Detection of HLA class II-dependent T helper antigen using antigen phage display

Major histocompatibility complex (MHC) class II-dependent antigens not only activate CD4+ T helper (Th) cells, but also cytolytic T lymphocytes and effector cells of the innate immune system. These antigens therefore are candidate vaccines against cancer and infectious agents. We have developed a novel approach using a model antigen, tetanus toxoid (TT), which provides the basis for the establishment of a novel strategy of cloning Th antigens. In the TT model system, a cDNA library encoding part of the TT light chain which contained a TT-associated Th epitope recognized by TT-specific Th clones was displayed on a phage vector (TT-phage) and presented to TT-specific Th cells by autologous Epstein-Barr virus-transformed B cells (APC). These TT-phages were able to specifically activate two different TT-specific CD4+ Th cell lines as demonstrated both in [3H]thymidine incorporation and cytokine release assays. Th cell stimulation by TT-phages was significant at a ratio of one TT-phage in 50 irrelevant phages. The described approach provides the basis for the development of a novel strategy of cloning MHC class II-dependent Th antigens, using available Th cells. This strategy has several potential advantages over existing antigen cloning methods or biochemical peptide isolation.     

A Novel Frameshift Mutation in TWIST2 Gene Causing Setleis Syndrome

The authors report on a child with Setleis syndrome (OMIM 227260). She is born to a consanguineous couple with bitemporal scar like defects resembling forceps marks. She had other classical features resembling autosomal recessive Setleis syndrome. The authors identified a novel homozygous deletion of a single nucleotide (c.91delC) in TWIST2 gene leading to the premature truncation of protein (p.R31GfsX71). Umbilical hernia and genital anomalies are being reported for the first time with this condition. This is the fourth mutation proven family of Setleis syndrome.     

Fibroblast growth factor-2 but not Mel-CAM and/or beta3 integrin promotes progression of melanocytes to melanoma

A variety of melanoma-associated antigens have been identified that mediate adhesion, growth, proteolysis, and modulation of immune response. However, the mechanisms by which human normal melanocytes become malignant are not clearly understood. Among the most consistent observations is the up-regulation of fibroblast growth factor-2 (FGF-2) and of the adhesion molecules beta3 integrin and Mel-CAM during melanoma progression. To evaluate the potential role of FGF-2, beta3 integrin and Mel-CAM in melanoma development we overexpressed FGF-2, beta3 integrin and Mel-CAM in normal human melanocytes using replication-deficient adenoviruses as a gene delivery vehicle. Fibroblast growth factor-2 overexpressing melanocytes in monolayer culture displayed cytological atypia. Furthermore, in human skin reconstructs where the physiological milieu is recreated in vitro, FGF-2-overexpressing melanocytes exhibited marked proliferation, upwards migration, cluster formation and type IV collagen expression within the epidermal compartment, simulating early radial growth phase melanoma. In contrast, overexpression of beta3 integrin and/or Mel-CAM in melanocytes did not affect their biological behaviour in human skin reconstructs. The described results of the current and previous studies emphasise the key role of FGF-2 in melanoma development and progression, underscoring the promise of FGF-2 as a target for therapy.     

Methylation markers: a potential force driving cancer diagnostics forward

Epigenetics, transcending genetics, genomics, and molecular biology, is now poised to be the avant-garde beacon of biological science. The rise of DNA methylation studies marks a new dawn in the field of epigenetics, which only a few decades ago was largely underestimated, but is now a dynamic area of research challenging and revising traditional paradigms of gene expression and behavior. Cancer research enjoys a major share of this attention to DNA methylation and it has been widely accepted for some time now that cancer is as much an epigenetic phenomenon as it is genetic. Epigenetic lesions and perturbations are acquired during the life of an individual and accumulate with aging and represent the flip side of the same coin that bears genetic mutations. Both events, either individually or in cooperation, result in the development and progression of cancer. Epigenetic research and the hunt for strong methylation markers has been ably mitigated by new and improved high throughput technology that has improved the efficacy and enabled the rapid progress of biomarker evaluation and validation. This review looks into some of the recent strides in biomarker research dealing exclusively with methylation markers and the potential key they may hold to the resilient door shut tight on cancer diagnostics and treatment.     

DNA methylation patterns in luminal breast cancers differ from non-luminal subtypes and can identify relapse risk independent of other clinical variables

The diversity of breast cancers reflects variations in underlying biology and affects the clinical implications for patients. Gene expression studies have identified five major subtypes- Luminal A, Luminal B, basal-like, ErbB2+ and Normal-Like. We set out to determine the role of DNA methylation in subtypes by performing genome-wide scans of CpG methylation in breast cancer samples with known expression-based subtypes. Unsupervised hierarchical clustering using a set of most varying loci clustered the tumors into a Luminal A majority (82%) cluster, Basal-like/ErbB2+ majority (86%) cluster and a non-specific cluster with samples that were also inconclusive in their expression-based subtype correlations. Contributing methylation loci were both gene associated loci (30%) and non-gene associated (70%), suggesting subtype dependant genome-wide alterations in the methylation landscape. The methylation patterns of significant differentially methylated genes in luminal A tumors are similar to those identified in CD24?+?luminal epithelial cells and the patterns in basal-like tumors similar to CD44?+?breast progenitor cells. CpG islands in the HOXA cluster and other homeobox (IRX2, DLX2, NKX2-2) genes were significantly more methylated in Luminal A tumors. A significant number of genes (2853, p?相似文献   

Stroma formation and angiogenesis by overexpression of growth factors,cytokines, and proteolytic enzymes in human skin grafted to SCID mice

Reorganization of skin during wound healing, inflammatory disorders, or cancer growth is the result of expression changes of multiple genes associated with tissue morphogenesis. We wanted to identify proteins involved in skin remodeling and select those that may be targeted for agonistic or antagonist therapeutic approaches in various disease processes. Full-thickness human skin was grafted to severe combined immunodeficient mice and injected intradermally with 38 different adenoviral vectors inserted with 37 different genes coding for growth factors, cytokines, proteolytic enzymes and their inhibitors, adhesion receptors, oncogenes, and tumor suppressor genes. Responses were characterized for infiltration of inflammatory cells, vascular density, matrix formation, fibroblast-like cell proliferation, and epidermal hyperplasia. Of the 17 growth factor vectors, 16 induced histological changes in human skin. Members of the VEGF and angiopoietin families induced neovascularization. PDGFs and TGF-betas stimulated connective tissue formation, and the chemokines IL-8 and MCP-1 attracted inflammatory neutrophils and monocytes, respectively. The serine protease uPA induced a vascular response similar to that of VEGF. Vectors with adhesion receptors, oncogenes and tumor suppressor genes had, with few exceptions, little effects on skin architecture. The overall results suggest that adenoviral vectors can effectively remodel the architecture of human skin for studies in morphogenesis, inflammatory skin disorders, wound healing, and cancer development.     

Differential effect of clofibrate on adriamycin cytotoxicity in P388 murine leukemia cells sensitive and resistant to adriamycin

Clofibrate (CPIB), an antihyperlipidemic agent, was utilized as a drug response modulator to modify the cytotoxicity of adriamycin (ADR) in vitro in P388 murine lymphocytic leukemia cells sensitive (P388/S) and resistant (P388/ADR) to ADR. CPIB elicited concentration and time dependent DNA biosynthesis inhibition which was completely reversible up to the concentration of 0.0025% in P388/S. However, only a partial reversibility of DNA biosynthesis inhibition was observed in P388/ADR cells treated with 0.0025% of CPIB. In both P388/S and P388/ADR there was complete and irreversible DNA biosynthesis inhibition at CPIB concentration of 0.005%. These findings were further confirmed by tumorigenicity analysis. CPIB was ineffective in altering ADR cytotoxicity in P388/S cells. However, in P388/ADR, CPIB enhanced ADR cytotoxicity at the lower concentrations of ADR and decreased the cytotoxicity upon increase in ADR concentrations. The enhancement in ADR cytotoxicity by CPIB in P388/ADR was due to increased ADR accumulation which was absent in P388/S cells. The present findings suggest the utility of CPIB as a selective agent to circumvent ADR resistance and to reduce host toxicity due to the drug.     

Thurston syndrome: report of a new case

Thurston syndrome (oro-facial-digital syndrome type V) is an autosomal recessive condition characterized by median cleft of the upper lip, postaxial polydactyly of hands and feet, and oral manifestations. According to earlier reports, the syndrome is predominantly seen in subjects of Indian descent. We report a cast of Thurston syndrome in a 13-year-old south Indian boy who presented with oral features, incomplete median cleft of upper lip, and polydactyly of both hands and left foot. A precise clinical differentiation must be made since considerable overlap of the features of the various other forms could give rise to difficulties in diagnosing the condition.