Hypermethylation of tumor suppressor genes is one of the hallmarks in the progression of brain tumors. Our objectives were to analyze the presence of the hypermethylation of EPB41L3, RASSF2 and TSP-1 genes in 132 diffuse gliomas (astrocytic and oligodendroglial tumors) and in 10 cases of normal brain, and to establish their association with the patients’ clinicopathological characteristics. Gene hypermethylation was analyzed by methylation-specific-PCR and confirmed by pyrosequencing (for EPB41L3 and TSP-1) and bisulfite-sequencing (for RASSF2). EPB41L3, RASSF2 and TSP-1 genes were hypermethylated only in tumors (29%, 10.6%, and 50%, respectively), confirming their cancer-specific role. Treatment of cells with the DNA-demethylating-agent 5-aza-2′-deoxycytidine restores their transcription, as confirmed by quantitative-reverse-transcription-PCR and immunofluorescence. Immunohistochemistry for EPB41L3, RASSF2 and TSP-1 was performed to analyze protein expression; p53, ki-67, and CD31 expression and 1p/19q co-deletion were considered to better characterize the tumors. EPB41L3 and TSP-1 hypermethylation was associated with worse (p = 0.047) and better (p = 0.037) prognosis, respectively. This observation was confirmed after adjusting the results for age and tumor grade, the role of TSP-1 being most pronounced in oligodendrogliomas (p = 0.001). We conclude that EPB41L3, RASSF2 and TSP-1 genes are involved in the pathogenesis of diffuse gliomas, and that EPB41L3 and TSP-1 hypermethylation are of prognostic significance.

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INTRODUCTION: High grade gliomas (HGG) represent approximately 10% of all pediatric central nervous system (CNS) tumors. Despite a variety of therapies, outcomes remain dismal. In contrast to adults with HGG, there is no apparent standard of care (SOC) for the treatment of children with HGG after surgery. We undertook an internet-based survey to better understand what the perceived SOC is for children. 3 years with newly diagnosed HGG. METHODS: An 8 question internet-based survey was e-mailed to 120 physicians who treat children with CNS tumors. Demographic data, including medical specialty, experience and institutional affiliations were collected. Respondents were asked what they consider as SOC for children with newly diagnosed HGG after a maximal surgical resection. RESULTS: The entire survey was completed by 62.5% (75/120) of respondents. 83% (62/75) identified themselves as pediatric oncologists/neuro-oncologists. The remaining were pediatric neurosurgeons, radiation oncologists and neurologists. 65% had .10 years' experience and approximately 84% worked in a large academic or cancer center. More than 70% answered that their affiliated institution sees more than 5 pediatric HGG patients each year. The most commonly answered SOC was to treat patients on any available Phase I or II clinical trial (26.7%). In the absence of a clinical trial, physicians most commonly answered that they personally would treat a newly diagnosed patient with focal radiation plus temozolomide followed by maintenance temozolomide (30.7%).