Abstract 2642: Dietary intake is associated with tumor suppressor DNA methylation in head and neck squamous cell carcinomas

Abstract

Abstract Background: Diet is associated with prognosis in several cancers, including head and neck, and has been hypothesized to influence epigenetic state by determining the availability of moieties involved in the modification of DNA and histone proteins. Tumor DNA methylation patterns are also hypothesized to be a prognostic factor in cancer, however, the link between diet and HNSCC tumor DNA methylation has not been characterized. Methods: Pretreatment data on usual food and nutrient consumption was collected via food frequency questionnaire (FFQ) on 49 cases identified through the UM Head and Neck SPORE. Tumor DNA methylation was assessed with the Illumina Goldengate Methylation Cancer Panel, which measures methylation at 1505 CpG sites across 807 genes related to cancer. To identify if dietary intake was associated with stochastic methylation in tumor suppressor genes, we calculated a “methylation score,” the sum of the individual hypermethylated tumor suppressor associated CpG sites. Gene specific analyses using linear modeling coupled with an empirical Bayes method of variance estimation were conducted to identify if methylation at individual CpG sites is associated with dietary intake. Results: Intake of antioxidant and methyl donor nutrients tended to be inversely associated with tumor suppressor methylation score. Individuals reporting the highest quartile of dietary folate, vitamin B12 and cruciferous vegetable intake, compared to those with lowest intake, had significantly less tumor suppressor gene methylation (p=0.04 and p=0.01, respectively), as did patients reporting the highest intake of cruciferous vegetables (p=0.04). In gene specific analyses, HPV positive individuals with the highest quartile of vitamin B12 intake were found to have significantly decreased methylation of four genes, RARB, PTHLH, SNRPN, and DCC. Conclusions: These preliminary results suggest that dietary intake may influence the tumor DNA methylation profile in HNSCC and that intake of specific micronutrients may enhance tumor suppression and possibly contribute to survival. Further studies will be needed to explore the effect of diet on head and neck cancer prevention and treatment. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2642. doi:1538-7445.AM2012-2642