Mutation analysis of gene PAX6 in human gliomas.
Gliomas are the most common tumors of the central nervous system. In spite of the marked advances in the characterization of the molecular pathogenesis of gliomas, these tumors remain incurable and, in most of the cases, resistant to treatments, due to their molecular heterogeneity. Gene PAX6, which encodes a transcription factor that plays an important role in the development of the central nervous system, was recently recognized as a tumor suppressor in gliomas. The objective of the present study was to analyze the mutational status of the coding and regulating regions of PAX6 in 94 gliomas: 81 astrocytomas (11 grade I, 23 grade II, 8 grade III, and 39 grade IV glioblastomas), 5 oligodendrogliomas (3 grade II, and 2 grade III), and 8 ependymomas (5 grade II, and 3 grade III). Two regulating regions (SX250 and EIE) and the 11 coding regions (exons 4-13, plus exon 5a resulting from alternative splicing) of gene PAX6 were analyzed and no mutation was found. Therefore, we conclude that the tumor suppressor role of PAX6, reported in previous studies on gliomas, is not due to mutation in its coding and regulating regions, suggesting the involvement of epigenetic mechanisms in the silencing of PAX6 in these tumors.
Pinto
G R
GR
Laboratório de Genética Humana e Biologia Molecular, Universidade Federal do Piauí, Parnaíba, PI, Brasil. pintogr@gmail.com
Clara
C A
CA
Santos
M J
MJ
Almeida
J R W
JR
Burbano
R R
RR
Rey
J A
JA
Casartelli
C
C
D000293:Adolescent; D000328:Adult; D000368:Aged; D001254:Astrocytoma / Q000235:genetics; D001483:Base Sequence; D016543:Central Nervous System Neoplasms / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D004252:DNA Mutational Analysis; D017931:DNA Primers / Q000235:genetics; D004273:DNA, Neoplasm / Q000235:genetics; D004806:Ependymoma / Q000235:genetics; D044127:Epigenesis, Genetic; D005136:Eye Proteins / Q000235:genetics*; D005260:Female; D020868:Gene Silencing; D005910:Glioma / Q000235:genetics*; D018398:Homeodomain Proteins / Q000235:genetics*; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009837:Oligodendroglioma / Q000235:genetics; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors / Q000235:genetics*; D016133:Polymerase Chain Reaction; D012097:Repressor Proteins / Q000235:genetics*
D017931:DNA Primers; D004273:DNA, Neoplasm; D005136:Eye Proteins; D018398:Homeodomain Proteins; D000071841:PAX6 Transcription Factor; C000605730:PAX6 protein, human; D051761:Paired Box Transcription Factors; D012097:Repressor Proteins