Celastrol increases anoikis sensitivity to suppress triple-negative breast cancer via EGFR pathway and p-EMT state regulation.

Faced with the highly malignant threat of metastatic triple-negative breast cancer (TNBC), the effect of traditional chemical agents is limited, and new anti-metastasis drug remains to be explored. Celastrol (Cel) is a bioactive compound derived from with significant anti-neoplastic effects in various cancers. In this study, we investigated the potential anti-metastatic effects of Cel on anoikis resistant TNBC cells (TNBC-AR) cells, including MDA-MB-231-AR cells and BT-549-AR cells. Using CCK-8 and colony formation assay, we demonstrated that Cel could inhibit the proliferation of MDA-MB-231-AR cells and BT-549-AR cells with IC value of 1.510 μM and 1.673 μM, respectively. The results of wound healing and transwell assays showed that Cel could potently inhibit the invasion and migration of TNBC-AR cells. Aggregation and flow cytometry experiments showed that Cel could inhibit the clusters formation and enhance the anoikis of TNBC-AR cells on the suspension conditions. Then we conducted bioinformatics analysis, Western blotting, and intervention experiments to explore the molecular mechanisms of Cel's anti-metastasis effects. The results of these experiments discovered that Cel treatment suppressed the p-EMT state in TNBC-AR cells, and this effect correlated with a reduction in EGFR/MEK/ERK pathway activation. Our findings suggest that Cel may be a promising candidate for therapeutic treatments of metastatic TNBC.