title: Vitamin E analog alpha-TEA, methylseleninic acid, and trans-resveratrol in combination synergistically inhibit human breast cancer cell growth.
abstract: Alpha-tocopherol ether-linked acetic acid analog [2,5,7,8-tetramethyl-2R-(4R, 8R-12-trimethyltridecyl) chroman-6-yloxyacetic acid (alpha-TEA)] is a novel form of vitamin E effective at killing cancer cells but not normal cells. alpha -TEA alone and together with methylseleninic acid (MSA) and trans-resveratrol (t-RES) were investigated for ability to induce apoptosis, DNA synthesis arrest, and cellular differentiation and inhibit colony formation in human MDA-MB-435-F-L breast cancer cells in culture. The 3 agents alone were effective in inhibiting cell growth by each of the 4 different assays, and 3-way combination treatments synergistically inhibited cell proliferation in each assay in comparison to individual treatments. Furthermore, combinations of alpha -TEA, t-RES, and MSA significantly enhanced levels of apoptosis in human breast (MDA-MB-231, MCF7, and T47D) and prostate (LnCaP, PC-3, and DU-145) cancer cell lines as well as in immortalized but nontumorigenic MCF10A cells but not primary cultures of human mammary epithelial cells. Western immunoblotting confirmed the induction of apoptosis in that the 3 agents induced poly(adenosine diphosphate-ribose) polymerase cleavage, with earlier detection and more complete cleavage seen in the combination treatment. Mechanistic studies showed combination treatments to inhibit cell proliferation via downregulation of cyclin D1 and induce apoptosis via activation of caspases 8 and 9 and downregulation of prosurvival proteins FLIP and survivin. In summary, the combination of alpha-TEA, MSA, and t-RES is more effective than single treatments for inhibiting cell proliferation, inducing cellular differentiation, and inducing cell death by apoptosis in human cancer cells in culture.
authors.affiliation: Institute for Cell and Molecular Biology, University of Texas at Austin, Austin, Texas 78712-1097, USA.
authors.forename: Rachel M
authors.initials: RM
authors.lastname: Snyder
authors.forename: Weiping
authors.initials: W
authors.lastname: Yu
authors.forename: Li
authors.initials: L
authors.lastname: Jia
authors.forename: Bob G
authors.initials: BG
authors.lastname: Sanders
authors.forename: Kimberly
authors.initials: K
authors.lastname: Kline
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000188:drug therapy*; D020169:Caspases / Q000187:drug effects / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004354:Drug Screening Assays, Antitumor; D004357:Drug Synergism; D005260:Female; D006801:Humans; D008297:Male; D016566:Organoselenium Compounds / Q000494:pharmacology*; D011471:Prostatic Neoplasms / Q000188:drug therapy; D000077185:Resveratrol; D013267:Stilbenes / Q000494:pharmacology*; D024505:Tocopherols / Q000494:pharmacology; D014810:Vitamin E / Q000031:analogs & derivatives* / Q000494:pharmacology
chemical_list: D000970:Antineoplastic Agents; D016566:Organoselenium Compounds; D013267:Stilbenes; D014810:Vitamin E; C008493:methylselenic acid; D020169:Caspases; C488288:2,5,7,8-tetramethyl-2R-(4R,8R,12-trimethyltridecyl)chroman-6-yloxy acetic acid; D000077185:Resveratrol; D024505:Tocopherols