40 research outputs found

    5-alpha-reductase type I (SRD5A1) is up-regulated in non-small cell lung cancer but does not impact proliferation, cell cycle distribution or apoptosis

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    <p>Abstract</p> <p>Background</p> <p>Non-small cell lung cancer (NSCLC) is one of the most frequent malignancies and has a high mortality rate due to late detection and lack of efficient treatments. Identifying novel drug targets for this indication may open the way for new treatment strategies. Comparison of gene expression profiles of NSCLC and normal adjacent tissue (NAT) allowed to determine that 5-alpha-reductase type I (SRD5A1) was up-regulated in NSCLC compared to NAT. This raised the question whether SRD5A1 was involved in sustained proliferation and survival of NSCLC.</p> <p>Methods</p> <p>siRNA-mediated silencing of SRD5A1 was performed in A549 and NCI-H460 lung cancer cell lines in order to determine the impact on proliferation, on distribution during the different phases of the cell cycle, and on apoptosis/necrosis. In addition, lung cancer cell lines were treated with 4-azasteroids, which specifically inhibit SRD5A1 activity, and the effects on proliferation were measured. Statistical analyses using ANOVA and post-hoc Tamhane-T2-test were performed. In the case of non-parametric data, the Kruskal-Wallis test and the post-hoc Mann-Whitney-U-test were used.</p> <p>Results</p> <p>The knock-down of SRDA51 expression was very efficient with the SRD5A1 transcripts being reduced to 10% of control levels. Knock-down efficiency was furthermore confirmed at the protein level. However, no effect of SRD5A1 silencing was observed in the proliferation assay, the cell cycle analysis, and the apoptosis/necrosis assay. Treatment of lung cancer cell lines with 4-azasteroids did not significantly inhibit proliferation.</p> <p>Conclusions</p> <p>In summary, the results suggest that SRD5A1 is not a crucial enzyme for the sustained proliferation of NSCLC cell lines.</p

    Comprehensive Analyses of Coagulation Parameters in Patients with Vascular Anomalies.

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    BACKGROUND Vascular anomalies comprise a diverse group of rare diseases with altered blood flow and are often associated with coagulation disorders. The most common example is a localized intravascular coagulopathy in venous malformations leading to elevated D-dimers. In severe cases, this may progress to a disseminated intravascular coagulopathy with subsequent consumption of fibrinogen and thrombocytes predisposing to serious bleeding. A separate coagulopathy is the Kasabach-Merritt phenomenon in kaposiform hemangioendothelioma characterized by platelet trapping leading to thrombocytopenia and eventually consumptive coagulopathy. Our previous work showed impaired von Willebrand factor and platelet aggregometry due to abnormal blood flow, i.e., in ventricular assist devices or extracorporeal membrane oxygenation. With altered blood flow also present in vascular anomalies, we hypothesized that, in particular, the von Willebrand factor parameters and the platelet function may be similarly impacted. METHODS We prospectively recruited 73 patients with different vascular anomaly entities and analyzed their coagulation parameters. RESULTS Acquired von Willebrand syndrome was observed in both of our patients with Kasabach-Merritt phenomenon. In six out of nine patients with complex lymphatic anomalies, both the vWF antigen and activity were upregulated. Platelet aggregometry was impaired in both patients with Kasabach-Merritt phenomenon and in seven out of eight patients with an arteriovenous malformation. CONCLUSIONS The analysis of coagulation parameters in our patients with vascular anomalies advanced our understanding of the underlying pathophysiologies of the observed coagulopathies. This may lead to new treatment options for the, in part, life-threatening bleeding risks in these patients in the future

    The VASCERN-VASCA working group diagnostic and management pathways for severe and/or rare infantile hemangiomas

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    The European Reference Network on Rare Multisystemic Vascular Diseases (VASCERN), is dedicated to gathering the best expertise in Europe and provide accessible cross-border healthcare to patients with rare vascular dis-eases. Infantile Hemangiomas (IH) are benign vascular tumors of infancy that rapidly growth in the first weeks of life, followed by stabilization and spontaneous regression. In rare cases the extent, the localization or the number of lesions may cause severe complications that need specific and careful management. Severe IH may be life-threatening due to airway obstruction, liver or cardiac failure or may harbor a risk of functional impairment, severe pain, and/or significant and permanent disfigurement. Rare IHs include syndromic variants associated with extracutaneous abnormalities (PHACE and LUMBAR syndromes), and large segmental hemangiomas. There are publications that focus on evidence-based medicine on propranolol treatment for IH and consensus state -ments on the management of rare infantile hemangiomas mostly focused on PHACES syndrome. The Vascular Anomalies Working Group (VASCA-WG) decided to develop a diagnostic and management pathway for severe and rare IHs with a Nominal Group Technique (NGT), a well-established, structured, multistep, facilitated group meeting technique used to generate consensus statements. The pathway was drawn following two face-to-facePeer reviewe

    The VASCERN-VASCA working group diagnostic and management pathways for lymphatic malformations

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    Lymphatic malformations (LMs) are developmental defects of lymphatic vessels. LMs are histologically benign lesions, however, due to localization, size, and unexpected swelling, they may cause serious complications that threaten vital functions such as compression of the airways. A large swelling of the face or neck may also be disfiguring and thus constitute a psychological strain for patients and their families. LMs are also highly immunologically reactive, and are prone to recurrent infections and inflammation causing pain as well as chronic oozing wounds.The European Reference Network on Rare Multisystemic Vascular Diseases (VASCERN) is dedicated to gathering the best expertise in Europe. There are only few available guidelines on management and follow up of LMs, which commonly focus on very specific situations, such as head and neck LM (Zhou et al., 2011). It is still unclear, what constitutes an indication for treatment of LMs and how to follow up the patients. The Vascular Anomalies Working Group (VASCA-WG) of VASCERN decided to develop a diagnostic and management pathway for the management of LMs with a Nominal Group Technique (NGT), a well-established, structured, multistep, facilitated group meeting technique used to generate consensus statements. The pathway was drawn following 2 face-to-face meetings and multiple web meetings to facilitate discussion, and by mail to avoid the influence of most authoritative members.The VASCA-WG has produced this opinion statement reflecting strategies developed by experts and patient representatives on how to approach patients with lymphatic malformations in a practical manner; we present an algorithmic view of the results of our work.Peer reviewe

    The VASCERN-VASCA Working Group Diagnostic and Management Pathways for Venous Malformations.

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    UNLABELLED To elaborate expert consensus patient pathways to guide patients and physicians toward efficient diagnostics and management of patients with venous malformations. METHODS VASCERN-VASCA (https://vascern.eu/) is a European network of multidisciplinary centers for Vascular Anomalies. The Nominal Group Technique was used to establish the pathways. Two facilitators were identified: one to propose initial discussion points and draw the pathways, and another to chair the discussion. A dermatologist (AD) was chosen as first facilitator due to her specific clinical and research experience. The draft was subsequently discussed within VASCERN-VASCA monthly virtual meetings and annual face-to-face meetings. RESULTS The Pathway starts from the clinical suspicion of a venous type malformation (VM) and lists the clinical characteristics to look for to support this suspicion. Strategies for subsequent imaging and histopathology are suggested. These aim to inform on the diagnosis and to separate the patients into 4 subtypes: (1) sporadic single VMs or (2) multifocal, (3) familial, multifocal, and (4) combined and/or syndromic VMs. The management of each type is detailed in subsequent pages of the pathway, which are color coded to identify sections on (1) clinical evaluations, (2) investigations, (3) treatments, and (4) associated genes. Actions relevant to all types are marked in separate boxes, including when imaging is recommended. When definite diagnoses have been reached, the pathway also points toward disease-specific additional investigations and recommendations for follow up. Options for management are discussed for each subtype, including conservative and invasive treatments, as well as novel molecular therapies. CONCLUSION The collaborative efforts of VASCERN-VASCA, a network of the 9 Expert Centers, has led to a consensus Diagnostic and Management Pathways for VMs to assist clinicians and patients. It also emphasizes the role of multidisciplinary expert centers in the management of VM patients. This pathway will become available on the VASCERN website (http://vascern.eu/)

    Targeting the microenvironment in the treatment of arteriovenous malformations

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    Extracranial arteriovenous malformations (AVMs) are regarded as rare diseases and are prone to complications such as pain, bleeding, relentless growth, and high volume of shunted blood. Due to the high vascular pressure endothelial cells of AVMs are exposed to mechanical stress. To control symptoms and lesion growth pharmacological treatment strategies are urgently needed in addition to surgery and interventional radiology. AVM cells were isolated from three patients and exposed to cyclic mechanical stretching for 24 h. Thalidomide and bevacizumab, both VEGF inhibitors, were tested for their ability to prevent the formation of circular networks and proliferation of CD31+ endothelial AVM cells. Furthermore, the effect of thalidomide and bevacizumab on stretched endothelial AVM cells was evaluated. In response to mechanical stress, VEGF gene and protein expression increased in patient AVM endothelial cells. Thalidomide and bevacizumab reduced endothelial AVM cell proliferation. Bevacizumab inhibited circular network formation of endothelial AVM cells and lowered VEGF gene and protein expression, even though the cells were exposed to mechanical stress. With promising in vitro results, bevacizumab was used to treat three patients with unresectable AVMs or to prevent regrowth after incomplete resection. Bevacizumab controlled bleeding, pulsation, and pain over the follow up of eight months with no patient-reported side effects. Overall, mechanical stress increases VEGF expression in the microenvironment of AVM cells. The monoclonal VEGF antibody bevacizumab alleviates this effect, prevents circular network formation and proliferation of AVM endothelial cells in vitro. The clinical application of bevacizumab in AVM treatment demonstrates effective symptom control with no side effects

    Metamorphosis of Subarachnoid Hemorrhage Research: from Delayed Vasospasm to Early Brain Injury

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    Delayed vasospasm that develops 3–7 days after aneurysmal subarachnoid hemorrhage (SAH) has traditionally been considered the most important determinant of delayed ischemic injury and poor outcome. Consequently, most therapies against delayed ischemic injury are directed towards reducing the incidence of vasospasm. The clinical trials based on this strategy, however, have so far claimed limited success; the incidence of vasospasm is reduced without reduction in delayed ischemic injury or improvement in the long-term outcome. This fact has shifted research interest to the early brain injury (first 72 h) evoked by SAH. In recent years, several pathological mechanisms that activate within minutes after the initial bleed and lead to early brain injury are identified. In addition, it is found that many of these mechanisms evolve with time and participate in the pathogenesis of delayed ischemic injury and poor outcome. Therefore, a therapy or therapies focused on these early mechanisms may not only prevent the early brain injury but may also help reduce the intensity of later developing neurological complications. This manuscript reviews the pathological mechanisms of early brain injury after SAH and summarizes the status of current therapies

    Efficacy of Sirolimus in Patients Requiring Tracheostomy for Life-Threatening Lymphatic Malformation of the Head and Neck : A Report From the European Reference Network

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    Publisher Copyright: © Copyright © 2021 Holm, te Loo, Schultze Kool, Salminen, Celis, Baselga, Duignan, Dvorakova, Irvine, Boon, Vikkula, Ghaffarpour, Niemeyer, Rössler and Kapp.Extensive lymphatic malformations (LMs) of the head and neck region may require tracheostomy to secure the airway. Treatment of these life-threatening LMs is usually multimodal and includes sclerotherapy and surgery, among others. Recently, systemic therapy with sirolimus has been introduced as an effective treatment for venous and lymphatic malformations; its efficacy and safety profile in patients with extensive LM requiring tracheostomy are, however, as yet not fully known. We performed a retrospective, multicenter review and identified 13 patients with an extensive LM of the head and neck region, who previously underwent placement of tracheostomy and subsequently received sirolimus treatment with the aim to improve the local respiratory situation and remove the tracheostomy. Under sirolimus therapy, tracheostomy could be reversed in 8/13 (62%) patients, a further 2/13 (15%) patients improved markedly, and removal of the tracheostomy was planned at the time of writing, while 3/13 (23%) patients showed insufficient or absent response to sirolimus, rendering tracheostomy reversal not feasible. The median duration of sirolimus treatment until removal of tracheostomy was 18 months (range, 8 months to 5.6 years). Adverse events of sirolimus therapy were common [10/13 (77%) patients], yet the majority of these were mild [9/10 (90%) patients] and only one severe adverse event was recorded, with ulceration and necrosis at a catheter insertion site. In conclusion, sirolimus can be considered an effective and safe salvage treatment in patients with extensive LM even after placement of a tracheostomy, as closure of the latter was possible in the majority of patients (62%) of our retrospective cohort. A better understanding of when to start sirolimus therapy, of the duration of treatment, and of factors allowing the prediction of treatment response will require further investigation.Peer reviewe

    Somatic RIT1 indels identified in arteriovenous malformations hyperactivate RAS-MAPK signaling and are amenable to MEK inhibition

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    Arteriovenous malformations (AVM) are benign vascular anomalies prone to pain, bleeding, and progressive growth. Treatment is often difficult and relapse after therapy is common. AVM are mainly caused by somatic mosaicism with pathogenic variants of the RAS-MAPK pathway. However, a causative variant is not identified in all patients. Using ultra-deep next generation sequencing we identified novel somatic RIT1 indel variants in lesional tissue of three AVM patients. RIT1 – not previously implicated in AVM development – encodes a RAS-like protein that can modulate RAS-MAPK signaling. For biochemical characterization, we expressed RIT1 variants in HEK293T cells, which led to a strong increase in ERK1/2 phosphorylation. Endothelial-specific mosaic overexpression of the RIT1 indels in zebrafish embryos induced AVM formation, highlighting the functional importance in vascular development. Both ERK1/2 hyperactivation in vitro and AVM formation in vivo could be suppressed by pharmacological MEK inhibition. Targeted treatment with the MEK inhibitor trametinib led to a significant decrease in bleeding episodes and AVM size in one patient. Our findings expand the genetic spectrum of AVM by identifying RIT1 as a novel gene involved in AVM formation and pave the way for targeted treatment and clinical trials in patients with AVM.Competing Interest StatementFriedrich G. Kapp has received consulting fees from Novartis. Jochen Rossler is currently an employee of Novartis Pharma. All other authors declare no conflicts of interest.Funding StatementThis study was funded by German Research Foundation (DFG), Foundation for Ageing Research of the HHU Dusseldorf, Walter Benjamin Fellowship from the German Research Foundation and Swiss national Research Foundation, Synergia grant.Author DeclarationsI confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.YesThe details of the IRB/oversight body that provided approval or exemption for the research described are given below:1. Institutional review board of the University Hospital Regensburg, Germany gave ethical approval for this work (17-854-101). 2. Institutional review board of the University Hospital of Bern, Switzerland gave ethical approval for this work (2017-01960). 3. Institutional review board of the Boston Childrens Hospital, Boston, MA, USA gave ethical approval for this work (IRB-P00025772).I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.YesI understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).YesI have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable.YesThe data that support the findings of this study are available from the corresponding author upon reasonable request
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