title: Genotype analysis of tumor-initiating cells expressing CD133 in neuroblastoma.
abstract: Neuroblastoma (NB) is the most common and lethal extracranial solid tumor of childhood. Despite aggressive therapy, more than half of the children with advanced NB will die of uncontrolled metastatic disease. After chemotherapy, tumor-initiating cells (TICs) could persist, cause relapses and metastasis. The aim of this study is to demonstrate the tumor-initiating properties of CD133high NB cells and to identify new specific genetic abnormalities. Isolation of the CD133high cell population from NB cell lines was followed by neurosphere formation, soft agar assays, and orthotopic injections in NOD/SCID/IL2Rγc-null mice. A differential genotyping analysis was performed with Affymetrix SNP 6.0 arrays on CD133low and CD133high populations and the frequency of the abnormalities of 36 NB tumors was determined. Our results show that CD133high NB cells possess tumor-initiating properties, as CD133high cells formed significantly more neurospheres and produced significantly more colonies in soft agar than CD133low. Injection of 500 CD133high cells was sufficient to generate primary tumors and frequent metastases in mice. Differential genotyping analysis demonstrated two common regions with gains (16p13.3 and 19p13.3) including the gene EFNA2 in the CD133high population, and two with loss of heterozygosity (16q12.1 and 21q21.3) in the CD133low population. The gain of EFNA2 correlated with increased expression of the corresponding protein. These abnormalities were found in NB samples and some were significantly correlated with CD133 expression. Our results show that CD133high NB cells have TICs properties and present different genotyping characteristics compared to CD133low cells. Our findings reveal insights into new therapeutic targets in NB TICs.
authors.affiliation: Centre de recherche CHU Sainte-Justine, Montréal, QC, Canada.
authors.forename: Sonia
authors.initials: S
authors.lastname: Cournoyer
authors.forename: Carine
authors.initials: C
authors.lastname: Nyalendo
authors.forename: Anissa
authors.initials: A
authors.lastname: Addioui
authors.forename: Assila
authors.initials: A
authors.lastname: Belounis
authors.forename: Mona
authors.initials: M
authors.lastname: Beaunoyer
authors.forename: Anne
authors.initials: A
authors.lastname: Aumont
authors.forename: Pierre
authors.initials: P
authors.lastname: Teira
authors.forename: Michel
authors.initials: M
authors.lastname: Duval
authors.forename: Karl
authors.initials: K
authors.lastname: Fernandes
authors.forename: Raouf
authors.initials: R
authors.lastname: Fetni
authors.forename: Elie
authors.initials: E
authors.lastname: Haddad
authors.forename: Hervé
authors.initials: H
authors.lastname: Sartelet
mesh_terms: D000071916:AC133 Antigen; D000310:Adrenal Gland Neoplasms; D000818:Animals; D015703:Antigens, CD / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D045744:Cell Line, Tumor; D002469:Cell Separation; D016009:Chi-Square Distribution; D002869:Chromosome Aberrations; D005260:Female; D005838:Genotype; D006023:Glycoproteins / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D008297:Male; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D016254:Mutagenesis, Insertional; D009368:Neoplasm Transplantation; D009447:Neuroblastoma / Q000235:genetics* / Q000378:metabolism; D010455:Peptides / Q000235:genetics* / Q000378:metabolism; D020641:Polymorphism, Single Nucleotide
chemical_list: D000071916:AC133 Antigen; D015703:Antigens, CD; D006023:Glycoproteins; C000606023:PROM1 protein, human; D010455:Peptides; C000606024:Prom1 protein, mouse