54 research outputs found

    Targeting receptor tyrosine kinases in malignant pleural mesothelioma: Focus on FGF-receptors

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    Fibroblast growth factor receptors (FGFRs) constitute a subfamily of receptor tyrosine kinases. Four different receptors, FGFR1-4, bind 18 different fibroblast growth factors (FGFs) and signal mainly along the mitogen-activated protein kinase (MAPK), the phosphatidylinositol 3 kinase (PI3K) and the phospholipase c gamma (PLC?) pathway. Physiologically, they are major regulators of embryonic development and metabolism. Deregulation of FGFR signals is increasingly recognized to play important roles in malignant diseases and may constitute a feasible therapeutic target. We recently investigated their role in malignant pleural mesothelioma (MPM), an aggressive malignancy mainly caused by asbestos exposure and with currently limited therapeutic options. We demonstrated high expression of several FGFs/FGFRs, especially FGFR1, FGF2 and FGF18 in cultured tumor cells and tissue specimens and identified FGFR-mediated signals as major driver of MPM cell growth, survival and migration. FGFR blockade by a tyrosine kinase inhibitor or by a dominant-negative receptor construct resulted in reduced MPM growth in vitro and in vivo and, furthermore, enhanced the efficacy of chemo- or radiotherapy. Several other receptor tyrosine kinases, including EGFR, MET and AXL were found to be overexpressed in MPM but translation into clinically successful therapeutic approaches has not yet been achieved. Inhibition of FGF-receptors may have the advantage of targeting both the tumor cells as well as the tumor vasculature and should be further evaluated

    The usefulness of MMP-9, TIMP-1 and MMP-9/TIMP-1 ratio for diagnosis and assessment of COPD severity

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    Background: Inflammation, oxidative stress and an imbalance between proteases and protease inhibitors are recognized pathophysiological features of chronic obstructive pulmonary disease (COPD). The aim of this study was to evaluate serum levels of matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1) in patients with COPD and to assess their relationship with lung function, symptom severity scores and recent acute exacerbations. Methods: In this observational cohort study, serum levels of MMP-9 and TIMP-1 and the MMP-9/TIMP-1 ratio in the peripheral blood of COPD patients with stable disease and healthy controls were determined, and their association with lung function (postbronchodilator spirometry, body plethysmography, single breath diffusion capacity for carbon monoxide), symptom severity scores (mMRC and CAT) and exacerbation history were assessed. Results: COPD patients (n = 98) had significantly higher levels of serum MMP-9 and TIMP-1 and a higher MMP-9/TIMP-1 ratio than healthy controls (n = 47) (p ≤ 0.001). The areas under the receiver operating characteristic curve for MMP-9, TIMP-1 and the MMP-9/TIMP-1 ratio for COPD diagnosis were 0.974, 0.961 and 0.910, respectively (all p < 0.05). MMP-9 and the MMP-9/TIMP-1 ratio were both negatively correlated with FVC, FEV1, FEV1/FVC, VC, and IC (all p < 0.05). For MMP-9, a positive correlation was found with RV/TLC% (p = 0.005), and a positive correlation was found for the MMP-9/TIMP-1 ratio with RV% and RV/TLC% (p = 0.013 and 0.002, respectively). Patients with COPD GOLD 3 and 4 presented greater MMP-9 levels and a greater MMP-9/TIMP-1 ratio compared to GOLD 1 and 2 patients (p ≤ 0.001). No correlation between diffusion capacity for carbon monoxide and number of acute exacerbations in the previous year was found. Conclusions: COPD patients have elevated serum levels of MMP-9 and TIMP-1 and MMP-9/TIMP-1 ratio. COPD patients have an imbalance between MMP-9 and TIMP-1 in favor of a pro-proteolytic environment, which overall indicates the importance of the MMP-9/TIMP-1 ratio as a potential biomarker for COPD diagnosis and severity

    High circulating activin A level is associated with tumor progression and predicts poor prognosis in lung adenocarcinoma

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    Activin A (ActA)/follistatin (FST) signaling has been shown to be deregulated in different tumor types including lung adenocarcinoma (LADC). Here, we report that serum ActA protein levels are significantly elevated in LADC patients (n=64) as compared to controls (n=46, p=0.015). ActA levels also correlated with more advanced disease stage (p<0.0001) and T (p=0.0035) and N (p=0.0002) factors. M1 patients had significantly higher ActA levels than M0 patients (p<0.001). High serum ActA level was associated with poor overall survival (p<0.0001) and was confirmed as an independent prognostic factor (p=0.004). Serum FST levels were increased only in female LADC patients (vs. female controls, p=0.031). Two out of five LADC cell lines secreted biologically active ActA, while FST was produced in all of them. Transcripts of both type I and II ActA receptors were detected in all five LADC cell lines. In conclusion, our study does not only suggest that measuring blood ActA levels in LADC patients might improve the prediction of prognosis, but also indicates that this parameter might be a novel non-invasive biomarker for identifying LADC patients with organ metastases

    Subtype-specific KRAS mutations in advanced lung adenocarcinoma: A retrospective study of patients treated with platinum-based chemotherapy

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    Background: Platinum-based chemotherapy is the most common treatment in advanced-stage lung adenocarcinoma. Because the clinical significance of KRAS mutational status in this setting has not yet been clearly determined, a mutation subtype-specific analysis was performed in the so far largest cohort of Caucasian patients with KRAS mutant advanced-stage lung adenocarcinoma treated with platinum-based chemotherapy. Methods: 505 Caucasian stage III-IV lung adenocarcinoma patients with known amino acid substitution-specific KRAS mutational status and treated with platinum-based chemotherapy were included. The correlations of subtype-specific KRAS mutations with smoking status, progression-free and overall survival (PFS and OS, respectively) and therapeutic response were analysed. Results: Among 338 KRAS wild-type, 147 codon 12 mutant and 20 codon 13 mutant patients, there were no mutation-related significant differences in PFS or OS (P values were 0.534 and 0.917, respectively). Eastern Cooperative Oncology Group (ECOG) status and clinical stage were significant independent prognostic factors. KRAS mutation showed a significant correlation with smoking status (P = 0.018). Importantly, however, G12V KRAS mutant patients were significantly more frequent among never-smokers than all other codon 12 KRAS mutant (G12x) subtypes (P = 0.016). Furthermore, this subgroup tended to have a higher response rate (66% versus 47%; P = 0.077). A modestly longer median PFS was also found in the G12V mutant cohort (233 days; versus 175 days in the G12x group; P = 0.145). Conclusions: While KRAS mutation status per se is neither prognostic nor predictive in stage III-IV lung adenocarcinoma, subtype-specific analysis may indeed identify clinically relevant subgroups of patients that may ultimately influence treatment decisions. © 2014 The Authors

    Targeting receptor tyrosine kinases in malignant pleural mesothelioma: Focus on FGF-receptors

    Get PDF
    Fibroblast growth factor receptors (FGFRs) constitute a subfamily of receptor tyrosine kinases. Four different receptors, FGFR1-4, bind 18 different fibroblast growth factors (FGFs) and signal mainly along the mitogen-activated protein kinase (MAPK), the phosphatidylinositol 3 kinase (PI3K) and the phospholipase c gamma (PLCγ) pathway. Physiologically, they are major regulators of embryonic development and metabolism. Deregulation of FGFR signals is increasingly recognized to play important roles in malignant diseases and may constitute a feasible therapeutic target. We recently investigated their role in malignant pleural mesothelioma (MPM), an aggressive malignancy mainly caused by asbestos exposure and with currently limited therapeutic options. We demonstrated high expression of several FGFs/FGFRs, especially FGFR1, FGF2 and FGF18 in cultured tumor cells and tissue specimens and identified FGFR-mediated signals as major driver of MPM cell growth, survival and migration. FGFR blockade by a tyrosine kinase inhibitor or by a dominant-negative receptor construct resulted in reduced MPM growth in vitro and in vivo and, furthermore, enhanced the efficacy of chemo- or radiotherapy. Several other receptor tyrosine kinases, including EGFR, MET and AXL were found to be overexpressed in MPM but translation into clinically successful therapeutic approaches has not yet been achieved. Inhibition of FGF-receptors may have the advantage of targeting both the tumor cells as well as the tumor vasculature and should be further evaluated
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