Hyperglycemia activates FGFR1 via TLR4/c-Src pathway to induce inflammatory cardiomyopathy in diabetes

Protein tyrosine kinases (RTKs) modulate a wide range of pathophysiological events in several non-malignant disorders, including diabetic complications. To find new targets driving the development of diabetic cardiomyopathy (DCM), we profiled an RTKs phosphorylation array in diabetic mouse hearts and identified increased phosphorylated fibroblast growth factor receptor 1 (p-FGFR1) levels in cardiomyocytes, indicating that FGFR1 may contribute to the pathogenesis of DCM. Using primary cardiomyocytes and H9C2 cell lines, we discovered that high-concentration glucose (HG) transactivates FGFR1 kinase domain through toll-like receptor 4 (TLR4) and c-Src, independent of FGF ligands. Knocking down the levels of either TLR4 or c-Src prevents HG-activated FGFR1 in cardiomyocytes. RNA-sequencing analysis indicates that the elevated FGFR1 activity induces pro-inflammatory responses via MAPKs-NFκB signaling pathway in HG-challenged cardiomyocytes, which further results in fibrosis and hypertrophy. We then generated cardiomyocyte-specific FGFR1 knockout mice and showed that a lack of FGFR1 in cardiomyocytes prevents diabetes-induced cardiac inflammation and preserves cardiac function in mice. Pharmacological inhibition of FGFR1 by a selective inhibitor, AZD4547, also prevents cardiac inflammation, fibrosis, and dysfunction in both type 1 and type 2 diabetic mice. These studies have identified FGFR1 as a new player in driving DCM and support further testing of FGFR1 inhibitors for possible cardioprotective benefits.

Fyn, Blk, and Lyn kinase inhibitors: A mini-review on medicinal attributes, research progress, and future insights

Fyn, Blk, and Lyn are part of a group of proteins called Src family kinases. They are crucial in controlling cell communication and their response to the growth, changes, and immune system. Blocking these proteins with inhibitors can be a way to treat diseases where these proteins are too active. The primary mode of action of these inhibitors is to inhibit the phosphorylation of Fyn, Blk, and Lyn receptors, which in turn affects how signals pass within the cells. This review shows the structural and functional aspects of Fyn, Blk, and Lyn kinases, highlighting the significance of their dysregulation in diseases such as cancer and autoimmune disorders. The discussion encompasses the design strategies, SAR analysis, and chemical characteristics of effective inhibitors, shedding light on their specificity and potency. Furthermore, it explores the progress of clinical trials of these inhibitors, emphasizing their potential therapeutic applications.

Abnormal phosphorylation of protein tyrosine in neurodegenerative diseases

Neurodegenerative diseases, including Alzheimer disease, Parkinson disease, amyotrophic lateral sclerosis, and multiple sclerosis, are chronic disorders of the CNS that are characterized by progressive neuronal dysfunction. These diseases have diverse clinical and pathological features and their pathogenetic mechanisms are not yet fully understood. Currently, widely accepted hypotheses include the accumulation of misfolded proteins, oxidative stress from reactive oxygen species, mitochondrial dysfunction, DNA damage, neurotrophin dysfunction, and neuroinflammatory processes. In the CNS of patients with neurodegenerative diseases, a variety of abnormally phosphorylated proteins play important roles in pathological processes such as neuroinflammation and intracellular accumulation of β-amyloid plaques and tau. In recent years, the roles of abnormal tyrosine phosphorylation of intracellular signaling molecules regulated by protein tyrosine kinases (PTKs) and protein tyrosine phosphatases (PTPs) in neurodegenerative diseases have attracted increasing attention. Here, we summarize the roles of signaling pathways related to protein tyrosine phosphorylation in the pathogenesis of neurodegenerative diseases and the progress of therapeutic studies targeting PTKs and PTPs that provide theoretical support for future studies on therapeutic strategies for these devastating and important neurodegenerative diseases.

A Cost-Effectiveness Analysis of Nivolumab Plus Ipilimumab Versus Pembrolizumab Plus Axitinib and Versus Avelumab Plus Axitinib in First-Line Treatment of Advanced Renal Cell Carcinoma

BACKGROUND

There now exist several viable first-line treatment options for metastatic renal cell carcinoma, making the choice of initial therapy difficult. Considering metrics other than patient factors may be necessary to select the most appropriate therapy. We aimed to assess the cost-effectiveness of the three combination therapies currently approved in treatment-naïve advanced or metastatic renal cell carcinoma-nivolumab + ipilimumab (NI), pembrolizumab + axitinib (PA), and avelumab + axitinib (AA)-from a US payer perspective.

PATIENTS AND METHODS

Our analysis was performed based on previously obtained data derived from progression-free survival and overall survival curves from CheckMate 214, KEYNOTE 426, and JAVELIN Renal 101.

RESULTS

The total costs of each treatment were found to be $437,556.12 for NI, $450,597.15 for PA, and $542,882.34 for AA, with quality-adjusted life-year (QALY) values of 4.04, 3.77, and 2.95 for each combination, respectively. The incremental cost-effectiveness ratio (ICER) of NI versus PA was ($47,504.73/QALY); for NI versus AA, it was ($96,533.11/QALY); for PA versus AA, it was ($113,015.87/QALY). Net health benefit scaled against a willingness-to-pay threshold of $150,000 per QALY was positive for NI versus PA at 0.36 and versus AA at 1.79, and this index was also positive for PA versus AA at 1.43, indicating that the additional value of these therapies versus their alternatives is greater than the extra cost.

CONCLUSION

NI was found to be the most cost-effective treatment option compared with the other considered therapies. PA was found to be cost effective compared to AA. When patient factors such as social issues and pre-existing conditions do not dictate their first-line therapy, clinicians may use this additional information to make financially conscious choices.

Inhibition of porcine epidemic diarrhea virus (PEDV) replication by A77 1726 through targeting JAK and Src tyrosine kinases

Porcine epidemic diarrhea (PED) virus (PEDV) is a coronavirus that primarily infects porcine intestinal epithelial cells and causes severe diarrhea and high fatality in piglets. A77 1726 is the active metabolite of leflunomide, a clinically approved anti-rheumatoid arthritis (RA) drug. A77 1726 inhibits the activity of protein tyrosine kinases (PTKs), p70 S6 kinase (S6K1), and dihydroorotate dehydrogenase (DHO-DHase). Whether A77 1726 can control coronavirus infections has not been investigated. Here we report that A77 1726 effectively restricted PEDV replication by inhibiting Janus kinases (JAKs) and Src kinase activities but not by inhibiting DHO-DHase and S6K1 activities. Overexpression of Src, JAK2 or its substrate STAT3 enhanced PEDV replication and attenuated the antiviral activity of A77 1726. Our study demonstrates for the first time the ability of A77 1726 to control coronavirus replication by inhibiting PTK activities. Leflunomide has potential therapeutic value for the control of PEDV and other coronavirus infections.

STAT Signaling in Glioma Cells

STAT (signal transducers and activators of transcription) are latent cytoplasmic transcription factors that function as downstream effectors of cytokine and growth factor receptor signaling. The canonical JAK/STAT signaling pathway involves the activation of Janus kinases (JAK) or growth factors receptor kinases, phosphorylation of STAT proteins, their dimerization and translocation into the nucleus where STATs act as transcription factors with pleiotropic downstream effects. STAT signaling is tightly controlled with restricted kinetics due to action of its negative regulators. While STAT1 is believed to play an important role in growth arrest and apoptosis, and to act as a tumor suppressor, STAT3 and 5 are involved in promoting cell cycle progression, cellular transformation, and preventing apoptosis. Aberrant activation of STATs, in particular STAT3 and STAT5, have been found in a large number of human tumors, including gliomas and may contribute to oncogenesis. In this chapter, we have (1) summarized the mechanisms of STAT activation in normal and malignant signaling; (2) discussed evidence for the critical role of constitutively activated STAT3 and STAT5 in glioma pathobiology; (3) disclosed molecular and pharmacological strategies to interfere with STAT signaling for potential therapeutic intervention in gliomas.

Machine learning identifies a core gene set predictive of acquired resistance to EGFR tyrosine kinase inhibitor

PURPOSE

Acquired resistance (AR) to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) is a major issue worldwide, for both patients and healthcare providers. However, precise prediction is currently infeasible due to the lack of an appropriate model. This study was conducted to develop and validate an individualized prediction model for automated detection of acquired EGFR-TKI resistance.

METHODS

Penalized regression was applied to construct a predictive model using publically available genomic cohorts of acquired EGFR-TKI resistance. To develop a model with enhanced generalizability, we merged multiple cohorts then updated the learning parameter via robust cross-study validation. Model performance was evaluated mainly using the area under the receiver operating characteristic curve.

RESULTS

Using a multi-study-derived machine learning method, we developed an extremely parsimonious model with generalized predictors (DDK3, CPS1, MOB3B, KRT6A), which has excellent prediction performance on blind cohorts for AR to EGFR-TKIs (gefitinib, erlotinib and afatinib) and monoclonal antibody against EGFR (cetuximab). In addition, our model also showed high performance for predicting intrinsic resistance (IR) to EGFR-TKIs from two large-scale pharmacogenomic resources, the Cancer Genome Project and the Cancer Cell Line Encyclopedia, suggesting that these general predictive features may work across AR and IR.

CONCLUSIONS

We successfully constructed a multi-study-derived prediction model for acquired EGFR-TKI resistance with excellent accuracy, generalizability and transferability.

Crosstalk between kinases, phosphatases and miRNAs in cancer

Reversible phosphorylation of proteins, performed by kinases and phosphatases, is the major post translational protein modification in eukaryotic cells. This intracellular event represents a critical regulatory mechanism of several signaling pathways and can be related to a vast array of diseases, including cancer. Cancer research has produced increasing evidence that kinase and phosphatase activity can be compromised by mutations and also by miRNA silencing, performed by small non-coding and endogenously produced RNA molecules that lead to translational repression. miRNAs are believed to target about one-third of human mRNAs while a single miRNA may target about 200 transcripts simultaneously. Regulation of the phosphorylation balance by miRNAs has been a topic of intense research over the last years, spanning topics going as far as cancer aggressiveness and chemotherapy resistance. By addressing recent studies that have shown miRNA expression patterns as phenotypic signatures of cancers and how miRNA influence cellular processes such as apoptosis, cell cycle control, angiogenesis, inflammation and DNA repair, we discuss how kinases, phosphatases and miRNAs cooperatively act in cancer biology.

T cell receptor-associated protein tyrosine kinases: the dynamics of tolerance regulation by phosphorylation and its role in systemic lupus erythematosus

There are different abnormalities that lead to the autoreactive phenotype in T cells from systemic lupus erythematosus (SLE) patients. Proximal signaling, involving the T-cell receptor (TCR) and its associated protein tyrosine kinases (PTKs), is significantly affected in SLE. This ultimately leads to aberrant responses, which include enhanced tyrosine phosphorylation and calcium release, as well as decreased IL-2 secretion. Lck, ZAP70 and Syk, which are PTKs with a major role in proximal signaling, all present abnormal functioning that contributes to an altered T cell response in these patients. A number of other molecules, especially regulatory proteins, are also involved. This review will focus on the PTKs that participate in proximal signaling, with specific emphasis on their relevance in maintaining peripheral tolerance, their abnormalities in SLE and how these contribute to an altered T cell response.

Tyrosine phosphorylation in Toll-like receptor signaling. Cytokine Growth Factor Rev. 2014;25:533-541. [PMID: 25022196 DOI: 10.1016/j.cytogfr.2014.06.002]

There is a wealth of knowledge about how different Ser/Thr protein kinases participate in Toll-like receptor (TLR) signaling. In many cases, we know the identities of the Ser/Thr residues of various components of the TLR-signaling pathways that are phosphorylated, the functional consequences of the phosphorylation and the responsible protein kinases. In contrast, the analysis of Tyr-phosphorylation of TLRs and their signaling proteins is currently incomplete, because several existing analyses are not systematic or they do not rely on robust experimental data. Nevertheless, it is clear that many TLRs require, for signaling, ligand-dependent phosphorylation of specific Tyr residues in their cytoplasmic domains; the list includes TLR2, TLR3, TLR4, TLR5, TLR8 and TLR9. In this article, we discuss the current status of knowledge of the effect of Tyr-phosphorylation of TLRs and their signaling proteins on their biochemical and biological functions, the possible identities of the relevant protein tyrosine kinases (PTKs) and the nature of regulations of PTK-mediated activation of TLR signaling pathways.

Design of the INPULSIS™ trials: two phase 3 trials of nintedanib in patients with idiopathic pulmonary fibrosis

BACKGROUND

Nintedanib is in clinical development as a treatment for idiopathic pulmonary fibrosis (IPF). Data from the Phase II TOMORROW study suggested that nintedanib 150 mg twice daily had clinical benefits with an acceptable safety profile.

METHODS

The INPULSIS™ trials are replicate Phase III, randomized, double-blind, studies comparing the efficacy and safety of nintedanib 150 mg twice daily with placebo in patients with IPF. Eligible patients were aged ≥40 years with a diagnosis of IPF within 5 years before randomization who had undergone a chest high-resolution computed tomography (HRCT) scan within 1-year before screening, and who had a forced vital capacity (FVC) of ≥50% predicted and a diffusing capacity for carbon monoxide of 30-79% predicted. Participants were randomized 3:2 to receive nintedanib or placebo for 52 weeks. The primary endpoint is the annual rate of decline in FVC. The key secondary endpoints are change from baseline in the total score on the St. George's Respiratory Questionnaire (a measure of health-related quality of life) over 52 weeks and time to first acute exacerbation.

RESULTS

Enrolment of 1066 patients in 24 countries was completed in September 2012. Results will be reported in the first half of 2014.

CONCLUSION

The INPULSIS™ trials will determine the efficacy of nintedanib in patients with IPF, including its impact on disease progression as defined by decline in FVC, acute exacerbations and health-related quality of life. In addition, they will characterise the adverse event profile of nintedanib in this patient population.

TRIAL REGISTRATION

Registered at ClinicalTrials.gov (identifiers: NCT01335464 and NCT01335477).

Tyrosine kinase inhibitory activity of dehydroabietylamine derivatives tested by homogeneous time-resolved fluorescence based high throughput screening model

Protein tyrosine kinases (PTKs) are attractive targets in searching for therapeutic agents against many diseases. In this study, a series of dehydroabietylamine derivatives were first determined to show PTK inhibitory activity using a high-throughput screening (HTS) method based on homogeneous time-resolved fluorescence (HTRF) technology. The structure-activity relationships of the dehydroabietylamine derivatives were established, and it was found that the compounds with a nitrogen-containing side chain had better inhibitory activity. Further studies showed that the compounds substituted with halogen in the phenyl ring resulted in higher inhibitory activity on the epidermal growth factor receptor (EGFR), and can be a guide to modify the structure of dehydroabietylamine derivatives. Dehydroabietylamine derivatives might be a new class of multi-targeted and effective PTK inhibitors with structure modifications.