-
Neurobiology of Disease Feb 2018Status epilepticus (SE) induces neuroinflammation and epileptogenesis, but the mechanisms are not yet fully delineated. The Fyn, a non-receptor Src family tyrosine...
Status epilepticus (SE) induces neuroinflammation and epileptogenesis, but the mechanisms are not yet fully delineated. The Fyn, a non-receptor Src family tyrosine kinase (SFK), and its immediate downstream target, PKCδ are emerging as potential mediators of neuroinflammation. In order to first determine the role of Fyn kinase signaling in SE, we tested the efficacy of a SFK inhibitor, saracatinib (25mg/kg, oral) in C57BL/6J mouse kainate model of acute seizures. Saracatinib pretreatment dampened SE severity and completely prevented mortality. We further utilized fyn and fyn mice (wildtype control for the fyn mice on same genetic background), and the rat kainate model, treated with saracatinib post-SE, to validate the role of Fyn/SFK in SE and epileptogenesis. We observed significant reduction in SE severity, epileptiform spikes, and electrographic non-convulsive seizures in fyn mice when compared to fyn mice. Interestingly, significant reductions in phosphorylated pSrc-416 and PKCδ (pPKCδ-507) and naive PKCδ were observed in fyn mice as compared to fyn mice suggesting that PKCδ signaling is a downstream mediator of Fyn in SE and epileptogenesis. Notably, fyn mice also showed a reduction in key proinflammatory mediators TNF-α, IL-1β, and iNOS mRNA expression; serum IL-6 and IL-12 levels; and nitro-oxidative stress markers such as 4-HNE, gp91, and 3-NT in the hippocampus. Immunohistochemistry revealed a significant increase in reactive microgliosis and neurodegeneration in the hippocampus and hilus of dentate gyrus in fyn mice in contrast to fyn mice. Interestingly, we did not observe upregulation of Fyn in pyramidal neurons of the hippocampus during post-SE in fyn mice, but it was upregulated in hilar neurons of the dentate gyrus when compared to naïve control. In reactive microglia, both Fyn and PKCδ were persistently upregulated during post-SE suggesting that Fyn-PKCδ may drive neuroinflammation during epileptogenesis. Since disabling the Fyn kinase prior to SE, either by treating with saracatinib or fyn gene knockout, suppressed seizures and the subsequent epileptogenic events, we further tested whether Fyn/SFK inhibition during post-SE modifies epileptogenesis. Telemetry-implanted, SE-induced, rats were treated with saracatinib and continuously monitored for a month. At 2h post-diazepam, the saracatinib (25mg/kg) or the vehicle was administered orally and repeated twice daily for first three days followed by a single dose/day for the next four days. The saracatinib post-treatment prevented epileptogenesis in >50% of the rats and significantly reduced spontaneous seizures and epileptiform spikes in the rest (one animal did not respond) when compared to the vehicle treated group, which had >24 seizures in a month. Collectively, the findings suggest that Fyn/SFK is a potential mediator of epileptogenesis and a therapeutic target to prevent/treat seizures and epileptogenesis.
Topics: Animals; Benzodioxoles; Disease Models, Animal; Enzyme Inhibitors; Epilepsy, Temporal Lobe; Inflammation; Mice; Mice, Inbred C57BL; Mice, Knockout; Protein Kinase C-delta; Proto-Oncogene Proteins c-fyn; Quinazolines; Rats; Rats, Sprague-Dawley; Signal Transduction; Status Epilepticus
PubMed: 29197620
DOI: 10.1016/j.nbd.2017.11.008 -
EMBO Reports Jul 2020Parkinson's disease (PD) is characterized by the loss of dopaminergic neurons located in the substantia nigra pars compacta and the presence of proteinaceous inclusions...
Parkinson's disease (PD) is characterized by the loss of dopaminergic neurons located in the substantia nigra pars compacta and the presence of proteinaceous inclusions called Lewy bodies and Lewy neurites in numerous brain regions. Increasing evidence indicates that Lewy pathology progressively involves additional regions of the nervous system as the disease advances, and the prion-like propagation of α-synuclein (α-syn) pathology promotes PD progression. Accordingly, the modulation of α-syn transmission may be important for the development of disease-modifying therapies in patients with PD. Here, we demonstrate that α-syn fibrils induce c-src activation in neurons, which depends on the FcγRIIb-SHP-1/-2-c-src pathway and enhances signals for the uptake of α-syn into neurons. Blockade of c-src activation inhibits the uptake of α-syn and the formation of Lewy body-like inclusions. Furthermore, the blockade of c-src activation also inhibits the release of α-syn via activation of autophagy. The brain-permeable c-src inhibitor, saracatinib, efficiently reduces α-syn propagation into neighboring regions in an in vivo model system. These results suggest a new therapeutic target against progressive PD.
Topics: Brain; Dopaminergic Neurons; Humans; Lewy Bodies; Parkinson Disease; alpha-Synuclein
PubMed: 32372484
DOI: 10.15252/embr.201948950 -
EBioMedicine Dec 2022Niemann-Pick disease type C (NPC) is a rare prematurely fatal lysosomal lipid storage disease with limited therapeutic options. The prominent neuropathological hallmarks...
BACKGROUND
Niemann-Pick disease type C (NPC) is a rare prematurely fatal lysosomal lipid storage disease with limited therapeutic options. The prominent neuropathological hallmarks include hypomyelination and cerebellar atrophy. We previously demonstrated the efficacy of recombinant human heat shock protein 70 (rhHSP70) in preclinical models of the disease. It reduced glycosphingolipid levels in the central nervous system (CNS), improving cerebellar myelination and improved behavioural phenotypes in Npc1 (Npc1) mice. Furthermore, treatment with arimoclomol, a well-characterised HSP amplifier, attenuated lysosomal storage in NPC patient fibroblasts and improved neurological symptoms in Npc1 mice. Taken together, these findings prompted the investigation of the effects of HSP amplification on CNS myelination.
METHODS
We administered bimoclomol daily or rhHSP70 6 times per week to Npc1 (BALB/cNctr-Npc1/J, also named Npc1) mice by intraperitoneal injection from P7 through P34 to investigate the impact on CNS myelination. The Src-kinase inhibitor saracatinib was administered with/without bimoclomol twice daily to explore the contribution of Fyn kinase to bimoclomol's effects.
FINDINGS
Treatment with either bimoclomol or rhHSP70 improved myelination and increased the numbers of mature oligodendrocytes (OLs) as well as the ratio of active-to-inactive forms of phosphorylated Fyn kinase in the cerebellum of Npc1 mice. Additionally, treatment with bimoclomol preserved cerebellar weight, an effect that was abrogated when co-administered with saracatinib, an inhibitor of Fyn kinase. Bimoclomol-treated mice also exhibited increased numbers of immature OLs within the cortex.
INTERPRETATION
These data increase our understanding of the mechanisms by which HSP70 regulates myelination and provide further support for the clinical development of HSP-amplifying therapies in the treatment of NPC.
FUNDING
Funding for this study was provided by Orphazyme A/S (Copenhagen, Denmark) and a Pathfinder Award from The Wellcome Trust.
Topics: Animals; Humans; Mice; Cerebellum; Disease Models, Animal; Heat-Shock Proteins; Mice, Inbred BALB C; Niemann-Pick C1 Protein; Niemann-Pick Disease, Type C; Pyridines; HSP70 Heat-Shock Proteins; Nerve Fibers, Myelinated; Myelin Sheath
PubMed: 36455410
DOI: 10.1016/j.ebiom.2022.104374 -
The Journal of Experimental Medicine Sep 2017Effective targeting of cancer stem cells (CSCs) requires neutralization of self-renewal and chemoresistance, but these phenotypes are often regulated by distinct...
Effective targeting of cancer stem cells (CSCs) requires neutralization of self-renewal and chemoresistance, but these phenotypes are often regulated by distinct molecular mechanisms. Here we report the ability to target both of these phenotypes via CD55, an intrinsic cell surface complement inhibitor, which was identified in a comparative analysis between CSCs and non-CSCs in endometrioid cancer models. In this context, CD55 functions in a complement-independent manner and required lipid raft localization for CSC maintenance and cisplatin resistance. CD55 regulated self-renewal and core pluripotency genes via ROR2/JNK signaling and in parallel cisplatin resistance via lymphocyte-specific protein tyrosine kinase (LCK) signaling, which induced DNA repair genes. Targeting LCK signaling via saracatinib, an inhibitor currently undergoing clinical evaluation, sensitized chemoresistant cells to cisplatin. Collectively, our findings identify CD55 as a unique signaling node that drives self-renewal and therapeutic resistance through a bifurcating signaling axis and provides an opportunity to target both signaling pathways in endometrioid tumors.
Topics: Animals; Antineoplastic Agents; CD55 Antigens; Cell Line, Tumor; Cell Self Renewal; Cisplatin; Drug Resistance, Neoplasm; Endometrial Neoplasms; Female; Mice; Mice, SCID; Neoplasm Transplantation; Neoplastic Stem Cells; Signal Transduction
PubMed: 28838952
DOI: 10.1084/jem.20170438 -
Antioxidants (Basel, Switzerland) Dec 2021Diisopropylfluorophosphate (DFP), an organophosphate nerve agent (OPNA), exposure causes status epilepticus (SE) and epileptogenesis. In this study, we tested the...
Saracatinib, a Src Tyrosine Kinase Inhibitor, as a Disease Modifier in the Rat DFP Model: Sex Differences, Neurobehavior, Gliosis, Neurodegeneration, and Nitro-Oxidative Stress.
Diisopropylfluorophosphate (DFP), an organophosphate nerve agent (OPNA), exposure causes status epilepticus (SE) and epileptogenesis. In this study, we tested the protective effects of saracatinib (AZD0530), a Src kinase inhibitor, in mixed-sex or male-only Sprague Dawley rats exposed to 4-5 mg/kg DFP followed by 2 mg/kg atropine and 25 mg/kg 2-pralidoxime. Midazolam (3 mg/kg) was given to the mixed-sex cohort (1 h post-DFP) and male-only cohort (~30 min post-DFP). Saracatinib (20 mg/kg, oral, daily for 7 days) or vehicle was given two hours later and euthanized eight days or ten weeks post-DFP. Brain immunohistochemistry (IHC) showed increased microgliosis, astrogliosis, and neurodegeneration in DFP-treated animals. In the 10-week post-DFP male-only group, there were no significant differences between groups in the novel object recognition, Morris water maze, rotarod, or forced swim test. Brain IHC revealed significant mitigation by saracatinib in contrast to vehicle-treated DFP animals in microgliosis, astrogliosis, neurodegeneration, and nitro-oxidative stressors, such as inducible nitric oxide synthase, GP91, and 3-Nitrotyrosine. These findings suggest the protective effects of saracatinib on brain pathology seem to depend on the initial SE severity. Further studies on dose optimization, including extended treatment regimen depending on the SE severity, are required to determine its disease-modifying potential in OPNA models.
PubMed: 35052568
DOI: 10.3390/antiox11010061 -
BMC Musculoskeletal Disorders Jun 2022Fibrodysplasia Ossificans Progressiva (FOP) is a genetic, progressive and devastating disease characterized by severe heterotopic ossification (HO), loss of mobility and...
Protocol paper: a multi-center, double-blinded, randomized, 6-month, placebo-controlled study followed by 12-month open label extension to evaluate the safety and efficacy of Saracatinib in Fibrodysplasia Ossificans Progressiva (STOPFOP).
BACKGROUND
Fibrodysplasia Ossificans Progressiva (FOP) is a genetic, progressive and devastating disease characterized by severe heterotopic ossification (HO), loss of mobility and early death. There are no FDA approved medications. The STOPFOP team identified AZD0530 (saracatinib) as a potent inhibitor of the ALK2/ACVR1-kinase which is the causative gene for this rare bone disease. AZD0530 was proven to prevent HO formation in FOP mouse models. The STOPFOP trial investigates the repositioning of AZD0530, originally developed for ovarian cancer treatment, to treat patients with FOP.
METHODS
The STOPFOP trial is a phase 2a study. It is designed as a European, multicentre, 6-month double blind randomized controlled trial of AZD0530 versus placebo, followed by a 12-month trial comparing open-label extended AZD0530 treatment with natural history data as a control. Enrollment will include 20 FOP patients, aged 18-65 years, with the classic FOP mutation (ALK2 R206H). The primary endpoint is objective change in heterotopic bone volume measured by low-dose whole-body computer tomography (CT) in the RCT phase. Secondary endpoints include F NaF PET activity and patient reported outcome measures.
DISCUSSION
Clinical trials in rare diseases with limited study populations pose unique challenges. An ideal solution for limiting risks in early clinical studies is drug repositioning - using existing clinical molecules for new disease indications. Using existing assets may also allow a more fluid transition into clinical practice. With positive study outcome, AZD0530 may provide a therapy for FOP that can be rapidly progressed due to the availability of existing safety data from 28 registered clinical trials with AZD0530 involving over 600 patients.
TRIAL REGISTRATION
EudraCT, 2019-003324-20. Registered 16 October 2019, https://www.clinicaltrialsregister.eu/ctr-search/trial/2019-003324-20/NL .
CLINICALTRIALS
gov , NCT04307953 . Registered 13 March 2020.
Topics: Adolescent; Adult; Aged; Benzodioxoles; Double-Blind Method; Humans; Middle Aged; Multicenter Studies as Topic; Mutation; Myositis Ossificans; Ossification, Heterotopic; Quinazolines; Randomized Controlled Trials as Topic; Young Adult
PubMed: 35650602
DOI: 10.1186/s12891-022-05471-x -
Annals of Oncology : Official Journal... May 2016Preclinical work suggests SRC proteins have a role in the development of resistance to vascular endothelial growth factor (VEGF) targeted therapy in metastatic... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Preclinical work suggests SRC proteins have a role in the development of resistance to vascular endothelial growth factor (VEGF) targeted therapy in metastatic clear-cell renal cancer (mRCC). This hypothesis was tested in this trial using the SRC inhibitor saracatinib and the VEGF inhibitor cediranib.
PATIENTS AND METHODS
Patients with disease progression after ≥1 VEGF-targeted therapy were eligible to participate in this double-blind, randomized (1:1) phase II study. The study compared the combination cediranib 30 mg once daily (o.d.) and saracatinib 175 mg o.d. (CS) (n = 69) or cediranib 45 mg o.d. and placebo o.d. (C) (n = 69). Archived tissue was used for biomarker analysis [SRC, focal adhesion kinase (FAK), von Hippel-Lindau, protein tyrosine phosphatase 1b and hypoxia-inducible factor 2α : n = 86]. The primary end point was progression-free survival (PFS) by RECIST v1.1.
RESULTS
Between 2010 and 2012, 138 patients were randomized across 16 UK sites. The characteristics of the two groups were well balanced. Partial responses were seen in 13.0% for C and 14.5% for CS (P > 0.05). There was no significant difference in PFS [5.4 months (3.6-7.3 months) for C and 3.9 (2.4-5.3 months) for CS; hazard ratio (HR) 1.18 (0.94-1.48)] or overall survival (OS) [14.2 months (11.2-16.8 months) for C and 10.0 (6.7-13.2 months) for CS; HR 1.28 (1.00-1.63)]. There was no significant difference in the frequency of key adverse events, dose reductions or drug discontinuations. None of the biomarkers were prognostic for PFS or OS. FAK overexpression correlated with an OS benefit [HR 2.29 (1.09-4.82), P > 0.05], but not PFS, for CS.
CONCLUSIONS
Saracatinib did not increase the efficacy of a VEGF-targeted therapy (cediranib) in this setting. Biomarker analysis did not identify consistent predictive biomarkers.
CLINICALTRIALSGOV
NCT00942877.
Topics: Aged; Benzodioxoles; Biomarkers, Tumor; Carcinoma, Renal Cell; Disease-Free Survival; Double-Blind Method; Female; Humans; Male; Middle Aged; Neoplasm Metastasis; Prognosis; Proportional Hazards Models; Quinazolines; Vascular Endothelial Growth Factor A
PubMed: 26802156
DOI: 10.1093/annonc/mdw014 -
American Journal of Respiratory Cell... May 2020Enhanced expression of the cellular antioxidant glutathione peroxidase (GPX)-1 prevents cigarette smoke-induced lung inflammation and tissue destruction. Subjects with...
Enhanced expression of the cellular antioxidant glutathione peroxidase (GPX)-1 prevents cigarette smoke-induced lung inflammation and tissue destruction. Subjects with chronic obstructive pulmonary disease (COPD), however, have decreased airway GPX-1 levels, rendering them more susceptible to disease onset and progression. The mechanisms that downregulate GPX-1 in the airway epithelium in COPD remain unknown. To ascertain these factors, analyses were conducted using human airway epithelial cells isolated from healthy subjects and human subjects with COPD and lung tissue from control and cigarette smoke-exposed A/J mice. Tyrosine phosphorylation modifies GPX-1 expression and cigarette smoke activates the tyrosine kinase c-Src. Therefore, studies were conducted to evaluate the role of c-Src on GPX-1 levels in COPD. These studies identified accelerated mRNA decay in COPD airway epithelial cells. Targeting the tyrosine kinase c-Src with siRNA inhibited mRNA degradation and restored GPX-1 protein levels in human airway epithelial cells. In contrast, silencing the tyrosine kinase c-Abl, or the transcriptional activator Nrf2, had no effect on mRNA stability. The chemical inhibitors for c-Src (saracatinib and dasanitib) restored mRNA levels and GPX-1 activity in COPD airway cells . Similarly, saracatinib prevented the loss of lung Gpx-1 expression in response to chronic smoke exposure . Thus, this study establishes that the decreased GPX-1 expression that occurs in COPD lungs is at least partially due to accelerated mRNA decay. Furthermore, these findings show that targeting c-Src represents a potential therapeutic approach to augment GPX-1 responses and counter smoke-induced lung disease.
Topics: Animals; Benzodioxoles; Enzyme Activation; Epithelial Cells; Epithelium; Female; Gene Expression Regulation; Glutathione Peroxidase; Humans; Lung; Male; Mice; Proto-Oncogene Proteins pp60(c-src); Pulmonary Disease, Chronic Obstructive; Quinazolines; RNA Stability; Smoking; Glutathione Peroxidase GPX1
PubMed: 31801023
DOI: 10.1165/rcmb.2019-0177OC -
JCI Insight Sep 2021GPCRs are highly desirable drug targets for human disease. Although GPCR dysfunction drives development and progression of many tumors, including breast cancer (BC),...
GPCRs are highly desirable drug targets for human disease. Although GPCR dysfunction drives development and progression of many tumors, including breast cancer (BC), targeting individual GPCRs has limited efficacy as a cancer therapy because numerous GPCRs are activated. Here, we sought a new way of blocking GPCR activation in HER2+ BC by targeting a subgroup of GPCRs that couple to Gi/o proteins (Gi/o-GPCRs). In mammary epithelial cells of transgenic mouse models, and BC cell lines, HER2 hyperactivation altered GPCR expression, particularly, Gi/o-GPCR expression. Gi/o-GPCR stimulation transactivated EGFR and HER2 and activated the PI3K/AKT and Src pathways. If we uncoupled Gi/o-GPCRs from their cognate Gi/o proteins by pertussis toxin (PTx), then BC cell proliferation and migration was inhibited in vitro and HER2-driven tumor formation and metastasis were suppressed in vivo. Moreover, targeting Gi/o-GPCR signaling via PTx, PI3K, or Src inhibitors enhanced HER2-targeted therapy. These results indicate that, in BC cells, HER2 hyperactivation drives aberrant Gi/o-GPCR signaling and Gi/o-GPCR signals converge on the PI3K/AKT and Src signaling pathways to promote cancer progression and resistance to HER2-targeted therapy. Our findings point to a way to pharmacologically deactivate GPCR signaling to block tumor growth and enhance therapeutic efficacy.
Topics: Animals; Antineoplastic Agents, Immunological; Benzodioxoles; Breast Neoplasms; Cell Line, Tumor; Cell Movement; Cell Proliferation; Drug Synergism; Epithelium; ErbB Receptors; Female; Humans; Indazoles; Lapatinib; Mammary Glands, Animal; Mice, Transgenic; Neoplasm Metastasis; Pertussis Toxin; Phosphoinositide-3 Kinase Inhibitors; Quinazolines; Receptor, ErbB-2; Receptors, G-Protein-Coupled; Signal Transduction; Sulfonamides; Trastuzumab; Up-Regulation
PubMed: 34343132
DOI: 10.1172/jci.insight.150532 -
Discover Oncology Dec 2022Bladder cancer (BCa) is one of the most common malignant tumors in the urogenital system, characterized by the high recurrence rate, mortality rate and poor prognosis....
PURPOSE
Bladder cancer (BCa) is one of the most common malignant tumors in the urogenital system, characterized by the high recurrence rate, mortality rate and poor prognosis. Based on cuproptosis-related long noncoding RNAs (CRLs), this study set out to create a prediction signature to evaluate the prognosis of patients with BCa.
METHODS
RNA-seq data including CRLs and related clinicopathological data were gathered from The Cancer Genome Atlas (TCGA) database (n = 428). The predictive signature was constructed after correlation analysis. Subsequently, relying on the analyzed data from the TCGA database and our sample collection, we examined and verified the connections between CRLs model and important indexes included prognosis, route and functional enrichment, tumor immune evasion, tumor mutation, and treatment sensitivity.
RESULTS
Patients in the high-risk group had lower overall survival (OS) than that of low-risk group. Compared with clinicopathological variables, CRLs features have better predictive value according to receiver operating characteristic (ROC) curve. The expression level of CRLs was highly associated with the tumor progress, tumor microenvironment and tumor immune escape. Additionally, we identified that the mutation of TP53, TTN, KMT2D and MUC16 gene were founded in patients with BCa. Lapatinib, pazopanib, saracatinib, gemcitabine, paclitaxel and palenolactone had good antitumor effects for BCa patients in the high-risk group (all P < 0.001).
CONCLUSION
This study revealed the effects of CRLs on BCa and further established CRLs model, which can be used in clinic for predicting prognosis, immunological response and treatment sensitivity inpatient with BCa.
PubMed: 36454396
DOI: 10.1007/s12672-022-00596-w