Inhibitory effects of compound DMBT on hypoxia-induced vasculogenic mimicry in human breast cancer

Breast cancer is one of the most serious malignant tumors that harm to women’s health. Vasculogenic mimicry (VM) is an alternative type of blood supplement independent of endothelial vessels, which refers to the formation of tumor cell-lined vessels and is associated with tumor invasion, metastasis and poor cancer patient prognosis. Prior antiangiogenic therapy just focused on vascular endothelial cells and did not significantly affect VM. DMBT, 6, 6′-bis (2, 3-dimethoxybenzoyl)-a, a-D-trehalose, has shown to have multiple anti-tumor invasion and metastasis activities; however the exact mechanism is not thoroughly elucidated. In this study, we examined key molecular mechanisms underlying VM by using breast cancer cells MDA-MB-231 and MCF-7. We found that following the hypoxia treatment, the cells were easily to form VM networks and DMBT could inhibit VM formation of both MDA-MB-231 and MCF-7 cells in hypoxic condition. When tumor cells exposed to hypoxia environment, the expression of VM related proteins such as HIF-1α, VE-cadherin, MMP-9, Cdc42, and EGFR, p-Akt, p-mTOR were increased but decreased when exposed to hypoxia medium with DMBT. In MDA-MB-231 cells, DMBT inhibit hypoxia-induced VM by suppress HIF-1α/VE-cadherin/MMPs signaling pathway and in MCF-7 cells, DMBT had little effect on HIF-1α or VE-cadherin but could inhibit cell autophagy to suppress VM formation. These results suggested that DMBT could serve as a therapeutic agent to inhibit VM formation in human breast cancer.