Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 19 de 19
Filter
Add more filters

Publication year range
1.
J Am Chem Soc ; 146(13): 8877-8886, 2024 Apr 03.
Article in English | MEDLINE | ID: mdl-38503564

ABSTRACT

Hypoxia inducible factor (HIF) is a heterodimeric transcription factor composed of an oxygen-regulated α subunit and a constitutively expressed ß subunit that serves as the master regulator of the cellular response to low oxygen concentrations. The HIF transcription factor senses and responds to hypoxia by significantly altering transcription and reprogramming cells to enable adaptation to a hypoxic microenvironment. Given the central role played by HIF in the survival and growth of tumors in hypoxia, inhibition of this transcription factor serves as a potential therapeutic approach for treating a variety of cancers. Here, we report the identification, optimization, and characterization of a series of cyclic peptides that disrupt the function of HIF-1 and HIF-2 transcription factors by inhibiting the interaction of both HIF-1α and HIF-2α with HIF-1ß. These compounds are shown to bind to HIF-α and disrupt the protein-protein interaction between the α and ß subunits of the transcription factor, resulting in disruption of hypoxia-response signaling by our lead molecule in several cancer cell lines.


Subject(s)
Hypoxia-Inducible Factor 1 , Neoplasms , Humans , Hypoxia-Inducible Factor 1/metabolism , Peptides, Cyclic/pharmacology , Peptides, Cyclic/metabolism , Hypoxia , Signal Transduction , Oxygen/metabolism , Cell Hypoxia , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , Neoplasms/drug therapy
2.
Biochem Soc Trans ; 51(1): 275-285, 2023 02 27.
Article in English | MEDLINE | ID: mdl-36645000

ABSTRACT

Antigen processing is an immunological mechanism by which intracellular peptides are transported to the cell surface while bound to Major Histocompatibility Complex molecules, where they can be surveyed by circulating CD8+ or CD4+ T-cells, potentially triggering an immunological response. The antigen processing pathway is a complex multistage filter that refines a huge pool of potential peptide ligands derived from protein degradation into a smaller ensemble for surface presentation. Each stage presents unique challenges due to the number of ligands, the polymorphic nature of MHC and other protein constituents of the pathway and the nature of the interactions between them. Predicting the ensemble of displayed peptide antigens, as well as their immunogenicity, is critical for improving T cell vaccines against pathogens and cancer. Our predictive abilities have always been hindered by an incomplete empirical understanding of the antigen processing pathway. In this review, we highlight the role of computational and structural approaches in improving our understanding of antigen processing, including structural biology, computer simulation, and machine learning techniques, with a particular focus on the MHC-I pathway.


Subject(s)
Antigen Presentation , Peptides , Ligands , Computer Simulation , Peptides/metabolism , Biology
3.
Clin Genet ; 103(2): 214-218, 2023 02.
Article in English | MEDLINE | ID: mdl-36148635

ABSTRACT

Renal Fanconi syndrome (RFS) is a generalised disorder of the proximal convoluted tubule. Many genes have been associated with RFS including those that cause systemic disorders such as cystinosis, as well as isolated RFS. We discuss the case of a 10-year-old female who presented with leg pain and raised creatinine on a screening blood test. Her mother has RFS and required a kidney transplant in her thirties. Further investigations confirmed RFS in the daughter. Exome sequencing was performed on the affected mother, child, and unaffected father. We identified a novel variant in GATM; c.965G>C p.(Arg322Pro) segregating dominantly in the mother and daughter. We validated our finding with molecular dynamics simulations and demonstrated a dynamic signature that differentiates our variant and two previously identified pathogenic variants in GATM from wildtype. Genetic testing has uncovered a novel pathogenic variant that predicts progression to end stage kidney failure and has important implications for family planning and cascade testing. We recommend that GATM is screened for in children presenting with RFS, in addition to adults, particularly with kidney failure, who may have had previous negative gene testing.


Subject(s)
Fanconi Syndrome , Kidney Failure, Chronic , Child , Adult , Female , Humans , Fanconi Syndrome/diagnosis , Fanconi Syndrome/genetics , Fanconi Syndrome/complications , Kidney Failure, Chronic/genetics , Kidney Failure, Chronic/complications , Genetic Testing , Causality
4.
Immunology ; 163(2): 169-184, 2021 06.
Article in English | MEDLINE | ID: mdl-33460454

ABSTRACT

Transmissible cancers are malignant cells that can spread between individuals of a population, akin to both a parasite and a mobile graft. The survival of the Tasmanian devil, the largest remaining marsupial carnivore, is threatened by the remarkable emergence of two independent lineages of transmissible cancer, devil facial tumour (DFT) 1 and devil facial tumour 2 (DFT2). To aid the development of a vaccine and to interrogate how histocompatibility barriers can be overcome, we analysed the peptides bound to major histocompatibility complex class I (MHC-I) molecules from Tasmanian devil cells and representative cell lines of each transmissible cancer. Here, we show that DFT1 + IFN-γ and DFT2 cell lines express a restricted repertoire of MHC-I allotypes compared with fibroblast cells, potentially reducing the breadth of peptide presentation. Comparison of the peptidomes from DFT1 + IFNγ, DFT2 and host fibroblast cells demonstrates a dominant motif, despite differences in MHC-I allotypes between the cell lines, with preference for a hydrophobic leucine residue at position 3 and position Ω of peptides. DFT1 and DFT2 both present peptides derived from neural proteins, which reflects a shared cellular origin that could be exploited for vaccine design. These results suggest that polymorphisms in MHC-I molecules between tumours and host can be 'hidden' by a common peptide motif, providing the potential for permissive passage of infectious cells and demonstrating complexity in mammalian histocompatibility barriers.


Subject(s)
Antigens, Neoplasm/metabolism , Cancer Vaccines/immunology , Facial Neoplasms/immunology , Immunotherapy/methods , Marsupialia/immunology , Neoplastic Cells, Circulating/pathology , Peptides/metabolism , Amino Acid Motifs/genetics , Animals , Antigen Presentation , Antigens, Neoplasm/genetics , Cell Line, Tumor , Histocompatibility , Histocompatibility Antigens Class I/metabolism , Peptides/genetics , Polymorphism, Genetic , Protein Binding
5.
Mol Phylogenet Evol ; 95: 67-78, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26642824

ABSTRACT

The tribe Empidini (Diptera: Empididae: Empidinae) is a diverse group with fourteen genera, seven of which are exclusive to the Neotropical region: Bolrhamphomyia Rafael, Chilerhamphomyia Rafael, Hystrichonotus Collin, Lamprempis Wheeler and Melander, Macrostomus Wiedemann, Opeatocerata Melander and Porphyrochroa Melander. Although Empidini itself is likely paraphyletic, many presumably monophyletic genera and species groups are recognized. Here, we apply DNA sequences from multiple genes to infer the phylogeny of Empidini, focusing on placing the Neotropical lineages within the entire tribe and identifying monophyletic groups. We included 98 Empidini taxa along with 18 outgrous terminals, spanning the diversity within the group. The results from the analyses performed are largely similar, with major groupings of genera in common. Specifically, the analyses recovered a monophyletic Hilarini and a paraphyletic Empidini. Most species from Chile and Argentina (Andean region) are found to belong to an early branching lineage within Empidinae, and are not monophyletic with other Empidini. A large portion of the remaining Neotropical Empidini (not Andean) comprises a single clade that includes four endemic genera and a number of Neotropical Empis Linneaus species. Macrostomus and Porphyrochroa each recovered as monophyletic and sister to one another, although generic placement of a few taxa remains uncertain due to conflicting morphological features. Lamprempis+Opeatocerata are also found to be sister-taxa in most analyses. Several large genera were found to be polyphyletic or paraphyletic including Empis and Rhamphomyia Meigen. We evaluate our findings and discuss them in light of current Empidinae taxonomy.


Subject(s)
Diptera/classification , Animals , Argentina , Chile , Diptera/genetics , Genetic Speciation , Phylogeny , Phylogeography , Tropical Climate
6.
Br J Nutr ; 112(12): 2018-27, 2014 Dec 28.
Article in English | MEDLINE | ID: mdl-25342229

ABSTRACT

Maternal nutritional status during pregnancy has been reported to be associated with childhood asthma and atopic disease. The Avon Longitudinal Study of Parents and Children has reported associations between reduced umbilical cord Fe status and childhood wheeze and eczema; however, follow-up was short and lung function was not measured. In the present study, the associations between maternal Fe status during pregnancy and childhood outcomes in the first 10 years of life were investigated in a subgroup of 157 mother-child pairs from a birth cohort with complete maternal, fetal ultrasound, blood and child follow-up data. Maternal Fe intake was assessed using FFQ at 32 weeks of gestation and Hb concentrations and serum Fe status (ferritin, soluble transferrin receptor and TfR-F (transferrin receptor:ferritin) index) were measured at 11 weeks of gestation and at delivery. Maternal Fe intake, Hb concentrations and serum Fe status were found to be not associated with fetal or birth measurements. Unit increases in first-trimester maternal serum TfR concentrations (OR 1.44, 95% CI 1.05, 1.99) and TfR-F index (OR 1.42, 95% CI 1.10, 1.82) (i.e. decreasing Fe status) were found to be associated with an increased risk of wheeze, while unit increases in serum ferritin concentrations (i.e., increasing Fe status) were found to be associated with increases in standardised mean peak expiratory flow (PEF) (ß 0.25, 95% CI 0.09, 0.42) and forced expiratory volume in the first second (FEV1) (ß 0.20, 95% CI 0.08, 0.32) up to 10 years of age. Increasing maternal serum TfR-F index at delivery was found to be associated with an increased risk of atopic sensitisation (OR 1.35, 95% CI 1.02, 1.79). The results of the present study suggest that reduced maternal Fe status during pregnancy is adversely associated with childhood wheeze, lung function and atopic sensitisation, justifying further studies on maternal Fe status and childhood asthma and atopic disease.


Subject(s)
Anemia, Iron-Deficiency/complications , Asthma/etiology , Ferritins/blood , Hypersensitivity, Immediate/etiology , Iron/blood , Prenatal Exposure Delayed Effects , Receptors, Transferrin/blood , Adult , Anemia, Iron-Deficiency/blood , Asthma/physiopathology , Child , Child, Preschool , Cohort Studies , Female , Forced Expiratory Volume , Hemoglobins/metabolism , Humans , Infant , Infant, Newborn , Iron/administration & dosage , Iron Deficiencies , Iron, Dietary/administration & dosage , Iron, Dietary/blood , Lung/physiopathology , Male , Nutritional Status , Odds Ratio , Peak Expiratory Flow Rate , Pregnancy , Pregnancy Complications/blood , Pregnancy Trimester, First , Respiratory Sounds/etiology , Respiratory Sounds/physiopathology , Surveys and Questionnaires
7.
Hum Genomics ; 6: 5, 2012 Jul 05.
Article in English | MEDLINE | ID: mdl-23245293

ABSTRACT

A genetic association study is a complicated process that involves collecting phenotypic data, generating genotypic data, analyzing associations between genotypic and phenotypic data, and interpreting genetic biomarkers identified. SNPTrack is an integrated bioinformatics system developed by the US Food and Drug Administration (FDA) to support the review and analysis of pharmacogenetics data resulting from FDA research or submitted by sponsors. The system integrates data management, analysis, and interpretation in a single platform for genetic association studies. Specifically, it stores genotyping data and single-nucleotide polymorphism (SNP) annotations along with study design data in an Oracle database. It also integrates popular genetic analysis tools, such as PLINK and Haploview. SNPTrack provides genetic analysis capabilities and captures analysis results in its database as SNP lists that can be cross-linked for biological interpretation to gene/protein annotations, Gene Ontology, and pathway analysis data. With SNPTrack, users can do the entire stream of bioinformatics jobs for genetic association studies. SNPTrack is freely available to the public at http://www.fda.gov/ScienceResearch/BioinformaticsTools/SNPTrack/default.htm.


Subject(s)
Computational Biology/methods , Databases, Genetic , Polymorphism, Single Nucleotide , Gene Ontology , Genetic Association Studies/methods , Genetic Predisposition to Disease/genetics , Genotype , Humans , Internet , Phenotype , Signal Transduction/genetics , Software
8.
Bioorg Med Chem Lett ; 21(6): 1827-31, 2011 Mar 15.
Article in English | MEDLINE | ID: mdl-21316220

ABSTRACT

This report describes the design and synthesis of a series of CCR2 antagonists incorporating novel non-aryl/heteroaryl RHS (right hand side) motifs. Previous SAR in the area has suggested an aryl/heteroaryl substituent as a necessary structural feature for binding to the CCR2 receptor. Herein we describe the SAR with regards to potency (binding to hCCR2), dofetilide activity and metabolic stability (in vitro HLM) for this series. The resulting outcome was the identification of compounds with excellent properties for the investigation of the role of CCR2 in disease.


Subject(s)
Drug Design , Receptors, CCR2/antagonists & inhibitors , Binding Sites , Models, Molecular , Structure-Activity Relationship
9.
J Immunol ; 183(11): 7063-72, 2009 Dec 01.
Article in English | MEDLINE | ID: mdl-19915065

ABSTRACT

The role of chromatin remodeling and histone posttranslational modifications and how they are integrated to control gene expression during the acquisition of cell-specific functions is poorly understood. We show here that following in vitro activation of CD4(+) and CD8(+) T lymphocytes, both cell types show rapid histone H3 loss at the granzyme B (gzmB) proximal promoter region. However, despite the gzmB proximal promoter being remodeled in both T cell subsets, only CD8(+) T cells express high levels of gzmB and display a distinct pattern of key epigenetic marks, notably differential H3 acetylation and methylation. These data suggest that for high levels of transcription to occur a distinct set of histone modifications needs to be established in addition to histone loss at the proximal promoter of gzmB.


Subject(s)
CD4-Positive T-Lymphocytes/metabolism , CD8-Positive T-Lymphocytes/metabolism , Chromatin Assembly and Disassembly , Epigenesis, Genetic , Granzymes/genetics , T-Lymphocyte Subsets/metabolism , Animals , CD4-Positive T-Lymphocytes/cytology , CD8-Positive T-Lymphocytes/cytology , Cell Differentiation/immunology , Cell Lineage , Flow Cytometry , Gene Expression , Gene Expression Regulation/immunology , Granzymes/biosynthesis , Histones/metabolism , Lymphocyte Activation/genetics , Mice , Microscopy, Confocal , Oligonucleotide Array Sequence Analysis , Promoter Regions, Genetic , RNA Polymerase II/genetics , RNA Polymerase II/metabolism , Reverse Transcriptase Polymerase Chain Reaction , T-Lymphocyte Subsets/cytology , Transcription, Genetic
10.
Am J Respir Crit Care Med ; 180(6): 547-52, 2009 Sep 15.
Article in English | MEDLINE | ID: mdl-19574442

ABSTRACT

RATIONALE: Advances in spirometry measurement techniques have made it possible to obtain measurements in children as young as 3 years of age; however, in practice, application remains limited by the lack of appropriate reference data for young children, which are often based on limited population-specific samples. OBJECTIVES: We aimed to build on previous models by collating existing reference data in young children (aged 3-7 yr), to produce updated prediction equations that span the preschool years and that are also linked to established reference equations for older children and adults. METHODS: The Asthma UK Collaborative Initiative was established to collate lung function data from healthy young children aged 3 to 7 years. Collaborators included researchers with access to pulmonary function test data in healthy preschool children. Spirometry centiles were created using the LMS (lambda, micro, sigma) method and extend previously published equations down to 3 years of age. MEASUREMENTS AND MAIN RESULTS: The Asthma UK centile charts for spirometry are based on the largest sample of healthy young Caucasian children aged 3-7 years (n = 3,777) from 15 centers across 11 countries and provide a continuous reference with a smooth transition into adolescence and adulthood. These equations improve existing pediatric equations by considering the between-subject variability to define a more appropriate age-dependent lower limit of normal. The collated data set reflects a variety of equipment, measurement protocols, and population characteristics and may be generalizable across different populations. CONCLUSIONS: We present prediction equations for spirometry for preschool children and provide a foundation that will facilitate continued updating.


Subject(s)
Asthma/diagnosis , Asthma/physiopathology , Spirometry/standards , Child , Child, Preschool , Forced Expiratory Volume , Humans , Reference Values , Respiratory Function Tests , Retrospective Studies , Severity of Illness Index , United Kingdom , White People
11.
ERJ Open Res ; 6(4)2020 Oct.
Article in English | MEDLINE | ID: mdl-33263054

ABSTRACT

BACKGROUND: Early reports suggest that most children infected with severe acute respiratory syndrome coronavirus 2 ("SARS-CoV-2") have mild symptoms. What is not known is whether children with chronic respiratory illnesses have exacerbations associated with SARS-CoV-2 virus. METHODS: An expert panel created a survey, which was circulated twice (in April and May 2020) to members of the Paediatric Assembly of the European Respiratory Society (ERS) and via the social media of the ERS. The survey stratified patients by the following conditions: asthma, cystic fibrosis (CF), bronchopulmonary dysplasia (BPD) and other respiratory conditions. RESULTS: In total 174 centres responded to at least one survey. 80 centres reported no cases, whereas 94 entered data from 945 children with coronavirus disease 2019 (COVID-19). SARS-CoV-2 was isolated from 49 children with asthma of whom 29 required no treatment, 19 needed supplemental oxygen and four children required mechanical ventilation. Of the 14 children with CF and COVID-19, 10 required no treatment and four had only minor symptoms. Among the nine children with BPD and COVID-19, two required no treatment, five required inpatient care and oxygen and two were admitted to a paediatric intensive care unit (PICU) requiring invasive ventilation. Data were available from 33 children with other conditions and SARS-CoV-2 of whom 20 required supplemental oxygen and 11 needed noninvasive or invasive ventilation. CONCLUSIONS: Within the participating centres, in children with asthma and CF, infection with SARS-CoV-2 was well tolerated, but a substantial minority of children with BPD and other conditions required ventilatory support indicating that these latter groups are at risk from SARS-CoV-2 infection.

12.
Pediatrics ; 142(5)2018 11.
Article in English | MEDLINE | ID: mdl-30348751

ABSTRACT

: media-1vid110.1542/5828355774001PEDS-VA_2018-1067Video Abstract BACKGROUND: Slipped capital femoral epiphysis (SCFE) is believed to be associated with childhood obesity, although the strength of the association is unknown. METHODS: We performed a cohort study using routine data from health screening examinations at primary school entry (5-6 years old) in Scotland, linked to a nationwide hospital admissions database. A subgroup had a further screening examination at primary school exit (11-12 years old). RESULTS: BMI was available for 597 017 children at 5 to 6 years old in school and 39 468 at 11 to 12 years old. There were 4.26 million child-years at risk for SCFE. Among children with obesity at 5 to 6 years old, 75% remained obese at 11 to 12 years old. There was a strong biological gradient between childhood BMI at 5 to 6 years old and SCFE, with the risk of disease increasing by a factor of 1.7 (95% confidence interval [CI] 1.5-1.9) for each integer increase in BMI z score. The risk of SCFE was almost negligible among children with the lowest BMI. Those with severe obesity at 5 to 6 years old had 5.9 times greater risk of SCFE (95% CI 3.9-9.0) compared with those with a normal BMI; those with severe obesity at 11 to 12 years had 17.0 times the risk of SCFE (95% CI 5.9-49.0). CONCLUSIONS: High childhood BMI is strongly associated with SCFE. The magnitude of the association, temporal relationship, and dose response added to the plausible mechanism offer the strongest evidence available to support a causal association.


Subject(s)
Pediatric Obesity/complications , Slipped Capital Femoral Epiphyses/etiology , Body Mass Index , Child , Child, Preschool , Cohort Studies , Databases, Factual , Female , Humans , Incidence , Male , Mass Screening , Risk Assessment/methods , Risk Factors , Scotland/epidemiology , Slipped Capital Femoral Epiphyses/epidemiology
13.
Mol Cell Biol ; 24(6): 2584-92, 2004 Mar.
Article in English | MEDLINE | ID: mdl-14993294

ABSTRACT

The murine cytokine thymic stromal lymphopoietin (TSLP) supports the development of B220+ IgM+ immature B cells and induces thymocyte proliferation in vitro. Human TSLP, by contrast, activates CD11c+ dendritic cells, but not B or T cells. Recent studies have demonstrated that the receptor for TSLP consists of a heterodimer of the interleukin 7 (IL-7) alpha chain and a novel protein that resembles the hematopoietic cytokine receptor common gamma chain. We examined signal transduction by the gamma-like chains using chimeric receptor proteins. The cytoplasmic domain of the human, but not of the murine, gamma-like chain, activates Jak2 and Stat5 and supports the proliferation of hematopoietic cell lines. In order to assess the role of the murine gamma-like chain in vivo, we generated gamma-like chain-deficient mice. Receptor-deficient mice are unresponsive to TSLP but exhibit no obvious phenotypic defects. In particular, hematopoietic cell development appeared normal. B-cell development, including the IgM+ compartment, was unaffected by loss of the TSLP pathway, as were T lymphopoiesis and lymphocyte proliferation in vitro. Cytokine receptors that utilize the common gamma chain signal through the lymphocyte-specific kinase Jak3. Mice deficient in Jak3 exhibit a SCID phenotype but harbor a residual B220+ splenic lymphocyte population. We demonstrate here that this residual lymphocyte population is lost in mice lacking both the gamma-like chain and Jak3.


Subject(s)
B-Lymphocytes/immunology , Receptors, Cytokine/metabolism , Animals , B-Lymphocytes/cytology , B-Lymphocytes/metabolism , Base Sequence , Cell Division , Cytokines/metabolism , Cytokines/pharmacology , DNA, Complementary/genetics , Humans , Immunoglobulins , In Vitro Techniques , Janus Kinase 3 , Mice , Mice, Inbred C57BL , Mice, Knockout , Molecular Sequence Data , Phenotype , Protein-Tyrosine Kinases/metabolism , Receptors, Cytokine/chemistry , Receptors, Cytokine/deficiency , Receptors, Cytokine/genetics , Recombinant Fusion Proteins/chemistry , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/metabolism , Signal Transduction , Thymic Stromal Lymphopoietin
14.
World J Emerg Surg ; 11(1): 46, 2016.
Article in English | MEDLINE | ID: mdl-27588036

ABSTRACT

BACKGROUND: We evaluated the ability of experienced trauma surgeons to accurately predict specific blunt injuries, as well as patient disposition from the emergency department (ED), based only on the initial clinical evaluation and prior to any imaging studies. It would be hypothesized that experienced trauma surgeons' initial clinical evaluation is accurate for excluding life-threatening blunt injuries and for appropriate admission triage decisions. METHODS: Using only their history and physical exam, and prior to any imaging studies, three (3) experienced trauma surgeons, with a combined Level 1 trauma experience of over 50 years, predicted injuries in patients with an initial GCS (Glasgow Coma Score) of 14-15. Additionally, ED disposition (ICU, floor, discharge to home) was also predicted. These predictions were compared to actual patient dispositions and to blunt injuries documented at discharge. RESULTS: A total of 101 patients with 92 blunt injuries were studied. 43/92 (46.7 %) injuries would have been missed by only performing an initial history and physical exam ("Missed injury"). A change in treatment, though often minor, was required in 19/43 (44.2 %) of the missed injuries. Only 1/43 (2.3 %) of these "missed injuries" (blunt aortic injury) required surgery. Sensitivity, specificity, and accuracy for injury prediction were 53.2, 95.9, and 92.3 % respectively. Positive and negative predictive values were 53.8 and 95.8 % respectively. Prediction of disposition from the ED was 77.8 % accurate. In 7/34 (20.6 %) patients, missed injuries led to changes in disposition. "Undertriage" occurred in 9/99 (9.1 %) patients (Predicted for floor but admitted to ICU). Additionally, 8/84 (9.5 %) patients predicted for floor admission were sent home from the ED; and 5/13 (38.5 %) patients predicted for ICU admission were actually sent to the floor after complete evaluations, giving an "overtriage" rate of 13/99 (13.1 %) patients. CONCLUSIONS: In a neurologically-intact group of trauma patients, experienced trauma surgeons would have missed 46.7 % of the actual injuries, based only on their history and physical exam. Once accurate diagnoses of injuries were completed, usually with the help of CT scans, admission dispositions changed in 20.6 % of patients. Treatment changes occurred in 44.2 % of the missed injuries, though usually minimal. Broad elimination of early imaging studies in alert, blunt trauma patients cannot be advocated.

16.
Mol Cancer ; 2: 1, 2003 Jan 03.
Article in English | MEDLINE | ID: mdl-12537587

ABSTRACT

BACKGROUND: Gleevec (aka STI571, Imatinib) is a recently FDA approved anti-tumor drug for chronic myelogenous leukemia. Gleevec binds specifically to BCR-ABL tyrosine kinase and inhibit the tyrosine kinase activity. It cross-reacts with another two important membrane tyrosine kinase receptors, c-kit and PDGF receptors. We sought to investigate if Gleevec has a potential role in treatment of non-small cell lung cancer. RESULTS: We have shown that Gleevec alone can inhibit the A549 lung cancer cell growth in dose-dependent manner, and the optimal concentration of Gleevec inhibition of A549 cell growth is at the range of 2-3 microM (IC50). We have also shown that A549 cells are resistant to cisplatin treatment (IC50 64 microM). Addition of Gleevec to the A549 cells treated with cisplatin resulted in a synergistic cell killing effect, suggesting that Gleevec can potentiate the effect of cisplatin on A549 cells. We also showed that the A549 lung cancer cells expresses the platelet derived growth factor receptor alpha, and the inhibitory effects of Gleevec on A549 cells is likely mediated through inhibition of PDGFR alpha phosphorylation. We further tested 33 lung cancer patients' tumor specimens to see the frequency of PDGFR-alpha expression by tissue micro-arrays and immunohistochemistry. We found that 16 of the 18 squamous carcinomas (89%), 11 of the 11 adenocarcinomas (100%), and 4 of the 4 small cell lung cancers (100%) expressed PDGFR-alpha. CONCLUSION: These results suggest a potential role of Gleevec as adjuvant therapeutic agent for treatment of non-small cell lung cancer.


Subject(s)
Cell Proliferation/drug effects , Cisplatin/pharmacology , Piperazines/pharmacology , Pyrimidines/pharmacology , Antineoplastic Agents/pharmacology , Benzamides , Cell Line , Cell Line, Tumor , Drug Synergism , Growth Inhibitors/pharmacology , Humans , Imatinib Mesylate , Immunohistochemistry , Lung Neoplasms/metabolism , Lung Neoplasms/pathology , Receptor, Platelet-Derived Growth Factor alpha/analysis , Receptor, Platelet-Derived Growth Factor beta/analysis , Tissue Array Analysis
17.
Invest Ophthalmol Vis Sci ; 49(8): 3611-6, 2008 Aug.
Article in English | MEDLINE | ID: mdl-18441306

ABSTRACT

PURPOSE: To determine whether single nucleotide polymorphisms (SNPs) in the vascular endothelial growth factor (VEGF) gene are associated with severity of diabetic retinopathy. METHODS: A case-control study was conducted in which 45 individuals with type 1 or 2 diabetes with proliferative diabetic retinopathy (PDR) and 61 individuals with type 1 or 2 diabetes without retinopathy (DWR) were genotyped for 14 SNPs in the VEGF promoter and gene. RESULTS: Three of the promoter SNP genotypes, -160C, -152A (rs13207351), and -116A (rs1570360), showed significant independent associations with PDR, as well as the minihaplotype CAA (P = 0.00017). Two promoter haplotypes were associated with severity of retinopathy: -460C, -417T, -172C, -165C, -160C, -152A, -141A, -116A, +405C was associated with PDR (OR [95% CI] = 29.92 [3.91, 228.78], P = 1.62 x 10(-5)) and -460C, -2417T, -172C, -165C, -160C, -152A, -141A, -116G, +405G was associated with DWR (OR = 0.05 [0.01, 0.35], P = 0.000373). Furthermore, two haplotype-tagged (ht) SNPs, +4618 (rs735286) and +5092 (rs2146323), and five htSNP haplotypes were associated with severity of retinopathy. When the nine promoter/5' untranslated region [UTR] and five htSNP genotypes were combined into a 14-SNP haplotype, a single haplotype, -460C, -417T, -172C, -165C, -160C, -152A, -141A, -116A, +405C, +674T, +4618C, +5092A, +9162C, +9512C was found to be significantly associated with the PDR group (OR = 18.45 [2.35, 144.67], P = 0.00622). CONCLUSIONS: A clear association was demonstrated between VEGF SNPs and severity of diabetic retinopathy. Furthermore, two of the htSNP haplotypes appear to be more generalized markers for angiogenesis, in that these have been found in prior work to be associated with neovascular age-related macular degeneration.


Subject(s)
Diabetic Retinopathy/genetics , Polymorphism, Single Nucleotide , Vascular Endothelial Growth Factor A/genetics , 5' Untranslated Regions/genetics , Adult , Aged , Aged, 80 and over , Case-Control Studies , Diabetes Mellitus, Type 1/genetics , Diabetes Mellitus, Type 2/genetics , Female , Haplotypes , Humans , Introns/genetics , Male , Middle Aged
18.
Hum Mol Genet ; 15(19): 2955-61, 2006 Oct 01.
Article in English | MEDLINE | ID: mdl-16940309

ABSTRACT

Age-related macular degeneration (AMD) is the most common cause of blindness in the elderly. Linkage has been shown to the vascular endothelial growth factor (VEGF) gene and ocular levels of VEGF are raised in individuals with the neovascular form of disease. To examine the role of VEGF further, we conducted a case-control study where 45 individuals with neovascular AMD and 94 age-matched controls were genotyped for 14 single nucleotide polymorphisms (SNPs) in the VEGF promoter and gene. The single SNP +674 CC genotype was significantly associated with AMD (OR=2.40, 95%CI 1.09-5.26, P=0.027). Haplotype analysis of SNPs +674, +4618, +5092, +9162 and +9512 revealed that CTCCT and TCACC were associated with AMD (OR=15.77, 95% CI 1.91-130.24, P=0.0161 and OR=9.95, 95%CI 3.22-30.74, P=0.000053, respectively). The haplotype TCACT was associated with the control group (P=0.0001832). Furthermore, haplotype analysis of promoter SNPs revealed that possession of the -460T, -417T, -172C, -165C, -160C, -152G, -141A, -116A, +405C haplotype was strongly associated with AMD (OR=18.24, 95%CI 2.25-148.25, P=0.0074). This is the most extensive analysis of the VEGF gene in AMD, demonstrating a clear association with the exudative form of disease, thereby creating the possibility for predictive testing. Smoking, high fat intake and hypertension are negative environmental risk factors in AMD, whereas increased consumption of dietary antioxidants can have a protective effect. Identification of those at risk in the population would allow individual counselling with lifestyle advice to reduce the risks of blindness. (Genbank accession nos M63971 and AF437895).


Subject(s)
Macular Degeneration/genetics , Neovascularization, Pathologic/genetics , Polymorphism, Single Nucleotide , Vascular Endothelial Growth Factor A/genetics , 5' Untranslated Regions , Aged , Base Sequence , Case-Control Studies , DNA Primers/genetics , Genotype , Haplotypes , Humans , Macular Degeneration/etiology , Macular Degeneration/prevention & control , Promoter Regions, Genetic , Risk Factors
19.
Infect Immun ; 72(12): 6884-91, 2004 Dec.
Article in English | MEDLINE | ID: mdl-15557609

ABSTRACT

Infection of C57BL/6 mice with Mycobacterium avium leads to the activation of both CD4+ and CD8+ gamma interferon (IFN-gamma)-producing T cells, although the CD8+ cells play no role in protection against infection. Using transfer of different lines of transgenic T cells with T-cell receptors (TCRs) which recognize irrelevant antigens, we show here that transferred CD8+ T cells from two of the three lines were activated to the same degree as the host cells, suggesting that the majority of the IFN-gamma-producing CD8+ T cells of the host represented bystander activation. The third line, specific for the male HY antigen, showed no activation. Activation required the participation of the CD28 coreceptor on T cells and was unaffected by the removal of CD44(hi) (memory phenotype) T cells. The transferred CD8+ T cells proliferated in vivo, although this was not essential for IFN-gamma production. Taken together, these data are highly reminiscent of homeostatic proliferation of TCR transgenic T cells upon transfer to lymphopenic hosts, and suggest low-affinity stimulation through the TCR, possibly by self peptides. The findings are discussed in relation to homeostatic proliferation and their significance in the possible induction of autoimmune disease.


Subject(s)
CD8-Positive T-Lymphocytes/immunology , Lymphocyte Activation , Mycobacterium avium , Tuberculosis/immunology , Animals , Interferon-gamma/biosynthesis , Interleukin-15/physiology , Interleukin-7/physiology , Mice , Mice, Inbred C57BL , Receptors, Antigen, T-Cell/physiology , Tuberculosis/veterinary
SELECTION OF CITATIONS
SEARCH DETAIL