RESUMEN
Bronchopulmonary neuroendocrine tumors (BP-NETs) comprise approximately 20% of all lung cancers and represent a spectrum of tumors arising from neuroendocrine cells of the BP-epithelium. Although they share structural, morphological, immunohistochemical, and ultrastructural features, they are separated into 4 subgroups: typical carcinoid tumor (TC), atypical carcinoid tumor (AC), large-cell neuroendocrine carcinoma (LCNEC), and small-cell lung carcinoma (SCLC), which exhibit considerably different biological characteristics. The clinical presentation includes cough, hemoptysis, and obstructive pneumonia but varies depending on site, size, and growth pattern. Less than 5% of BP-NETs exhibit hormonally related symptoms such as carcinoid syndrome, Cushing, acromegaly, and SIADH. SCLC is the most common BP-NET, while LCNEC is rare, approximately 10% and < or =1%, respectively, of all lung cancers. Both SCLC and LCNEC progress rapidly, are aggressively metastatic, and exhibit a poor prognosis. The incidence of BP-carcinoids (TC and AC) in the US was 1.57 of 100,000 in 2003 (an unexplained and substantial increase over the last 30 years, approximately 6% per year). No curative treatment except for radical surgery (almost never feasible) exists. The slow-growing TC exhibit a fairly good prognosis ( approximately 88%, 5-year survival), whereas AC demonstrate a 5-year survival of approximately 50%, and the highly malignant LCNEC and SCLC5-year survival of 15% to 57% and <5%, respectively. This review provides a broad overview on BP-NETs and focuses on the evolution of the disease, general features, and current diagnostic and therapeutic options.
Asunto(s)
Neoplasias Pulmonares , Tumores Neuroendocrinos , Neoplasias de los Bronquios/diagnóstico , Neoplasias de los Bronquios/genética , Neoplasias de los Bronquios/patología , Neoplasias de los Bronquios/terapia , Tumor Carcinoide/diagnóstico , Tumor Carcinoide/genética , Tumor Carcinoide/patología , Tumor Carcinoide/terapia , Carcinoma de Células Grandes/diagnóstico , Carcinoma de Células Grandes/genética , Carcinoma de Células Grandes/patología , Carcinoma de Células Grandes/terapia , Carcinoma de Células Pequeñas/diagnóstico , Carcinoma de Células Pequeñas/genética , Carcinoma de Células Pequeñas/patología , Carcinoma de Células Pequeñas/terapia , Humanos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patología , Neoplasias Pulmonares/terapia , Modelos Biológicos , Metástasis de la Neoplasia , Tumores Neuroendocrinos/diagnóstico , Tumores Neuroendocrinos/genética , Tumores Neuroendocrinos/patología , Tumores Neuroendocrinos/terapia , PronósticoRESUMEN
The IkappaB kinase complex IKK is a central component of the signaling cascade that controls NF-kappaB-dependent gene transcription. So far, its function in the brain is largely unknown. Here, we show that IKK is activated in a mouse model of stroke. To investigate the function of IKK in brain ischemia we generated mice that contain a targeted deletion of Ikbkb (which encodes IKK2) in mouse neurons and mice that express a dominant inhibitor of IKK in neurons. In both lines, inhibition of IKK activity markedly reduced infarct size. In contrast, constitutive activation of IKK2 enlarged the infarct size. A selective small-molecule inhibitor of IKK mimicked the effect of genetic IKK inhibition in neurons, reducing the infarct volume and cell death in a therapeutic time window of 4.5 h. These data indicate a key function of IKK in ischemic brain damage and suggest a potential role for IKK inhibitors in stroke therapy.