RESUMO
BACKGROUND & OBJECTIVE: 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. METHODS: p53 gene mutation in 41 specimens of human gliomas was analyzed by polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) and DNA sequencing. RESULTS: 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%). CONCLUSIONS: 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.
Assuntos
Astrocitoma/genética , Neoplasias Encefálicas/genética , Genes p53/genética , Mutação de Sentido Incorreto , Proteína Supressora de Tumor p53/genética , Adolescente , Adulto , Idoso , Sequência de Aminoácidos , Sequência de Bases , Criança , Éxons , Feminino , Mutação da Fase de Leitura , Glioblastoma/genética , Humanos , Masculino , Pessoa de Meia-Idade , Oligodendroglioma/genética , Mutação Puntual , Reação em Cadeia da Polimerase , Polimorfismo Conformacional de Fita Simples , Análise de Sequência de DNA , Adulto JovemRESUMO
AIM: To detect the expression of calcitonin-gene-related peptide (CGRP), adrenocorticotropin (ACTH), and serotonin (5-HT) in normal human lymph nodes and explore their influences on immune system. METHODS: The expression of CGRP, ACTH and 5-HT in the lymph nodes, including proliferative lymph nodes, were detected by SABC Immunohistochemical staining. RESULTS: In 35 cases of lymph node specimens, the positive rates of CGRP, ACTH and 5-HT expression were 88.5%(31/35), 85.4%(30/35) and 94.2%(33/35) respectively. These 3 molecules had a similar distribution in germinal center of lymph nodes, mainly in the cells of paracortical region, the cells in germinal center of lymph follicles and macrophages, etc. CONCLUSION: There are considerably high positive rates of CGRP, ACTH and 5-HT in human peripheral lymph nodes, and their distribution area are basically coincident with that of immunocytes in the lymph nodes.
