Functional sphere profiling reveals the complexity of neuroblastoma tumor-initiating cell model.
Neuroblastoma (NB) is a neural crest-derived childhood tumor characterized by a remarkable phenotypic diversity, ranging from spontaneous regression to fatal metastatic disease. Although the cancer stem cell (CSC) model provides a trail to characterize the cells responsible for tumor onset, the NB tumor-initiating cell (TIC) has not been identified. In this study, the relevance of the CSC model in NB was investigated by taking advantage of typical functional stem cell characteristics. A predictive association was established between self-renewal, as assessed by serial sphere formation, and clinical aggressiveness in primary tumors. Moreover, cell subsets gradually selected during serial sphere culture harbored increased in vivo tumorigenicity, only highlighted in an orthotopic microenvironment. A microarray time course analysis of serial spheres passages from metastatic cells allowed us to specifically "profile" the NB stem cell-like phenotype and to identify CD133, ABC transporter, and WNT and NOTCH genes as spheres markers. On the basis of combined sphere markers expression, at least two distinct tumorigenic cell subpopulations were identified, also shown to preexist in primary NB. However, sphere markers-mediated cell sorting of parental tumor failed to recapitulate the TIC phenotype in the orthotopic model, highlighting the complexity of the CSC model. Our data support the NB stem-like cells as a dynamic and heterogeneous cell population strongly dependent on microenvironmental signals and add novel candidate genes as potential therapeutic targets in the control of high-risk NB.
Paediatric Oncology Research Unit, University Hospital of Lausanne, Rue du Bugnon 46, Lausanne, Switzerland.
Aurélie
A
Coulon
Marjorie
M
Flahaut
Annick
A
Mühlethaler-Mottet
Roland
R
Meier
Julie
J
Liberman
Katia
K
Balmas-Bourloud
Katya
K
Nardou
Pu
P
Yan
Stéphane
S
Tercier
Jean-Marc
JM
Joseph
Lukas
L
Sommer
Nicole
N
Gross
D000071916:AC133 Antigen; D018528:ATP-Binding Cassette Transporters / Q000235:genetics / Q000378:metabolism; D000818:Animals; D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism; D015153:Blotting, Western; D002648:Child; D002675:Child, Preschool; D005260:Female; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D006023:Glycoproteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D014411:Neoplastic Stem Cells / Q000378:metabolism* / Q000473:pathology; D009447:Neuroblastoma / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D020411:Oligonucleotide Array Sequence Analysis; D010455:Peptides / Q000235:genetics / Q000378:metabolism; D051880:Receptors, Notch / Q000235:genetics / Q000378:metabolism; D018874:Spheroids, Cellular / Q000378:metabolism* / Q000473:pathology; D014183:Transplantation, Heterologous; D014407:Tumor Cells, Cultured; D051153:Wnt Proteins / Q000235:genetics / Q000378:metabolism
D000071916:AC133 Antigen; D018528:ATP-Binding Cassette Transporters; D015703:Antigens, CD; D014408:Biomarkers, Tumor; D006023:Glycoproteins; C000606023:PROM1 protein, human; D010455:Peptides; C000606024:Prom1 protein, mouse; D051880:Receptors, Notch; D051153:Wnt Proteins