Associations of keratinocyte cancers with snp variants in the sonic hedgehog pathway

Abstract

Background: Sonic Hedgehog (SHH) pathway dysregulation is implicated in basal cell carcinoma (BCC) development. To evaluate the possible wider role of SHH gene variants in skin carcinogenesis, we assessed associations of genes in the SHH pathway with lifetime development of any keratinocyte cancer (KC), and with developing either BCCs or squamous cell carcinomas (SCCs) exclusively, in a 25-year prospective, population-based study of 1,621 Australians. Methods: We genotyped 795 unrelated adults with available blood samples: 311 cases with any KC (186 developing BCCs-only, 55 SCCs-only, 70 BCCs and SCCs) and 484 controls. We compared allele frequencies of 158 independent SNPs across 43 SHH genes between cases and controls, and performed a gene-based analysis. Results: We found associations between SNP rs4848627 (GLI2) (related to DNA synthesis in keratinocytes) and development of any KC (OR = 1.53; 95% CI = 1.06-2.13, P < 0.01) and SCCs exclusively (OR = 2.12; 95%CI = 1.39-3.23, P < 0.01). SNP rs3217882 located in CCND2 was associated with exclusive BCC development (OR = 1.43, CI = 1.12-1.82, P < 0.01). The gene-based analysis suggested an association of PRKACG (protein kinase cAMP-activated catalytic subunit gamma) with any KC (P = 0.013). Conclusion: We conclude that variants located in genes in the SHH pathway may are involved in SCC as well as BCC development.