Abstract 4458: Discovery of novel epigenetic biomarkers in premalignant/malignant oral cavity lesions by methylation arrays

Abstract

Abstract Purpose: The incidence of the oral squamous cell carcinoma (OSCC) is around 50% of all head and neck cancer (HNC), the sixth most common type of cancer in the world. Aberrant hyper/hypo-methylation in the promoter region of some known or putative tumor suppressor/protoonco-genes occurs frequently during the development of various cancers including OSCC. Both of genetic and environmental factors play roles in the carcinogenesis of malignant lesions. Etiological factors predisposing to OSCC are smoking, alcohol and tobacco consumption, snuffuse, viral factors, chronic irritation, iron and various vitamin deficiencies, poor oral hygiene and diseases such as syphilis. Despite the advances in cancer diagnosis and treatment, the 5-year survival rate of OSCC patients is poor and because of advanced stage of disease, it has high mortality and morbidity. Another the most important ethiological factor of OSCC is oral premalignant lesions (OPML), since OPML is related with malignant transformation. In our study, we included three different OPML associated with different risks of leading to malignancy: Oral leukoplakia has a high risk of conversion into malignancy, whereas oral lichen planus and oral lichenoid dysplasia are associated with lower risk. We aimed to investigate the epigenetic characterization of OSCC and OPML relative to the epigenetic changes in these groups. Experimental Design: Tumor and corresponding healthy tissues from 12 and 10 Turkish patients with OPML and OSCC, respectively were collected. The samples were analyzed histopatologically and after DNA extraction and bisulfite modification, methylation patterns of the samples were investigated by using the Illumina Infinium HumanMethylation450 (450K) BeadChip array. Results: According to our preliminary results obtained from the methylation array experiments, CpG regions in the UOX, ABCC12, FCRLB, ABL2, LGR6 and SLC22A18 genes were found unmethylated while CpGs located in YPEL-3 were highly methylated (p<0.005). Conclusion: We concluded the UOX, ABCC12, FCRLB, ABL2, LGR6, SLC22A18 and YPEL-3 may be potential biomarker candidate genes playing role in the transformation mechanism of OPML/OSCC. In the further studies, we will compare the methylation patterns between OPML subgroups to discriminate the potential candidates. *This study was supported by the Scientific and Technological Research Council of Turkey (TUBITAK-SBAG-114S497). Citation Format: Semra Demokan, Sevde Comert, Cansu Ozkoklesen, Murat Ulusan, Gulsum Ak, Canan Alatli, Nejat Dalay. Discovery of novel epigenetic biomarkers in premalignant/malignant oral cavity lesions by methylation arrays. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4458.