia L ，Yang ZX ，Hou F ，Deng ZY ... -  《-》

Crosstalk between hepatic tumor cells and macrophages via Wnt/β-catenin signaling promotes M2-like macrophage polarization and reinforces tumor malignant behaviors.

Yang Y ，Ye YC ，Chen Y ，Zhao JL ，Gao CC ，Han H ，Liu WC ，Qin HY ... -  《Cell Death & Disease》

Promotion of epithelial-mesenchymal transformation by hepatocellular carcinoma-educated macrophages through Wnt2b/β-catenin/c-Myc signaling and reprogramming glycolysis.

Jiang Y ，Han Q ，Zhao H ，Zhang J ... -  《JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH》

Tumor-associated macrophages promote cancer stem cell-like properties via transforming growth factor-beta1-induced epithelial-mesenchymal transition in hepatocellular carcinoma.

Tumor-associated macrophages (TAMs), a crucial component of immune cells infiltrated in tumor microenvironment, have been found to be associated with progression and metastasis of hepatocellular carcinoma (HCC). In this study, we aimed to clarify the mechanism underlying the crosstalk between TAMs and cancer stem cells (CSCs) in HCC. Mouse macrophage cell line RAW264.7 cells were used to investigate the effects of TAMs on mouse hepatoma cell line Hepa1-6 cells in vivo and vitro. A total of 90 clinical samples had pathology-proven HCC were used to evaluate the distribution of TAMs and CSCs and analyze their value in predicting the prognosis. In the study, we have found that the number of TAMs has a positive correlation with the density of CSCs in the marginal of human HCC. Our results show that, cocultured with TAM-conditioned medium (CM) promoted CSC-like properties in Hepa1-6 cells, which underwent EMT and gained higher invasive capability. TAMs secreted more transforming growth factor- beta1 (TGF-beta1) than other phenotypes of macrophage. Furthermore, depletion of TGF-beta1 blocked acquisition of CSC-like properties by inhibition of TGF-beta1-induced EMT. High expression of CD68 in the EpCAM positive expression HCC tissues was strongly associated with both poor cancer-free survival and overall survival in patients. Our results indicate that the TAMs promote CSC-like properties via TGF-beta1-induced EMT and they may contribute to investigate the prognosis of HCC.

Fan QM ，Jing YY ，Yu GF ，Kou XR ，Ye F ，Gao L ，Li R ，Zhao QD ，Yang Y ，Lu ZH ，Wei LX ... -  《-》