Effects of mechlorethamine (HN2, nitrogen mustard) on UV-induced carcinogenesis in hairless mouse skin.

The influence of mechlorethamine (HN2, nitrogen mustard) on UV-induced carcinogenesis was examined in the hairless mouse skin in vivo. Noncarcinogenic amounts of topically applied HN2 and carcinogenic levels of UVB energy were used in the study. The HN2 applications significantly accelerated the appearance and growth of cutaneous tumors in this study. Thus HN2 acted as either a promoter or cocarcinogen for UV-induced cancer formation. Although the mechanism of this effect was not established, combinations of UVB radiation and HN2 topical therapy pointed to an increased incidence of cutaneous tumors in human skin.