dl-alpha-tocopherol induces apoptosis in erythroleukemia, prostate, and breast cancer cells.
Vitamin E, best known as a potent antioxidant, has been shown to have other functions that are not mediated by this activity. Recent reports have suggested that vitamin E may inhibit smooth muscle cell and also cancer cell growth. We have studied the effect of dl-alpha-tocopherol (vitamin E) on a series of well-established cancer cell lines that included two erythroleukemia cell lines and a hormone-responsive breast and prostate cancer cell line. Cell proliferation was examined in these cell lines, which were maintained at optimal growth conditions. A dose-dependent inhibition of cell growth was found in all cell lines examined, with the MCF-7 breast and CRL-1740 prostate cancer cell lines showing potent suppression of growth at 0.1 mM vitamin E, whereas the erythroleukemia cell lines, HEL and OCIM-1, responded only at > 0.25 mM vitamin E with inhibition of proliferation. Studies of [3H]thymidine incorporation showed that vitamin E supplementation reduced DNA synthesis in all cell lines. Analysis of high-molecular-weight DNA revealed extensive fragmentation, indicating apoptosis of all cell lines supplemented with vitamin E. Our studies thus give evidence of a general inhibition of cell proliferation by dl-alpha-tocopherol, with breast and prostate cancer cells distinctly more sensitive than erythroleukemia cells.
Sigounas
G
G
Division of Hematology/Oncology, East Carolina University School of Medicine, Greenville, NC 27858, USA. sigounas@brody.med.ecu.edu
Anagnostou
A
A
Steiner
M
M
D017209:Apoptosis / Q000187:drug effects*; D001943:Breast Neoplasms / Q000473:pathology*; D002455:Cell Division / Q000187:drug effects; D004247:DNA / Q000096:biosynthesis; D053938:DNA Fragmentation; D004587:Electrophoresis, Agar Gel; D006801:Humans; D004915:Leukemia, Erythroblastic, Acute / Q000473:pathology*; D008297:Male; D011471:Prostatic Neoplasms / Q000473:pathology*; D014407:Tumor Cells, Cultured; D014810:Vitamin E / Q000494:pharmacology*
D014810:Vitamin E; D004247:DNA