PT - JOURNAL ARTICLE AU - Kailin Jiao AU - Jing Zhen AU - Maoxuan Wu AU - Mengying Teng AU - Keke Yang AU - Qian Zhou AU - Chunyan Hu AU - Ming Zhou AU - Yuan Li AU - Zhong Li TI - 27-Hydroxycholesterol-induced EndMT acts <em>via</em> STAT3 signaling to promote breast cancer cell migration by altering the tumor microenvironment AID - 10.20892/j.issn.2095-3941.2019.0262 DP - 2020 Feb 15 TA - Cancer Biology and Medicine PG - 88--100 VI - 17 IP - 1 4099 - http://www.cancerbiomed.org/content/17/1/88.short 4100 - http://www.cancerbiomed.org/content/17/1/88.full SO - Cancer Biol Med2020 Feb 15; 17 AB - Objective: The endothelial to mesenchymal transition (EndMT) plays a major role in cancer metastasis by regulating the complexity of the tumor microenvironment (TME). Here, we investigated whether 27-hydroxycholesterol (27HC) induces EndMT in endothelial cells (ECs).Methods: EndMT markers in the human microvascular endothelial cell-1 (HMEC-1) cell line and human umbilical vein endothelial cells (HUVECs) stimulated with 27HC were evaluated with Western blot. Epithelial to mesenchymal transition (EMT) markers in breast cancer (BC) cells cultured in conditioned medium were investigated with quantitative real time polymerase chain reaction (qRT-PCR). The MMP-2 and MMP-9 mRNA expression and activity were detected with qRT-PCR and gelatin zymography assays, respectively. The effect of activated STAT3 on 27HC-induced EndMT was validated by Western blot, immunofluorescence staining, and cell transfection assays. The migration ability of BC cells was evaluated with Transwell assays.Results: We found that 27HC induced EndMT in HMEC-1 and HUVECs, and 27HC-induced EndMT facilitated EMT and BC cell migration. The 27HC-induced EMT of BC cells also promoted EndMT and HUVEC migration. Investigation of the underlying molecular mechanisms revealed that STAT3 knockdown repressed EndMT in HUVECs as well as migration in BC cells induced with 27HC. In addition, C646 and resveratrol, inhibitors of STAT3 acetylation, repressed the expression of Ac-STAT3, p-STAT3, and EndMT markers in HUVECs exposed to 27HC; these HUVECs in turn attenuated the migration ability of BC cells in 27HC-induced EndMT.Conclusions: Cross-talk between 27HC-induced EndMT and EMT was observed in the TME. Moreover, activation of STAT3 signaling was found to be involved in 27HC-induced EndMT.