Genome-wide CRISPR/Cas9 screening reveals lipid metabolism and inflammatory signalling as modulators of ganoderic acid DM cytotoxicity.

Ganoderic acid DM (GA-DM), a triterpenoid derived from Ganoderma lucidum, exhibits anti-cancer and anti-diabetic activities, but the underlying mechanisms of action remain unclear. To identify genetic modulators of the GA-DM response, we conducted a genome-wide CRISPR/Cas9 knockout screen in human melanoma cells. The screen revealed key roles for genes regulating lipid metabolism and inflammatory signalling, particularly those involved in the SREBP (sterol regulatory element-binding protein) and NF-jB (nuclear factor kappa-light-chain-enhancer of activated B cells) pathways, in the cellular response to GA-DM. While loss of genes involved in the regulation of cholesterol biosynthesis conferred resistance to GA-DM, disruption of genes involved in ubiquitin-mediated proteolysis and the Hippo pathway sensitised cells to GA-DM. Inflammatory genes enriched at later time points suggests that a delayed cellular response contributes to cytotoxicity. Our findings propose a mechanistic model wherein GA-DM perturbs lipid and inflammatory pathways to exert cytotoxic effects and highlight potential targets to enhance its therapeutic efficacy. This work demonstrates the utility of functional genomics in elucidating the mechanisms of action of natural products and guiding rational drug development.