Altered gene expression in squamous cell carcinoma arising from congenital unilateral linear porokeratosis.

Congenital unilateral linear porokeratosis (CULP) is a rare disorder of keratinization that shares clinical and molecular similarities with psoriasis. It also has an increased risk for malignant transformation to cutaneous squamous cell carcinoma (SCC). We investigated the expression of psoriasin, human beta-defensin-2, cathelicidin antimicrobial peptide/LL-37, e-cadherin, involucrin, p16(INK4a) , p53, cyclin D1 and microchromosome maintenance protein 7 in healthy skin and in lesions of psoriasis, CULP and SCC from the same patient. p16(INK4a) was overexpressed in CULP but not in the subsequent SCC. Psoriasin was overexpressed in psoriasis, CULP and SCC compared with healthy skin. Speculatively, p16(INK4a) and psoriasin could be involved in the pathogenesis of CULP. Moreover, psoriasin may play a role in the malignant transformation of CULP to SCC.