Exploring the anticancer potential of ergosterol and ergosta-5,22,25-triene-3-ol against colorectal cancer: Insights from experimental models and molecular mechanisms

Abstract

Colorectal cancer (CRC) is the third most frequently diagnosed cancer and second leading cause of cancer associated mortality globally. Aberrant cholesterol metabolism due to altered expression and activity of Liver X Receptors (LXRs) contribute significantly to the development of CRC. Previously, we had identified ergosterol (ERG) and ergosta-5,22,25-triene-3-ol (ERG2) as LXR agonists with selective cytotoxicity towards colon cancer cells. The present study was designed to further understand their anticancer potential and mechanism of action. In HCT116 cell, both ERG and ERG2 increased the cell population in the late stage apoptosis via increasing the expression of Bax, CD95, and decreasing the expression of Bcl-2. They also suppressed cell survival and proliferation by reducing the protein expression of cyclin D1, Ras, and MEK1/2, and inhibiting the phosphorylation of PI3K. Erg and Erg2 also suppressed cell invasion and metastasis, which was evident from the decrease in cell migration of HCT116, SW620 cells and protein expression of MMP2 and MMP9. The present study also assessed the chemopreventive potential of ergosterol by using the DMH + DSS induced experimental model of CRC. In line with the findings of the in vitro experiments, ergosterol administration significantly reduced tumor burden, volume, and Ki-67 expression in DMH + DSS + ERG group animals, along with a marked decrease in cancer-like features in the colonic mucosa. It also induced apoptosis and inhibited β-catenin and PI3K/Akt signaling, while upregulating cholesterol efflux genes. Taken together, the findings of the current study are suggestive of the immense anticancer potential of ergosterol mediated through its pleiotropic mode of action.