RESUMO
Identification of tumor-derived proteins in the circulation may allow for early detection of cancer and evaluation of therapeutic responses. To identify circulating tumor-derived proteins, mice were immunized with concentrated culture medium conditioned by human breast cancer cells. Antibodies generated by hybridomas were screened against conditioned media from both normal epithelial cells and tumor cells. Antibody selectively reacting with tumor cell-conditioned media was further characterized. This led to the development of a monoclonal antibody (Alper-p280) that reacts with a newly identified 280-kDa secreted variant of human filamin-A. Circulating filamin-A was detected in patient plasma samples using Alper-p280 in an ELISA assay. Human plasma samples from 134 patients with brain, breast, or ovarian cancer, 15 patients with active arthritis, and 76 healthy controls were analyzed. Filamin-A protein levels in human cell lines and tissues were analyzed by western blotting, immunohistochemistry, and electron and confocal microscopy. Circulating filamin-A was detected in the plasma of 109 of 143 patients with breast cancer and primary brain tumors. Plasma levels of filamin-A showed 89.5% sensitivity (95% confidence interval [CI] = 0.67% to 0.99%) and 97.8% specificity (95% CI = 0.88% to 0.99%) for glioblastoma at a cut-off of 21.0 ng/mL. Plasma levels of filamin-A (>36.0 ng/mL) had 96.7% sensitivity (95% CI = 0.80% to 0.99%) and 67.8% specificity (95% CI = 0.54% to 0.79%) for metastatic breast cancer. Filamin-A levels were increased in malignant breast or brain tissues, but not in normal control tissues. Filamin-A localized to lysosomes in MDA.MB.231 breast cancer cells, but not in normal human mammary epithelial cells, suggesting that filamin-A may undergo cancer-specific processing. Plasma filamin-A appears to be a specific and sensitive marker for patients with high-grade astrocytoma or metastatic breast cancer. Additional novel cancer biomarkers have been identified and are being developed alongside Alper-p280 for use in diagnosis of breast carcinoma and high-grade astrocytoma, and for use in the evaluation of therapeutic responses.
Assuntos
Anticorpos Monoclonais/imunologia , Astrocitoma/sangue , Neoplasias da Mama/sangue , Carcinoma Ductal de Mama/sangue , Carcinoma Ductal de Mama/secundário , Proteínas Contráteis/sangue , Proteínas Contráteis/imunologia , Proteínas dos Microfilamentos/sangue , Proteínas dos Microfilamentos/imunologia , Animais , Artrite/sangue , Artrite/imunologia , Artrite/patologia , Astrocitoma/imunologia , Astrocitoma/patologia , Biomarcadores Tumorais/sangue , Western Blotting , Encéfalo/metabolismo , Encéfalo/patologia , Mama/metabolismo , Mama/patologia , Neoplasias da Mama/imunologia , Neoplasias da Mama/patologia , Carcinoma Ductal de Mama/imunologia , Carcinoma Intraductal não Infiltrante/sangue , Carcinoma Intraductal não Infiltrante/imunologia , Carcinoma Intraductal não Infiltrante/secundário , Carcinoma Lobular/sangue , Carcinoma Lobular/imunologia , Carcinoma Lobular/secundário , Estudos de Casos e Controles , Meios de Cultivo Condicionados/farmacologia , Ensaio de Imunoadsorção Enzimática , Feminino , Filaminas , Humanos , Imunização , Técnicas Imunoenzimáticas , Metástase Linfática , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Invasividade Neoplásica , Estadiamento de Neoplasias , Neoplasias Ovarianas/sangue , Neoplasias Ovarianas/imunologia , Neoplasias Ovarianas/patologia , Prognóstico , Sensibilidade e Especificidade , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Células Tumorais CultivadasRESUMO
Lymphoepithelioma-like carcinoma (LELC) of the breast is a rare, newly recognized subtype of breast carcinoma. Distinction from medullary carcinoma is important because of the difference in biologic behavior of these two neoplasms and LELC of the breast is regarded as an unusual form of lobular carcinoma. We present the case of a 56-year-old female with a breast mass measuring 2 cm in diameter, which was diagnosed as invasive lobular carcinoma with LELC pattern. This is the ninth case reported in the English literature and to the best of our knowledge the first one with lymph node metastasis.
