title: Human hedgehog interacting protein expression and promoter methylation in medulloblastoma cell lines and primary tumor samples.
abstract: Medulloblastoma is the most common pediatric brain tumor and its development is affected by genetic and epigenetic factors. In this study we found there is low or no expression of the hedgehog interacting protein (HHIP), a negative regulator of the sonic hedgehog pathway, in most medulloblastoma cell lines and primary samples explored. We proceeded to promoter methylation assays of this gene by MCA-Meth, and found that HHIP was hypermethylated in all medulloblastoma cell lines, but only in 2 out of 14 (14%) primary tumor samples. Methylation correlated with low or unexpressed HHIP in cell lines but not in primary tumor samples. These results suggest the possibility of epigenetic regulation of HHIP in medulloblastoma, similarly to gastric, hepatic and pancreatic cancer. However, HHIP seems to be not only under regulation of promoter methylation, but under other factors involved in the control of its low levels of expression in medulloblastoma.
authors.affiliation: Brain Tumor Biology Unit-CIFA, University of Navarra School of Sciences, Irunlarrea 1, 31008, Pamplona, Spain.
authors.forename: Mehdi H
authors.initials: MH
authors.lastname: Shahi
authors.forename: Mohammad
authors.initials: M
authors.lastname: Afzal
authors.forename: Subrata
authors.initials: S
authors.lastname: Sinha
authors.forename: Charles G
authors.initials: CG
authors.lastname: Eberhart
authors.forename: Juan A
authors.initials: JA
authors.lastname: Rey
authors.forename: Xing
authors.initials: X
authors.lastname: Fan
authors.forename: Javier S
authors.initials: JS
authors.lastname: Castresana
mesh_terms: D000293:Adolescent; D000328:Adult; D002352:Carrier Proteins / Q000235:genetics*; D045744:Cell Line, Tumor; D002528:Cerebellar Neoplasms / Q000235:genetics* / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D019175:DNA Methylation / Q000235:genetics*; D005260:Female; D015870:Gene Expression; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D008527:Medulloblastoma / Q000235:genetics* / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D055815:Young Adult
chemical_list: D002352:Carrier Proteins; C117596:HHIP protein, human; D008562:Membrane Glycoproteins