Studies on basal cell carcinoma with emphasis on the role of the human homologue of the Drosophila patched gene

This study focused on basal cell carcinoma (BCC) and the role of the human homologue of the Drosophila patched gene (PTCH) in its development. It was found that stromelysin 3 (ST3) expression in the mesenchyme surrounding BCC tumor cells correlated with tumor invasiveness and fibrosis. Research on Swedish families with Nevoid Basal Cell Carcinoma Syndrome (NBCCS) localized the NBCCS gene to chromosome 9q22.3, identifying PTCH as the gene involved. PTCH mutations, often resulting in truncated proteins, were found in both hereditary and sporadic BCCs, with consistent overexpression of PTCH mRNA in tumor cells. This overexpression was also observed in trichoepithelioma (TE), suggesting a shared pathogenic pathway for similar skin tumors. The findings indicated a gatekeeper mechanism in skin tumorigenesis involving alterations in the PTCH signaling pathway.