Abstract 4806: Claudin downregulation in head and neck squamous cell carcinoma (HNSCC) may be caused by aberrant promoter methylation

Abstract

Abstract Claudins are a family of transmembrane proteins that compose the tight junctions, playing an essential role in cell-to-cell adhesion, maintenance of cell polarity and recruiting signaling proteins. The expression of these proteins has been found to be altered in several human cancers, suggesting that this family of proteins might represent potential molecular markers for cancer detection, diagnosis and therapy. We analyzed the expression profile of a claudin member gene in Head and Neck Squamous Cell Carcinomas (HNSCC) cases using Real-Time PCR, and found low expression in 78% of the evaluated cases. The expression of this gene was restored in an HNSCC cell line after treatment with the demethylating agent 5-Aza-2′-Deoxycytidine. After that, we designed primers for methylation analysis (MSP) and examined the expression and methylation status of this gene in several cell lines. A positive correlation between the expression level and methylation pattern was found. Besides, preliminary analyses of aberrant methylation status in HNSCC and normal samples showed 100% of specificity and 24% of sensitivity. This result suggests that aberrant methylation of claudin members could play a major role in the expression control of this gene. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4806. doi:10.1158/1538-7445.AM2011-4806