Different types of tissue composition in inflammatory or reparative upper airway disorders.

BACKGROUND: Composition changes of extracellular matrix (ECM) can lead to functional disorders of the upper airways (UA). The aim of this study was to systematically measure both the association patterns and the correlation degree between tissue composition parameters in UA inflammatory diseases. METHODOLOGY: Nasal samples were obtained from patients with chronic rhinosinusitis with (CRS+NP), without nasal polyps (CRS), with post-operative adhesions (S) and normal nasal mucosa (NM). A reproducible semi-quantitative method, which takes epithelial and lamina propria damages into account was applied for haematoxylin and eosin, alpha-smooth muscle actin, reticulin, elastin, laminin and collagen type IV stainings. RESULTS: The most severe cases of epithelial shedding have been found in a significant higher amount in CRS+NP when compared with NM. The most severe cases of inflammatory reaction were mainly found in CRS+NP. CRS+NP had significantly more severe cases of oedema than NM. Excluding elastin, networks in other ECM proteins were found modified in fibrotic fields but to a lesser extend in oedematous regions in all conditions. CONCLUSION: Although non specific, oedema in the lamina propria is a key-feature of CRS+NP, while fibrosis, massively present in CRS and S, affects profoundly the distribution of ECM proteins in these areas.

EGFR in melanoma: clinical significance and potential therapeutic target.

BACKGROUND: The role of epidermal growth factor receptor (EGFR) has been established in a range of neoplasms. In melanoma, data on EGFR protein expression are conflicting. Fluorescence in situ hybridization (FISH) analysis for EGFR gene expression in melanoma showed EGFR gene amplification to be linked with worse prognosis. Cetuximab has been shown to suppress the formation of metastasis in mice. METHODS: EGFR protein expression and gene copy number status were evaluated by means of immunohistochemistry and FISH in melanoma samples of patients with known clinicopathological data. Associations between EGFR expression and prognostic parameters were investigated. The effect of different cetuximab concentrations on the BLM melanoma cell line was evaluated by means of methyl tetrazolium (MTT), sulforhodamine B (SRB) and Matrigel invasion assays. RESULTS: EGFR protein expression was more frequently observed in patients with a positive sentinel lymph node. However, EGFR immunostaining has no predictive value. The presence of EGFR polysomy was associated with thicker tumors. Treatment of the BLM melanoma cell line with different concentrations of cetuximab reduced the invasive capacity of the cells, but did not alter cell viability or growth. CONCLUSION: EGFR appears to be involved in progression and metastasis of a subset of melanomas. Targeting EGFR could therefore represent a therapeutic option for these melanomas.

Identification of the nasal mucosa as a new target for leptin action.

UNLABELLED: The aim of this study was to examine systemic and local nasal leptin and leptin receptor expression in patients with nasal polyposis and healthy controls. METHODS AND RESULTS: Serum leptin and soluble leptin receptor levels were examined by enzyme-linked immunosorbent assay (ELISA). The presence of leptin and leptin receptor mRNA was investigated using reverse transcriptase-polymerase chain reaction (RT-PCR), and tissue leptin and leptin receptor protein expression was analysed by immunohistochemistry and ELISA. Serum levels of biologically active leptin were significantly elevated in patients with nasal polyps compared with control subjects. These serum leptin levels were strongly correlated with the levels found in tissue in both study groups, although leptin was not significantly elevated in nasal polyp tissue. Using RT-PCR, we showed that both leptin and its receptors were produced in nasal mucosa. Finally, immunohistochemistry showed that leptin and leptin receptor protein were expressed in several cells of the normal and inflamed nasal mucosa. CONCLUSIONS: Leptin receptors and their biological ligand leptin are expressed in the nasal mucosa, suggesting a possible role in upper airway immunology.

Antitumor activity of the selective MDM2 antagonist nutlin-3 against chemoresistant neuroblastoma with wild-type p53.

BACKGROUND: Restoring p53 function by antagonizing its interaction with the negative regulator MDM2 is an appealing nongenotoxic approach to treating tumors with wild-type p53. Mutational inactivation of p53 is rare in neuroblastoma tumors at diagnosis and occurs in only a subset of multidrug-resistant neuroblastomas. METHODS: The antiproliferative and cytotoxic effect of nutlin-3, a small-molecule MDM2 antagonist, was examined in chemosensitive (UKF-NB-3) and matched chemoresistant neuroblastoma cells with wild-type p53 (UKF-NB-3(r)DOX20) or with mutant p53 (UKF-NB-3(r)VCR10). Activation of the p53 pathway was assessed by expression analysis of p53 target genes, flow cytometric cell cycle analysis, and apoptosis assays. Mice with established chemoresistant tumor xenografts were treated orally with nutlin-3 or vehicle control (n = 5-10 mice per group) and were used to evaluate effects on tumor growth, p53 pathway activity, and metastatic tumor burden. All statistical tests were two-sided. RESULTS: Nutlin-3 induced a similar activation of the p53 pathway in UKF-NB-3 and UKF-NB-3(r)DOX20 cells, as evidenced by increased expression of p53 target genes, G1 cell cycle arrest, and induction of apoptosis. No such response was observed in UKF-NB-3(r)VCR10 cells with mutant p53. Oral administration of nutlin-3 to UKF-NB-3(r)DOX20 xenograft-bearing mice led to inhibition of primary tumor growth (mean tumor volume after 3 weeks of treatment, nutlin-3- vs vehicle-treated mice: 772 vs 1661 mm3, difference = 890 mm3, 95% confidence interval = 469 to 1311 mm3, P < .001), p53 pathway activation, and reduction in the extent of metastatic disease. The growth of UKF-NB-3(r)VCR10 xenografts was unaffected by nutlin-3. CONCLUSIONS: Nutlin-3 activates the p53 pathway and suppresses tumor growth in this model system of chemoresistant neuroblastoma, provided that wild-type p53 is present.

Human mast cells express leptin and leptin receptors.

Mast cells are immune cells that produce and secrete a variety of mediators and cytokines that influence various inflammatory and immune processes. Leptin is a cytokine regulating metabolic, endocrine as well as immune functions via the leptin receptor which is expressed by many immune cells. However, there are no data about leptin receptor expression in mast cells. Immunohistochemical and immunofluorescent double stainings showed the expression of leptin and leptin receptors in mast cells in human skin and several parts of the respiratory, gastrointestinal and urogenital tract. Leptin was expressed in mast cells expressing the classification marker chymase, whereas a variable expression was observed in tryptase positive mast cells. For leptin receptors, the expression pattern was tissue dependent and not related to tryptase or chymase expression. Our results demonstrate the expression of leptin and leptin receptors on mast cells, suggesting paracrine and/or autocrine immunomodulatory effects of leptin on mast cells.