Basic Science for the Clinician 48: Tyrosine Kinases in Disease (original) (raw)
Related papers
Tyrosine Kinase Inhibitors for the Treatment of Rheumatoid Arthritis
Current Topics in Medicinal Chemistry, 2013
Tyrosine kinases (TK) are enzymes capable of transferring phosphate groups to tyrosine residues in cytoplasmic proteins or the intracellular domains of transmembrane receptors. TK play critical roles in diverse biological functions including cellular processes such as adhesion, motility, proliferation, cell cycle control, cell death, as well as biological functions at the whole-organism level such as growth and development, metabolism or immune defense. TK inhibitors including spleen TK (fostamatinib) and Janus kinases (tofacitinib) inhibitors are two novel oral therapies that have demonstrated short-term good clinical responses in active rheumatoid arthritis patients with and inadequate responses to methotrexate or other traditional (non-biologic) disease-modifying antirheumatic drugs (DMARDs). Those responses are comparable to responses rates from pivotal trials of TNF inhibitors. TK inhibitors are generally well tolerated but not free of adverse effects. Several side effects had been described including gastrointestinal symptoms, neutropenia, hypertension, elevated liver function test and lipid alterations among others.
Effects of a novel tyrosine kinase inhibitor in rheumatoid arthritis synovial fibroblasts
Annals of the Rheumatic Diseases, 2007
OBJECTIVE: Biologicals have revolutionised the treatment of rheumatoid arthritis (RA). However, progressive joint destruction can still be observed in many patients and the search for novel molecular therapies targeting specific signalling pathways is ongoing. In the present study, we investigated the effects of GW282974, a novel compound directed against tyrosine kinase activity with respect to the potential suppression of inflammation and destruction. METHODS: Synovial tissue specimens were obtained from RA patients undergoing surgical joint replacement. Rheumatoid arthritis synovial fibroblasts (RASFs) were stimulated with cytokines and GW282974 was added in different concentrations. Gene expression was checked by TaqMan PCR, using 18S as housekeeping gene. Protein analysis was quantified by ELISA. Cell growth and proliferation was measured using the "ViaLight" proliferation assay. RESULTS: EGF had no effect on the gene expression profile of RASFs when used as single stimulatory agent. In combination with pro-inflammatory mediators however, EGF showed a synergistic effect. The expression of matrix metalloproteinases, inflammatory cytokines and cyclooxygenase-2 on mRNA levels was strongly increased, whereas the addition of GW282974 abrogated these effects in a dose-dependent manner. These data could be confirmed on protein/lipid levels analysing the supernatants of RASFs by ELISA. Similarly, cell growth and proliferation of RASFs were inhibited by GW282974 in a dose-and time-dependent manner. By contrast, no cytotoxic effects were seen within the concentrations used. DISCUSSION: GW282974 appears to interfere with the inflammatory and the destructive pathways in RASFs and might therefore be used as novel therapeutic strategy for the treatment of RA.
Tyrosine kinases as targets for the treatment of rheumatoid arthritis
Nature reviews. Rheumatology, 2009
As critical regulators of numerous cell signaling pathways, tyrosine kinases are implicated in the pathogenesis of several diseases, including rheumatoid arthritis (RA). In the absence of disease, synoviocytes produce factors that provide nutrition and lubrication for the surrounding cartilage tissue; few cellular infiltrates are seen in the synovium. In RA, however, macrophages, neutrophils, T cells and B cells infiltrate the synovium and produce cytokines, chemokines and degradative enzymes that promote inflammation and joint destruction. In addition, the synovial lining expands owing to the proliferation of synoviocytes and infiltration of inflammatory cells to form a pannus, which invades the surrounding bone and cartilage. Many of these cell responses are regulated by tyrosine kinases that operate in specific signaling pathways, and inhibition of a number of these kinases might be expected to provide benefit in RA.
Kinase inhibitors: A new tool for the treatment of rheumatoid arthritis
Clinical Immunology, 2013
Despite aggressive immunosuppression with biologics and traditional DMARDs, achieving disease remission remains an unmet goal for most rheumatoid arthritis (RA) patients. In this context, there is a demand for novel treatment strategies, with kinase inhibitors expected to enrich the existing therapeutic armamentarium. In RA some kinases participate in the generation of pathogenic signaling cascades. Pharmacologic inhibition of kinases that mediate pathogenic signal transduction heralds a new era for RA therapeutics. Oral inhibitors of JAKs, Syk, PI3Ks, MAPKs and Btk are under development or in clinical trials in patients with RA. In this review, we discuss the scientific rationale for the use of kinase inhibitors in RA and summarize the experience from clinical trials.
Proceedings of the National Academy of Sciences of the United States of America, 1986
The platelet-derived growth factor receptor (PDGF-R), a 180-kDa single-chain polypeptide, was purified from membranes of the human osteogenic sarcoma cell line MG-63. Purification was achieved by treatment of membranes with PDGF and ATP, followed by solubilization with nonionic detergent and successive chromatography on solid-phase antiphosphotyrosine monoclonal antibody and DEAE-cellulose. The PDGF-R, which was estimated to be 5040% pure by NaDodSO4/polyacrylamide gel electrophoresis of 32P-labeled preparations, was free of contaminating epidermal growth factor receptor and had no detectable phosphatase activity.
Novel small molecule therapeutics in rheumatoid arthritis
Rheumatology, 2013
A new wave of emerging therapies for the treatment of autoimmune and inflammatory diseases is under development. These therapies interrupt intracellular signalling through kinase inhibition. By interrupting one or more kinases it is possible to modulate the function of cellular structures such as surface receptors, signalling proteins and transcription of nuclear proteins and thus influence the behaviour of the cell types targeted. With these advances comes the significant potential to develop highly effective orally bioavailable therapeutics. The targets generating the greatest enthusiasm at this time for the treatment of autoimmune and inflammatory diseases include Janus-associated kinase, spleen tyrosine kinase, phosphodiesterase-4, Bruton's tyrosine kinase and phosphatidylinositol-3 kinase. Ultimately human trials will help us understand the potential risks and benefits of these novel approaches across a number of diseases.
Bruton’s Tyrosine Kinase Inhibition for the Treatment of Rheumatoid Arthritis
ImmunoTargets and Therapy
Bruton's tyrosine kinase (BTK) inhibitors are an emerging class of drugs that inhibit B cell receptor activation, FC-γ receptor signaling, and osteoclast proliferation. Following on approval for treatment of hematologic malignancies, BTK inhibitors are now under investigation to treat a number of different autoimmune diseases, including rheumatoid arthritis (RA). While the results of BTK inhibitors in RA animal models have been promising, the ensuing human clinical trial outcomes have been rather equivocal. This review will outline the mechanisms of BTK inhibition and its potential impact on immune mediated disease, the types of BTK inhibitors being studied for RA, the findings from both preclinical and clinical trials of BTK inhibitors in RA, and directions for future research.