Elevated c-myc expression in childhood medulloblastomas.
Medulloblastoma is a rare brain tumor usually occurring in late childhood or early adolescence. Little is known regarding the cell of origin or cellular events leading to its malignant transformation. We have studied the expression of developmentally regulated mRNA in tumor samples by the Northern hybridization assay to determine a relative stage at which a block to further differentiation occurs. In a series of five medulloblastoma tumors analyzed, only one of eight markers for cellular differentiation, the glial fibrillary acidic protein mRNA, was expressed at significant levels. Interestingly, three of six medulloblastoma tumor samples were found to have elevated levels of c-myc mRNA. In one of these tumors, we have found evidence of mutation of the c-myc protooncogene. We discuss possible mechanisms of c-myc activation in medulloblastoma tumors.
MacGregor
D N
DN
Department of Pediatrics, New York University Medical Center, New York 10016.
Ziff
E B
EB
D001483:Base Sequence; D002528:Cerebellar Neoplasms / Q000235:genetics*; D002648:Child; D015342:DNA Probes; D015870:Gene Expression; D006801:Humans; D008527:Medulloblastoma / Q000235:genetics*; D008969:Molecular Sequence Data; D009154:Mutation; D011518:Proto-Oncogene Proteins / Q000235:genetics; D016271:Proto-Oncogene Proteins c-myc; D011519:Proto-Oncogenes; D012333:RNA, Messenger / Q000235:genetics; D012334:RNA, Neoplasm / Q000235:genetics; D014158:Transcription, Genetic
D015342:DNA Probes; D011518:Proto-Oncogene Proteins; D016271:Proto-Oncogene Proteins c-myc; D012333:RNA, Messenger; D012334:RNA, Neoplasm