RESUMO
BACKGROUND: Previous reports related the presence of mouse mammary tumor virus (MMTV)-like gene sequences to human breast carcinoma. The aim of this study was to determine whether MMTV-like env gene sequences are present in breast cancer samples of Mexican women and in breast and lung cancer cell lines. METHODS: Using specific primers for MMTV, we tested 3 breast cancer cell lines, 4 non-small lung cancer cell lines and 119 breast cancer samples from Mexican women. RESULTS: MMTV-like gene sequences were amplified in the lung cancer cell INER-51, but not in the MCF-7 cell line that has been used as a positive control in other reports and in 5 of 119 (4.2%) breast cancer biopsy tissues. Furthermore, the identity of sequences of PCR products from INER-51 and a breast cancer-positive sample are 98 and 99% when compared with the env region of MMTV (GenBank accession No. AY161347). CONCLUSION: These results indicate that MMTV-like gene sequences are present in the Mexican population.
Assuntos
Neoplasias da Mama/virologia , Genes env , Vírus do Tumor Mamário do Camundongo/genética , Vírus do Tumor Mamário do Camundongo/isolamento & purificação , Neoplasias da Mama/patologia , Linhagem Celular , Primers do DNA , DNA de Neoplasias/análise , Feminino , Humanos , México , Dados de Sequência MolecularRESUMO
OBJECTIVE: Our aim was to identify and describe the main symptoms, clinical presentation, and radiographic changes in malignant mesothelioma (MM) patients. MATERIAL AND METHODS: We reviewed the medical and X-ray records of all patients diagnosed with MM, admitted between 1991 and 1998 to the National Institute of Respiratory Diseases (INER), which is a governmental institution specialized in chest disease in Mexico City. The following data were collected: Age, occupation, asbestos exposure, latency, family history of cancer, clinical symptoms, and X-ray changes. Data are presented as percentages by sex and age group. RESULTS: We found 45 cases of MM; in 80% of them a history of asbestos exposure could not be documented. The 51-60 years age group had the highest frequency of MM. Dispnea and chest pain were the presenting symptoms in most patients. Pleural effusion and pleural thickening were the X-ray abnormalities observed in 75% of the patients. CONCLUSIONS: The clinical and radiographic findings among patients with MM without asbestos exposure were similar to those with a history of asbestos exposure.
Assuntos
Amianto/efeitos adversos , Exposição Ambiental/estatística & dados numéricos , Mesotelioma/epidemiologia , Neoplasias Pleurais/epidemiologia , Adulto , Idade de Início , Idoso , Dor no Peito/etiologia , Tosse/etiologia , Dispneia/etiologia , Feminino , Hemoptise/etiologia , Humanos , Masculino , Mesotelioma/diagnóstico por imagem , Mesotelioma/etiologia , Mesotelioma/patologia , México/epidemiologia , Pessoa de Meia-Idade , Neoplasias/genética , Exposição Ocupacional/estatística & dados numéricos , Derrame Pleural Maligno/diagnóstico por imagem , Derrame Pleural Maligno/etiologia , Neoplasias Pleurais/diagnóstico por imagem , Neoplasias Pleurais/etiologia , Neoplasias Pleurais/patologia , Radiografia , Estudos RetrospectivosRESUMO
The T lymphocytes recognize antigens through antigen receptors (TcRs) and the major histocompatibility complex (MHC) molecules: they lysate the cells that bear the antigen, or release cytokines that are mediators of the immune response. The TcRs recognize antigens in the form of short peptides bound to MHC molecules. So far, there are two isotypes of TcR: gamma/delta and alpha/beta, which appear in the sequence during T-cell ontogeny. The process of selection of TcRs during thymic ontogeny obeys to molecular mechanisms which generate intracellular events that will participate in the gene expression of the TcR. The aim of the present paper is to review the molecular, structural, and functional aspects of the TcRs, and their role in human autoimmune infectious disease.
Assuntos
Doenças Autoimunes/imunologia , Infecções/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Linfócitos T/imunologia , Animais , Antígenos de Bactérias/imunologia , Antígenos de Protozoários/imunologia , Antígenos Virais/imunologia , Citotoxicidade Imunológica , Humanos , Camundongos , Receptores de Antígenos de Linfócitos T/química , Receptores de Antígenos de Linfócitos T/genética , Transdução de Sinais , Linfócitos T/metabolismoRESUMO
The immune system is a tight network of different types of cells and molecules. The coordinated action of these elements mounts a precise immune response against tumor cells. However, these cells present several escape mechanisms, leading to tumor progression. This paper shows several cellular and molecular events involved in the regulation of the immune response against tumor cells. The interaction of several molecules such as MHC, TcR, adhesins, tumor antigens and cytokines are discussed, as well as the most recent knowledge about escape mechanisms and immunotherapy.