Petromurin C modulates ERα-dependent gene expression in MCF-7 breast cancer cells via probably interactions with estrogen receptor alpha in AF-2 location

Recently, petromurin C (PmC), a bis-indolyl benzoquinone derived from the marine fungus Aspergillus subramanianii 1901NT-1.40.2, was found to exhibit estrogen receptor-dependent selective cytotoxicity towards MCF-7 breast cancer cells. This study proposed the interaction of PmC with estrogen receptor alpha (ERα) using surface plasmon resonance, revealing biphasic dissociation kinetics. Treatment of MCF-7 cells with PmC mainly enhanced the expression of ERα-dependent genes REA (PHB2), CCNG2, GREB1, and IGFBP4, whose expression initially decreased but then increased. These changes in gene expression align with the previously reported anti-proliferative effects of PmC. This is the first report demonstrating that bis-indolyl benzoquinone derivatives possible target ERα, which may explain the cytotoxic activities of PmC to breast cancer cells.