1-sulfooxymethylpyrene is an electrophilic mutagen and ultimate carcinogen of 1-methyl- and 1-hydroxymethylpyrene

1-Hydroxymethylpyrene and 1-sulfooxymethylpyrene were tested for complete carcinogenic activity by repeated s.c. injection in groups of 12 female Sprague Dawley rats, respectively. A dose of 0.2 mu mol of either 1-sulfooxymethylpyrene or 1-hydroxymethylpyrene was administered every other weekday for 20 doses (i.e., total dose 4 mu mol) to each of 12 rats, beginning at 30 days of age. Once. week the rats were weighed then palpated for the appearance of tumors. Tumor-bearing rats were sacrificed 20-50 days after the appearance of first palpable tumor. By 52 weeks, 1-sulfooxymethylpyrene had induced sarcomas at the site of injection in 58% of the rats with an average induction time of 33 weeks. By contrast, 20, 0.2 mu mol doses of 1-hydroxymethylpyrene failed to induce tumors at the site of injection in a group of 12 rats. Similarly, neither of the two control groups produced rumors. The present experiment, together with previous data, strongly supports the hypothesis that 1-sulfooxymethylpyrene is either itself an ultimate carcinogen or a direct precursor of an ultimate carcinogen, the highly reactive benzylic carbonium ion, which reacts with DNA to form aralkyl-DNA adducts in a chain of events leading to malignant growth. (C) 1996 Academic Press, Inc.