Abstract 2789: Investigating the role of DNA methylation in pediatric choroid plexus tumors

Choroid plexus tumors (CPTs) are rare neoplasms of the central nervous system most commonly found in the pediatric population. CPTs represent 1- 4% of all childhood brain tumors, with 10- 20% occurring during the first year of life. Within this family of tumors, choroid plexus carcinoma (CPC) is the malignant neoplasm which is categorized as a grade III tumor by the WHO. Choroid plexus papilloma (CPP) is a benign form classified as a grade I tumor, and atypical choroid plexus papilloma (aCPP) as a grade II tumor. Distinction between these tumor subtypes is essential for treatment stratification. Previous studies performed in our laboratory suggest that CPTs are highly unstable and harbor unique patterns of chromosome-wide gains and losses. To better understand the complexities of tumor biology of CPTs as well as to identify better molecular biomarkers to distinguish between aggressive and benign forms of CPTs we performed a genome-wide DNA methylation study using Illumina Human Methylation450 BeadChip. We analyzed genome-wide DNA methylation profiles from 34 CPT (14 CPCs, 5 aCPPs and 15 CPPs) samples. Differential DNA methylation analysis did not identify significant differences between aCPPs and CPPs, therefore we explored CPC-specific DNA methylation signature in comparison to CPPs. Using a median beta value difference of 0.3 or greater and an FDR adjusted p-value Citation Format: Malgorzata Pienkowska, Sanaa Choufani, Andrei Turinsky, Diana Merino, Ana Novokmet, Michael Brudno, Rosanna Weksberg, Adam Shlien, Cynthia Hawkins, Eric Bouffet, Uri Tabori, Richard Gilbertson, David Malkin. Investigating the role of DNA methylation in pediatric choroid plexus tumors. [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 2789.