Vitamin E succinate (VES) and all-trans-retinoic acid (RA) were determined to be growth inhibitory for B lymphoma cells in vitro. RL, an Epstein-Barr virus-negative human cell line, was growth suppressed 87% with VES (5 μg/ml) and 58% with RA (10-6M); both agents blocked the cells in G1 of the cell cycle. The antiproliferative effect of VES seems to be independent of its potential antioxidant property because both fat- and water-soluble antioxidants were found to have no effect on RL cell proliferation. VES and RA increased IgM antibody concentrations in cell supernatants 5.8-and 9.9- fold, respectively. DNA fragmentation and flow cytometry studies showed VES- and RA-induced apoptosis in RL cells. VES- and RA-treated RL cells gradually underwent apoptosis over time with maximal induction occurring at days 6 and 5 of culture, respectively. A role for transforming growth factor β in VES- and RA-mediated RL growth suppression is indicated by increased ligand and type II receptor protein expression. Furthermore, neutralizing antibodies to transforming growth factor β1 partially blocked the growth suppressive action of both VES and RA, thus suggesting that a TGF-β autocrine negative loop was involved in VES and RA suppression of RL cell growth.
|Original language||English (US)|
|Number of pages||9|
|Journal||Cell Growth and Differentiation|
|State||Published - 1995|
ASJC Scopus subject areas
- Cell Biology
- Molecular Biology