title: Potent inhibitory effect of δ-tocopherol on prostate cancer cells cultured in vitro and grown as xenograft tumors in vivo.
abstract: In the present study, the effects of δ-tocopherol (δ-T) on growth and apoptosis of human prostate cancer cells were determined and compared with that of α-tocopherol (α-T), a commonly used form of vitamin E. Treatment of human prostate cancer cells with δ-T resulted in strong growth inhibition and apoptosis stimulation, while the effects of α-T were modest. The strong effects of δ-T on the cells were associated with suppression of androgen receptor (AR) activity and decreased level of prostate specific antigen (PSA) that is a downstream target of the AR signaling. In the in vivo study, we found that δ-T had a more potent inhibitory effect on the formation and growth of prostate xenograft tumors than that of α-T. Moreover, δ-T inhibited proliferation and stimulated apoptosis in the tumors. The present study identified δ-T as a better form of vitamin E than α-T for future clinical studies of prostate cancer prevention.
authors.affiliation: Allan H. Conney Laboratory for Anticancer Research, Guangdong University of Technology , Guangzhou 510006, People's Republic of China.
authors.forename: Huarong
authors.initials: H
authors.lastname: Huang
authors.forename: Yan
authors.initials: Y
authors.lastname: He
authors.forename: Xiao-Xing
authors.initials: XX
authors.lastname: Cui
authors.forename: Susan
authors.initials: S
authors.lastname: Goodin
authors.forename: Hong
authors.initials: H
authors.lastname: Wang
authors.forename: Zhi Yun
authors.initials: ZY
authors.lastname: Du
authors.forename: Dongli
authors.initials: D
authors.lastname: Li
authors.forename: Kun
authors.initials: K
authors.lastname: Zhang
authors.forename: Ah-Ng
authors.initials: AN
authors.lastname: Tony Kong
authors.forename: Robert S
authors.initials: RS
authors.lastname: DiPaola
authors.forename: Chung S
authors.initials: CS
authors.lastname: Yang
authors.forename: Allan H
authors.initials: AH
authors.lastname: Conney
authors.forename: Xi
authors.initials: X
authors.lastname: Zheng
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D006801:Humans; D008297:Male; D016513:Mice, SCID; D017430:Prostate-Specific Antigen / Q000378:metabolism; D011471:Prostatic Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D011944:Receptors, Androgen / Q000378:metabolism; D024505:Tocopherols / Q000008:administration & dosage*; D023041:Xenograft Model Antitumor Assays
chemical_list: D011944:Receptors, Androgen; D017430:Prostate-Specific Antigen; C479072:delta-tocopherol; D024505:Tocopherols
keywords: AR signaling; apoptosis; prostate cancer; tocopherol; vitamin E; xenograft tumor