Gamma-tocopherol induces apoptosis in androgen-responsive LNCaP prostate cancer cells via caspase-dependent and independent mechanisms.
We found that gamma-tocopherol, the predominant vitamin E form in diets, but not alpha-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. gamma-Tocopherol induced apoptosis in androgen-sensitive LNCaP but not androgen-resistant PC-3 cells. Consequently, gamma-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 gamma-tocopherol may be valuable in the prevention and therapy for certain types of cancer.
Jiang
Qing
Q
Department of Foods and Nutrition, Purdue University, West Lafayette, IN 47907, USA. Qjiang@purdue.edu
Wong
Jeff
J
Ames
Bruce N
BN
D000728:Androgens / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D020169:Caspases / Q000378:metabolism*; D002455:Cell Division / Q000187:drug effects; D004789:Enzyme Activation / Q000187:drug effects; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology; D008297:Male; D011467:Prostate / Q000187:drug effects; D011471:Prostatic Neoplasms / Q000473:pathology*; D014407:Tumor Cells, Cultured; D024504:gamma-Tocopherol / Q000494:pharmacology*
D000728:Androgens; D024504:gamma-Tocopherol; D020169:Caspases