43 resultados para Liver cancer stem cell


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The current approach to prostate cancer diagnosis has major limitations including the inability of prostate-specific antigen (PSA) assays to accurately differentiate between prostate cancer and benign prostate hyperplasia (BPH) and the imprecision of transrectal ultrasound (TRUS) biopsy sampling. We have employed cDNA microarray screening to compare gene expression patterns in BPH and tumour samples to identify expression markers that may be useful in discriminating between these conditions. Screening of 3 individual cDNA arrays identified 8 genes with expression 3-fold greater in 6 tumour tissues than in 1 nontumour sample and I BPH sample. Real-time PCR was used to confirm the overexpression of these 8 genes and 12 genes selected from the literature against a panel of 17 tumours and I 1 BPH samples. Two genes, delta-catenin (delta-catenin; CTNND2) and prostate-specific membrane antigen (PSMA; FOLH1), were significantly overexpressed in prostate cancer compared to BPH. Prostate epithelial cells stained positively for S-catenin and PSMA in our prostate cancer tissues, whereas the majority of our BPH tissues were negative for both markers. Thus we have identified delta-catenin (not previously associated with prostatic adenocarcinoma) and confirmed the potential of PSMA as potential candidates for the diagnosis and management of prostate cancer. (C) 2002 Wiley-Liss. Inc.

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Purpose: The purpose of this investigation was to evaluate the impact of undertaking peripheral blood stem cell transplantation (PBST) on T-cell number and function, and to determine the role of a mixed type, moderate intensity exercise program in facilitating the recovery of T-cell number and function. Methods: Immunological measures of white blood cell, lymphocyte, CD3(+), CD4(+), and CD8(+) counts, and CD3(+) cell function were assessed pretransplant (PI), immediately posttransplant (PII), and 1 month (II), 2 months (12) and 3 months (PIII) posttransplant. After PII, 12 patients were divided equally into a control group (CG) or exercise intervention group (EG). Results: Lower total T-cell, helper T-cell, and suppressor T-cell counts (P < 0.01), as well as lower T-cell function (P < 0.01), when compared with normative data, were found at PI. More specifically, 88% of the group had CD3(+), CD4(+), and CD8(+) counts that were more than 40%, 20%, and 50% below normal at PI, respectively. Undertaking a PBST caused further adverse changes to the total leukocyte, lymphocyte, CD3(+), CD4(+) and CD8(+) count. and the helper/suppressor ratio. Although CD8(+) counts had returned to normal by PIII, CD3(+), CD4(+), and the CD4(+)/CD8(+) ratio remained significantly lower than normative data (P < 0.01), with 66%, 100%, and 100% of the subject group reporting counts and ratios, respectively, below the normal range. Conclusion: The PBST patients were immunocompromised before undertaking the transplant, and the transplant procedure imposed further adverse changes to the leukocyte and lymphocyte counts. The leukocyte and CD8(+) counts returned to normal within 3 months posttransplant; however, the other immunological parameters assessed demonstrated a delayed recovery. Although participation in the exercise program did not facilitate a faster immune cell recovery, neither did the exercise program hinder or delay recovery.

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Columnar cell lesions (CCLs) of the breast are a spectrum of lesions that have posed difficulties to pathologists for many years, prompting discussion concerning their biologic and clinical significance. We present a study of CCL in context with hyperplasia of usual type (HUT) and the more advanced lesions ductal carcinoma in situ (DCIS) and invasive ductal carcinoma. A total of 81 lesions from 18 patients were subjected to a comprehensive morphologic review based upon a modified version of Schnitt's classification system for CCL, immunophenotypic analysis (estrogen receptor [ER], progesterone receptor [PgR], Her2/neu, cytokeratin 5/6 [CK5/6], cytokeratin 14 [CK14], E-cadherin, p53) and for the first time, a whole genome molecular analysis by comparative genomic hybridization. Multiple CCLs from 3 patients were studied in particular detail, with topographic information and/or showing a morphologic spectrum of CCL within individual terminal duct lobular units. CCLs were ER an PgR positive, CK5/6 and CK14 negative, exhibit low numbers of genetic alterations and recurrent 16q loss, features that are similar to those of low grade in situ and invasive carcinoma. The molecular genetic profiles closely reflect the degree of proliferation and atypia in CCL, indicating some of these lesions represent both a morphologic and molecular continuum. In addition, overlapping chromosomal alterations between CCL and more advanced lesions within individual terminal duct lobular units suggest a commonality in molecular evolution. These data further support the hypothesis that CCLs are a nonobligate, intermediary step in the development of some forms of low grade in situ and invasive carcinoma. Copyright: © 2005 Lippincott Williams & Wilkins, Inc.

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The pathways involved in the maintenance of human embryonic stem (hES) cells remain largely unknown, although some signaling pathways have been identified in mouse embryonic stem (mES) cells. Fibroblast feeder layers are used to maintain the undifferentiated growth of hES cells and an examination of the conditioned media (CM) of human neonatal fibroblasts (HNFs) could provide insights into the maintenance of hES cells. The neonatal foreskin fibroblast line (HNF02) used in this study was shown to have a normal 2n = 46, XY chromosomal complement and to support the undifferentiated growth of the Embryonic Stem Cell International Pte. Ltd.-hES3 cell line. The CM of HNF02 was examined using two-dimensional liquid chromatography-tandem mass spectrometry (2-D LCMS) and two-dimensional electrophoresis (2-DE) followed by matrix-assisted laser desorption/ionization-time of flight tandem mass spectrometry (2-DE/MALDI). A total of 102 proteins were identified, 19 by 2-DE/MALDI, 53 by 2-D LCMS and 30 by both techniques. These proteins were classified into 15 functional groups. Proteins identified in the extracellular matrix and differentiation and growth factor functional categories were considered most likely to be involved in the maintenance of hES cell growth, differentiation and pluripotency as these groups contained proteins involved in a variety of events including cell adhesion, cell proliferation and inhibition of cell proliferation, Writ signaling and inhibition of bone morphogenetic proteins.

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Animal models of autoimmune disease and case reports of patients with these diseases who have been involved in bone marrow transplants have provided important data implicating the haemopoietic stem cell in rheumatic disease pathogenesis. Animal and human examples exist for both cure and transfer of rheumatoid arthritis, systemic lupus erythematosus (SLE) and other organ-specific diseases using allogeneic haemopoietic stem cell transplantation. This would suggest that the stem cell in these diseases is abnormal and could be cured by replacement of a normal stem cell although more in vitro data are required in this area. Given the morbidity and increased mortality in some patients with severe autoimmune diseases and the increasing safety of autologous haemopoietic stem cell transplantation (HSCT), pilot studies have been conducted using HSCT in rheumatic diseases. It is still unclear whether an autologous graft will cure these diseases but significant remissions have been obtained which have provided important data for the design of randomized trials of HSCT versus more conventional therapy. Several trials are now open to accrual under the auspices of the European Bone Marrow Transplant Group/European League Against Rheumatism (EBMT/EULAR) registry. Future clinical and laboratory research will need to document the abnormalities of the stem cell of a rheumatic patient because new therapies based on gene therapy or stem cell differentiation could be apllied to these diseases. With increasing safety of allogeneic HSCT it is not unreasonable to predict cure of some rheumatic diseases in the near future.

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Prospective studies have shown rapid engraftment using granulocyte-colony-stimulating factor-mobilized peripheral blood stem cells (G-PBSCs) for allogeneic transplantation, though the risks for graft-versus-host disease (GVHD) may be increased. It was hypothesized that the use of G-CSF to prime bone marrow (GBM) would allow rapid engraftment without increased risk for GVHD compared with G-PBSC. Patients were randomized to receive G-BM or G-PBSCs for allogeneic stem cell transplantation. The study was designed (beta < .8) to detect a difference in the incidence of chronic GVHD of 33% ( < .05). The plan was to recruit 100 patients and to conduct an interim analysis when the 6-month follow-up point was reached for the first 50 patients. Fifty-seven consecutive patients were recruited (G-BM, n = 28; G-PBSC, n = 29). Patients in the G-PBSC group received 3-fold more CD34(+) and 9-fold more CD3(+) cells. Median times to neutrophil (G-BM, 16 days; G-PBSC, 14 days; P < .1) and platelet engraftment (G-BM, 14 days; G-PBSC, 12 days; P < .1) were similar. The use of G-PBSC was associated with steroid refractory acute GVHD (G-BM, 0%; G-PBSC, 32%; P < .001), chronic GVHD (G-BM, 22%; G-PBSC, 80%; P < .02), and prolonged requirement for immunosuppressive therapy (G-BM, 173 days; G-PBSC, 680 days; P < .009). Survival was similar for the 2 groups. Compared with G-PBSC the use of G-BM resulted in comparable engraftment, reduced severity of acute GVHD, and less subsequent chronic GVHD. (Blood. 2001;98:3186-3191) (C) 2001 by The American Society of Hematology.

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The contribution of the UV component of sunlight to the development of skin cancer is widely acknowledged, although the molecular mechanisms that are disrupted by UV radiation (UVR) resulting in the loss of normal growth controls of the epidermal stem cell keratinocytes and melanocytes is still poorly understood. alpha-Melanocyte stimulating hormone (alpha-MSH), acting via its receptor MC1, has a key role in skin pigmentation and the melanizing response after exposure to UVR. The cell cycle inhibitor p16/CDKN2A also appears to have an important function in a cell cycle checkpoint response in skin after exposure to UVR. Both of these genes have been identified as risk factors in skin cancer, MC1R variants are associated with increased risk to both melanoma and nonmelanoma skin cancers, and p16/CDKN2A with increased risk of melanoma. Here we demonstrate that the increased expression of p16 after exposure to sub-erythemal doses of UVR is potentiated by alpha-MSH, a ligand for MC1R, and this effect is mimicked by cAMP, the intracellular mediator of alpha-MSH signaling via the MC1 receptor. This link between p16 and MC1R may provide a molecular basis for the increased skin cancer risk associated with MC1R polymorphisms.

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The use of electrotransfer for DNA delivery to prokaryotic cells, and eukaryotic cells in vitro, has been well known and widely used for many years. However, it is only recently that electric fields have been used to enhance DNA transfer to animal cells in vivo, and this is known as DNA electrotransfer or in vivo DNA electroporation. Some of the advantages of this method of somatic cell gene transfer are that it is a simple method that can be used to transfer almost any DNA construct to animal cells and tissues in vivo; multiple constructs can be co-transfected; it is equally applicable to dividing and nondividing cells; the DNA of interest does not need to be subeloned into a specific viral transfer vector and there is no need for the production of high titre viral stocks; and, as no viral genes are expressed there is less chance of an adverse immunologic reaction to vector sequences. The ease with which efficient in vivo gene transfer can be achieved with in vivo DNA electrotransfer is now allowing genetic analysis to be applied to a number of classic animal model systems where transgenic and embryonic stem cell techniques are not well developed, but for which a wealth of detailed descriptive embryological information is available, or surgical manipulation is much more feasible. As well as exciting applications in developmental biology, in vivo DNA electrotransfer is also being used to transfer genes to skeletal muscle and drive expression of therapeutically active proteins, and to examine exogenous gene and protein function in normal adult cells situated within the complex environment of a tissue and organ system in vivo. Thus, in effect providing the in vivo equivalent of the in vitro transient transfection assay. As the widespread use of in vivo electroporation has really only just begun, it is likely that the future will hold many more applications for this technology in basic research, biotechnology and clinical research areas.

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The BCR-ABL fusion proteins, b2a2 and b3a2, are potential targets for a beneficial graft-versus-leukemia (GVL) effect after allogeneic stem cell transplantation for chronic myeloid leukemia (CML). This study demonstrates that CD4(+) T cells specific to the b2a2 peptide can be generated from a normal allogeneic stem cell transplant donor after stimulation with monocyte-derived dendritic cells (Mo-DC) using culture conditions applicable to clinical use. Stimulation of donor T-cell enriched mononuclear cells (MNC) with b2a2-pulsed Mo-DC produced approximately 3 x 10(9) b2a2-specific CD4(+) T cells. The CD4(+) T cells were HLA-DR7 restricted. These results confirm that the generation of donor derived b2a2-specific T cells for clinical use is feasible and warrants clinical testing after stem cell transplantation.

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Keratinocyte Growth factor (KGF) is an epithelial cell growth factor of the fibroblast growth factor family and is produced by fibroblasts and microvascular endothelium in response to proinflammatory cytokines and steroid hormones. KGF is a heparin binding growth factor that exerts effects on epithelial cells in a paracrine fashion through interaction with KGF receptors. Preclinical data has demonstrated that KGF can prevent lung and gastrointestinal toxicity following chemotherapy and radiation and preliminary clinical data in the later setting supports these findings. In the experimental allogeneic bone marrow transplant scenario KGF has shown significant ability to prevent graft-versus-host disease by maintaining gastrointestinal tract integrity and acting as a cytokine shield to prevent subsequent proinflammatory cytokine generation. Within this setting KGF has also shown an ability to prevent experimental idiopathic pneumonia syndrome by stimulating production of surfactant protein A, promoting alveolar epithelialization and attenuating immune-mediated injury. Perhaps most unexpectantly, KGF appears able to maintain thymic function during allogeneic stern cell transplantation and so promote T cell engraftment and reconstitution. These data suggest that KGF will find a therapeutic role in the prevention of epithelial toxicity following intensive chemotherapy and radiotherapy protocols and in allogeneic stem cell transplantation.

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HLA-B*4402 and B*4403 are naturally occurring MHC class I alleles that are both found at a hi,,h frequency in all human populations, and vet they only differ by one residue on the alpha2 helix (B*4402 Aspl56-->B*4403 Leu156) CTLs discriminate between HLA-B*4402 and B*4403, and these allotypes stimulate strong mutual allogeneic responses reflecting their known barrier to hemopoeitic stem cell transplantation. Although HLA-B*4402 and B*4403 share >95% of their peptide repertoire, B*4403 presents more unique peptides than B*4402, consistent with the stronger T cell alloreactivity observed toward B*4403 compared with B*4402. Crystal structures of B*4402 and B*4403 show how the polymorphisin at position 156 is completely buried and yet alters both the peptide and the heavy chain conformation, relaxing ligand selection by B*4403 compared with B*4402. Thus, the polymorphism between HLA-B*4402 and B 4403 modifies both peptide repertoire and T cell recognition, and is reflected lit the paradoxically powerful alloreactivity that occurs across this minimal mismatch. The findings suggest that these closely related class I genes are maintained lit diverse human populations through their differential impact on the selection of peptide ligands and the T cell repertoire.

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The consumption of excess alcohol in patients with liver iron storage diseases, in particular the iron-overload disease hereditary haemochromatosis (HH), has important clinical consequences. HH, a common genetic disorder amongst people of European descent, results in a slow, progressive accumulation of excess hepatic iron. If left untreated, the condition may lead to fibrosis, cirrhosis and primary hepatocellular carcinoma. The consumption of excess alcohol remains an important cause of hepatic cirrhosis and alcohol consumption itself may lead to altered iron homeostasis. Both alcohol and iron independently have been shown to result in increased oxidative stress causing lipid peroxidation and tissue damage. Therefore, the added effects of both toxins may exacerbate the pathogenesis of disease and impose an increased risk of cirrhosis. This review discusses the concomitant effects of alcohol and iron on the pathogenesis of liver disease. We also discuss the implications of co-existent alcohol and iron in end-stage liver disease.