title: EPB41L3, TSP-1 and RASSF2 as new clinically relevant prognostic biomarkers in diffuse gliomas.
abstract: 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.
authors.affiliation: Cancer Epigenetics Group, Navarrabiomed-Fundación Miguel Servet, Navarra, Spain.
authors.forename: N
authors.initials: N
authors.lastname: Perez-Janices
authors.affiliation: Cancer Epigenetics Group, Navarrabiomed-Fundación Miguel Servet, Navarra, Spain.
authors.forename: I
authors.initials: I
authors.lastname: Blanco-Luquin
authors.affiliation: Department of Pathology Section A, Complejo Hospitalario de Navarra, Navarra Health Service, Navarra, Spain.
authors.forename: M T
authors.initials: MT
authors.lastname: Tuñón
authors.affiliation: Department of Pathology Section A, Complejo Hospitalario de Navarra, Navarra Health Service, Navarra, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Barba-Ramos
authors.affiliation: Navarrabiomed-Fundación Miguel Servet, Navarra, Spain. Red de Evaluación en Servicios Sanitarios y Enfermedades Crónicas (REDISSEC), Navarra, Spain.
authors.forename: B
authors.initials: B
authors.lastname: Ibáñez
authors.affiliation: Department of Neurosurgery, Complejo Hospitalario de Navarra, Navarra Health Service, Navarra, Spain.
authors.forename: I
authors.initials: I
authors.lastname: Zazpe-Cenoz
authors.affiliation: Department of Medical Oncology, Complejo Hospitalario de Navarra, Navarra Health Service, Navarra, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Martinez-Aguillo
authors.affiliation: Department of Medical Oncology, Complejo Hospitalario de Navarra, Navarra Health Service, Navarra, Spain.
authors.forename: B
authors.initials: B
authors.lastname: Hernandez
authors.affiliation: Department of Radiation Oncology, Complejo Hospitalario de Navarra, Navarra Health Service, Navarra, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Martínez-Lopez
authors.affiliation: Cancer Epigenetics Laboratory, Instituto Universitario de Oncología del Principado de Asturias (IUOPA), HUCA, Universidad de Oviedo, Asturias, Spain.
authors.forename: A F
authors.initials: AF
authors.lastname: Fernández
authors.affiliation: Department of Pathology Section A, Complejo Hospitalario de Navarra, Navarra Health Service, Navarra, Spain.
authors.forename: M R
authors.initials: MR
authors.lastname: Mercado
authors.affiliation: Department of Radiology, Complejo Hospitalario de Navarra, Navarra Health Service, Navarra, Spain.
authors.forename: T
authors.initials: T
authors.lastname: Cabada
authors.affiliation: Navarrabiomed-Fundación Miguel Servet, Navarra, Spain.
authors.forename: D
authors.initials: D
authors.lastname: Escors
authors.affiliation: Confocal Microscopy Core Unit, Spanish National Cancer Research Centre, Madrid, Spain.
authors.forename: D
authors.initials: D
authors.lastname: Megias
authors.affiliation: Cancer Epigenetics Group, Navarrabiomed-Fundación Miguel Servet, Navarra, Spain.
authors.forename: D
authors.initials: D
authors.lastname: Guerrero-Setas
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis; D001932:Brain Neoplasms / Q000235:genetics* / Q000401:mortality; D019175:DNA Methylation / Q000235:genetics; D018572:Disease-Free Survival; D005260:Female; D005455:Fluorescent Antibody Technique; D005910:Glioma / Q000235:genetics* / Q000401:mortality; D006801:Humans; D007150:Immunohistochemistry; D053208:Kaplan-Meier Estimate; D008297:Male; D008840:Microfilament Proteins / Q000235:genetics*; D008875:Middle Aged; D011379:Prognosis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019700:Thrombospondin 1 / Q000235:genetics*; D025521:Tumor Suppressor Proteins / Q000235:genetics*
chemical_list: D014408:Biomarkers, Tumor; C116887:EPB41L3 protein, human; D008840:Microfilament Proteins; C425300:RASSF2 protein, human; D019700:Thrombospondin 1; D025521:Tumor Suppressor Proteins