RESUMO
Epidermal growth factor receptor (EGFR) gene overexpression has been implicated in the development of many types of tumors, including glioblastomas, the most frequent diffusely infiltrating astrocytomas. However, little is known about the influence of the polymorphisms of EGFR on EGFR production and/or activity, possibly modulating the susceptibility to astrocytomas. This study aimed to examine the association of two EGFR promoter polymorphisms (c.-191C>A and c.-216G>T) and the c.2073A>T polymorphism located in exon 16 with susceptibility to astrocytomas, EGFR gene expression and survival in a case-control study of 193 astrocytoma patients and 200 cancer-free controls. We found that the variant TT genotype of the EGFR c.2073A>T polymorphism was associated with a significantly decreased risk of astrocytoma when compared with the AA genotype [sex- and age-adjusted odds ratio 0.51, 95% confidence interval 0.26-0.98]. No association of the two promoter EGFR polymorphisms (or combinations of these polymorphisms) and risk of astrocytomas, EGFR expression or survival was found. Our findings suggest that modulation of the EGFR c.2073A>T polymorphism could play a role in future therapeutic approaches to astrocytoma.
Assuntos
Astrocitoma/genética , Neoplasias Encefálicas/genética , Receptores ErbB/genética , Polimorfismo Genético , Adulto , Idoso , Alelos , Astrocitoma/etnologia , Neoplasias Encefálicas/etnologia , Brasil , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Resultado do TratamentoRESUMO
Gene silencing may occur in breast cancer samples from patients presenting with occult metastatic cells in the bone marrow and one mechanism regulating gene suppression is heterochromatin formation. We have studied whether members of the heterochromatin protein 1 family (HP1Hs alpha, HP1Hs beta and HP1Hs gamma), which take part in chromatin packaging and gene expression regulation, were differentially expressed in tumors from patients with and without occult metastatic cells in their bone marrow. Tumor samples and bone marrow aspirates were obtained from 37 breast cancer patients. Median age was 63 years and 68% of the patients presented with clinical stage I/II disease. Presence of occult metastatic cells in bone marrow was detected through keratin-19 expression by nested RT-PCR in samples from 20 patients (54.1%). The presence of occult metastatic cells in bone marrow was not associated with node involvement, histological grade, estrogen receptor and ERBB2 immunoexpression. Relative gene expression of HP1Hs alpha, HP1Hs beta and HP1Hs gamma was determined by realtime RT-PCR and did not vary according to the presence of occult metastatic cells in bone marrow. In addition, the combined expression of these three transcripts could not be used to classify samples according to the presence of bone marrow micrometastasis. Our work indicates that regulation of heterochromatin formation through HP1 family members may not be the sole mechanism implicated in the metastatic process to the bone marrow.
Assuntos
Neoplasias da Medula Óssea/metabolismo , Neoplasias da Medula Óssea/secundário , Neoplasias da Mama/metabolismo , Proteínas Cromossômicas não Histona/biossíntese , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/biossíntese , Biomarcadores Tumorais/genética , Neoplasias da Medula Óssea/patologia , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Homólogo 5 da Proteína Cromobox , Proteínas Cromossômicas não Histona/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Queratinas/biossíntese , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , Isoformas de Proteínas , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
The aim of this study was to analyse distribution of meningoencephalitis caused by mumps virus in children related to sex, age and seasonal influences. Thirty seven children were evaluated, ages ranging from 2 to 14 years. They were seen at Emergency Unit of Faculdade de Medicina do Triângulo Mineiro and at Hospital da Criança, in Uberaba-MG, Brazil, from March 1st 1991 to February 1st 1993 and they were hospitalized for about 5 days. Through a protocol findings were studied during hospitalization and clinical course stressing epidemiology, symptomatology, cerebrospinal fluid studies, electroencephalogram and cortical function analysis. Only epidemiological data were considered in the present study. Data analysis revealed male predominance, at a range from 5 to 9 years and great number of occurrences at the last quarter of the year.