Zerumbone mediated CD1d inhibition suppresses epithelial to mesenchymal transition in triple negative breast cancer.

UNLABELLED: Triple-negative breast cancer (TNBC) is characterized by aggressive metastatic behavior driven through epithelial-to-mesenchymal transition (EMT). CD1d, a non-classical MHC molecule, modulates immune responses via Natural Killer T (NKT) cells and is implicated in tumor progression. This study examines the effect of CD1d inhibition on EMT in TNBC. We demonstrate that Zerumbone (ZER, 20 µM), a phytochemical, downregulates CD1d, reducing EMT markers, cell migration, and adhesion in MDA-MB-468 and MDA-MB-231 TNBC cell lines. Conversely, CD1d upregulation by α-galactosylceramide (AGC, 2 µM) and thymosin α-1 (TA, 2 µM) promotes EMT, enhances migration and adhesion. Immunofluorescence and Western blot analyses confirmed ZER suppresses CD1d, vimentin, N-cadherin, and FASN, while increasing E-cadherin, indicating mesenchymal-to-epithelial transition (MET). AGC and TA elevate CD1d and EMT markers. Molecular docking and dynamics simulations show ZER’s stable binding to CD1d (-8.13 kcal/mol), supporting the in vitro data and it is predicted to act as a potential CD1d antagonist. These findings suggest that CD1d inhibition may represent a potential strategy to attenuate EMT associated phenotypes in TNBC. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12672-026-04400-x.