Figure 6. Pharmacologic inhibition or genetic knock-down of FASN impedes PI3K-mTORC1 signaling and induces apoptosis in OC cells as demonstrated by Western blot analysis.
(A) G28UCM-treated SKOV3 cells reveal early upregulation of HIF-1α and REDD1 and concurrent inhibition (de-phosphorylation) of the mTORC1 downstream effector ribosomal S6 protein (pS6). Subsequently, REDD1 and pAKT become decreased, whereas pAMPKα gets increased. Levels of pERK peak at 24–48 h. Cleavage products of caspase 3 and PARP1 indicating apoptosis occur after 24 h of treatment. ‘-‘ First indication of down-regulation, ‘+’ first indication of up-regulation. OD optical density of specific band relative to actin band normalized to untreated control cells (0 μM G28UCM). (B) FASN siRNAs abrogate FASN protein expression in A2780 cells 72 h post-transfection and down-regulate HIF-1α, REDD1, pmTOR, mTOR, pp70S6K, p4EBP1, and 4EBP1, whereas levels of pAMPKα, pERK1/2, ERK1/2, and cleaved PARP increase. Actin was used as loading control. ◄cleaved PARP.