345 resultados para HUMAN METASTATIC MELANOMA
Resumo:
Mice expressing human cholesteryl ester transfer protein (huCETP) are more resistant to Escherichia coli bacterial wall LIPS because death rates 5 days after intraperitoneal inoculation of LIPS were higher in wild-type than in huCETP(+/-) mice, whereas all huCETP(+/+) mice remained alive. After LIPS inoculation, plasma concentrations of TNF-alpha and IL-6 increased less in huCETP(+/+) than in wild-type mice. LPS in vitro elicited lower TNF-alpha production by CETP expressing than by wild-type macrophages. In addition, TNF-alpha production by RAW 264.7 murine macrophages increased on incubation with LPS but decreased in a dose-dependent manner when human CETP was added to the medium. Human CETP in vitro enhanced the LIPS binding to plasma high-density lipoprotein/low-density lipoprotein. The liver uptake of intravenous infused C-14-LPS from Salmonella typhimurium was greater in huCETP(+/+) than in wild-type mice. Present data indicate for the first time that CETP is an endogenous component involved in the first line of defense against an exacerbated production of proinflammatory mediators.
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P>Human immunodeficiency virus (HIV)-1 protease is a known target of CD8+ T cell responses, but it is the only HIV-1 protein in which no fully characterized HIV-1 protease CD4 epitopes have been identified to date. We investigated the recognition of HIV-1 protease by CD4+ T cells from 75 HIV-1-infected, protease inhibitor (PI)-treated patients, using the 5,6-carboxyfluorescein diacetate succinimidyl ester-based proliferation assay. In order to identify putative promiscuous CD4+ T cell epitopes, we used the TEPITOPE algorithm to scan the sequence of the HXB2 HIV-1 protease. Protease regions 4-23, 45-64 and 73-95 were identified; 32 sequence variants of the mentioned regions, encoding frequent PI-induced mutations and polymorphisms, were also tested. On average, each peptide bound to five of 15 tested common human leucocyte antigen D-related (HLA-DR) molecules. More than 80% of the patients displayed CD4+ as well as CD8+ T cell recognition of at least one of the protease peptides. All 35 peptides were recognized. The response was not associated with particular HLA-DR or -DQ alleles. Our results thus indicate that protease is a frequent target of CD4+ along with CD8+ proliferative T cell responses by the majority of HIV-1-infected patients under PI therapy. The frequent finding of matching CD4+ and CD8+ T cell responses to the same peptides may indicate that CD4+ T cells provide cognate T cell help for the maintenance of long-living protease-specific functional CD8+ T cells.
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BACKGROUND: Persons with human immunodeficiency virus (HIV) risk behaviors are excluded from donation to reduce the risk of transfusion-transmitted infection. Persons donating to be tested for HIV may therefore deny risk behaviors. STUDY DESIGN AND METHODS: A random sample of donors completed a survey on motivations, knowledge, and attitudes on the screening process. Donors were considered test seekers if they agreed with two statements ""I think that blood donation is a good, fast, and anonymous way to get my blood tested"" and ""I donate to get my test results."" This study was conducted from June to November 2006 at the largest blood bank in Sao Paulo, Brazil. RESULTS: Of 3061 participants, 208 (7%) were test seekers. They tended to be male and had a lower educational level. They were more likely to have incorrect knowledge about blood safety (e.g., not knowing that a unit can test antibody negative and still transmit infection, 60% vs. 42%, p = 0.02), express dissatisfaction with screening questions (e.g., feeling that important questions were not asked, 14% vs. 5%, p < 0.01), and concur that donors do not answer questions truthfully (e.g., donors have more sexual partners than they admit, 29% vs. 18%, p < 0.01). Test seekers were more likely to believe that it is acceptable to donate blood to get tested for HIV (41% vs. 10%, p < 0.01). CONCLUSIONS: Test-seeking motivation, coupled with low knowledge of window period risk, is counter to improving blood safety and to donor prevention needs. Donor education needs to be improved along with availability of appropriate HIV counseling and testing.
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In ascending aorta aneurysms, there is an enlargement of the whole vessel, whereas aortic dissections (ADs) are characterized by the cleavage of the wall into 2 sheets at the external half. We searched if alterations in collagen could be related to these diseases. Sections of aortas from 14 case patients with acute dissections, 10 case patients with aneurysms, and 9 control subjects were stained with picrosirius. Slides were analyzed under polarized microscopy to evaluate the structure of collagen fibers. The proportion of collagen was calculated in each half of the medial layer by color detection in a computerized image analysis system. Collagen appearance under polarized light was consistent with collagenolysis. The mean collagen proportions at the inner and outer halves, respectively, were 0.50 +/- 0.13 and 0.40 +/- 0.08 in the control group, 0.20 +/- 0.10 and 0.18 +/- 0.12 in the AD group, and 0.33 +/- 0.12 and 0.19 +/- 0.12 in the aneurysm group. The AD (P < .01) and control (P = .04) groups had less collagen at the external half, no difference was found in the aneurysm group (P = .71). In both halves, there was less collagen in the case patients than in the control subjects (all P < .01), but at the internal half, the decrease was significantly greater in the case patients with aneurysms than in those with dissections (P = .03; at the external half, P = .99). Aortic dissections and aneurysms show a decrease in collagen content that could be related to a weakness of the wall underlying the diseases, but the locations of the decrease differ: in dissections, it is situated mostly at the external portion of the media (site of cleavage), whereas in aneurysms, it is more diffuse, consistent with the global enlargement. (c) 2008 Elsevier Inc. All rights reserved.
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HLA-G is a non-classic Human Leukocyte Antigen (HLA-G) Class I of low polymorphism and restricted tissue distribution that displays tolerogenic functions. In heart transplantation and in combined liver/renal allograft transplantation, the expression of HLA-G has been associated with a lower incidence of acute graft rejection episodes and absence of chronic dysfunction. Since the expression of HLA-G in renal biopsies has been investigated only in few patients who received a combined kidney and liver transplant, in this study we performed a cross-sectional study, systematically comparing the expression of HLA-G in post-transplanted renal grafts, stratifying patients according to the presence or absence of rejection. Patients and Methods: Seventy-three renal specimens (10 with acute rejection and 13 with chronic allograft nephropathy, and 50 with no signs of rejection) were immunohistochemically evaluated for HLA-G expression. Results: In the group as a whole, HLA-G molecules were detected in 40 cases (54.8%). Among specimens that presented HLA-G expression, 2 out of 40 (5%) exhibited acute rejection, 2 (5%) exhibited chronic allograft nephropathy, and the remaining 36 (90%) exhibited no signs of rejection. The comparison between patients with rejection and those without rejection showed that the expression of HLA-G was significantly increased in specimens exhibiting no signs of rejection (p<0.0001). Considering only patients with acute rejection, 8 out of 10 patients showed no HLA-G expression in their kidney biopsies when compared to patients exhibiting no signs of rejection and absence of HLA-G was observed in 14 out of 50 (p=0.0032). Similarly, considering only patients with chronic allograft nephropathy, absence of HLA-G expression was observed in I I out of 13 specimens, whereas in patients without rejection absence of HLA-G was observed in 14 out of 50 (p=0.003). Therapy with tacrolimus was significantly associated with the expression of HLA-G and a better graft prognosis. Conclusions: Our results suggest that HLA-G expression in the kidney allograft and the use of tacrolimus are associated with a lower frequency of acute renal rejection and chronic allograft nephropathy. (c) 2007 Elsevier B.V. All rights reserved.
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Background: UV radiation is the major environmental factor related to development of cutaneous melanoma. Besides sun exposure and the influence of latitude, some host characteristics such as skin phototype and hair and eye color are also risk factors for melanoma. Polymorphisms in DNA repair genes could be good candidates for susceptibility genes, mainly in geographical regions exposed to high solar radiation. Objective: Evaluate the role of host characteristic.; and DNA repair polymorphism in melanoma risk in Brazil. Methods: We carried out a hospital-based case-control study in Brazil to evaluate the contribution of host factors and polymorphisms in DNA repair to melanoma risk. A total of 412 patients (202 with melanoma and 210 controls) were analyzed regarding host characteristics for melanoma risk as well as for 11 polymorphisms in DNA repair genes. Results: We found an association of host characteristics with melanoma development, such as eye and hair color, fair skin, history of pigmented lesions removed, sunburns in childhood and adolescence, and also European ancestry. Regarding DNA repair gene polymorphisms, we found protection for the XPG 1104 His/His genotype (OR 0.32; 95% CI 0.13-0.75), and increased risk for three polymorphisms in the XPC gene (PAT+; IV-6A and 939Gln), which represent a haplotype for XPC. Melanoma risk was higher in individuals carrying the complete XPC haplotype than each individual polymorphism (OR 3.64; 95% CI 1.77-7.48). Conclusions: Our data indicate that the host factors European ancestry and XPC polymorphisms contributed to melanoma risk in a region exposed to high sun radiation. (C) 2011 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.
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Background/Purpose: The median survival for patients with metastatic colorectal cancer (mCRC) has progressively increased over the past decades. Since the introduction of 5-fluorouracil (5-FU)-based chemotherapy, followed by hepatic resection of metastases, and more recently the adoption of newer chemotherapeutic regimens associated with targeted therapy, the gains are getting more substantial. Despite the recognition of the potential for long-term survival after surgical resection of metastatic disease, long-term survival data to determine the potential curative role of chemotherapy alone is lacking. Methods: We performed a retrospective review of 2751 patients who presented with mCRC at The MD Anderson Cancer Center from 1990 through 2003. Patients alive at 5 years who achieved complete response with chemotherapy and were not submitted to any surgical or interventional procedures directed to the metastatic sites were included in the analysis. Results: The 5-year overall survival rate for all patients with mCRC during this period was 10.8%. Among these long-term survivors, 2.2% achieved a sustained complete response after chemotherapy (all 6 with fluoropyrimidines and 2 with irinotecan) as the only treatment modality and were without evidence of disease until the last follow-up visit (median of 10.3 years). This number corresponds to 0.24% (6 of 2541) of all patients with mCRC included in this review. Conclusion: Cure with chemotherapy alone is possible for a very small number of patients with metastatic colorectal cancer. Improved therapies are increasing complete response rates, but the impact of modern chemotherapy on durable complete responses will require additional follow up.
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We investigated whether the administration of IL-2 combined with endostatin gene therapy was able to produce additive or even synergistic immunomodulatory activity in a mouse model of metastatic renal carcinoma. Renca cells were injected into the tail vein of BALB/c mice. After 24 h, the animals were randomly divided into four groups (5 mice/group). One group of mice was the control, the second group received treatment with 100,000 UI of Recombinant IL-2 (Proleukin, Chiron) twice a day, 1 day per week during 2 weeks (IL-2), the third group received treatment with a subcutaneous inoculation of 3.6 x 10(6) endostatin-producing cells, and the fourth group received both therapies (IL-2 + ES). Mice were treated for 2 weeks. In the survival studies, 10 mice/group daily, mice were monitored daily until they died. The presence of metastases led to a twofold increase in endostatin levels. Subcutaneous inoculation of NIH/3T3-LendSN cells resulted in a 2.75 and 2.78-fold increase in endostatin levels in the ES and IL-2 + ES group, respectively. At the end of the study, there was a significant decrease in lung wet weight, lung nodules area, and microvascular area (MVA) in all treated groups compared with the control group (P < 0.001). The significant difference in lung wet weight and lung nodules area between groups IL-2 and IL-2 + ES revealed a synergistic antitumor effect of the combined treatment (P < 0.05). The IL-2 + ES therapy Kaplan-Meier survival curves showed that the probability of survival was significantly higher for mice treated with the combined therapy (log-rank test, P = 0.0028). Conjugated therapy caused an increase in the infiltration of CD4, CD8 and CD49b lymphocytes. An increase in the amount of CD8 cells (P < 0.01) was observed when animals received both ES and IL-2, suggesting an additive effect of ES over IL-2 treatment. A synergistic effect of ES on the infiltration of CD4 (P < 0.001) and CD49b cells (P < 0.01) was also observed over the effect of IL-2. Here, we show that ES led to an increase in CD4 T helper cells as well as cytotoxic lymphocytes, such as NK cells and CD8 cells, within tumors of IL-2 treated mice. This means that ES plays a role in supporting the actions of T cells.
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While many studies have addressed the direct effects of 1 alpha,25(OH)(2)D(3) on breast cancer (BC) cells, stromal-epithelial interactions, which are important for the tumor development, have been largely ignored. In addition, high concentrations of the hormone, which cannot be attained in vivo, have been used. Our aim was to establish a more physiological breast cancer model, represented by BC tissue slices, which maintain epithelial-mesenchymal interactions, cultured with a relatively low 1 alpha,25(OH)(2)D(3) concentration, in order to evaluate the vitamin D pathway. Freshly excised human BC samples were sliced and cultured in complete culture media containing vehicle, 0.5 nM or 100 nM 1 alpha,25(OH)(2)D(3) for 24 h. BC slices remained viable for at least 24 h, as evaluated by preserved tissue morphology in hematoxylin and eosin (HE) stained sections and bromodeoxyuridine (BrdU) incorporation by 10% of tumor cells. VDR mRNA expression was detected in all samples and CYP24A1 mRNA expression was induced by 1 alpha,25(OH)(2)D(3) in both concentrations (but mainly with 100 nM). Our results indicate that the vitamin D signaling pathway is functional in BC slices, a model which preserves stromal-epithelial interactions and mimics in vivo conditions. (C) 2010 Elsevier Ltd. All rights reserved.
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Resting state functional magnetic resonance imaging (fMRI) reveals a distinct network of correlated brain function representing a default mode state of the human brain The underlying structural basis of this functional connectivity pattern is still widely unexplored We combined fractional anisotropy measures of fiber tract integrity derived from diffusion tensor imaging (DTI) and resting state fMRI data obtained at 3 Tesla from 20 healthy elderly subjects (56 to 83 years of age) to determine white matter microstructure e 7 underlying default mode connectivity We hypothesized that the functional connectivity between the posterior cingulate and hippocampus from resting state fMRI data Would be associated with the white matter microstructure in the cingulate bundle and fiber tracts connecting posterior cingulate gyrus With lateral temporal lobes, medial temporal lobes, and precuneus This was demonstrated at the p<0001 level using a voxel-based multivariate analysis of covariance (MANCOVA) approach In addition, we used a data-driven technique of joint independent component analysis (ICA) that uncovers spatial pattern that are linked across modalities. It revealed a pattern of white matter tracts including cingulate bundle and associated fiber tracts resembling the findings from the hypothesis-driven analysis and was linked to the pattern of default mode network (DMN) connectivity in the resting state fMRI data Out findings support the notion that the functional connectivity between the posterior cingulate and hippocampus and the functional connectivity across the entire DMN is based oil distinct pattern of anatomical connectivity within the cerebral white matter (C) 2009 Elsevier Inc All rights reserved
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Purpose We investigated the efficacy of fluorouracil (FU), leucovorin, irinotecan, and bevacizumab (FOLFIRI + B) in a phase II trial in patients previously untreated for metastatic colorectal cancer (mCRC), and changes during treatment in plasma cytokines and angiogenic factors (CAFs) as potential markers of treatment response and therapeutic resistance. Patients and Methods We conducted a phase II, two-institution trial of FOLFIRI + B. Each 14-day cycle consisted of bevacizumab (5 mg/kg), irinotecan (180 mg/m(2)), bolus FU (400 mg/m(2)), and leucovorin (400 mg/m(2)) followed by a 46-hour infusion of FU (2,400 mg/m(2)). Levels of 37 CAFs were assessed using multiplex-bead assays and enzyme-linked immunosorbent assay at baseline, during treatment, and at the time of progressive disease (PD). Results Forty-three patients were enrolled. Median progression-free survival (PFS), the primary end point of the study, was 12.8 months. Median overall survival was 31.3 months, with a response rate of 65%. Elevated interleukin-8 at baseline was associated with a shorter PFS (11 v 15.1 months, P = .03). Before the radiographic development of PD, several CAFs associated with angiogenesis and myeloid recruitment increased compared to baseline, including basic fibroblast growth factor (P = .046), hepatocyte growth factor (P = .046), placental growth factor (P < .001), stromal-derived factor-1 (P = .04), and macrophage chemoattractant protein-3 (P < .001). Conclusion Efficacy and tolerability of FOLFIRI + B appeared favorable to historical controls in this single arm study. Before radiographic progression, there was a shift in balance of CAFs, with a rise in alternate pro-angiogenic cytokines and myeloid recruitment factors in subsets of patients that may represent mechanisms of resistance.
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The ADAM23 gene is frequently silenced in different types of tumors, and, in breast tumors, silencing is correlated with tumor progression, suggesting that it might be associated with the acquisition of a metastatic phenotype. ADAM23 exerts its function mainly through the disintegrin domain, because its metalloprotease domain is inactive. Analysis of ADAM23 binding to integrins has revealed a specific interaction with alpha(v)beta(3) integrin mediated by the disintegrin domain. Altered expression of alpha(v)beta(3) integrin has been observed in different types of tumors, and expression of this integrin in the activated form has been shown to promote metastasis formation. Here, we investigated the possibility that interaction between ADAM23 and alpha(v)beta(3) integrin might negatively modulate alpha(v)beta(3) activation during metastatic progression. ADAM23 expression was knocked down using short hairpin RNA in the MDA-MB-435 cell line, which has been extensively used as a model for alpha(v)beta(3) integrin activation. Ablation of ADAM23 enhanced alpha(v)beta(3) integrin activation by at least 2- to 4-fold and ADAM23 knockdown cells showed enhanced migration and adhesion to classic alpha(v)beta(3) integrin ligands. Ablation of ADAM23 expression also enhanced pulmonary tumor cell arrest in immunodeficient mice. To complement our findings with clinical evidence, we showed that silencing of ADAM23 gene by DNA promoter hypermethylation in a collection of 94 primary breast tumors was significantly associated with lower distant metastases-free and disease-specific survivals and was an independent prognostic factor for poor disease outcome. Our results strongly support a functional role of ADAM23 during metastatic progression by negatively modulating alpha(v)beta(3) integrin activation. [Cancer Res 2009;69(13):5546-52]
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The taxane docetaxel is currently the most effective chemotherapeutic drug for the treatment of advanced breast cancer. However, a considerable proportion of breast cancer patients do not respond positively to docetaxel. The mechanisms of docetaxel resistance are poorly understood. Overexpression of ERBB2 occurs in 15-30% of breast tumors and is associated with chemoresistance to a variety of anticancer drugs. In the present study, we sought to identify genes involved in ERBB2-mediated chemoresistance to docetaxel. We generated SAGE libraries from two human mammary cell lines expressing basal (HB4a) and high (C5.2) levels of ERBB2 before and after intensive exposure to docetaxel and identified potential ERBB2 target genes implicated in a variety of cellular processes including cell proliferation, cell adhesion, apoptosis and cytoskeleton organization. Comparison of the transcriptome of the cell lines before and after docetaxel exposure revealed substantially different expression patterns. Twenty-one differentially expressed genes between HB4a and C5.2 cell lines, before and after docetaxel treatment, were further analyzed by qPCR. The alterations in the expression patterns in HB4a and C5.2 cell lines in response to docetaxel treatment observed by SAGE analysis were confirmed by qPCR for the majority of the genes analyzed. Our study provides a comprehensive view of the expression changes induced in two human mammary cells expressing different levels of ERBB2 in response to docetaxel that could contribute to the elucidation of the mechanisms involved in ERBB2-mediated chemoresistance in breast cancer.
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Superparamagnetic iron oxide nanoparticles (SPIONs) are applied in stem cell labeling because of their high magnetic susceptibility as compared with ordinary paramagnetic species, their low toxicity, and their ease of magnetic manipulation. The present work is the study of CD133(+) stem cell labeling by SPIONs coupled to a specific antibody (AC133), resulting in the antigenic labeling of the CD133+ stem cell, and a method was developed for the quantification of the SPION content per cell, necessary for molecular imaging optimization. Flow cytometry analysis established the efficiency of the selection process and helped determine that the CD133 cells selected by chromatographic affinity express the transmembrane glycoprotein CD133. The presence of antibodies coupled to the SPION, expressed in the cell membrane, was observed by transmission electron microscopy. Quantification of the SPION concentration in the marked cells using the ferromagnetic resonance technique resulted in a value of 1.70 x 10 (13) mol iron (9.5 pg) or 7.0 x 10 (6) nanoparticles per cell ( the measurement was carried out in a volume of 2 mu L containing about 6.16 x 10 5 pg iron, equivalent to 4.5 x 10 (11) SPIONs). (c) 2008 Elsevier Inc. All rights reserved.
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Objectives: To examine the effects of triiodothyronine (T(3)), 17 beta-estradiol (E(2)), and tamoxifen (TAM) on transforming growth factor (TGF)-alpha gene expression in primary breast cancer cell cultures and interactions between the different treatments. Methods and results: Patients included in the study (no.=12) had been newly diagnosed with breast cancer. Fresh human breast carcinoma tissue was cut into 0.3-mm slices. These slices were placed in six 35-mm dishes on 2-ml organ culture medium. Dishes received the following treatments: dish 1: ethanol; dish 2: T(3); dish 3: T(3)+TAM; dish 4: TAM; dish 5: E(2); dish 6: E(2)+TAM. TGF-alpha mRNA content was normalized to glyceraldehyde-3-phosphate dehydrogenase mRNA levels. All tissues included in this study were positive for estrogen receptor (ER) and thyroid hormone receptor expression. Treatment with T(3) for 48 h significantly increased TGF-alpha mRNA levels compared to controls (15-fold), and concomitant treatment with TAM reduced expression to 3.4-fold compared to controls. When only TAM was added to the culture medium, TGF-alpha mRNA expression increased 5.3-fold, significantly higher than with all other treatment modalities. Conclusion: We demonstrate that TGF-alpha mRNA expression is more efficiently upregulated by T(3) than E(2). Concomitant treatment with TAM had a mitigating effect on the T(3) effect, while E(2) induced TGF-alpha upregulation. Our findings show some similarities between primary culture and breast cancer cell lines, but also some important differences: a) induction of TGF-alpha, a mitogenic protein, by TAM; b) a differential effect of TAM that may depend on relative expression of ER alpha and beta; and c) supraphysiological doses of T3 may induce mitogenic signals in breast cancer tissue under conditions of low circulating E(2).. Endocrinol. Invest. 31: 1047-1051, 2008) (c) 2008, Editrice Kurtis