Expression of the serine protease DESC1 correlates directly with normal keratinocyte differentiation and inversely with head and neck squamous cell carcinoma progression.

ABSTRACT

BACKGROUND: As part of ongoing studies aimed at identifying the molecular events involved in head and neck squamous cell carcinoma progression, we recently isolated a novel serine protease, DESC1. This study was conducted to further characterize DESC1. METHODS: Specimens of normal, dysplastic, and carcinomatous oropharyngeal mucosa (n = 31) were evaluated for DESC1 immunoreactivity using standard streptavidin-biotin immunoperoxidase techniques. Between-lesion stain intensity values were analyzed using multiple Wilcoxon tests. DESC1 expression was also evaluated in cultured human keratinocytes after induction of differentiation by calcium challenge, with subsequent real-time reverse transcriptase-polymerase chain reaction quantification. RESULTS: DESC1 immunoreactivity decreased as lesions approached a malignant phenotype. Post hoc testing comparing the different lesion types and DESC1 staining values showed significance between "normal" and "carcinoma" (p = .0017) groups. Induction of normal keratinocyte differentiation by calcium challenge was accompanied by an increase in DESC1 expression (p = .002). CONCLUSIONS: These results suggest downregulation of DESC1 during squamous cell carcinoma progression and upregulation during normal epithelial differentiation.