[Mutations of p53 gene in 41 cases of human brain gliomas]

p53 gene plays an important role in regulating cell cycle, maintaining completeness of cellular genomes, inducing cell differentiation and apoptosis. p53 gene mutation occurs usually in gliomas, especially astrocytomas. This study was to investigate p53 gene mutation and its correlation to the development of glioma.

p53 gene mutation in 41 specimens of human gliomas was analyzed by polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) and DNA sequencing.

p53 gene mutations were found in 17 (41.5%) of the 41 specimens of gliomas. The p53 mutations located on exons 5-8: 7 cases (41.2%) on exon 5; 1 (5.9%) on exon 6; 4 (23.5%) on exon 7; 5 (29.4%) on exon 8. The mutation rate of p53 gene was significantly higher in grade III-IV gliomas than in grade I-II gliomas (P<0.01). DNA sequencing indicated that the p53 gene mutations were point mutations and deletions of exons in the 17 positive cases, including 13 cases (76.5%) of missense mutation, 2 cases (11.8%) of samesense mutation, and 2 cases (11.8%) of frame shift mutation. G_A and A-->G were major base mutations (55.6%).

p53 mutations always locate on exons 5 and 8. Missense mutation is major mutant type of p53 gene. p53 mutation plays an important role in the development and malignant transformation of human gliomas.