Aneuploidy of sex chromosomes in basal cell carcinoma: Its clonality and involvement in the development of carcinogenesis

Although basal cell carcinoma (BCC) is a major skin cancer, the mechanism o f carcinogenesis with regard to cytogenetic abnormalities has not been full y investigated. In the present study, we carried out cytogenetic analyses o f 18 patients (9 male and 9 female) with BCC. Aneuploidy was seen by Q-band ing method in more than half of the cases and was mostly loss of the sex ch romosome. We also performed FISH to the interphase nuclei of various tissue s and short-term cultured BCC cells. The frequency of sex chromosomal aneup loidy was significantly higher in all samples from BCC patients (peripheral blood lymphocytes, non-lesional tissues, BCC tumor tissues and cultured BC C cells) than in age-matched normal controls. In addition, we analyzed clon ality of BCC tissues using a human androgen receptor gene assay and found u niparental pattern of inactive X-chromosomes. This indicates that BCC cells were monoclonal in origin and the development of BCC might be correlated w ith sex chromosomal aneuploidy, which acquired accumulation of genetic muta tions.