γ‐Tocopherol Induces Apoptosis in Androgen‐Responsive LNCaP Prostate Cancer Cells via Caspase‐Dependent and Independent Mechanisms

Abstract
Abstract: We found that γ‐tocopherol, the predominant vitamin E form in diets, but not α‐tocopherol, which is the exclusive form of vitamin E in most supplements, exhibited antiproliferation effect on prostate (PC‐3, LNCaP) and lung (A549) cancer cells. γ‐Tocopherol induced apoptosis in androgen‐sensitive LNCaP but not androgen‐resistant PC‐3 cells. Consequently, γ‐tocopherol treatment caused cytochrome c release and caspase‐9, ‐3 and ‐7 activation. However, the apoptosis could not be completely reversed by an irreversible pancaspase inhibitor, indicating that an alternative caspase‐independent pathway may also be involved. Our study suggests that γ‐tocopherol may be valuable in the prevention and therapy for certain types of cancer.