Inhibition of β-oxidative respiration is a therapeutic window associated with the cancer chemo-preventive activity of PPARγ agonists

We demonstrate expression and coordinate induction of PPARγ and lipogenic enzymes (HMG-CoA synthase, HMG-CoA reductase and fatty acid synthase) in a murine lung alveolar carcinoma cell line (Line 1) treated with the PPARγ agonist troglitazone (TRO) [0-100 μM]. We postulate that TRO induces a shift in cellular energy metabolism towards fatty acid oxidation (β-oxidative respiration). Accordingly, co-treatment with TRO [30 μM] and increasing concentrations of trimetazidine (TMZ) [0.1-3 mM], an inhibitor of β-oxidation, results in a dose dependent decrease cellular ATP levels and a dose dependent induction of apoptosis. These findings, suggest that inhibition of β-oxidative respiration is a therapeutic window associated with the cancer chemo-preventive activity of PPARγ agonists.