Cyclo-oxygenase-2 (COX-2) inhibition reduces apoptosis in acute myocardial infarction.
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Animals↗
Biomedical subjects
S Scarpa
Publications and source records attributed to S Scarpa.
Nuclear and cytoplasmic expression of survivin in 67 surgically resected pancreatic cancer patients.
Pancreatic cancer is one of the most aggressive gastrointestinal cancer with less than 10% long-term survivors. The apoptotic pathway deregulation is a postulated mechanism of carcinogenesis of this tumour. The present study investigated the prognostic role of apoptosis and apoptosis-involved proteins in a series of surgically resected pancreatic cancer patients. All patients affected by pancreatic adenocarcinoma and treated with surgical resection from 1988 to 2003 were considered for the study. Patients' clinical data and pathological tumour features were recorded. Survivin and Cox-2 expression were evaluated by immunohistochemical staining. Apoptotic cells were identified using the TUNEL method. Tumour specimen of 67 resected patients was included in the study. By univariate analysis, survival was influenced by Survivin overexpression. The nuclear Survivin overexpression was associated with better prognosis (P = 0.0009), while its cytoplasmic overexpression resulted a negative prognostic factor (P = 0.0127). Also, the apoptotic index was a statistically significant prognostic factor in a univariate model (P = 0.0142). By a multivariate Cox regression analysis, both the nuclear (P = 0.002) and cytoplasmic (P = 0.040) Survivin overexpression maintained the prognostic statistical value. This is the first study reporting a statistical significant prognostic relevance of nuclear and cytoplasmic Survivin overexpression in pancreatic cancer. In particular, patients with high nuclear Survivin staining showed a longer survival, whereas patients with high cytoplasmic Survivin staining had a shorter overall survival.
Aged↗
Role of extracellular matrix in regulation of staurosporine-induced apoptosis in breast cancer cells.
Autocrine and paracrine mechanisms modulate the synthesis and secretion of extracellular matrix (ECM); moreover, each component of the ECM is capable of modulating the synthesis and release of other ECM molecules. Therefore, the synthesis of ECM glycoprotein fibronectin and laminin was studied in the human breast cancer cell lines MCF7 and MDA MB 23, plated on different ECM. Our results showed that the cells plated on a fibronectin substrate increased laminin synthesis: this event correlated with an increase in alpha2 and alpha3 integrin subunits. Staurosporine-induced apoptosis was then analyzed in the cell lines plated on different ECM. Staurosporine treatment determined the apoptosis of 35 and 33% respectively of MDA MB 231 and MCF7; these values increased to 60 and 64% in cells plated on laminin, to 48 and 63% in cells plated on fibronectin and to 64 and 69% in cells plated on matrigel. Moreover, staurosporine treatment decreased bcl-2 expression in the cells plated on fibronectin and laminin. Yet, staurosporine treatment determined PARP cleavage and PARP partial disappearance when the cells were plated on matrigel. Finally, a partial loss of function mutant Ras protein that activated only Raf pathway, was expressed in MCF7, in order to identify whether the increase of apoptosis induced by extracellular matrix involved the Raf/MAP kinase pathway. The increase of apoptosis of the cells plated on matrigel suggested that the activation of the Raf pathway is probably involved in the decrease of survival on matrigel. These data demonstrate that the modification of ECM modulates the apoptotic process of breast cancer cells and suggest that it is worthwhile to dissect the role of ECM in the control of apoptotic process.
Apoptosis↗
Cyclo-oxygenase-2 (COX-2) expression at the site of recent myocardial infarction: friend or foe?
BACKGROUND: Cyclo-oxygenase-2 (COX-2) is induced in cardiomyocytes only in response to stress, such as ischaemia. OBJECTIVE: To assess COX-2 expression at the site of recent myocardial infarction. METHODS: COX-2 expression was evaluated by specific immunostaining in cardiomyocytes from 23 subjects who died 10-60 days after acute myocardial infarction. The relation between COX-2 myocardial expression and apoptotic rate was investigated. Cardiomyocyte apoptotic rate was defined as the number of cells co-expressing in situ end labelling of DNA fragmentation (TUNEL) and immunostaining for activated caspase-3. RESULTS: COX-2 expression was found in cardiomyocytes at the site of infarction in nine of 23 cases (39%). It was associated with fivefold higher apoptotic rates (median 17.9% (interquartile range 11.0-25.4%) v 3.7% (0.6-12.8%); p = 0.016), and apoptotic rate increased progressively from mild to intense COX-2 staining (p for trend 0.009). COX-2 expression co-localised with TUNEL nuclear staining in myocytes, and there was a high concordance between COX-2 and hypoxia induced factor 1-alpha staining (78%, p = 0.021) and between COX-2 and bax (83%, p = 0.014). Subjects showing myocardial COX-2 expression were more likely to have enlarged hearts (p = 0.050), and intense COX-2 staining was strictly associated with symptomatic heart failure (p = 0.035). CONCLUSIONS: COX-2 is expressed in cardiomyocytes in nearly 40% of cases at the site of recent acute myocardial infarction, even late after the index event. Its expression was associated with extremely high apoptotic rates. These findings suggest a potential cause-effect link between COX-2 expression and enhanced myocardial apoptosis in ischaemic cardiomyopathy.
Aged↗
Surviving acute myocardial infarction: survivin expression in viable cardiomyocytes after infarction.
BACKGROUND: Apoptosis is a key feature in postinfarction remodelling leading to progressive myocyte loss. Both proapoptotic and antiapoptotic factors contribute to the delicate balance between death and survival. The survivin pathway has emerged as essential in the control of apoptosis, although its role in heart disease is unknown. AIM: To evaluate survivin expression after acute myocardial infarction (AMI). METHODS: Survivin expression was assessed immunohistochemically in the peri-infarct and remote viable myocardium in 17 consecutive patients who died 1-30 weeks after AMI and in four control hearts. RESULTS: Survivin was expressed by myocytes in the peri-infarct area in eight patients and in the remote region in 13 patients. The rate of survivin expression after AMI was significantly higher in the remote versus peri-infarct regions and compared with control hearts. Its expression was inversely associated with the presence of dilated cardiopathy and of apoptosis, independently from the gross pathology infarct size. CONCLUSIONS: Survivin myocardial expression after AMI may be associated with the survival of at risk myocardium and may be indicative of more favourable remodelling after AMI. These findings identify a potential new target for the treatment of postinfarction remodelling.
Apoptosis↗
Prognostic significance of cyclooxygenase-2 (COX-2) and expression of cell cycle inhibitors p21 and p27 in human pleural malignant mesothelioma.
BACKGROUND: A study was undertaken to analyse the potential prognostic value of the immunohistochemical expression of cyclooxygenase-2 (COX-2) and p27 in 29 malignant mesotheliomas already screened for the expression of p21 and p53. METHODS: Immunohistochemistry was used to determine the expression of COX-2 and p27. The correlation with survival of these factors and of p21 and p53 expression was assessed by univariate and multivariate analyses. RESULTS: A positive statistically significant correlation was found between p27 and p21 expression (p<0.0001), but there was a negative correlation between COX-2 expression and both p27 (p = 0.001) and p21 (p<0.0001). No statistically significant correlation was recorded between p53 and all the other immunohistochemical parameters. Univariate analysis showed that overall survival was strongly influenced by p21, p27, and COX-2 expression, but multivariate Cox regression analysis showed that the only immunohistochemical parameter to influence overall survival of patients with mesothelioma was COX-2. CONCLUSIONS: These findings suggest that COX-2 expression may be a useful prognostic parameter for mesothelioma.
Cell Cycle Proteins↗
The antineoplastic role of bisphosphonates: from basic research to clinical evidence.
Bisphosphonates are now well established as successful agents for the prevention and treatment of postmenopausal osteoporosis, corticosteroid-induced bone loss and Paget's disease. Bisphosphonates have also recently become important in the management of cancer-induced bone disease, and they now have a widely recognized role for patients with multiple myeloma and bone metastases secondary to breast cancer and prostate cancer. Recent studies suggest that, besides the strong antiosteoclastic activity, the efficacy of such compounds in the oncological setting could also be due also to direct antitumor effect, exerted at different levels. Here, after a brief analysis of the chemical structure, we will review the antineoplastic and biological properties of bisphosphonates. We will start from well estabilished mechanisms of action and go on to discuss the latest evidence and hypotheses. In particular, we will review the antiresorptive properties in malignant osteolysis and the recent evidence of a direct antitumor effect. Furthermore, this review will analyze the influence of bisphosphonates on cancer growth factor release, their effect on cancer cell adhesion, invasion and viability, the proapoptotic potential on cancer cells, the antiangiogenic effect, and, finally, the immunomodulating properties of bisphosphonates on the gammadelta T cell population.
Apoptosis↗
Angiotensin-converting enzyme inhibition modulates high-glucose-induced extracellular matrix changes in mouse glomerular epithelial cells.
BACKGROUND/AIM: Extracellular matrix alterations are involved in the pathogenesis of diabetic nephropathy. We evaluated the effects of high glucose concentrations and inhibition of angiotensin-converting enzyme on the laminin and fibronectin production by glomerular epithelial cells. METHODS: Glomerular epithelial cells were cultured in 5 and 30 mmol/l glucose, with and without enalaprilat (0.3 mmol/l). Laminin and fibronectin were measured (35S-methionine, immunoprecipitation), and their mRNA expression was evaluated (RT-PCR). RESULTS: The laminin concentration was higher in the cells than in the medium, where an increase of its content was observed under high-glucose conditions (p < 0.01). Fibronectin, found only in the medium, was not modified by the high glucose concentration. Following enalaprilat administration, the laminin concentration was decreased under high-glucose conditions, both in the cell and in the medium (p < 0.001), whereas the fibronectin concentration was increased under high-glucose conditions (p < 0.001). The mRNA expression of laminin and fibronectin under high-glucose conditions only slightly increased. Enalaprilat decreased the fibronectin mRNA synthesis dramatically (>50%, p < 0.0001) under high-glucose conditions. CONCLUSIONS: Enalaprilat normalizes the abnormal, high-glucose-induced concentration of laminin, while it decreases the fibronectin synthesis. The improvement of the renal function in diabetic patients treated with angiotensin-converting enzyme inhibitors may, in part, be due to a modulator effect on extracellular matrix content and composition.
Angiotensin-Converting Enzyme Inhibitors↗
Gene silencing by S-adenosylmethionine in muscle differentiation.
A well-characterised experimental system, the myogenin gene in C2C12 muscle cell culture, was chosen to better understand the methylation mechanism underlying the regulation of gene expression. We already demonstrated that demethylation dynamics of a specific CpG site in the 5'-flanking region of myogenin well correlates with gene expression and terminal differentiation. Here we demonstrate that S-adenosylmethionine-sulphate-p-toluenesulphonate (SAM) inhibits myogenin expression and myoblast differentiation by delaying the demethylation of specific CpG in differentiating myoblasts. These results suggest new perspectives in methylation mechanisms and the use of SAM in the partial silencing of gene expression, as it could be required in disease treatment.
Animals↗
Erythroid differentiation and regulatory gene expression are modulated by adenosine derivatives interfering with S-adenosylmethionine metabolic pathway.
The differentiation of murine erythroleukemia cells and the expression of SCL, Id1 and c-myc regulatory genes were studied. The first gene is a positive regulator of differentiation, while the other two are both negative regulators of differentiation and positive regulators of proliferation. Accordingly, our data show that when differentiation is stimulated SCL is upregulated while Id1 and c-myc are, coordinately, downregulated. The cultures were treated with two adenosine derivatives, 3-deazaadenosine and 3-deazaaristeromycin, known to act on the metabolic pathway of the methyl donor S-adenosylmethionin, in order to assess the possibility of a coordinated modulation, by these drugs, of regulatory gene expression and erythroid cell differentiation. 3-Deazaaristeromycin caused the simultaneous downregulation of Id1 and c-myc, whereas 3-deazaadenosine caused their upregulation; both drugs produced a transient increase in SCL expression. The use of these drugs evidenced a predominant regulatory effect of negative regulators in the control of erythroid differentiation. The distinct effects of the two drugs on regulatory gene expression led to an increased differentiation induced by 3-deazaaristeromycin and to a reduced differentiation induced by 3-deazaadenosine, if compared with controls. Southern analysis of DNA digested with methylation-specific restriction endonucleases showed that the administration of 3-deazaaristeromycin resulted in hypomethylation of SCL and c-myc, thus evidencing, in these cells, a clear correlation between DNA hypomethylation and differentiation but no straightforward correlation between DNA methylation and gene expression.
Adenosine↗
The dynamics of myogenin site-specific demethylation is strongly correlated with its expression and with muscle differentiation.
The molecular mechanisms underlying the activation of tissue-specific genes have not yet been fully clarified. We analyzed the methylation status of specific CCGG sites in the 5'-flanking region and exon 1 of myogenin gene, a very important myogenic differentiation factor. We demonstrated a loss of methylation, at the onset of C2C12 muscle cell line differentiation, limited to the CCGG site of myogenin 5'-flanking region, which was strongly correlated with the transcriptional activation of this gene and with myogenic differentiation. The same CCGG site was also found to be hypomethylated, in vivo, in embryonic mouse muscle (a myogenin-expressing tissue), as opposed to nonmuscle (nonexpressing) tissues that had a fully methylated site. In a C2C12-derived clone with enhanced myogenic ability, demethylation occurred within 2 h of induction of differentiation, suggesting the involvement of some active demethylation mechanism(s) that occur in the absence of DNA replication. Exposure to drugs that inhibit DNA methylation by acting on the S-adenosylmethionine metabolism produced a further reduction, to a few minutes, in the duration of the demethylation dynamics. These effects suggest that the final site-specific DNA methylation pattern of tissue-specific genes is defined through a continuous, relatively fast interplay between active DNA demethylation and re-methylation mechanisms.
Animals↗
Increased TGFbeta type II receptor expression suppresses the malignant phenotype and induces differentiation of human neuroblastoma cells.
TGFbeta can modulate neuroblastoma (NB) cell proliferation and differentiation in vitro. In this study we used a NB cell line (LAN-5) which has been shown to partially respond to TGFbeta and to present high levels of TGFbeta receptor type I and low levels of receptor type II (TbetaRII) on the cell surface. To evaluate the role of TbetaRII in mediating TGFbeta effects, LAN-5 cells were transfected with an expression vector containing the human full-length TbetaRII cDNA or with the empty vector pcDNA3. Compared to control CLV3 cells (transfected with empty plasmid) and parental LAN-5 cells, isolated neomycin-resistant clones (CL1 and CL3) expressed higher levels of TbetaRII, had reduced cell growth rate in vitro, and were unable to form tumors in vivo. Furthermore, isolated clones modified their morphology, assuming a terminally differentiated neuronal phenotype. Immunocytochemical staining demonstrated a basal increased expression of neural-specific markers, such as axonal growth-associated protein (GAP43) and neurofilaments (NF200). TGFbeta treatment further increased the synthesis of NF200 and GAP43 in the transfected clones as revealed by Western blot analysis. These data indicate that TbetaRII overexpression potentiates the TGFbeta signal transduction pathway, reverting NB cell neoplastic phenotype with the reduction of proliferation rate and the induction of terminal maturation.
Animals↗
T-cell cytokine pattern at three time points during specific immunotherapy for mite-sensitive asthma.
BACKGROUND: Several lines of evidence indicate that specific immunotherapy may act by modifying the patterns of cytokines produced by helper T cells. However, different protocols have been used and different results obtained. OBJECTIVES: To quantify the effect of specific immunotherapy on the TH1/TH2 T-cell cytokine pattern at the single cell level. METHODS: We examined the interferon-gamma/interleukin-4 ratio in peripheral blood CD4+ and CD8+ T cells from 12 subjects with house dust mite-sensitive asthma using a flow cytometric method of intracellular cytokine detection. Cytokine production was determined following stimulation with phorbol myristate acetate/ionomycin, a policlonal activator. Subjects were examined at three occasions: before specific immunotherapy, after the 3-months dose increase phase and after 1 year of treatment. During the treatment year patients kept a diary in which they recorded: (a) symptoms of asthma according to a 0-3 grading (0 = absent, 1 = mild, 2 = moderate, 3 = severe); (b) number of puffs (100 microg) per day of salbutamol required to control symptoms; and (c) peak expiratory flow. RESULTS: Specific immunotherapy improved clinical indices of disease activity including symptom scores and medication use during the treatment year, and had a marked effect in increasing the interferon-gamma/interleukin-4 ratio in peripheral blood CD4+ T cells already after the dose increase phase (5.47 +/- 1.5 vs 4.07 +/- 1.49%, P = 0.03) with and a further rise after 1 year's treatment (16.12 +/- 2.8 vs 4.07 +/- 1.49 and 16.12 +/- 2.8 vs 5.47 +/- 1.5%, P = 0.001 and P = 0.002, respectively). There were no significant changes in the interferon-gamma/interleukin-4 ratio in peripheral blood CD8+ T cells at the three times of the study. CONCLUSIONS: These data add to view that the efficacy of specific immunotherapy may be attributed to a modified cytokine secretion of CD4+ T cells.
Adult↗
HMGI(Y) and HMGI-C genes are expressed in neuroblastoma cell lines and tumors and affect retinoic acid responsiveness.
HMGI-C and HMGI(Y) are architectural DNA-binding proteins that participate in the conformational regulation of active chromatin. Their pattern of expression in embryonal and adult tissues, the analysis of the "pygmy" phenotype induced by the inactivation of the HMGI-C gene, and their frequent qualitative or quantitative alteration in experimental and human tumors indicate their pivotal role in the control of cell growth, differentiation, and tumorigenesis in several tissues representative of the epithelial, mesenchymal, and hematopoietic lineages. In contrast, very little information is available on their expression and function in neural cells. Here, we investigated the expression of the HMGI(Y) and HMGI-C genes in neuroblastoma (NB), a tumor arising from an alteration of the normal differentiation of neural crest-derived cells and in embryonal and adult adrenal tissue. Although HMGI(Y) is constitutively expressed in the embryonal and adult adrenal gland and in all of the NB cell lines and ex vivo tumors examined, its regulation appears to be associated to growth inhibition and differentiation because we observed that HMGI(Y) expression is reduced by retinoic acid (RA) in several NB cell lines that are induced to differentiate into postmitotic neurons, whereas it is up-regulated by RA in cells that fail to differentiate. Furthermore, the decrease of HMGI(Y) expression observed in RA-induced growth arrest and differentiation is abrogated in cells that have been made insensitive to this drug by NMYC overexpression. In contrast, HMGI-C expression is down-regulated during the development of the adrenal gland, completely absent in the adult individual, and only detectable in a subset of ex vivo NB tumors and in RA-resistant NB cell lines. We provide evidence of a causal link between HMGI-C expression and resistance to the growth arrest induced by RA in NB cell lines because exogenous HMGI-C expression in HMGI-C-negative and RA-sensitive cells is sufficient to convert them into RA-resistant cells. Therefore, we suggest that HMGI-C and HMGI(Y) may participate in growth- and differentiation-related tumor progression events of neuroectodermal derivatives.
Adrenal Glands↗
Nicotine regulates basic fibroblastic growth factor and transforming growth factor beta1 production in endothelial cells.
Nicotine, a constituent of cigarette smoking, may induce atherosclerosis through the production of growth factors. The pattern of bFGF and TGF beta1 production and release by bovine aortic endothelial cells (EC) stimulated with nicotine (from 6 x 10(-4) to 6 x 10(-8) M) was studied. EC viability and count were assessed. The presence of bFGF and TGF beta1 in serum-free conditioned media was determined by the inhibition antibody-binding assay and Western blot analysis. Mitogenic activity of nicotine on EC was also determined. Polymerase chain reaction (PCR) was used to study the expression of bFGF and TGF beta1. The bFGF release after nicotine stimulation was greater than controls, whereas TGF beta1 release was lower. At a nicotine concentration of 6 x 10(-6) M we noted the greatest mitogenic activity. The addition of monoclonal antibody anti-bFGF decreased the tritiated thymidine uptake of EC exposed to nicotine but the addition of monoclonal antibody anti-TGF beta1 had no significant effect. bFGF mRNA expression was significantly higher in EC exposed to nicotine than in controls, whereas TGF beta1 mRNA expression was not modified. From these data we concluded that nicotine regulates bFGF production and release and TGF beta1 release and may have a key role in the development and progression of atherosclerosis.
Animals↗
Thrombospondin-1 is a mediator of the neurotypic differentiation induced by EGF in thymic epithelial cells.
Thymic epithelial cell component originates from cranial neural crest as well as from endoderm and ectoderm of the third pharyngeal pouch and branchial cleft. Epidermal growth factor (EGF) has been previously shown to play a crucial role in directing thymic epithelial cells toward a neural-oriented cell fate. To identify genes that are involved in the EGF-induced neurotypic differentiation of the thymic stroma-derived TC-1S cell line, we studied EGF-treated and untreated cells by RNA fingerprinting PCR-based differential screening. We obtained 23 distinct sequences including 18 known genes and 5 sequences previously unreported, which are currently under characterization. Here, we describe the involvement of one of the isolated genes, the thrombospondin-1, as a mediator of the neurotypic differentiation induced by EGF in TC-1S cells. We show that thrombospondin-1 mRNA and protein levels are increased by EGF. Moreover, exogenous thrombospondin-1 is able to enhance the outgrowth of neurite-like processes as well as the expression of neurofilaments and neural cell adhesion molecule in TC-1S cells. These observations suggest that the up-regulation of thrombospondin-1 synthesis induced by EGF contributes to the differentiation choice of thymic epithelial cells toward a neural fate, reminiscent of their neural crest origin.
Animals↗
Migration of mesothelioma cells correlates with histotype-specific synthesis of extracellular matrix.
Three human pleural malignant mesothelioma cell cultures (MM) of epithelioid (E1), fibrous (F1) and byphasic (B1) histotype were studied in their synthesis of the extracellular matrix (ECM) components laminin (LM), fibronectin (FN), type IV collagen (cIV), and in their chemotactic and haptotactic migration towards the ECM produced proteins. MM-B1 showed the highest FN synthesis and release; MM-E1 produced the highest quantity of basement membrane constituents LM and cIV; MM-F1 weakly produced and released FN, LM and cIV. MM-B1 had the highest chemotactic and haptotactic motility, MM-F1 migrated toward the lowest concentration of LM while had reduced chemotactic activity toward FN and cIV; MM-E1 had the lowest migratory activity toward each ECM substrate. We demonstrated that three MM of different histotype are characterized by different ECM production and that these differences determine a variable ability of each MM to spread and migrate towards ECM substrates.
Cell Movement↗
Thymectomy and multiple sclerosis: ultrastructural study of an experimental model.
Transmission electron microscopy was performed on specimens of the thymus of rats induced for acute experimental allergic encephalomyelitis (EAE). The ultrastructural alterations of the thymus were progressive and correlated with EAE development. The thymic disorganization was due to a progressive degeneration of both epithelial cells and thymocytes. These data suggest a direct involvement of the epithelial thymic cells and thymocytes in EAE pathogenesis and may suggest the intriguing therapeutic concept of thymectomy in the management of multiple sclerosis.
Animals↗