Supplying LSD1 with FAD in pancreatic cancer: A matter of protein-protein interaction?

Lysine-specific demethylase 1 (LSD1) is a key regulator in cancer epigenetic, and its activity is reliant on flavin adenine dinucleotide (FAD) as a cofactor. In this study, we investigated the correlation between LSD1 and FAD synthase isoform 2 (FADS2) protein levels in pancreatic ductal adenocarcinoma (PDAC) cell lines. We first assessed LSD1 protein and mRNA levels in mutant p53-expressing PANC-1 and MiaPaCa2 cells and p53-null AsPc-1 cells, compared to human pancreatic ductal epithelial (HPDE) controls. Our results confirmed elevated LSD1 protein levels in PANC-1 and MiaPaCa2, but not in AsPc-1, despite mRNA overexpression across all cell lines. Similarly, FADS2 levels were significantly upregulated in PANC-1 and MiaPaCa2, but not in AsPc-1, highlighting a possible link between FADS2 expression and p53 gain-of-function mutations. These results prompted us to better investigate the functional relationship between FADS2 and LSD1 by performing in cellulo protein-protein interaction analyses. Our results indicate a direct interaction between LSD1 and FADS2, while no significant interaction was observed between LSD1 and FADS1. These findings reinforce the role of FAD synthesis and its delivery to LSD1 as critical events in cancer progression and shed light on potential implications of FADS2-LSD1 dynamics as targeted therapies in cancer.