DIFFERENTIAL SENSITIVITY AMONG 3 HUMAN SUBPOPULATIONS IN RESPONSE TO 4-NITROQUINOLINE-1-OXIDE AND TO BLEOMYCIN

An assay employing the UV-mimetic mutagen 4-nitroquinoline-1-oxide (4N QO) to estimate a person's UV-sensitivity was developed. This sensitiv ity may be translated into an individual's susceptibility to acquire c utaneous malignancies. We used cytogenetic recordings on cultured lymp hocytes from 103 normal individuals, 62 melanoma patients, and 71 pati ents with head and neck cancer. The frequency of chromosome damage (ch romatid breaks) caused by exposure to 4NQO was used to measure sensiti vity. Preliminary results showed that a significantly higher proportio n of melanoma patients was 4NQO sensitive compared to the other two gr oups, whose 4NQO sensitivity was statistically not different. Although a number of theoretical and technical problems remain to be resolved and a great deal of additional information (especially clinical and ep idemiological) is needed, it appears that 4NQO sensitivity may be effe ctively employed as a biological marker for identification of individu als at risk for melanoma (and possibly other cutaneous neoplasms as we ll).