Search results for " Member 2"
showing 10 items of 39 documents
Erratum to: Donor age and long-term culture do not negatively influence the stem potential of limbal fibroblast-like stem cells
2016
In regenerative medicine the maintenance of stem cell properties is of crucial importance. Ageing is considered a cause of reduced stemness capability. The limbus is a stem niche of easy access and harbors two stem cell populations: epithelial stem cells and fibroblast-like stem cells. Our aim was to investigate whether donor age and/or long-term culture have any influence on stem cell marker expression and the profiles in the fibroblast-like stem cell population.Fibroblast-like stem cells were isolated and digested from 25 limbus samples of normal human corneo-scleral rings and long-term cultures were obtained. SSEA4 expression and sphere-forming capability were evaluated; cytofluorimetric…
Lack of efficacy of mitoxantrone in primary progressive Multiple Sclerosis irrespective of pharmacogenetic factors: A multi-center, retrospective ana…
2014
Abstract Background Mitoxantrone is used on an off-label basis in primary progressive MS (PPMS). ABC -transporter-genotypes are associated with therapeutic response in relapsing/secondary progressive MS (RP/SPMS). Objective To evaluate potential pharmacogenetic response markers for mitoxantrone in PPMS. Methods 41 mitoxantrone-treated PPMS-patients, 155 mitoxantrone-treated RP/SPMS-patients and 43 PPMS-controls were retrospectively assessed for clinical therapy-response and in correlation with four single-nucleotide-polymorphisms in ABCB1 - and ABCG2 -genes. Results 53.7% PPMS-patients were mitoxantrone-responders, in comparison to 78.1% of RP/SPMS-patients (p = 0.039). There was no associa…
Defects in the Human Leukocyte Antigen Class I Antigen Processing Machinery in Head and Neck Squamous Cell Carcinoma: Association with Clinical Outco…
2005
AbstractPurpose: Human leukocyte antigen (HLA) class I antigen defects, which are frequently present in head and neck squamous cell carcinoma (HNSCC) cells may provide the tumor with an escape mechanism from immune surveillance. Scanty information is available about mechanisms underlying HLA class I antigen defects in both lesions and cell lines from HNSCC. In this study, we investigate the role of antigen processing machinery (APM) component abnormalities in the generation of deficient HLA class I surface expression of HNSCC cells.Experimental Design: Using immunohistochemistry, Western blot, and RT-PCR analyses we correlated the expression of the IFN-γ inducible proteasome subunits and of…
TAP off - tumors on
1997
Abstract The molecular characterization of T-cell-defined tumor-associated antigens has provided targets for cell-mediated immunotherapy for malignant diseases. The success of this strategy is negatively influenced by structural and functional abnormalities of major histocompatibility complex (MHC) class I molecules, which provide tumor cells with resistance to T-cell-mediated immune recognition. This article reviews the physiology of the MHC class I processing machinery and describes the deficiencies of this pathway in malignant cells.
High frequency of a non-functional TAP1/LMP2 promoter polymorphism in human tumors
2002
The Tap1 and Tap2 genes encoding for a heterodimeric peptide transporter play a key role in antigen processing and presentation. The TAP complex mediates the transport of peptides generated by the IFN-gamma-inducible proteasome subunits LMP2, 7 and 10 from the cytosol into the endoplasmic reticulum (ER), where they bind to MHC class I molecules. In contrast to the frequent polymorphisms within the rat Tap genes which exert functional differences, polymorphic regions within the human Tap genes have been demonstrated, but not systematically analyzed in terms of their functional significance. Both the Tap1 and Lmp2 genes are transcribed from a bidirectional intergenic promoter which is regulat…
Vitamin E transport, membrane incorporation and cell metabolism: Is α-tocopherol in lipid rafts an oar in the lifeboat?
2010
International audience; Vitamin E is composed of closely related compounds, including tocopherols and tocotrienols. Studies of the last decade provide strong support for a specific role of alpha-tocopherol in cell signalling and the regulation of gene expression. It produces significant effects on inflammation, cell proliferation and apoptosis that are not shared by other vitamin E isomers with similar antioxidant properties. The different behaviours of vitamin E isomers might relate, at least in part, to the specific effects they exert at the plasma membrane. alpha-Tocopherol is not randomly distributed throughout the phospholipid bilayer of biological membranes, and as compared with other…
A comprehensive study of polymorphisms in the ABCB1, ABCC2, ABCG2, NR1I2 genes and lymphoma risk.
2011
Owing to their role in controlling the efflux of toxic compounds, transporters are central players in the process of detoxification and elimination of xenobiotics, which in turn is related to cancer risk. Among these transporters, ATP-binding cassette B1/multidrug resistance 1 (ABCB1/MDR1), ABCC2/multidrug resistance protein 2 (MRP2) and ABCG2/breast cancer resistance protein (BCRP) affect susceptibility to many hematopoietic malignancies. The maintenance of regulated expression of these transporters is governed through the activation of intracellular "xenosensors" like the nuclear receptor 1I2/pregnane X receptor (NR1I2/PXR). SNPs in genes encoding these regulators have also been implicate…
Upregulation of Major Histocompatibility Complex Class I on Liver Cells by Hepatitis C Virus Core Protein via p53 and TAP1 Impairs Natural Killer Cel…
2003
ABSTRACTThe mechanisms of immune evasion and the role of the early immune response in chronic infection caused by hepatitis C virus (HCV) are still unclear. Here, we present evidence for a cascade of molecular events that the virus initiates to subvert the innate immune attack. The HCV core protein induced p53-dependent gene expression of TAP1 (transporter associated with antigen processing 1) and consecutive major histocompatibility complex (MHC) class I upregulation. Moreover, in p53-deficient liver cell lines, only reconstitution with wild-type p53, but not mutated p53 lacking DNA binding capacity, showed this effect. As a consequence of increased MHC class I expression, a significantly …
Impaired Transporter Associated with Antigen Processing (TAP) Function Attributable to a Single Amino Acid Alteration in the Peptide TAP Subunit TAP1
2003
Abstract The heterodimeric peptide transporter TAP belongs to the ABC transporter family. Sequence comparisons with the P-glycoprotein and cystic fibrosis transmembrane conductance regulator and the functional properties of selective amino acids in these ABC transporters postulated that the glutamic acid at position 263 and the phenylalanine at position 265 of the TAP1 subunit could affect peptide transporter function. To define the role of both amino acids, TAP1 mutants containing a deletion or a substitution to alanine at position 263 or 265 were generated and stably expressed in murine and human TAP1−/− cells. The different TAP1 mutants were characterized in terms of expression and funct…
Genetic background in nonalcoholic fatty liver disease: A comprehensive review
2015
In the Western world, nonalcoholic fatty liver disease (NAFLD) is considered as one of the most significant liver diseases of the twenty-first century. Its development is certainly driven by environmental factors, but it is also regulated by genetic background. The role of heritability has been widely demonstrated by several epidemiological, familial, and twin studies and case series, and likely reflects the wide inter-individual and inter-ethnic genetic variability in systemic metabolism and wound healing response processes. Consistent with this idea, genome-wide association studies have clearly identified Patatin-like phosholipase domain-containing 3 gene variant I148M as a major player i…