ABSTRACT: We examined FASN knockdown LNCaP cells obtained by shRNA transduction with Mission lentiviral transduction particles (SHCLNV-NM 00410, TRCN3128, Sigma) (FASN-RNAi cells). In this study, we used cells transfected with non-targeting shRNA as a control (control-RNAi cells). The expression of genes related to cellular proliferation (phospholipase A2, group IVA, PLA2G4A; tensin 3, TNS3; glypican 4 GPC4), cell adhesion and extracellular matrix organization [peroxidasin homolog (Drosophila) PXDN; sarcoglycan epsilon, SGCE; von Willebrand factor, VWF; hydroxysteroid (17-beta) dehydrogenase 12, HSD17B12; cysteine-rich secretory protein LCCL domain containing 2, CRISPLD2], and cell motility (TNS3, RAP2B member of RAS oncogene family, RAP2B) were shown to be down-regulated by FASN inhibition with RNAi. FASN inhibition led to down-regulation of the PLA2G4A and HSD17B12 genes encoding phospholipase A2 and 17-beta hydroxysteroid dehydrogenase, respectively, which are the key enzymes related to production of an intracellular second messenger arachidonic acid and androgen hormones, both playing roles in promotion of tumor progression. We also found that the genes related to arachidonic acid signalling, including RGS2, SPAG16, VWF and RAP2B, were also suppressed with FASN inhibition. Gene expression profiling therefore demonstrated that FASN inhibition induces down-regulation of genes related to cell proliferation, cell adhesion, migration, and invasion, as well as the production of arachidonic acid and androgen hormones, both of which drive tumor progression.
