Methylation-associated PHOX2B gene silencing is a rare event in human neuroblastoma.
Neuroblastoma (NB), an embryonic tumour originating from neural crest cells, is one of the most common solid tumours in childhood. Although NB is characterised by numerous recurrent, large-scale chromosome rearrangements, the genes targeted by these imbalances have remained elusive. We recently identified the paired-like homeobox 2B (PHOX2B, MIM 603851) gene as disease-causing in dysautonomic disorders including Congenital Central Hypoventilation Syndrome (CCHS), Hirschsprung disease (HSCR) and NB in various combinations. Most patients with NB due to a germline heterozygous PHOX2B gene mutation are familial and/or syndromic. PHOX2B, at chromosome 4p12, does not lie in a commonly rearranged locus in NB. To evaluate the role of PHOX2B in sporadic, isolated NB, we analysed 13 NB cell lines and 45 tumours for expression, mutations of coding and promoter sequences, loss of heterozygosity (LOH), or aberrant hypermethylation of PHOX2B (13 cell lines and 18 tumours). We didn't identify any mutation but LOH in about 10% of the cases and aberrant CpG dinucleotide methylation of the 500 bp PHOX2B promoter region in 4/31 tumours and cell lines (12.9%). Altogether, both germinal and somatic anomalies at the PHOX2B locus are found in NB.
de Pontual
Loïc
L
Unité de Recherches sur les Handicaps Génétiques de l'Enfant INSERM U-781, et Département de Génétique, Université René-Descartes, Faculté de Médecine, Hôpitaux de Paris, Hôpital Necker-Enfants Malades, 149, rue de Sèvres, 75743 Paris Cedex 15, France.
Trochet
Delphine
D
Bourdeaut
Franck
F
Thomas
Sophie
S
Etchevers
Heather
H
Chompret
Agnes
A
Minard
Véronique
V
Valteau
Dominique
D
Brugieres
Laurence
L
Munnich
Arnold
A
Delattre
Olivier
O
Lyonnet
Stanislas
S
Janoueix-Lerosey
Isabelle
I
Amiel
Jeanne
J
D045744:Cell Line, Tumor; D004252:DNA Mutational Analysis / Q000379:methods; D005260:Female; D005787:Gene Frequency; D020868:Gene Silencing; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D018398:Homeodomain Proteins / Q000235:genetics*; D006801:Humans; D019656:Loss of Heterozygosity; D008297:Male; D008745:Methylation; D009447:Neuroblastoma / Q000235:genetics*; D010375:Pedigree; D014157:Transcription Factors / Q000235:genetics*
D018398:Homeodomain Proteins; C109220:NBPhox protein; D014157:Transcription Factors