Neuron-specific hel-N1 and HuD as novel molecular markers of neuroblastoma: a correlation of HuD messenger RNA levels with favorable prognostic features.
Hel-N1 and HuD belong to the elav gene family and encode neuron-specific RNA-binding proteins that are temporally regulated in neural development. Recently, these genes have been detected in small cell lung carcinoma, a neuroendocrine tumor, with HuD down-regulated in poorly differentiated, variant subsets. We, therefore, sought to determine: (a) the extent to which Hel-N1 and HuD are expressed in neuroblastoma (NB); and (b) whether the individual patterns of expression are associated with clinical features of the tumor. We used a sensitive and quantitative RNase protection assay that reliably distinguishes between these homologous genes, and with it we show that Hel-N1 and HuD transcripts were detected in 100% of cultured cells (11 of 11) and 97% of primary tumor samples (35 of 36). Densitometric quantification of transcripts indicated that the levels of HuD and Hel-N1 varied in all samples. In primary NB tissue, samples that expressed the highest Hel-N1 or HuD levels were N-myc unamplified. With HuD, the level in unamplified primary tumors was significantly higher than that of amplified tumors (0.80 +/- 0.12 versus 0.33 +/- 0.12, P < 0.02). HuD expression in prognostically favorable tumor stages was also significantly higher than unfavorable stages (0.98 +/- 0.19 versus 0.47 +/- 0.08, P < 0.03). In summary, the ubiquitous detection of HuD and Hel-N1 in NB indicates that they are molecular neuronal markers of this tumor. Furthermore, high HuD mRNA levels may predict a clinically favorable outcome.
Ball
N S
NS
Laboratory of Medical Genetics and Department of Neurology, University of Alabama, Birmingham, Alabama 35294, USA.
King
P H
PH
D014408:Biomarkers, Tumor / Q000032:analysis* / Q000096:biosynthesis / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D051959:ELAV Proteins; D000067777:ELAV-Like Protein 2; D000067779:ELAV-Like Protein 4; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D005810:Multigene Family; D009363:Neoplasm Proteins / Q000032:analysis* / Q000096:biosynthesis / Q000235:genetics; D009419:Nerve Tissue Proteins / Q000032:analysis* / Q000096:biosynthesis / Q000235:genetics; D009447:Neuroblastoma / Q000737:chemistry* / Q000235:genetics / Q000401:mortality / Q000473:pathology; D009474:Neurons / Q000201:enzymology; D011379:Prognosis; D012333:RNA, Messenger / Q000096:biosynthesis*; D012334:RNA, Neoplasm / Q000096:biosynthesis*; D016601:RNA-Binding Proteins / Q000032:analysis* / Q000096:biosynthesis / Q000235:genetics; D016037:Single-Blind Method; D016019:Survival Analysis; D014407:Tumor Cells, Cultured
D014408:Biomarkers, Tumor; D051959:ELAV Proteins; D000067777:ELAV-Like Protein 2; D000067779:ELAV-Like Protein 4; C086811:ELAVL2 protein, human; C498010:ELAVL4 protein, human; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D016601:RNA-Binding Proteins