L-ascorbic acid-induced DNA strand breaks and cross links in human neuroblastoma cells.

The effect of high concentrations of L-ascorbic acid on the in vivo and in vitro growth of human neuroblastoma has been investigated. Directly implemented into cell culture it decreased the DNA, RNA and protein synthesis, and mitosis of neuroblastoma cells, without affecting normal neuronal cells. In vivo treatment of young nude mice bearing human neuroblastoma with 500 mg/kg L-ascorbic acid for the first 10 days markedly inhibited the growth of tumor mass. As determined by alkaline elution, both DNA strand breaks and DNA cross links were observed in tumor cells treated with 1 X 10(-4) M L-ascorbic acid for 2 h. DNA-DNA and DNA-protein cross links in cells treated with L-ascorbic acid were revealed by the proteinase potassium assay. The results indicated that L-ascorbic acid can be a very effective and selective agent against human neuroblastoma.