The Phox2 pathway is differentially expressed in neuroblastoma tumors, but no mutations were found in the candidate tumor suppressor gene PHOX2A.
Neuroblastoma (NB), a tumor of the sympathetic nervous system, is the most common solid tumor in childhood. By microarray expression analysis (Affymetrix HU133A) important players in the noradrenalin biosynthesis pathway (DBH, DDC, GATA2, GATA3, PHOX2A, PHOX2B, SLC6A2 SLC18A1 and TH) were found to be among the top ranked genes in showing lower expression in unfavorable NB tumor types as compared to favorable ones. By quantitative PCR with TaqMan, this result was significantly verified for all transcripts (p<0.05, one-tailed) in a new set of 11 primary NB tumors (5 favorable vs. 6 unfavorable). PHOX2A, a downstream target of Phox2b, was found to be the sixth ranked gene from the microarray gene list. Since the PHOX2A gene is localized in a tumor suppressor candidate region at 11q, we screened this gene for mutations by DNA sequencing in 47 tumors of different stages. However, no critical changes were found that could support its role in tumor development or progression. Overall, the findings in this study either suggest that expression of this pathway could be a predictive differentiation marker of NB tumors, or our results could also imply that the noradrenalin biosynthesis pathway is involved in tumor pathogenesis.
Wilzén
Annica
A
Department of Clinical Genetics, Gothenburg University, S-416 85 Gothenburg, Sweden.
Nilsson
Staffan
S
Sjöberg
Rose-Marie
RM
Kogner
Per
P
Martinsson
Tommy
T
Abel
Frida
F
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001483:Base Sequence; D045744:Cell Line, Tumor; D002648:Child; D002675:Child, Preschool; D004252:DNA Mutational Analysis; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D016147:Genes, Tumor Suppressor; D018398:Homeodomain Proteins / Q000096:biosynthesis* / Q000235:genetics; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D046228:Microarray Analysis; D008875:Middle Aged; D008969:Molecular Sequence Data; D009447:Neuroblastoma / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D055815:Young Adult
D018398:Homeodomain Proteins; C491061:PHOX2A protein, human