Abstract 5247: Analysis of stemness gene expression and CD133 abnormal methylation in neuroblastoma cell lines

Abstract

Abstract Neuroblastoma is the most common extracranial solid tumor of childhood. Cellular heterogeneity is a hallmark of this embryonal malignancy, 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 12 neuroblastoma cell lines. RT-PCR and flow citometry 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). Also, glial and neuronal markers like NCAM1, GFAP and B-TUBULIN III (TUBB3) were analyzed. Interestingly, we found that neuroblastoma cell lines showed a particular pattern of expression suggesting the presence of a subpopulation of immature stem like cancer cells. Epigenetic changes regarding the CD133 (Prominin-1) promoter gene were also analyzed. This protein has been extensively used to enrich putative cancer propagating stem-like cell populations of different kinds of solid tumors. We found unusual DNA methylation, as 7 of the 12 neuroblastoma cell lines analysed featured a half-methylated state. An increase of RNA and protein levels of CD133 was achieved following demethylation assays using 5-aza-2′-deoxycytidine. Because cancer stem cells are believed responsible for tumor metastasis, escape from anticancer therapies and disease relapse, their therapeutic targeting and analysis is crucial in neuroblastoma. Also, the regulation of CD133 by epigenetic changes may provide an innovative mechanism of CD133 expression as its regulation still remains unclear. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5247.