Neoplastic transformation of Syrian hamster embryo cells by bisulfite is accompanied with a decrease in the number of functioning replicons.

Bisulfite, a chemical that at neutral pH does no induce mutations at two loci in Chinese hamster V-79 cells, induces transformation of Syrian hamster embryo cells. Although bisulfite affects DNA metabolism, there was no evidence of bisulfite-induced DNA damage. Bisulfite induced no excision repair replication, caused no DNA strand breaks detectable in alkaline sucrose gradients, had no effect on the size distribution of DNA nascent daughter strands, and did not affect excision on post-replication repair of u.v.-induced damage. However, bisulfite did induce a dose-dependent decrease in the rate of DNA replication per cell, apparently due to a reduction in the number of functioning replicons. Since the data indicate that bisulfite causes no detectable DNA damage, it appears that bisulfite induces transformation by a non-mutagenic event that could involve the inhibition of semi-conservative DNA synthesis.