214 resultados para MAST CELL TUMOUR
Resumo:
Female sex hormones (FSHs) exert profound regulatory effects on the course of lung inflammation due to allergic and non-allergic immune responses. As pollution is one of the pivotal factors to induce lung dysfunction, in this study we investigated the modulatory role of FSHs on lung inflammation after a formaldehyde (FA) exposure. For this purpose, lung and systemic inflammatory responses were evaluated in terms of leukocytes countings in bronchoalveolar lavage (BAL), peripheral blood and bone marrow lavage from 7-day ovariectomized (OVx) and Sham-OVx rats subjected to FA inhalation for 3 consecutive days. The hypothesized link between effects of FSHs on expression of adhesion molecules and mast cells degranulation was also studied. Once exposed to FA, Sham-OVx rats increased the number of total cells recovered in BAL and of leukocytes in peripheral blood, and decreased the counts in bone marrow. By contrast, in OVx rats upon FA exposure there was a reduction of the total cells counts in BAL and of blood leukocytes: lung expressions of ICAM-1 and Mac-1 were depressed, but the number of bone marrow cells did not vary. Estradiol treatment of OVx rats increased the total cells in BAL and decreased the number of blood leukocytes, whereas the number of bone marrow cell remained unaltered. Progesterone treatment, in turn increased the total cells in BAL and blood leukocytes, but decreased the number of bone marrow cells. OVx rats exposed to FA developed tracheal hyperresponsiveness to methacholine (MCh). A similarly altered response was found between the tracheal segments of Sham-OVx rats after FA exposure and that found in tracheae of naive rats. Estradiol treatment prevented FA-induced tracheal hyperresponsiveness to MCh whereas progesterone was ineffective in this regard. In addition, OVx rats upon FA exposure significantly increased both, the ability of mast cell degranulation and serum corticosterone levels. In conclusion, it was found that FSHs act by distinct control mechanisms on FA-induced lung inflammation and tracheal hyperresponsiveness, since at low circulating levels of FSHs (such as those after OVx) there is some resistance to the development of a lung inflammatory response, but the cholinergic tracheal responsiveness is exacerbated. Our data also help to understand the involvement of FSHs on mast cells activity after pollutants exposure and add information regarding the role of FSHs on the mechanisms related to endothelium-leukocyte interactions. (C) 2011 Elsevier Ireland Ltd. All rights reserved.
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Background: Gamma-linolenic acid is a known inhibitor of tumour cell proliferation and migration in both in vitro and in vivo conditions. The aim of the present study was to determine the mechanisms by which gamma-linolenic acid (GLA) osmotic pump infusion alters glioma cell proliferation, and whether it affects cell cycle control and angiogenesis in the C6 glioma in vivo. Methods: Established C6 rat gliomas were treated for 14 days with 5 mM GLA in CSF or CSF alone. Tumour size was estimated, microvessel density (MVD) counted and protein and mRNA expression measured by immunohistochemistry, western blotting and RT-PCR. Results: GLA caused a significant decrease in tumour size (75 +/- 8.8%) and reduced MVD by 44 +/- 5.4%. These changes were associated with reduced expression of vascular endothelial growth factor (VEGF) (71 +/- 16%) and the VEGF receptor Flt1 (57 +/- 5.8%) but not Flk1. Expression of ERK1/2 was also reduced by 27 +/- 7.7% and 31 +/- 8.7% respectively. mRNA expression of matrix metalloproteinase-2 (MMP2) was reduced by 35 +/- 6.8% and zymography showed MMP2 proteolytic activity was reduced by 32 +/- 8.5%. GLA altered the expression of several proteins involved in cell cycle control. pRb protein expression was decreased (62 +/- 18%) while E2F1 remained unchanged. Cyclin D1 protein expression was increased by 42 +/- 12% in the presence of GLA. The cyclin dependent kinase inhibitors p21 and p27 responded differently to GLA, p27 expression was increased (27 +/- 7.3%) while p21 remained unchanged. The expression of p53 was increased (44 +/- 16%) by GLA. Finally, the BrdU incorporation studies found a significant inhibition (32 +/- 11%) of BrdU incorporation into the tumour in vivo. Conclusion: Overall the findings reported in the present study lend further support to the potential of GLA as an inhibitor of glioma cell proliferation in vivo and show it has direct effects upon cell cycle control and angiogenesis. These effects involve changes in protein expression of VEGF, Flt1, ERK1, ERK2, MMP2, Cyclin D1, pRb, p53 and p27. Combination therapy using drugs with other, complementary targets and GLA could lead to gains in treatment efficacy in this notoriously difficult to treat tumour.
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Aims: This study has compared the tissue expression of the p53 tumour suppressor protein and DNA repair proteins APE1, hMSH2 and ERCC1 in normal, dysplastic and malignant lip epithelium. Methods and results: Morphological analysis and immunohistochemistry were performed on archived specimens of normal lip mucosa (n = 15), actinic cheilitis (AC) (n = 30), and lip squamous cell carcinoma (LSCC) (n = 27). AC samples were classified morphologically according to the severity of epithelial dysplasia and risk of malignant transformation. LSCC samples were morphologically staged according to WHO and invasive front grading (IFG) criteria. Differences between groups and morphological stages were determined by bivariate statistical analysis. Progressive increases in the percentage of epithelial cells expressing p53 and APE1 were associated with increases in morphological malignancy from normal lip mucosa to LSCC. There was also a significant reduction in epithelial cells expressing hMSH2 and ERCC1 proteins in the AC and LSCC groups. A higher percentage of malignant cells expressing APE1 was found in samples with an aggressive morphological IFG grade. Conclusions: Our data showed that epithelial cells from premalignant to malignant lip disease exhibited changes in the expression of p53, APE1, hMSH2 and ERCC1 proteins; these molecular change might contribute to lip carcinogenesis.
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The immunologic characterization of chronic idiopathic urticaria (CIU), mainly regarding cytokine profile needs more investigation. We examined circulating inflammatory cytokine levels, T-cell induced secretion, and cytokine mRNA expression in patients with CIU subjected to the intradermal autologous serum skin test (ASST). Increased levels of circulating pro-inflammatory cytokines, such as TNF-alpha, IL-1 beta, IL-12p70, and IL-6 have been observed in most of patients with CIU, together with an enhancement of IL-2 secretion following T-cell stimulation. Highlighting the inflammatory profile in CIU found in ASST positive, is the enhanced B-cell proliferative responsiveness and increased IL-17 secretion levels. ASST-positive patients also exhibited impaired IL-4 secretion associated with increased IL-10 production. Altered cytokine expression in patients with ASST-negative, was the down-modulation of spontaneous IL-10 mRNA expression levels in peripheral blood mononuclear cells. Our findings support the concept of immunologic dysregulation in CIU, revealing a systemic inflammatory profile associated with disturbed cytokine production by T cells, mainly related to IL-17 and IL-10 production. (c) 2008 Elsevier B.V. All rights reserved.
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Aims: Claudins, a large family of essential tight junction (TJ) proteins, are abnormally regulated in human carcinomas, especially claudin-7. The aim of this study was to investigate claudin-7 expression and alterations in oral squamous cell carcinoma (OSCC). Methods and results: Expression of claudin-7 was analysed in 132 cases of OSCC organized in a tissue microarray. Claudin-7 mRNA transcript was evaluated using real-time polymerase chain reaction and the methylation status of the promoter was also assessed. Claudin-7 was negative in 58.3% of the cases. Loss of claudin-7 protein expression was associated with recurrence (P = 0.019), tumour size (P = 0.014), clinical stage of OSCC (P = 0.055) and disease-free survival (P = 0.015). Down-regulation of the claudin-7 mRNA transcripts was observed in 78% of the cases, in accordance with immunoexpression. Analysis of the methylation status of the promoter region of claudin-7 revealed that treatment of O28 cells (that did not express claudin-7 mRNA transcripts) with 5-Aza-2`-Deoxycytidine (5-Aza-dC) led to the re-expression of claudin-7 mRNA transcript. Conclusion: Loss of claudin-7 expression is associated with important subcellular processes in OSCC with impact on clinical parameters.
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Objectives Microsatellite instability (MSI) induction by alkylating agent-based chemotherapy (ACHT) may underlie both tumor resistance to chemotherapy and secondary leukaemias in cancer patients. We investigated if ACHT could induce MSI in tumor-derived plasma-circulating DNA (pfDNA) and in normal peripheral blood mononuclear (PBMN) cells. We also evaluated if amifostine could interfere with this process in an in-vitro model. Methods MSI was determined in pfDNA, PBMN cells and urine cell-free DNA (ufDNA) of 33 breast cancer patients before and after ACHT. MCF-7 cells and PBMN from normal donors were exposed in vitro to melphalan, with or without amifostine. Results We observed at least one MSI event in PBMN cells, pfDNA or ufDNA of 87, 80 and 80% of patients, respectively. In vitro, melphalan induced MSI in both MCF-7 and normal PBMN cells. In PBMN cells, ACHT-induced MSI occurred together with a significant decrease in the expression of the DNA mismatch repair gene hMSH2. Amifostine decreased hMSH2 expression and also prevented MSI induction only in normal PBMN cells. Conclusions ACHT induced MSI in PBMN cells and in tumour-derived pfDNA. Because of its protective effect against ACHT induction of MSI in normal PBMN cells in vitro, amifostine may be a potential agent for preventing secondary leukaemias in patients exposed to ACHT.
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In order to quantify presence of residual BCC in patients with histologic positive margins after the first excison and to correlate the presence of residual tumor in re-excised lesions with the location of the positive margin on the first excision, a retrospective evaluation of 2053 surgically treated BCC was performed. Only 38.3% of the re-excised lesions showed residual tumor. In the group of re-excised lesions where residual BCC was found, 13% had lateral positive margin in the first excision, 39% had deep positive margin and 48% had both lateral and deep positive margins. In the group of re-excised lesions where no residual BCC was found, 49% of the primary excised lesions had lateral positive margin, 32% had deep positive margin and 19% had both deep and lateral positive margins. The association between residual tumor and positive margins was statistically significant (p = 0.01). Our findings confirm that presence of residual tumour is more likely when both lateral and deep margins are compromised.
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In the present study, we investigate whether mast cells and macrophages are involved in the control of IL-1 beta-induced neutrophil migration, as well as the participation of chemotactic mediators. IL-1 beta induced a dose-dependent neutrophil migration to the peritoneal cavity of rats which depends on LTB4, PAF and cytokines, since the animal treatment with inhibitors of these mediators (MK 886, PCA 4248 and dexamethasone respectively) inhibited IL-1 beta-induced neutrophil migration. The neutrophil migration induced by IL-1 beta is dependent on mast cells and macrophages, since depletion of mast cells reduced the process whereas the increase of macrophage population enhanced the migration. Moreover, mast cells or macrophages stimulated with IL-1 beta released a neutrophil chemotactic factor, which mimicked the neutrophil migration induced by IL-1 beta. The chemotactic activity of the supernatant of IL-1 beta-stimulated macrophages is due to the presence of LTB4, since MK 886 inhibited its release. Moreover, the chemotactic activity of IL-1 beta-stimulated mast cells supernatant is due to the presence of IL-1 beta and TNF-alpha, since antibodies against these cytokines inhibited its activity. Furthermore, significant amounts of these cytokines were detected in the supernatant. In conclusion, our results suggest that neutrophil migration induced by IL-1 beta depends upon LTB4 released by macrophages and upon IL-1 beta and TNF alpha released by mast cells.
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Most meningiomas are benign tumours of arachnoidal origin, although a small number have high proliferative rates and invasive properties which complicate complete surgical resection and are associated with increased recurrence rates. Few prognostic indicators exist for meningiomas and further research is necessary to identify factors that influence tumour invasion, oedema and recurrence. Paraffin sections from 25 intracranial meningiomas were analysed for expression of the proteins vascular endothelial growth factor (VEGF), VEGF receptors Flt1 and Flk1, E-cadherin, metalloproteinases 2 and 9 (MMP2, MMP9), CD44, receptor for hyaluronic acid-mediated motility (RHAMM), hyaluronic acid (HA), CD45, cyclooxygenase 2 (COX2), brain fatty acid binding protein (BFABP), Ki67, and proliferating cell nuclear antigen (PCNA). Correlations among protein expression were found for several markers of proliferation (Ki67, PCNA, MI) and microvessel density (MVD). COX2 expression increased with increasing with tumour grade and correlated with Ki67, PCNA, MI, MVD, and BFABP. BFABP expression also correlated with Ki67 and PCNA expression. Relationships were also identified among angiogenic factors (VEGF, Flt1, Flk1) and proliferation markers. Oedema was found to correlate with MMP9 expression and MMP9 also correlated with proliferation markers. No correlations were found for MMP2, E-cadherin, or CD44 in meningiomas. In conclusion Ki67, PCNA, MI, MVD, BFABP, and COX2 were significantly correlated with meningioma tumour grade and with each other. These findings, by correlating both intracellular fatty acid transport and eicosanoid metabolism with tumour proliferation, as determined by Ki67 labelling and mitotic index, suggest fatty acids are involved in the progression of meningiomas.
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Polyunsaturated fatty acids (PUFAs) are known to inhibit cell proliferation of many tumour types both in vitro and in vivo. Their capacity to interfere with cell proliferation has been linked to their induction of reactive oxygen species (ROS) production in tumour tissues leading to cell death through apoptosis. However, the exact mechanisms of action of PUFAs are far from clear, particularly in brain tumours. The loss of bound hexokinase from the mitochondrial voltage-dependent anion channel has been directly related to loss of protection from apoptosis, and PUFAs can induce this loss of bound hexokinase in tumour cells. Tumour cells overexpressing Akt activity, including gliomas, are sensitised to ROS damage by the Akt protein and may be good targets for chemotherapeutic agents, which produce ROS, such as PUFAs. Cardiolipin peroxidation may be an initial event in the release of cytochrome c from the mitochondria, and enriching cardiolipin with PUFA acyl chains may lead to increased peroxidation and therefore an increase in apoptosis. A better understanding of the metabolism of fatty acids and eicosanoids in primary brain tumours such as gliomas and their influence on energy balance will be fundamental to the possible targeting of mitochondria in tumour treatment.
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Aims Claudins are integral transmembrane proteins of the tight junctions, critical for maintaining cell adhesion and polarity. Alterations in the expression of individual claudins have been detected in carcinomas and appear to correlate with tumour progression. Methods In this study, a panel of anti-claudin antibodies (anti-claudins 1, 2, 3, 4, 5 and 7) was employed to map claudin expression in 136 cases of oral squamous cell carcinoma (OSCC) organised in a tissue microarray. Results Claudins were expressed in a reticular pattern up to the prickle layer in normal mucosal epithelium. In OSCC, claudins were strongly present in well-differentiated tumours, they presented mild and low expression in moderately differentiated OSCC, and were negative in poorly differentiated OSCC; the absences of claudin 1 (p = 0.002) and claudin 4 (p<0.001) were associated with moderately/poorly differentiated tumours. Strong expression of claudin 4 was associated with decreased perineural infiltration (p = 0.024). Claudins 5 and 7 were mostly negative or weakly expressed in all cases studied. Expression of claudin 7 was associated with the early clinical stages of the disease, whereas loss of claudin 7 tended to be more frequent in advanced stages of OSCC (p = 0.054). Absence of claudin 7 was also associated with absent vascular infiltration (p = 0.045) and with presence of recurrence (p = 0.052). Conclusions Claudin expression patterns showed a strong correlation with histological type of OSCC; claudin expression was decreased in areas of invasion, and negative in poorly differentiated tumours. This pattern may be related to evolution and prognosis of these tumours, especially in the case of claudin 7, which seems to be associated with a poor prognosis in OSCC.
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Objectives: The aim was to verify the concordance of CT evaluation among four radiologists (two oral and maxillofacial and two medical radiologists) at the TN (tumour/node) stage and in the follow-up of oral cavity and oropharyngeal cancer patients. The study also compared differences between clinical and CT examinations in determining the TN stage. Methods: The following clinical and tomographic findings of 15 non-treated oral cavity and oropharyngeal cancer patients were compared: tumour size, bone invasion and lymph node metastases. In another 15 patients, who had previously been treated, a clinical and tomographic analysis comparison for the presence of tumoural recurrence, post-therapeutic changes in muscles and lymph node metastases was performed. The concordances of tomographic evaluation between the radiologists were analysed using the kappa index. Results: Significant agreement was verified between all radiologists for the T stage, but not for the N stage. In the group of treated patients, CT disclosed post-therapeutic changes in muscles, tumour recurrence and lymph node metastases, but no concordance for the detection of lymph node metastases was found between radiologists. In the first group, for all radiologists, no concordance was demonstrated between clinical and tomographic staging. CT was effective for delimitating advanced lesions and for detecting lymph node involvement in N0 stage patients. CT revealed two cases of bone invasion not clinically detected. Conclusions: Interprofessional relationships must be stimulated to improve diagnoses, and to promote a multidisciplinary approach to oral cavity and oropharyngeal cancer. Although CT was important in the diagnosis and follow-up of cancer patients, differences between medical and dental analyses should be acknowledged. Dentomaxillofacial Radiology (2010) 39, 140-148. doi: 10.1259/dmfr/69910245
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Objective: To investigate the presence and distribution of substance P (SP) and neurokinin I receptor (NK-IR) in oral squamous cell carcinoma (OSCC) and their relationship with proliferation. Patients and Methods: Ninety OSCCs from 73 patients were immunohistochemically analyzed using monoclonal antibodies against SP, NK-IR and Ki-67 in a case and control study. Results: Seventy-one percent (n=49) of cases expressed SP on tumour cell membrane, 81.3% (n=69) in cytoplasm, 39.4% (n=28) in nucleus, 81.6% (n=71) in infiltrating lymphocytes, and 58.1% (n=43) in peritumoural or intratumoural blood vessels; 14% (n=12) of cases expressed NK-1R on tumour cell membrane, 50% (n=43) in cytoplasm, 48.3% (n=42) in infiltrating lymphocytes and 22.5% (n=18) in tumour blood vessels. All cases expressed Ki-67, which was expressed in >25% of tumour cells in 79.8% of cases (n=63). Direct significant associations were observed in SP expression between different tissue levels (p<0.01), between SP and NK-IR tumour cell membrane expression (p<0.01), and between joint,SP and NK-IR expression in tumour cell cytoplasm and a higher expression of Ki-67 (p<0.05). Conclusion: The ubiquitous presence of SP strongly suggests a role for SP/NK-1R complex in tumour development and progression and possibly for NK-IR antagonists, such as L-773060, in the management of patients with oral cancer.
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Objective: The aim of this study was to determine whether the differential assessment of epithelial proliferation is useful to diagnose premalignant fields and assess the risk of multiple tumours. Material and methods: We analysed 83 oral carcinomas with associated non-tumour epithelium classified as distant or close according to its distance (> or < 1 cm) from the invasion point, and as squamous hyperplasia, mild, moderate, severe dysplasia or carcinoma in situ. Twenty-five healthy oral mucosa samples were used as controls. An immunohistochemical technique was applied using Mib-1. Ki-67 in premalignant epithelium was assessed in basal layer, parabasal layer, medium and upper third. Results: Parabasal expression was significantly higher or showed a tendency to be higher in close and distant epithelia with any histological grade than in the controls. Parabasal Ki-67 significantly differed between distant epithelia associated with multiple vs single tumours (P < 0.001) and between distant epithelia associated with multiple tumours vs controls (P < 0.001). This difference was not observed between distant epithelia associated with single tumours and controls (P = 0.175). The cut-off point that differentiated epithelia associated with multiple tumours was > 50% of Ki-67 + parabasal cells in distant epithelia, which yielded 0.88 sensitivity and 0.79 specificity. Conclusions: The concept of a precancerous field may be linked to an increase in the proliferative activity of parabasal cells.
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The objective of the present work was to induce somatic embryogenesis from zygotic embryos of Passiflora cincinnata Masters. Zygotic embryos formed calli on media with different concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) and 4.5 mu M benzyladenine (BA) after 30 days of in vitro culture. A concentration of 18.1 mu M 2,4-D resulted in the largest number of somatic embryos. Embryogenic calli were yellowish and friable, forming whitish proembryogenic masses. Morphologically, embryogenic cells were small and had large nuclei and dense cytoplasm, whereas non-embryogenic cells were elongated, with small nuclei and less dense cytoplasm. Calli cultured under white light on basal Murashige and Skoog`s medium with activated charcoal produced embryos in all developmental stages. There were differences among the treatments, with some leading to the production of calli with embryos and some only to callus formation. Some abnormalities were associated with somatic embryos, including fused axes, fused cotyledons and polycotyledonary embryos. Production of secondary somatic embryos occurred in the first cycle of primary embryo development. Secondary embryos differentiated from the surface of the protodermal layer of primary embryos with intense cell proliferation, successive mitotic divisions in the initial phase of embryoid development, and a vascular system formed with no connection to the parental tissue. This secondary embryogenic system of P. cincinnata is characterized by intense proliferation and maintenance of embryogenic competence after successive subcultures. This reproducible protocol opens new prospects for massive propagation and is an alternative to the current organogenesis-based transformation protocol.