PP081: Ceramide synthase isoforms in malignant transformation of oral mucosal dysplasia

Abstract

Purpose To study the differential expression of Ceramide Synthase isoforms in oral mucosal dysplasia and its malignant transformation. Methods We identified 12 cases of oral mucosal dysplasia with subsequent malignant transformation from the College of Dental Medicine, Division of Oral Pathology Database at the Medical University of South Carolina. These were formalin fixed paraffin embedded (FFPE) biopsy specimens of dysplasia from one oral subsite at one time point and a matching specimen from the same subsite and same patient at a later time-point with frank invasive squamous cell carcinoma. We also identified 42 cases of alveolar ridge keratosis which were age and gender matched to our set of cases with malignant transformation. Two sections, 5 microns each from the FFPE blocks to extract RNA using the High Pure RNA FFPE micro-kit from Roche Applied Sciences (Catalog No. 04823125001), followed by reverse transcription and q-PCR using Ceramide Synthase (CerS) isoform 1, 4 and 6 probes. Results CerS 1 levels are higher in malignancy compared to the matched dysplasia samples whereas CerS 4 levels are lower in malignancy compared to the matched dysplasia samples. The levels of CerS6 are not significantly changed across the two sample sets. Conclusion Ceramide synthase isoforms play a role in malignant transformation of oral mucosal dysplasia however the mechanism needs to be further studied and understood. This could be a novel marker for early detection of potentially malignant lesions in the oral mucosa and may serve as a target for chemoprevention strategies in oral squamous cell carcinoma.