168 research outputs found
Chronic myeloid leukemia cells require the bone morphogenic protein pathway for cell cycle progression and self-renewal
Leukaemic stem cell (LSC) persistence remains a major obstacle to curing chronic myeloid leukaemia (CML). The bone morphogenic protein (BMP) pathway is deregulated in CML, with altered expression and response to the BMP ligands shown to impact on LSC expansion and behaviour. In this study, we determined whether alterations in the BMP pathway gene signature had any predictive value for therapeutic response by profiling 60 CML samples at diagnosis from the UK SPIRIT2 trial and correlating the data to treatment response using the 18-month follow-up data. There was significant deregulation of several genes involved in the BMP pathway with ACV1C, INHBA, SMAD7, SNAIL1 and SMURF2 showing differential expression in relation to response. Therapeutic targeting of CML cells using BMP receptor inhibitors, in combination with tyrosine kinase inhibitor (TKI), indicate a synergistic mode of action. Furthermore, dual treatment resulted in altered cell cycle gene transcription and irreversible cell cycle arrest, along with increased apoptosis compared to single agents. Targeting CML CD34+ cells with BMP receptor inhibitors resulted in fewer cell divisions, reduced numbers of CD34+ cells and colony formation when compared to normal donor CD34+ cells, both in the presence and absence of BMP4. In an induced pluripotent stem cell (iPSC) model generated from CD34+ hematopoietic cells, we demonstrate altered cell cycle profiles and dynamics of ALK expression in CML-iPSCs in the presence and absence of BMP4 stimulation, when compared to normal iPSC. Moreover, dual targeting with TKI and BMP inhibitor prevented the self-renewal of CML-iPSC and increased meso-endodermal differentiation. These findings indicate that transformed stem cells may be more reliant on BMP signalling than normal stem cells. These changes offer a therapeutic window in CML, with intervention using BMP inhibitors in combination with TKI having the potential to target LSC self-renewal and improve long-term outcome for patients
Bone marrow niche crosses paths with BMPs: a road to protection and persistence in CML
Chronic myeloid leukaemia (CML) is a paradigm of precision medicine, being one of the first cancers to be treated with targeted therapy. This has revolutionised CML therapy and patient outcome, with high survival rates. However, this now means an ever-increasing number of patients are living with the disease on life-long tyrosine kinase inhibitor (TKI) therapy, with most patients anticipated to have near normal life expectancy. Unfortunately, in a significant number of patients, TKIs are not curative. This low-level disease persistence suggests that despite a molecularly targeted therapeutic approach, there are BCR-ABL1-independent mechanisms exploited to sustain the survival of a small cell population of leukaemic stem cells (LSCs). In CML, LSCs display many features akin to haemopoietic stem cells, namely quiescence, self-renewal and the ability to produce mature progeny, this all occurs through intrinsic and extrinsic signals within the specialised microenvironment of the bone marrow (BM) niche. One important avenue of investigation in CML is how the disease highjacks the BM, thereby remodelling this microenvironment to create a niche, which enables LSC persistence and resistance to TKI treatment. In this review, we explore how changes in growth factor levels, in particular, the bone morphogenetic proteins (BMPs) and pro-inflammatory cytokines, impact on cell behaviour, extracellular matrix deposition and bone remodelling in CML. We also discuss the challenges in targeting LSCs and the potential of dual targeting using combination therapies against BMP receptors and BCR-ABL1
Complexities of modelling the bone marrow microenvironment to facilitate haematopoietic research
Haematopoiesis occurs in the bone marrow (BM), within a specialised microenvironment referred to as the stem cell niche, where the haematopoietic stem cells (HSCs) reside and are regulated for quiescence, self-renewal and differentiation through intrinsic and extrinsic mechanisms. The BM contains at least two distinctive HSC supportive niches: an endosteal osteoblastic niche, which supports quiescence and self-renewal and a more vascular/peri-sinusoidal niche that promotes proliferation and differentiation. Both associate with supporting mesenchymal stromal cells (MSCs). Within the more hypoxic osteoblastic niche, HSCs specifically interact with the osteoblasts that line the endosteal surface, which secrete several important HSC quiescence and maintenance regulatory factors. In vivo imaging indicates that the HSCs and progenitors located further away, in the vicinity of sinusoidal endothelial cells, are more proliferative. Here HSCs interact with endothelial cells via specific cell adhesion molecules. Endothelial cells also secrete several factors important for HSC homeostasis and proliferation. In addition, HSCs and MSCs are embedded within the extracellular matrix (ECM), an important network of proteins such as collagen, elastin, laminin, proteoglycans, vitronectin and fibronectin. The ECM provides mechanical characteristics such as stiffness and elasticity important for cell behaviour regulation. ECM proteins are also able to bind, sequester, display and distribute growth factors across the BM, thus directly affecting stem cell fate and regulation of haematopoiesis. These important physical and chemical features of the BM require careful consideration when creating three dimensional models of the BM
Refractive Changes after Glaucoma Surgery-A Comparison between Trabeculectomy and XEN Microstent Implantation.
Best-corrected visual acuity often decreases temporarily or permanently after trabeculectomy (TE). The purpose of this study was to compare visual acuity and refractive changes after TE or XEN microstent implantation (XEN) in primary open-angle glaucoma (POAG) or pseudoexfoliation glaucoma (PEX) cases naïve to prior glaucoma surgery over a 24-month follow-up period. We analyzed 149 consecutive glaucoma patients who received either TE or XEN because of medically uncontrollable POAG or PEX. Intraocular pressure (IOP), IOP-lowering medication use, subjective and objective refraction and best-corrected visual acuity were evaluated. In addition, surgically induced astigmatism (SIA) was calculated and compared using the vector analysis method described by Jaffe and Clayman. A total of 93 eyes (85 POAG; 8 PEX) were treated with TE and 56 eyes (50 POAG; 6 PEX) with XEN. After 24 months, the mean IOP and number of IOP-lowering medications used decreased significantly after TE (p < 0.01) and XEN (p < 0.01). In the TE group, mean best-corrected visual acuity (BCVA) changed from 0.16 ± 0.26 to 0.23 ± 0.28 logMAR (p < 0.01) after 24 months, while mean BCVA did not change significantly in the XEN group (preoperative: 0.40 ± 0.50 logMAR, postoperative: 0.36 ± 0.49 logMAR; p = 0.28). SIA was almost the same in both groups at the end of the 24-month follow-up period (0.75 ± 0.60 diopters after TE and 0.81 ± 0.56 diopters after XEN; p = 0.57). In addition, there was no significant correlation between SIA and the observed BCVA changes or SIA and IOP reduction 12 or 24 months after TE or XEN. Our results demonstrate that TE and XEN are effective methods for reducing IOP and IOP-lowering medication use. The SIA was nearly similar in both groups. The SIA does not seem responsible for the decreased visual acuity after TE
Two Year Functional and Structural Changes-A Comparison between Trabeculectomy and XEN Microstent Implantation Using Spectral Domain Optical Coherence Tomography.
The aim of this study was to analyze retinal nerve fiber layer (RNFL) thickness after trabeculectomy (TE) versus XEN microstent implantation (XEN) in primary open-angle glaucoma (POAG) cases naïve to prior incisional glaucoma surgery. We examined 119 consecutive glaucoma patients retrospectively, who received a TE or XEN for medically uncontrolled POAG. Intraocular pressure (IOP), amount of IOP-lowering medication, mean deviation of standard automated perimetry and peripapillary RNFL thickness were evaluated during the first 24 months after surgery. Fifty eyes were treated with TE and 69 eyes with XEN. Mean IOP decreased from 25.1 ± 0.8 to 13.3 ± 0.6 mm Hg (p < 0.01) and mean number of IOP-lowering eye drops from 3.2 ± 0.2 to 0.4 ± 0.1 (p < 0.01) 24 months after TE. In 69 eyes undergoing XEN, mean IOP dropped from 24.8 ± 0.6 to 15.0 ± 0.4 mm Hg (p < 0.01) and medication from 3.0 ± 0.1 to 0.6 ± 0.1 (p < 0.01) during the 24 months follow-up. Mean deviation of standard automated perimetry remained stable in TE (8.5 ± 0.7 to 8.1 ± 0.8 dB; p = 0.54) and XEN group (11,0 ± 0.5 to 11.5 ± 0.5 dB; p = 0.12) after 24 months, while mean RNFL thickness further deteriorated in the TE (-2.28 ± 0.65 µm/year) and XEN (-0.68 ± 0.34 µm/year) group. Postoperative RNFL loss develops after TE and XEN despite effective and significant lowering of IOP and amount of IOP-lowering medication. RNFL loss was more pronounced in the first year after glaucoma surgery
Functional Monitoring after Trabeculectomy or XEN Microstent Implantation Using Spectral Domain Optical Coherence Tomography and Visual Field Indices—A Retrospective Comparative Cohort Study
The aim of this study was to compare the efficacy of trabeculectomy (TE), single XEN microstent implantation (solo XEN) or combined XEN implantation and cataract surgery (combined XEN) in primary open-angle glaucoma cases, naïve to prior surgical treatment, using a monocentric retrospective comparative cohort study. Intraocular pressure (IOP) and the number of IOP-lowering drugs (Meds) were monitored during the first 24 months after surgery. Further disease progression was monitored using peripapillary retinal nerve fiber layer (RNFL) thickness examinations using spectral domain optical coherence tomography (OCT) as well as visual acuity (VA) and visual field (VF) tests. In the TE group (52 eyes), the mean IOP decreased from 24.9 ± 5.9 to 13.9 ± 4.2 mmHg (p < 0.001) and Meds decreased from 3.2 ± 1.2 to 0.5 ± 1.1 (p < 0.001). In the solo XEN (38 eyes) and the combined XEN groups, the mean IOP decreased from 24.1 ± 4.7 to 15.7 ± 3.0 mmHg (p < 0.001) and 25.4 ± 5.6 to 14.7 ± 3.2 mmHg (p < 0.001), while Meds decreased from 3.3 ± 0.8 to 0.8 ± 1.2 (p < 0.001) and 2.7 ± 1.2 to 0.4 ± 1.0 (p < 0.001), respectively. The VF and VA indices showed no sign of further deterioration, the RNFL thickness further decreased in all treatment groups after surgery. TE and XEN led to comparable reductions in IOP and Meds. Although the VA and VF indices remained unaltered, the RNFL thickness continuously decreased in all treatment groups during the 24-month follow-up
Fatigue, quality of life and metabolic changes in men treated with first-line enzalutamide versus abiraterone plus prednisolone for metastatic castration-resistant prostate cancer (HEAT):A randomised trial protocol
Effect of Trans-Nasal Evaporative Intra-arrest Cooling on Functional Neurologic Outcome in Out-of-Hospital Cardiac Arrest : The PRINCESS Randomized Clinical Trial
© 2019 American Medical Association. All rights reserved.Importance: Therapeutic hypothermia may increase survival with good neurologic outcome after cardiac arrest. Trans-nasal evaporative cooling is a method used to induce cooling, primarily of the brain, during cardiopulmonary resuscitation (ie, intra-arrest). Objective: To determine whether prehospital trans-nasal evaporative intra-arrest cooling improves survival with good neurologic outcome compared with cooling initiated after hospital arrival. Design, Setting, and Participants: The PRINCESS trial was an investigator-initiated, randomized, clinical, international multicenter study with blinded assessment of the outcome, performed by emergency medical services in 7 European countries from July 2010 to January 2018, with final follow-up on April 29, 2018. In total, 677 patients with bystander-witnessed out-of-hospital cardiac arrest were enrolled. Interventions: Patients were randomly assigned to receive trans-nasal evaporative intra-arrest cooling (n = 343) or standard care (n = 334). Patients admitted to the hospital in both groups received systemic therapeutic hypothermia at 32°C to 34°C for 24 hours. Main Outcomes and Measures: The primary outcome was survival with good neurologic outcome, defined as Cerebral Performance Category (CPC) 1-2, at 90 days. Secondary outcomes were survival at 90 days and time to reach core body temperature less than 34°C. Results: Among the 677 randomized patients (median age, 65 years; 172 [25%] women), 671 completed the trial. Median time to core temperature less than 34°C was 105 minutes in the intervention group vs 182 minutes in the control group (P < .001). The number of patients with CPC 1-2 at 90 days was 56 of 337 (16.6%) in the intervention cooling group vs 45 of 334 (13.5%) in the control group (difference, 3.1% [95% CI, -2.3% to 8.5%]; relative risk [RR], 1.23 [95% CI, 0.86-1.72]; P = .25). In the intervention group, 60 of 337 patients (17.8%) were alive at 90 days vs 52 of 334 (15.6%) in the control group (difference, 2.2% [95% CI, -3.4% to 7.9%]; RR, 1.14 [95% CI, 0.81-1.57]; P = .44). Minor nosebleed was the most common device-related adverse event, reported in 45 of 337 patients (13%) in the intervention group. The adverse event rate within 7 days was similar between groups. Conclusions and Relevance: Among patients with out-of-hospital cardiac arrest, trans-nasal evaporative intra-arrest cooling compared with usual care did not result in a statistically significant improvement in survival with good neurologic outcome at 90 days. Trial Registration: ClinicalTrials.gov Identifier: NCT01400373.Peer reviewedFinal Accepted Versio
Comparative Microbiome and Metabolome Analyses of the Marine Tunicate Ciona intestinalis from Native and Invaded Habitats
Massive fouling by the invasive ascidian Ciona intestinalis in Prince Edward Island (PEI, Canada) has been causing devastating losses to the local blue mussel farms. In order to gain first insights into so far unexplored factors that may contribute to the invasiveness of C. intestinalis in PEI, we undertook comparative microbiome and metabolome studies on specific tissues from C. intestinalis populations collected in invaded (PEI) and native regions (Helgoland and Kiel, Germany). Microbial community analyses and untargeted metabolomics revealed clear location- and tissue-specific patterns showing that biogeography and the sampled tissue shape the microbiome and metabolome of C. intestinalis. Moreover, we observed higher microbial and chemical diversity in C. intestinalis from PEI than in the native populations. Bacterial OTUs specific to C. intestinalis from PEI included Cyanobacteria (e.g., Leptolyngbya sp.) and Rhodobacteraceae (e.g., Roseobacter sp.), while populations from native sampling sites showed higher abundances of e.g., Firmicutes (Helgoland) and Epsilonproteobacteria (Kiel). Altogether 121 abundant metabolites were putatively annotated in the global ascidian metabolome, of which 18 were only detected in the invasive PEI population (e.g., polyketides and terpenoids), while six (e.g., sphingolipids) or none were exclusive to the native specimens from Helgoland and Kiel, respectively. Some identified bacteria and metabolites reportedly possess bioactive properties (e.g., antifouling and antibiotic) that may contribute to the overall fitness of C. intestinalis. Hence, this first study provides a basis for future studies on factors underlying the global invasiveness of Ciona species
ERNST: Demonstrating Advanced Infrared Detection from a 12U CubeSat
The ERNST mission will demonstrate complex infrared detection capabilities using a 12U CubeSat platform. ERNST’s main payload is an advanced cryogenically-cooled infrared imager that implicates demanding requirements in terms of power demand, heat dissipation, and vibration response for a nanosatellite. The optical bench that integrates optics, a filter-wheel for switching between spectral bands, and the detector-cooler system has been additively designed and manufactured, giving it a bionic appearance and combined with a highly efficient radiator. An onboard radiation monitor and a COTS camera complete the mission payloads. The ERNST 12U platform is based on high-performance CubeSat subsystems for avionics, UHF, and X-band communication, attitude control, and power management. The commercial components are made compatible through a backplane solution. In-house developments include a fast DPU and an autonomous de-orbit dragsail. The platform provides 30 Watt (OAP) and \u3e6U payload volume. After comprehensive environmental and functional testing of the Engineering Model, the Flight Model is currently being integrated. Starting operations in February 2023, ERNST will verify early warning concepts and technology
- …