Vitamin E succinate promotes breast cancer tumor dormancy.
BACKGROUND
Vitamin E succinate (VES) is the most potent antitumor analogue of vitamin E. Despite many reports of VES's antitumor activity in vitro, there is little information about its antitumor effects in vivo.


METHODS
We investigated the effect of VES on the growth of human breast cancer cells in vitro and in vivo.


RESULTS
VES decreased cell viability in MDA-MB-231 and MCF-7 human breast cancer cells. Although VES increased apoptosis in MDA-MB-231 cells, it had no effect on apoptosis in MCF-7 cells. The inhibitory effect of VES on cell growth was specific for the intact molecule because a markedly reduced effect was noted when either vitamin E or succinic acid was administered alone. VES inhibited the growth of MDA-MB-231 cells in nude mice. Also, VES was found to inhibit vascular endothelial growth factor (VEGF) gene expression in MDA-MB-231 cells.


CONCLUSIONS
VES inhibits the growth of breast cancer cells in vitro and in vivo. This is the first report of VES inhibition of established tumor growth in vivo. The mechanism of VES's in vivo effects may involve inhibition of tumor angiogenesis since VES inhibits VEGF gene expression.
Malafa
M P
MP
Department of Surgery, Southern Illinois University School of Medicine, Springfield, Illinois 62794, USA. mmalafa@siumed.edu
Neitzel
L T
LT
D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology; D002455:Cell Division / Q000187:drug effects; D016228:Endothelial Growth Factors / Q000037:antagonists & inhibitors / Q000235:genetics; D005260:Female; D006801:Humans; D008222:Lymphokines / Q000037:antagonists & inhibitors / Q000235:genetics; D008325:Mammary Neoplasms, Experimental / Q000188:drug therapy; D051379:Mice; D008819:Mice, Nude; D018919:Neovascularization, Physiologic / Q000187:drug effects; D024505:Tocopherols; D014407:Tumor Cells, Cultured; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D014810:Vitamin E / Q000031:analogs & derivatives* / Q000494:pharmacology
D000970:Antineoplastic Agents; D016228:Endothelial Growth Factors; D008222:Lymphokines; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D014810:Vitamin E; D024505:Tocopherols