title: Analysis of stemness gene expression and CD133 abnormal methylation in neuroblastoma cell lines.
abstract: Neuroblastoma is the most common extracranial solid tumor in children, accounting for up to 10% of all childhood malignancies. Cellular heterogeneity is a hallmark of this embryonal cancer, as distinct neural crest lineages can be found within the same tumor sample. The aim of our study was to investigate the presence of a subpopulation of immature cells with features of cancer-like stem cells in 10 neuroblastoma cell lines. RT-PCR and flow cytometry were performed in order to analyze different kinds of 'stemness genes' such as: NESTIN (NES), CD133, SOX-2, BMI1, c-KIT, MELK1, MUSASHI-1 (MSI1), FAS, CD44 and VIMENTIN (VIM). In addition, glial and neuronal markers such as NCAM1, GFAP and B-TUBULIN III (TUBB3) were analyzed. Epigenetic changes within the CD133 (Prominin-1) gene promoter were also analyzed. Neuroblastoma cell lines showed a particular pattern of expression, suggesting the presence of an immature cancer stem cell-like subpopulation. The CD133 protein, commonly used to enrich putative cancer propagating stem cell-like populations in different kinds of solid tumors, presented a half-methylated DNA state in 7 of the 12 neuroblastoma cell lines analyzed. An increase in RNA and protein levels of CD133 was achieved following demethylation by assays using 5-aza-2'-deoxycytidine (5-Aza-dC). Since cancer stem cells are believed to be responsible for tumor metastasis, escape from anticancer therapies and disease relapse, their therapeutic targeting and analysis is crucial in neuroblastoma. Moreover, the regulation of CD133 by epigenetic changes may provide an innovative mechanism of CD133 expression as its regulation still remains unclear.
authors.affiliation: Brain Tumor Biology Unit-CIFA, University of Navarra School of Sciences, Pamplona, Spain.
authors.forename: Paula
authors.initials: P
authors.lastname: Schiapparelli
authors.forename: Mónica
authors.initials: M
authors.lastname: Enguita-Germán
authors.forename: Jana
authors.initials: J
authors.lastname: Balbuena
authors.forename: Juan A
authors.initials: JA
authors.lastname: Rey
authors.forename: Paula
authors.initials: P
authors.lastname: Lázcoz
authors.forename: Javier S
authors.initials: JS
authors.lastname: Castresana
mesh_terms: D000071916:AC133 Antigen; D015703:Antigens, CD / Q000096:biosynthesis / Q000235:genetics*; D045744:Cell Line, Tumor; D019175:DNA Methylation; D057890:Epigenomics; D005434:Flow Cytometry; D015972:Gene Expression Regulation, Neoplastic; D006023:Glycoproteins / Q000096:biosynthesis / Q000235:genetics*; D006801:Humans; D014411:Neoplastic Stem Cells / Q000378:metabolism / Q000473:pathology / Q000502:physiology*; D009447:Neuroblastoma / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D010455:Peptides / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D000071916:AC133 Antigen; D015703:Antigens, CD; D006023:Glycoproteins; C000606023:PROM1 protein, human; D010455:Peptides