Neurotrophins and neurotrophin receptors in pulmonary sarcoidosis - granulomas as a source of expression.

BACKGROUND: Pulmonary sarcoidosis is an inflammatory disease, characterized by an accumulation of CD4+ lymphocytes and the formation of non-caseating epithelioid cell granulomas in the lungs. The disease either resolves spontaneously or develops into a chronic disease with fibrosis. The neurotrophins nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) have been suggested to be important mediators of inflammation and mediate tissue remodelling. In support of this, we have recently reported enhanced NGF levels in the airways of patients with pulmonary sarcoidosis. However, less is known about levels of BDNF and NT-3, and moreover, knowledge in the cellular sources of neurotrophins and the distribution of the corresponding neurotrophin receptors in airway tissue in sarcoidosis is lacking. METHODS: The concentrations of NGF, BDNF and NT-3 in bronchoalveolar lavage fluid (BALF) of 41 patients with newly diagnosed pulmonary sarcoidosis and 27 healthy controls were determined with ELISA. The localization of neurotrophins and neurotrophin receptors were examined by immunohistochemistry on transbronchial lung biopsies from sarcoidosis patients. RESULTS: The sarcoidosis patients showed significantly enhanced NT-3 and NGF levels in BALF, whereas BDNF was undetectable in both patients and controls. NT-3 levels in BALF were found higher in patients with non-Löfgren sarcoidosis as compared to patients with Löfgren's syndrome, and in more advanced disease stage. Epithelioid cells and multinucleated giant cells within the sarcoid granulomas showed marked immunoreactivity for NGF, BDNF and NT-3. Also, immunoreactivity for the neurotrophin receptor TrkA, TrkB and TrkC, was found within the granulomas. In addition, alveolar macrophages showed positive immunoreactivity for NGF, BDNF and NT-3 as well as for TrkA, TrkB and TrkC. CONCLUSIONS: This study provides evidence of enhanced neurotrophin levels locally within the airways of patients with sarcoidosis. Findings suggest that sarcoid granuloma cells and alveolar macrophages are possible cellular sources of, as well as targets for, neurotrophins in the airways of these patients.

Prostate cancer cell lines lack amplification: overexpression of HER2.

The potential overexpression of HER2 in prostate cancer cells has attended significant interest during the past few years, both as potential target for HER2 pathway focused therapy and as a mechanism involved in the progression to androgen independence. Conflicting results have been reported concerning HER2 status on clinical material, differences which generally have been attributed to methodological differences. Nevertheless, HER2 has been utilized for targeted therapy of prostate cancer in a number of preclinical studies and is still regarded as an exciting target molecule. In this study, the HER2 status of three widely used prostate cancer cell lines and corresponding xenografts has been analysed. By use of validated and FDA approved analytical staining techniques none of these cell lines or xenografts were shown to overexpress/amplify HER2, as demonstrated by immunohistochemistry and fluorescence in situ hybridization. These findings are important for the interpretation and understanding of the therapeutic effects when developing drugs targeting HER2 in prostate cancer cell lines and also emphasize the importance of using broad and validated analytical techniques.