Photoreactivation: evaluation of pyrimidine dimers in ultraviolet radiation-induced cell transformation.

The PRE repairs DNA by the specific and exclusive monomerization of pyrimidine dimers. Photoreactivation thus provides an analytical test for determining the role of pyrimidine dimers in UV damage to biologic systems. We have shown the first UV transformation of cultured human cells (judged by ability to grow in soft agar). Preliminary results indicate that 1) lesions leading to cell transformation are subject to photoreactivation and 2) pyrimidine dimers may well be important in solar carcinogenesis.