Epigenetic landscape in IDH1 mutant glioma

A1 Investigations of the functional interactions between CIC and ATXN1L in Oligodendroglioma D. Wong, V. Leblanc, S. Chittaranjan, M. Marra, S. Yip BC Cancer Agency, UBC, Vancouver, BC, Canada doi:10.1017/cjn.2017.2 Oligodendroglioma (ODG) is a subtype of low grade glioma marked by unique clinical and genomic characteristics including slow predictable progression, IDH mutation, and 1p19qcodeletion. ODGs are more sensitive to treatment leading to a favorable prognosis. Recently, mutations in CIC, a gene found on chromosome 19q, have been found in up to 70% of IDH mutated, 1p19q-codeleted ODGs. The high frequency of CIC mutations in a hemizygous state indicates that loss or altered function of the CIC protein may be crucially associated with the unique biology of ODG. Previous studies of CIC have shown this protein to be a transcriptional repressor of ETS transcription factors and a negative regulator of the MAPK pathway. CIC and ataxin-1-like (ATXN1L) are also closely involved in the pathology of spinocerebellar ataxia (SCA). However, their relationship and role in brain tumour biology has yet to be elucidated. In this study, we explore the molecular, proteomic, and functional relationship between CIC and ATXN1L which may lead to unique insights on the clinical behavior of ODG as well as identify potential molecular therapeutic targets in this enigmatic brain tumour.