Vitamin E Increases the Growth Inhibitory and Differentiating Effects of Tumor Therapeutic Agents on Neuroblastoma and Glioma Cells in Culture

Abstract

The effects of vitamin E in combination with several pharmacological agents on neuroblastoma (NBP2) and glioma (C-6) cells in culture for the criteria of growth inhibition (due to cell death and reduction of cell division) and morphological changes were studied. Vitamin E in combination with 5-FU [5-fluorouracil], adriamycin, R020-1724 [4-(3-butoxy-4-methoxybenzyl)-2-imidazolidinone], vincristine, sodium butyrate, chlorozotocin or PGE1 [prostaglandin E1] produced a synergistic effect on growth inhibition of NB cells, whereas vitamin E with bleomycin, CCNU [1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea], DTIC [5-(3,3-dimethyl-1-triazeno)-imidazole-4-carboxamide], mutamycin or cis-platinum produced an additive effect for the same criterion. In glioma cell culture, vitamin E with vincristine, R020-1724 and CCNU produced a synergistic growth inhibition; whereas, vitamin E with bleomycin, 5-FU, adriamycin, DTIC, papaverine, mutamycin and cis-platinum produced an additive effect for this criterion. Vitamin E failed to enhance the effect of sodium butyrate, PGE1, chlorozotocin on glioma cells. Bleomycin, CCNU, chlorozotocin or vitamin E at concentrations used in this study did not increase the morphological differentiation of NB cells, however, vitamin E in combination with 1 of these agents markedly enhanced the number of morphologically differentiated NB cells. Adriamycin, PGE1, R020-1724, papaverine, mutamycin, and cis-platinum increased the expression of morphological differentiation of NB cells, but vitamin E enhanced the effect of these agents for this criterion. Treatment of glioma cells with vitamin E and pharmacological agents did not significantly change morphological differentiation. Vitamin E may modulate the effects of pharmacological agents.