title: Vitamin E succinate inhibits the function of androgen receptor and the expression of prostate-specific antigen in prostate cancer cells.
abstract: Although epidemiological evidence indicates that a daily supplement of vitamin E may reduce the risk of prostate cancer, the detailed mechanism underlying this effect remains unclear. Here we demonstrate that alpha-tocopheryl succinate (VES) can suppress the expression of prostate-specific antigen (PSA), a marker for the progression of prostate cancer. VES can also suppress androgen receptor (AR) expression by means of transcriptional and posttranscriptional modulation, but not ligand binding, nuclear translocation, or AR dimerization. This VES-mediated inhibition of AR is selective because VES does not repress the expression of other nuclear receptors. Cell growth studies further show that VES inhibits the growth of prostate cancer LNCaP cells. In contrast, hydroxyflutamide (HF), an antiandrogen currently used to treat prostate cancer patients, only slightly inhibits LNCaP cell growth. Interestingly, simultaneous addition of HF and VES results in a more significant inhibition of LNCaP cell growth. Moreover, selenomethionine (SM), a prostate cancer treatment adjuvant, shows an inhibitory effect on LNCaP cell growth, yet has no effect on the AR/PSA pathway. Together, our data indicate that VES may suppress androgen/AR-mediated cell growth and PSA expression by inhibiting AR expression at both the transcription and translation levels. This previously undescribed mechanism may explain how VES inhibits the growth of prostate cancer cells and help us to establish new therapeutic concepts for the prevention and treatment of prostate cancer.
authors.affiliation: Department of Urology, University of Rochester, Rochester, NY 14642, USA.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.forename: Jing
authors.initials: J
authors.lastname: Ni
authors.forename: Edward M
authors.initials: EM
authors.lastname: Messing
authors.forename: Eugene
authors.initials: E
authors.lastname: Chang
authors.forename: Chin-Rang
authors.initials: CR
authors.lastname: Yang
authors.forename: Shuyuan
authors.initials: S
authors.lastname: Yeh
mesh_terms: D059002:Androgen Receptor Antagonists; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D019556:COS Cells; D002455:Cell Division / Q000187:drug effects; D002522:Chlorocebus aethiops; D019281:Dimerization; D005347:Fibroblasts / Q000473:pathology; D015972:Gene Expression Regulation, Neoplastic / Q000502:physiology*; D006801:Humans; D008297:Male; D017430:Prostate-Specific Antigen / Q000235:genetics*; D011471:Prostatic Neoplasms / Q000473:pathology; D014176:Protein Biosynthesis / Q000187:drug effects; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics; D018168:Receptors, Retinoic Acid / Q000235:genetics; D047488:Retinoid X Receptors; D012643:Selenium / Q000494:pharmacology; D024505:Tocopherols; D014157:Transcription Factors / Q000235:genetics; D014407:Tumor Cells, Cultured; D014810:Vitamin E / Q000031:analogs & derivatives* / Q000494:pharmacology*
chemical_list: D059002:Androgen Receptor Antagonists; D000975:Antioxidants; D018160:Receptors, Cytoplasmic and Nuclear; D018168:Receptors, Retinoic Acid; D047488:Retinoid X Receptors; D014157:Transcription Factors; D014810:Vitamin E; D017430:Prostate-Specific Antigen; D012643:Selenium; D024505:Tocopherols