Molecular cytogenetic analysis of basal cell carcinoma DNA using comparative genomic hybridization

In an attempt to define genomic copy number changes associated with the dev elopment of basal cell carcinoma, we investigated 15 sporadic tumors by com parative genomic hybridization. With the incorporation of tissue micro diss ection and degenerate oligonucleotide primed-polymerase chain reaction we w ere able to isolate, and then universally amplify, DNA from the tumor type. This combined approach allows the investigation of chromosomal imbalances within a histologically distinct region of tissue. Using comparative genomi c hybridization we have observed novel and recurrent chromosomal gains at 6 p (47%), 6q (20%), 9p (20%), 7 (13%), and X (13%). In addition comparative genomic hybridization revealed regional loss on 9q in 33% of tested tumors encompassing 9q22.3 to which the putative tumor suppressor gene, Patched, h as been mapped. The deletion of Patched has been indicated in the developme nt of hereditary and sporadic basal cell carcinomas. The identification of these recurrent genetic aberrations suggests that basal cell carcinomas may not be as genetically stable as previously thought. Further investigation of these regions may lead to the identification of other genes responsible for basal cell carcinoma formation.