Effects Of Of DMBT, A Trehalose Derivative, On Tumor Anti-invasion And Anti-metastasis

Tumor invasion and metastasis is the basic biological features in malignant tumor and the main cause of death in cancer patients, development of efficient anti-invasive agents is an important research challenge. Metastasis is a multi-step biochemical process, which includes the proliferation of tumor cell and angiogenesis in the primary tumor, and its adhesion properties to change and fall off from the primary site, the secretion of proteolytic enzymes and collagenase degradation of extracellular matrix (extracellular matrix, ECM) and basement membrane, extravasation out of the vessel, migration to form a new target organ through proliferation and angiogenesis foci. Among them, inhibiting the activity of proteolytic enzymes and angiogenesis is an important point of anti-tumor invasion and metastasis.In recent decades, natural products have become an important source of innovative drug and drug lead compounds. The structure optimization of natural active substance with anti-tumor invasion and metastasis activity is an important way to discover the innovative drugs of tumor metastasis. Brartemiein is a trehalose-based inhibitor of tumor cell invasion produced by the actinomycete of the genus Nonomuraea. In order to explore the preliminary structure-activity relationship and obtain more potent inhibitors, a series of Brartemiein analogs were synthesized through the Mitsunobu coupling of the secondary hydroxyls benzyl protected a,a-D-trehalose with benzoic acid derivatives, followed by modifieation off functional groups and deprotection. These compounds were evaluated for their inhibitory activity against invasion of murine colon26-L5carcinoma cells in vitro. Among the synthetic analogs tested, compound6,6’-bis(2,3-dimethoxybenzoyl)-a,a-D-trehalose is2.6-fold more potent against murine colon26-L5carcinoma cells in vitro. But the effects of DMBT on breast cancer and melanoma were not known.In this study, the effects of DMBT on invasion and metastasis in MD A-MB-231cells and B16BL6cells were investigated. MTT assay and trypan blue exclusion test showed that no obvious inhibitory or cytotoxic effect of DMBTwas found. Transwell migration assay and scratch assay showed that2-8μM DMBT could effectively inhibit metastsis of MD A-MB-231cells and B16BL6cells. Transwell invasion assay showed that2μM,4μM DMBT could effectively inhibit invasion of MD A-MB-231cells and B16BL6cells. DMBT could inhibit tube formation of HUVECs. Western blotting and Gelatin zymography showed that DMBT inhibited activity of MMP-9and VEGF. Western blotting demonstrated that DMBT effectively suppressed the expression of VEGF, p-VEGFR-2, p-EGFR, and p-Akt in MD A-MB-231cells. In vivo, DMBT could significantly suppress lung metastasis in mice produced by highly metastatic MDA-MB-231-luc-D2L2HN cells by using BLI analysis. In B16BL6cells, Western blotting and Real-time PCR indicated that the chemopreventive effect of DMBT was attributed to the inhibition of the VEGF and MMP-9through Akt/GSK-3β/β-catenin and Akt/mTOR signaling pathways. We examined the effects of lung metastasis produced by highly metastatic B16BL6melanoma cells by using experimental metastasis models and BLI analysis. DMBT could significantly suppress lung metastasis in mice. The chicken chorioallantoic membrane assay observed that10mg/ml DMBTcould significantly inhibit angiogenesis. These results suggested that DMBT could be a promising lead molecule for the anti-metastasis and serve as a therapeutic agent to inhibit cancer cell invasion and metastasis.