[Show abstract][Hide abstract] ABSTRACT: Treatment of acute myocardial infarction with stem cell transplantation has achieved beneficial effects in many clinical trials. The bone marrow microenvironment of ST-elevation myocardial infarction (STEMI) patients has never been studied even though myocardial infarction is known to cause an imbalance in the acid-base status of these patients. The aim of this study was to assess if the blood gas levels in the bone marrow of STEMI patients affect the characteristics of the bone marrow cells (BMCs) and, furthermore, do they influence the change in cardiac function after autologous BMC transplantation. The arterial, venous and bone marrow blood gas concentrations were also compared.
Blood gas analysis of the bone marrow aspirate and peripheral blood was performed for 27 STEMI patients receiving autologous stem cell therapy after percutaneous coronary intervention. Cells from the bone marrow aspirate were further cultured and the bone marrow mesenchymal stem cell (MSC) proliferation rate was determined by MTT assay and the MSC osteogenic differentiation capacity by alkaline phosphatase (ALP) activity assay. All the patients underwent a 2D-echocardiography at baseline and 4 months after STEMI.
As expected, the levels of pO(2), pCO(2), base excess and HCO(3) were similar in venous blood and bone marrow. Surprisingly, bone marrow showed significantly lower pH and Na(+) and elevated K(+) levels compared to arterial and venous blood. There was a positive correlation between the bone marrow pCO(2) and HCO(3) levels and MSC osteogenic differentiation capacity. In contrast, bone marrow pCO(2) and HCO(3) levels displayed a negative correlation with the proliferation rate of MSCs. Patients with the HCO(3) level below the median value exhibited a more marked change in LVEF after BMC treatment than patients with HCO(3) level above the median (11.13 ± 8.07% vs. 2.67 ± 11.89%, P = 0.014).
Low bone marrow pCO(2) and HCO(3) levels may represent the optimal environment for BMCs in terms of their efficacy in autologous stem cell therapy in STEMI patients.
Journal of Translational Medicine 04/2012; 10:66. · 3.99 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Purpose: Beneficial mechanisms of bone marrow cell (BMC) therapy for acute ST-segment elevation myocardial infarct (STEMI) are largely unknown in humans. Therefore, we evaluated the feasibility of serial positron emission tomography (PET) and MRI studies to provide insight into the effects of BMCs on the healing process of ischemic myocardial damage. Methods: Nineteen patients with successful primary reteplase thrombolysis (mean 2.4 h after symptoms) for STEMI were randomized for BMC therapy (2.9 × 10(6) CD34+ cells) or placebo after bone marrow aspiration in a double-blind, multi-center study. Three days post-MI, coronary angioplasty, and paclitaxel eluting stent implantation preceded either BMC or placebo therapy. Cardiac PET and MRI studies were performed 7-12 days after therapies and repeated after 6 months, and images were analyzed at a central core laboratory. Results: In BMC-treated patients, there was a decrease in [(11)C]-HED defect size (-4.9 ± 4.0 vs. -1.6 ± 2.2%, p = 0.08) and an increase in [(18)F]-FDG uptake in the infarct area at risk (0.06 ± 0.09 vs. -0.05 ± 0.16, p = 0.07) compared to controls, as well as less left ventricular dilatation (-4.4 ± 13.3 vs. 8.0 ± 16.7 mL/m(2), p = 0.12) at 6 months follow-up. However, BMC treatment was inferior to placebo in terms of changes in rest perfusion in the area at risk (-0.09 ± 0.17 vs. 0.10 ± 0.17, p = 0.03) and infarct size (0.4 ± 4.2 vs. -5.1 ± 5.9 g, p = 0.047), and no effect was observed on ejection fraction (p = 0.37). Conclusion: After the acute phase of STEMI, BMC therapy showed only minor trends of long-term benefit in patients with rapid successful thrombolysis. There was a trend of more decrease in innervation defect size and enhanced glucose metabolism in the infarct-related myocardium and also a trend of less ventricular dilatation in the BMC-treated group compared to placebo. However, no consistently better outcome was observed in the BMC-treated group compared to placebo.
[Show abstract][Hide abstract] ABSTRACT: Intracoronary administration of autologous bone marrow stem cells (BMC) has been shown to result in a subtle improvement of global left ventricular ejection fraction after ST-elevation myocardial infarction (STEMI), but the overall benefits of BMC therapy are still unclear. We studied the influence of intracoronary injections of BMC on levels of natriuretic peptides and inflammatory mediators, which are well established prognostic biomarkers, in patients with STEMI.
In this randomized, double-blind study, consecutive patients with an acute STEMI treated with thrombolysis followed by PCI 2-6 days after STEMI, were randomly assigned to receive either intracoronary BMC or placebo medium into the infarct-related artery. Blood samples were drawn for biochemical determinations.
From baseline to 6 months, there was a significant decrease in the levels of N-terminal probrain natriuretic peptide (NT-proBNP), interleukin-6 (IL-6) and high-sensitivity C-reactive protein (hsCRP) in the whole patient population (P < 0.001 for all). However, no difference was observed between the BMC group (n = 39) and the placebo group (n = 39) in the change of the levels of NT-proANP (median -54 vs. +112 pmol/L), NT-proBNP (-88 vs. -115 pmol/L) or inflammatory markers IL-6 (-3.86 vs. -5.61 pg/mL), hsCRP (-20.29 vs. -22.36 mg/L) and tumor necrosis factor α (-0.12 vs. -0.80 pg/mL) between baseline and 6 months.
Intracoronary BMC therapy does not appear to exert any significant effects on the secretion of natriuretic peptides or inflammatory biomarkers in STEMI patients.
Clinical Research in Cardiology 10/2010; 100(4):317-25. · 4.17 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To assess the determinants of functional recovery in patients with ST-elevation myocardial infarction (STEMI) treated initially with thrombolysis, followed by percutaneous coronary intervention and intracoronary injection of bone marrow-derived stem cells (BMC).
A randomised, placebo-controlled, double-blind study (substudy of FINCELL).
Two tertiary cardiac centres.
78 patients with STEMI randomly assigned to receive either intracoronary BMC (n=39) or placebo (n=39) into the infarct-related artery.
Thrombolysis a few hours after symptom onset, percutaneous coronary intervention and intracoronary injection of BMC 2-6 days later.
Efficacy of the BMC treatment was assessed by measurement of the change of global left ventricular ejection fraction (LVEF) from baseline to 6 months after STEMI. Various predefined variables (eg, the levels of certain natriuretic peptides and inflammatory cytokines) were analysed as determinants of improvement of LVEF.
In the BMC group, the most powerful determinant of the change in LVEF was the baseline LVEF (r=-0.58, p<0.001). Patients with baseline LVEF at or below the median (< or = 62.5%) experienced a more marked improvement in LVEF (+12.7 + or - 12.5 %units, p<0.001) than those above the median (-0.8 + or - 6.3 %units, p=0.10). Elevated N-terminal probrain natriuretic peptide (p<0.001) and N-terminal proatrial natriuretic peptide (p=0.052) levels were also associated with improvement in LVEF in the BMC group but not in the placebo group.
The global LVEF recovers most significantly after intracoronary infusion of BMC in patients with the most severe impairment of LVEF on admission. The baseline levels of natriuretic peptides seem also to be associated with LVEF recovery after BMC treatment. Trial registration ClinicalTrials.gov number, NCT00363324.
[Show abstract][Hide abstract] ABSTRACT: : To test a hypothesis that interferon-α (IFN) treatment might restore normal immunoglobulin (Ig) production in multiple myeloma (MM), the effect of IFN on Ig isotype (IgG and IgA) production by peripheral blood (PB) and bone marrow (BM) mononuclear cells (MNCs) in MM patients was analyzed by ELISA. IFN at a concentration of 1000 U/ml was found to enhance IgA production by PB MNCs in IgA-MM and had a trend to stimulate IgG production in IgG-MM. The effect of IFN on nonparaprotein Ig isotype production was more variable, with mostly neutral or inhibitory effects being seen in both the MM subtypes. In contrast to the influences observed in MM patients, IFN at the same concentration inhibited both IgG and IgA production by PB MNCs in healthy controls. In studying BM cells, IFN was found to reduce IgA production in IgA-MM, but had a neutral effect on IgG production in IgG-MM. In the controls, the production of both the IgG and the IgA isotypes by BM MNCs was decreased by IFN.On the basis of these results it seems that the disease itself somehow affects the Ig-producing cells in MM, when measured as different responses of the cells to exogenous IFN in vitro. The results do not support the hypothesis that IFN treatment could restore normal Ig production in MM patients.
European Journal Of Haematology 08/2009; 57(2):171-177. · 2.41 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We have previously reported a Candida krusei outbreak during which a number of our patients were infected or colonized by several different closely related Candida krusei genotypes. The treatment response in many of our patients was at best modest and the patients remained positive for Candida krusei. We speculated that extended exposure to antifungals in patients with an incomplete treatment response might lead to the conditions for selection of drug resistance in the multiple Candida krusei clones. Therefore, we followed the in vitro susceptibility of the Candida krusei isolates taken from our patients before and during the antifungal treatment. A total of 28 Candida krusei isolates from 11 patients with prolonged exposure to antifungal medication were analyzed for their in vitro susceptibility to commonly used drugs. We found that MIC(50) values of all Candida krusei isolates was 12 microg/ml for fluconazole, 0.19 microg/ml for voriconazole, 1.0 microg/ml for amphotericin B, and 1.0 microgt/ml for caspofungin with the corresponding MIC(90) values being 16 microg/ml, 0.5 microg/ml, 2.0 microg/ml, and 1.0 micro/ml, respectively. Extended antifungal exposure did not change these MIC values. We conclude that resistance development in Candida krusei during prolonged antifungal treatment may not be common and the treatment failure of our patients was not likely due to the development of drug resistance by the etiologic agent.
Medical mycology: official publication of the International Society for Human and Animal Mycology 03/2009; 48(1):79-84. · 2.26 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To assess the efficacy and safety of bone marrow cell (BMC) therapy after thrombolytic therapy of an acute ST-elevation myocardial infarction (STEMI).
Patients with STEMI treated with thrombolysis followed by percutaneous coronary intervention (PCI) 2-6 days after STEMI were randomly assigned to receive intracoronary BMCs (n = 40) or placebo medium (n = 40), collected and prepared 3-6 h prior PCI and injected into the infarct artery immediately after stenting. Efficacy was assessed by the measurement of global left ventricular ejection fraction (LVEF) by left ventricular angiography and 2-D echocardiography, and safety by measuring arrhythmia risk variables and restenosis of the stented vessel by intravascular ultrasound. At 6 months, BMC group had a greater absolute increase of global LVEF than placebo group, measured either by angiography (mean +/- SD increase 7.1 +/- 12.3 vs. 1.2 +/- 11.5%, P = 0.05) or by 2-D echocardiography (mean +/- SD increase 4.0 +/- 11.2 vs. -1.4 +/- 10.2%, P = 0.03). No differences were observed between the groups in the adverse clinical events, arrhythmia risk variables, or the minimal lumen diameter of the stented coronary lesion.
Intracoronary BMC therapy is associated with an improvement of global LVEF and neutral effects on arrhythmia risk profile and restenosis of the stented coronary lesions in patients after thrombolytic therapy of STEMI.
European Heart Journal 11/2008; 29(22):2723-32. · 14.72 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Candida krusei infections are associated with high mortality. In order to explore ways to prevent these infections, we investigated potential routes for nosocomial spread and possible clonality of C. krusei in a haematological unit which had experienced an unusually high incidence of cases.
We searched for C. krusei contamination of the hospital environment and determined the level of colonization in patients and health care workers. We also analyzed the possible association between exposure to prophylactic antifungals or chemotherapeutic agents and occurrence of C. krusei. The C. krusei isolates found were genotyped by pulsed-field electrophoresis method in order to determine possible relatedness of the cases.
Twelve patients with invasive C. krusei infection and ten patients with potentially significant infection or mucosal colonization were documented within nine months. We were unable to identify any exogenic source of infection or colonization. Genetic analysis of the isolates showed little evidence of clonal transmission of C. krusei strains between the patients. Instead, each patient was colonized or infected by several different closely related genotypes. No association between medications and occurrence of C. krusei was found.
Little evidence of nosocomial spread of a single C. krusei clone was found. The outbreak may have been controlled by cessation of prophylactic antifungals and by intensifying infection control measures, e.g. hand hygiene and cohorting of the patients, although no clear association with these factors was demonstrated.
[Show abstract][Hide abstract] ABSTRACT: Apoptosis plays an important role in cancer biology. We investigated the expression of caspases 3 and 8 in malignant mesothelioma and malignant mesothelioma cell lines and putative changes in their ultrastructural expression prior and after exposure to epirubicin. Further studies were conducted to compare these changes to the localization and expression of the bcl-2 group of proteins bcl-X, bax and mcl-1, and Fas-Fas ligand in the same cells. In the histological samples, caspase 3 and 8 immunoreactivity was seen in 27/37 (73%) and 16/37 (43%) of the mesotheliomas. The immunostaining was cytoplasmic diffuse, granular, and occasionally nuclear. All six mesothelioma cell lines expressed caspases 3 and 8 by immunoblotting. After exposure to epirubicin the extent of apoptosis was increased in all cell lines investigated, being weakest in the most resistant M38K cell line. Immunoelectron microscopy revealed immunogold labeling for caspases 3 and 8 in the mitochondria with the accumulation of caspase 3 in the apoptotic bodies, while the mitochondrial localization of the bcl-2 proteins appeared to be very stable. Fas receptor could be detected by flow cytometry, whereas the most resistant cell line (M38K) lacked Fas ligand when assessed by RT-PCR. These results suggest the importance of caspase 3 during the apoptotic process of mesothelioma cells and indicate that epirubicin-induced apoptosis is independent of the mitochondrial pathway.
[Show abstract][Hide abstract] ABSTRACT: Cigarette smoke, the major risk factor for lung cancer, induces an accumulation of reactive oxygen species. These have multiple effects on cell defense, cell proliferation and cell death. Thus, compounds involved in the regulators of redox balance can be hypothesized to play a fundamental role in both carcinogenesis and tumor progression. Here, we have evaluated the expressions of all 6 peroxiredoxins (Prxs I-VI) in lung carcinomas. Prxs represent a protein family with the capability of breaking down hydrogen peroxide; thus, they can participate in cellular antioxidant defense, regulate cell proliferation and increase drug resistance of cultured cells. Altogether 92 cases were investigated by immunohistochemistry, including 32 adenocarcinomas, 45 squamous cell, 9 small cell and 6 other carcinomas. Additionally, 11 cases with adenocarcinoma or squamous cell carcinoma were studied by Western analysis and/or by RT-PCR. Prxs I, II, IV and VI were particularly elevated in lung carcinomas as assessed by immunohistochemistry and/or RT-PCR. Western analysis revealed that Prxs I and IV were significantly elevated in tumors compared to nonmalignant tissue (p = 0.04 and 0.002, respectively). There were remarkable variations in Prx expression in various tumor subtypes, the most striking being Prx IV expression, which was mainly associated with adenocarcinoma. Elevated Prx VI expression was associated with high-grade squamous cell carcinoma (p = 0.03) and Prx II expression, with advanced tumor stage (p = 0.01). Our results suggest that Prxs may have effects on the progression of lung cancer.
International Journal of Cancer 10/2004; 111(4):514-21. · 5.01 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Glutaredoxins (Grx) are thiol-disulfide oxidoreductases with antioxidant capacity and catalytic functions closely associated with glutathione, an antioxidant abundantly present in human lung. The present study investigated the expression of both human glutaredoxins in cultured human lung cells and lung homogenates by reverse-transcription polymerase chain reaction and Western blotting. Immunohistochemical studies were conducted with 38 human lung specimens, including healthy lung, parenchymal sarcoidosis, extrinsic allergic alveolitis, and usual interstitial pneumonia (UIP). The ultrastructural localization of Grx1 was assessed by immunoelectron microscopy. In addition, cultured airway epithelial cells were exposed to tumor necrosis factor (TNF)-alpha and transforming growth factor (TGF)-beta. Both Grx1 and Grx2 could be detected at the mRNA and protein level in cultured human lung cells, but only Grx1 was prominently expressed in lung homogenates and alveolar macrophages. Immunohistochemically, Grx1 was highly concentrated to alveolar macrophages and weakly positive in the bronchial epithelium. Grx1 was ultrastructurally localized to the plasma membrane, cytoplasmic vacuoles, and nucleus. The expression of Grx1 decreased in alveolar macrophages of sarcoidosis and allergic alveolitis compared with the case for controls (P < 0.001), and bronchial epithelium of these diseases revealed no Grx1 immunoreactivity. Fibroblast foci and other fibrotic areas in UIP were mainly negative. In A549 cells, Grx1 was down-regulated by TGF-beta, whereas TNF-alpha caused no clear effect. Overall, high expression of Grx1 in alveolar macrophages suggests its importance in the primary defense of human lung. Decreased expression of Grx1 further suggests the impairment of this system both in inflammatory and fibrotic lung diseases, consistent with the down-regulation of Grx1 by TGF-beta in vitro.
Human Pathlogy 08/2004; 35(8):1000-7. · 2.81 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: In the present study, the effects of 9-cis retinoic acid (RA) and 13-cis RA on acute myeloblastic leukaemia (AML) cell growth and the induction of apoptosis as well as its relationship with bcl-2 and p53 were compared with those of all-trans RA (ATRA). The study was performed with the subclones of the retinoid-sensitive OCI/AML-2 cell line. The most prominent inhibitory effect on clonogenic cell growth and morphological apoptosis was shown by 9-cis RA. In addition, Western blotting revealed the most obvious translocation of p53 from cytosol to nucleus in the case of 9-cis RA, which was the only retinoid able to change the conformation of p53 from mutational to wild type, as demonstrated by flow cytometry. There was no difference between the retinoids in the downregulation of bcl-2 as analysed by Western blotting and flow cytometry. The RA receptor (RAR)-alpha antagonist had no effect on apoptosis in any of the three retinoids studied using the annexin V method. In conclusion, this study shows that 9-cis RA was a more potent agent than ATRA or 13-cis RA in inducing growth arrest and apoptosis in the OCI/AML-2 subclones. The effect was associated with the downregulation of bcl-2 and was hardly mediated through the RAR-alpha receptor, but might be related to the activation of p53.
British Journal of Haematology 09/2002; 118(2):401-10. · 4.96 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We investigated the role of glutathione and nitric oxide synthase (NOS) in fiber-induced cell and DNA toxicity using alkaline (pH 13) single-cell gel electrophoresis (the Comet assay). Transformed cultured human pleural mesothelial (MeT-5A) cells and alveolar epithelial cells (A549) were exposed to crocidolite asbestos fibers (1-10 microg/cm(2)) in the presence of buthionine sulfoximine (BSO) or L-arginine-methyl ester (L-NAME). BSO inhibits gamma-glutamylcysteine synthetase (gamma-GCS) and causes glutathione depletion, and L-NAME inhibits nitric oxide generation. Studies were also conducted to assess the expression of the heavy and light subunits of gamma-GCS in human pleural mesothelium and bronchial epithelium in vivo and the induction of inducible NOS (iNOS) by asbestos fibers. Asbestos fibers caused DNA single-strand breaks, and the process was significantly enhanced by BSO (69% compared to the non-treated cells). A549 cells had a 3.5-fold glutathione content compared to MeT-5A cells, which was consistent with the higher resistance of these cells against oxidants and fibers. Flow cytometry of iNOS showed no change of iNOS by the fibers in either cell type in vitro. L-NAME had no effects on the DNA single-strand breaks in the Comet assay, either. Studies on lung biopsies showed that the immunoreactivities of both gamma-GCS subunits were very low in healthy human mesothelium in vivo. We conclude that glutathione may play an essential role in protecting intact cells against fiber-induced oxidative DNA alterations, and low gamma-GCS reactivity in pleural mesothelium may be associated with the high sensitivity of mesothelial cells to fiber-induced toxicity.
Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis 03/2002; 514(1-2):7-17. · 4.44 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We assessed the distribution and expression of inducible nitric oxide synthase (i-NOS), endothelial nitric oxide synthase (e-NOS), and xanthine oxidase (XAO) in usual interstitial pneumonia, desquamative interstitial pneumonia, and granulomatous diseases. The material consisted of biopsy specimens from 5 healthy subjects (nonsmokers), 9 patients with usual interstitial pneumonia, 11 with desquamative interstitial pneumonia, 14 with sarcoidosis, and 8 with extrinsic allergic alveolitis. i-NOS was expressed intensively in inflammatory but not infibrotic lesions. It was expressed most prominently in alveolar macrophages and alveolar epithelium of all disorders and in the granulomas of sarcoidosis and extrinsic allergic alveolitis. In contrast with i-NOS, e-NOS was expressed prominently in control lung tissue samples but also in granulomas of sarcoidosis and extrinsic allergic alveolitis. Reverse transcription-polymerase chain reaction performed on bronchoalveolar lavage fluid samples from patients with sarcoidosis or usual interstitial pneumonia andfrom healthy subjects indicated positivity for XAO, but immunohistochemical analysis in samples from healthy lung and all parenchymal lung disorders showed no immunoreactivity for XAO. i-NOS has an important role in the pathogenesis of interstitial lung diseases, being up-regulated during the inflammatory but not during the fibrotic disease stage.
American Journal of Clinical Pathology 02/2002; 117(1):132-42. · 3.01 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: It is generally accepted that the vascular endothelial growth factor (VEGF) signal system has no role in the maintenance of normal blood cell formation, although it obviously regulates the development of primitive hematopoiesis during an early stage of embryogenesis. The VEGF signaling pathway, however, might have some role in malignant hematopoiesis, since malignant hematopoietic cells, including acute myeloid leukemia (AML) cells, have been shown to express VEGF and its receptors. In endothelial cells, the VEGF/Flk-1/KDR signal system is a very important generator of nitric oxide (NO) through the activation of its downstream effectors phosphatidylinositol-3-OH-kinase (PI3-K), Akt kinase and endothelial NO synthase (eNOS). It is known that NO regulates hematopoiesis and modulates AML cell growth. The role of the VEGF signaling pathway in the control of AML cell growth through eNOS, however, has not been studied. By using the OCI/AML-2 cell line, which expresses VEGF receptor-2, ie Flk-1/KDR, eNOS and VEGF, as analyzed by flow cytometry, and produces VEGF into growth medium, as analyzed by ELISA, we showed that the Akt kinase and NOS activities in these cells were decreased by the inhibitors of VEGF, Flk-1/KDR and PI3-K, and NOS activity also by the direct inhibitor of NOS. The decreased NOS activity led to inhibition of clonogenic cell growth and, to some extent, induction of apoptosis. We also found that blast cells of bone marrow samples randomly taken from 14 AML patients uniformly expressed Flk-1/KDR and to varying degrees eNOS and VEGF, as analyzed by immunohistochemistry. We conclude that autocrine VEGF through Flk-1/KDR, by activating eNOS to produce NO through PI3-K/Akt kinase, maintains clonogenic cell growth in the OCI/AML-2 cell line. Since the patient samples did not express VEGF in all cases, it is possible that in vivo the regulatory connection between these two signal systems is also mediated via endocrine VEGF in addition to autocrine or paracrine VEGF.
[Show abstract][Hide abstract] ABSTRACT: To investigate endothelial nitric oxide synthase (eNOS) expression in malignant mesothelioma and its association with expression of vascular endothelial growth factor (VEGF), its receptors FLK1 and FLT1, and vascular density.
eNOS, VEGF, FLK1 and FLT1 were studied in 36 histological mesothelioma samples by immunohistochemistry. Two mesothelioma (M14K, M38K) and one non-neoplastic mesothelial cell line (MET-5A) were studied for eNOS mRNA expression by reverse transcriptase-polymerase chain reaction (RT-PCR). Vascular density was determined by staining the samples with an antibody to factor VIII. RT-PCR showed that mesothelioma cells synthesize eNOS in vitro. eNOS immunoreactivity was found in 32/36 (89%) tumours. VEGF, FLK1 and FLT1 expression was found in 17 (45%), 24 (69%) and 25 (71%) cases, respectively. FLK1 or FLT1 immunoreactivity was more often seen in epithelioid and biphasic mesotheliomas than in sarcomatoid ones (P=0.007 and P=0.011, respectively). There was a significant association between FLK1 and FLT1 immunoreactivity (P=0.032). No significant association was found between FLK1, FLT1, VEGF and eNOS immunoreactivity and vascular density.
eNOS is strongly expressed in malignant mesothelioma. Since eNOS did not associate with VEGF, FLK1 or FLT1, its synthesis seems not to be regulated through VEGF in malignant mesothelioma as has been shown in non-neoplastic endothelial cells.
[Show abstract][Hide abstract] ABSTRACT: We investigated the expression of thioredoxin (Trx) and thioredoxin reductase (TrxR) in 89 non-small cell lung carcinomas. Additionally, immortalized human bronchial epithelial cells (BEAS 2B) and four human lung carcinoma cells lines (A549, SK-MES-1, CALU-6, and A427) were studied by Western blot and reverse transcription-PCR for the synthesis of Trx and TrxR protein and mRNA expression in vitro. The histological samples were also studied for immunohistochemical p53 and proliferating cell nuclear antigen expression and apoptosis. In non-neoplastic lung, Trx and TrxR expression was seen in bronchial epithelial cells and alveolar macrophages, metaplastic alveolar epithelial cells, and chondrocytes of the bronchus. In non-small cell lung carcinomas, there was a widespread expression of Trx and TrxR with only three and eight cases negative, respectively. Trx and TrxR expression was located in both cytoplasmic and nuclear compartments of the cells. There was a statistical association between cytoplasmic and nuclear Trx or TrxR expression. Grade I-II tumors showed stronger cytoplasmic and nuclear Trx and TrxR immunoreactivity than grade III tumors. No association was found between p53 and proliferating cell nuclear antigen expression and Trx or TrxR immunoreactivity. However, apoptosis was inversely associated with nuclear Trx and TrxR positivity. In the cell lines studied, both non-neoplastic BEAS 2B cells and all of the carcinoma cell lines expressed Trx and TrxR proteins and mRNA. The results show that these redox-regulating proteins are highly expressed in lung carcinomas taking part in activation of transcriptional factors and regulation of apoptosis in non-small cell lung carcinoma. In high-grade tumors, Trx and TrxR expression is diminished, suggesting loss of redox regulation in tumors with low differentiation.
Clinical Cancer Research 07/2001; 7(6):1750-7. · 8.19 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Thioredoxin (Trx) with a redoxactive dithiol together with NADPH and thioredoxin reductase (TrxR) is a major disulfide reductase regulating cellular redox state and cell proliferation and possibly contributing to the drug resistance of malignant cells. We assessed the Trx system in malignant pleural mesothelioma cell lines, in nonmalignant pleural mesothelium and in biopsies of malignant pleural mesothelioma. The mRNA and immunoreactive proteins of Trx and cytosolic and mitochondrial TrxR were positive in all four human mesothelioma cell lines investigated. Six cases of nonmalignant, histologically healthy pleural mesothelium showed no Trx or TrxR immunoreactivity, whereas immunohistochemistry on 26 biopsies of human malignant pleural mesothelioma showed positive Trx in all cases and positive TrxR in 23 (88%) of the cases. Moderate or strong immunoreactivity for Trx or TrxR was detected in 85% (22 cases) and 61% (14 cases) of the mesothelioma cases, respectively. Both Trx and TrxR staining patterns were mainly diffuse and cytoplasmic, but in 39% of the mesothelioma cases prominent nuclear staining could also be detected. Although staining for Trx and TrxR was seen in tumor cells, no significant association could be demonstrated between Trx or TrxR expression and tumor cell proliferation or apoptosis in the biopsies of mesothelioma. There was no significant association between the intensity of Trx or TrxR immunoreactivity and patient survival, which may possibly be related to moderate or intense Trx and TrxR reactivity in most of the cases. Although the Trx system may have an important role in the drug resistance of malignant mesothelioma, these studies also suggest that multiple factors contribute to the promotion, cell proliferation and apoptosis of malignant mesothelioma cells in vivo.
International Journal of Cancer 06/2001; 95(3):198-204. · 5.01 Impact Factor