DeltaN-p73alpha accumulates in human neuroblastic tumors.
Neuroblastic tumors (NTs), occurring in early childhood, display a wide spectrum of differentiation. Recurrent deletions involving the p73 locus are frequently observed in undifferentiated NTs. To address the question of the possible implication of p73 in neuroblastic differentiation, we investigated the status of the expression of this gene in a panel of differentiated and undifferentiated tumors. Although mutations were not found, p73 transcript profiles differed between undifferentiated and differentiated tumors. The frequency of the transcripts lacking exon 2 (species 1-3) appeared to be higher in undifferentiated than in differentiating and differentiated NTs. In contrast, products from using an alternate promoter (DeltaN-p73) were present in all NTs. In addition, only DeltaN-p73, but not full-length proteins, were detected by immunoblotting, suggesting a greater stability of N-truncated isoforms. Importantly, as in the adrenal medulla, most NTs showed p73-positive immunohistological staining with a cellular distribution and intensity varying according to the neuronal differentiation. Surprisingly, we observed redistribution of p73 from the nucleus to the cytoplasm during neuroblastic differentiation. Our data suggest that, in undifferentiated NTs, a link may exist between the accumulation of DeltaN-p73alpha variants and the "nuclear exclusion" of p53.
Douc-Rasy
Sétha
S
Département de Biologie Clinique, Centre National de Recherche Scientifique-Unité Mixte de Recherche 1598, Institut Gustave Roussy, 39, rue Camille Desmoulins, 94805 Villejuif Cedex, France.
Barrois
Michel
M
Echeynne
Maria
M
Kaghad
Mourad
M
Blanc
Etienne
E
Raguenez
Gilda
G
Goldschneider
David
D
Terrier-Lacombe
Marie-José
MJ
Hartmann
Olivier
O
Moll
Ute
U
Caput
Daniel
D
Bénard
Jean
J
D000313:Adrenal Medulla / Q000166:cytology / Q000378:metabolism; D002454:Cell Differentiation; D002648:Child; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D005091:Exons; D016147:Genes, Tumor Suppressor; D006801:Humans; D007150:Immunohistochemistry; D009380:Neoplasms, Nerve Tissue / Q000235:genetics / Q000378:metabolism*; D009447:Neuroblastoma / Q000235:genetics / Q000378:metabolism*; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D020033:Protein Isoforms; D014407:Tumor Cells, Cultured; D000072160:Tumor Protein p73; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D025521:Tumor Suppressor Proteins
D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D020033:Protein Isoforms; C000606460:TP73 protein, human; D000072160:Tumor Protein p73; D016159:Tumor Suppressor Protein p53; D025521:Tumor Suppressor Proteins