In vitro studies on inhibition capability of fungal-sourced bassiatin versus tamoxifen against ERα, EGFR and VEGFR on breast cancer cells.

Bassiatin which is produced by some fungi, is morpholine-based depsipeptide. Recent studies show that bassiatin inhibits MCF-7 breast cancer cell proliferation with its anti-oestrogenic effect. In this study, bassiatin's inhibition versus Tamoxifen was examined by comparing the effects on epidermal growth factor receptor and vascular endothelial growth factor receptor in addition to oestrogen receptor on breast cells. For this purpose, 15 concentrations of bassiatin, tamoxifen and combination of both were treated in terms of cytotoxicity on MCF-7, MDA-MB-231, SK-BR-3 and SVCT cell lines. For cell cycle analyses, MCF-7 and SVCT cell lines were incubated with 37.5 μM bassiatin, tamoxifen and combined substance for 24 h and 48 h. After treatment, cell distribution in each phase of the cell cycle was measured with flow cytometer. Furthermore, each interaction related to receptors were investigated with immunoassay ELISA kits. As a result, bassiatin-induced MCF-7 cell cycle arrest was shown in G0/G1 and G2/M phases at the presence of bassiatin. It was also found that bassiatin is more effective at all examined receptors on breast cancer cells than tamoxifen. These results show that bassiatin can be used effectively in breast cancer treatment as a new anticancer agent because of its multiple inhibition effects.