ZEB2 stably represses RAB25 expression through epigenetic regulation by SIRT1 and DNMTs during epithelial-to-mesenchymal transition

Background: Epithelial mesenchymal transition (EMT) is tightly regulated by a network of transcription factors (EMT-TFs). Among them is the nuclear factor ZEB2, a member of the zinc-finger E-box binding homeobox family. ZEB2 nuclear localization has been identified in several cancer types, and its overexpression is correlated with the malignant progression. ZEB2 transcriptionally represses epithelial genes, such as E-cadherin (CDH1), by directly binding to the promoter of the genes it regulates and activating mesenchymal genes by a mechanism in which there is no full agreement. Recent studies showed that EMT-TFs interact with epigenetic regulatory enzymes that alter the epigenome, thereby providing another level of control. The role of epigenetic regulation on ZEB2 function is not well understood. In this study, we aimed to characterize the epigenetic effect of ZEB2 repressive function on the regulation of a small Rab GTPase RAB25. Results: Using cellular models with conditional ZEB2 expression, we show a clear transcriptional repression of RAB25 and CDH1. RAB25 contributes to the partial suppression of ZEB2-mediated cell migration. Furthermore, a highly significant reverse correlation between RAB25 and ZEB2 expression in several human cancer types could be identified. Mechanistically, ZEB2 binds specifically to E-box sequences on the RAB25 promoter. ZEB2 binding is associated with the local increase in DNA methylation requiring DNA methyltransferases as well as histone deacetylation (H3K9Ac) depending on the activity of SIRT1. Surprisingly, SIRT1 and DNMTs did not interact directly with ZEB2, and while SIRT1 inhibition decreased the stability of long-term repression, it did not prevent down-regulation of RAB25 and CDH1 by ZEB2. Conclusions: ZEB2 expression is resulting in drastic changes at the chromatin level with both clear DNA hypermethylation and histone modifications. Here, we revealed that SIRT1-mediated H3K9 deacetylation helps to maintain gene repression but is not required for the direct ZEB2 repressive function. Targeting epigenetic enzymes to prevent EMT is an appealing approach to limit cancer dissemination, but inhibiting SIRT1 activity alone might have limited effect and will require drug combination to efficiently prevent EMT

Utilization of predefined stimulation groups by essential tremor patients treated with VIM-DBS

Objective: To identify the utilization and general acceptance of switching between predefined stimulation groups in essential tremor (ET) patients treated with deep brain stimulation (DBS) of the ventral intermediate nucleus (VIM) of the thalamus.MethodsThirty-eight patients treated with VIM-DBS completed a telephone survey. This was designed to identify the general utilization of patient controllers and the specific usage of stimulation groups.ResultsThirty-eight patients were interviewed via phone. More than half (21 of 38 patients, 55%) of all contacted ET patients were aware of the possibility of switching between pre-defined stimulation programs themselves. Again, more than half of these patients (13 of the 21 patients) switch between the different programs on a regular basis (8 monthly, 2 weekly, and 3 daily), mainly due to occurring side effects. Age did not differ between the group of patients switching between stimulation groups, and those who did not (65.38 years (±11.36) vs. 69.15 years (±9.92), p = 0.297).ConclusionSome patients frequently use different stimulation settings, mainly to be able to control side effects when necessary. All patients – independent of their age - and especially patients with stimulation induced side effects, should therefore be informed about the possibility to switch between predefined stimulation groups. We propose a training for patients by specialized nurses, to give them confidence in handling the patient controllers

AXL Receptor Tyrosine Kinase as a Therapeutic Target in Hematological Malignancies: Focus on Multiple Myeloma

AXL belongs to the TAM (TYRO3, AXL, and MERTK) receptor family, a unique subfamily of the receptor tyrosine kinases. Their common ligand is growth arrest-specific protein 6 (GAS6). The GAS6/TAM signaling pathway regulates many important cell processes and plays an essential role in immunity, hemostasis, and erythropoiesis. In cancer, AXL overexpression and activation has been associated with cell proliferation, chemotherapy resistance, tumor angiogenesis, invasion, and metastasis; and has been correlated with a poor prognosis. In hematological malignancies, the expression and function of AXL is highly diverse, not only between the different tumor types but also in the surrounding tumor microenvironment. Most research and clinical evidence has been provided for AXL inhibitors in acute myeloid leukemia. However, recent studies also revealed an important role of AXL in lymphoid leukemia, lymphoma, and multiple myeloma. In this review, we summarize the basic functions of AXL in various cell types and the role of AXL in different hematological cancers, with a focus on AXL in the dormancy of multiple myeloma. In addition, we provide an update on the most promising AXL inhibitors currently in preclinical/clinical evaluation and discuss future perspectives in this emerging field

Deep brain stimulation of the posterior subthalamic area and the thalamus in patients with essential tremor: study protocol for a randomized controlled pilot trial

BACKGROUND: Deep brain stimulation (DBS) of the ventral intermediate nucleus (VIM) of the thalamus is effective in medication refractory essential tremor (ET). In recent years, evidence has accumulated that the region ventral to the VIM, the posterior subthalamic area (PSA), might be an equally or even more effective target for electrode implantation. However, this evidence is primarily based on case series, cross-sectional observations, and retrospective data. METHODS/DESIGN: A prospective crossover pilot study investigating the effects of PSA stimulation in medication refractory ET patients was designed. In this study, bilateral electrodes are implanted such that at least one of the electrode contacts is located in the PSA and VIM, respectively. This implantation approach allows (1) a prospective double-blind investigation of the effects of PSA stimulation compared to baseline, as well as (2) a crossover comparison between VIM and PSA stimulation with respect to tremor suppression and side effect profiles. DISCUSSION: The results of this double-blinded, prospective study will allow a better understanding of the effects and side effects of PSA compared to VIM-DBS in patients with ET. TRIAL REGISTRATION: German Clinical Trials Register: DRKS00004235 . Registered on 4 July 2012

The Effect of Uni- and Bilateral Thalamic Deep Brain Stimulation on Speech in Patients With Essential Tremor: Acoustics and Intelligibility

BackgroundDeep brain stimulation (DBS) of the ventral intermediate nucleus (VIM) is performed to suppress medically-resistant essential tremor (ET). However, stimulation induced dysarthria (SID) is a common side effect, limiting the extent to which tremor can be suppressed. To date, the exact pathogenesis of SID in VIM-DBS treated ET patients is unknown. ObjectiveWe investigate the effect of inactivated, uni- and bilateral VIM-DBS on speech production in patients with ET. We employ acoustic measures, tempo, and intelligibility ratings and patient's self-estimated speech to quantify SID, with a focus on comparing bilateral to unilateral stimulation effects and the effect of electrode position on speech. MethodsSixteen German ET patients participated in this study. Each patient was acoustically recorded with DBS-off, unilateral-right-hemispheric-DBS-on, unilateral-left-hemispheric-DBS-on, and bilateral-DBS-on during an oral diadochokinesis task and a read German standard text. To capture the extent of speech impairment, we measured syllable duration and intensity ratio during the DDK task. Naive listeners rated speech tempo and speech intelligibility of the read text on a 5-point-scale. Patients had to rate their ability to speak. ResultsWe found an effect of bilateral compared to unilateral and inactivated stimulation on syllable durations and intensity ratio, as well as on external intelligibility ratings and patients' VAS scores. Additionally, VAS scores are associated with more laterally located active contacts. For speech ratings, we found an effect of syllable duration such that tempo and intelligibility was rated worse for speakers exhibiting greater syllable durations. ConclusionOur data confirms that SID is more pronounced under bilateral compared to unilateral stimulation. Laterally located electrodes are associated with more severe SID according to patient's self-ratings. We can confirm the relation between diadochokinetic rate and SID in that listener's tempo and intelligibility ratings can be predicted by measured syllable durations from DDK tasks

DBS of the PSA and the VIM in essential tremor

Objective To evaluate deep brain stimulation (DBS) of the posterior subthalamic area (PSA) in essential tremor (ET) and compare it to the ventral intermediate nucleus of the thalamus (VIM) in terms of stimulation efficacy, efficiency, and side effects.Methods DBS leads were implanted such that contacts were placed in the VIM, on the intercommissural line, and in the PSA. Thirteen patients with ET entered a randomized, double-blind crossover phase and completed a 1-year follow-up.Results PSA-DBS significantly reduced tremor severity and improved quality of life. There were no relevant differences in quality and frequency of stimulation side effects between VIM and PSA, with a tendency toward greater tremor improvement with PSA stimulation. Clinical benefit was achieved at significantly lower stimulation amplitudes in the PSA. The majority of patients remained with PSA-DBS after 1 year.Conclusion In accordance with previous retrospective investigations, our prospective data suggest that PSA-DBS is at least equally effective as but possibly more efficient than VIM-DBS.Classification of evidence This study provides Class I evidence that for patients with essential tremor, PSA-DBS is not significantly different from VIM-DBS in suppressing tremor, but clinical benefit from PSA-DBS is attained at lower stimulation amplitudes

Targeting S100A9 protein affects mTOR-ER stress signaling and increases venetoclax sensitivity in Acute Myeloid Leukemia

Abstract Acute Myeloid Leukemia (AML) is a heterogeneous disease with limited treatment options and a high demand for novel targeted therapies. Since myeloid-related protein S100A9 is abundantly expressed in AML, we aimed to unravel the therapeutic impact and underlying mechanisms of targeting both intracellular and extracellular S100A9 protein in AML cell lines and primary patient samples. S100A9 silencing in AML cell lines resulted in increased apoptosis and reduced AML cell viability and proliferation. These therapeutic effects were associated with a decrease in mTOR and endoplasmic reticulum stress signaling. Comparable results on AML cell proliferation and mTOR signaling could be observed using the clinically available S100A9 inhibitor tasquinimod. Interestingly, while siRNA-mediated targeting of S100A9 affected both extracellular acidification and mitochondrial metabolism, tasquinimod only affected the mitochondrial function of AML cells. Finally, we found that S100A9-targeting approaches could significantly increase venetoclax sensitivity in AML cells, which was associated with a downregulation of BCL-2 and c-MYC in the combination group compared to single agent therapy. This study identifies S100A9 as a novel molecular target to treat AML and supports the therapeutic evaluation of tasquinimod in venetoclax-based regimens for AML patients

Tasquinimod suppresses tumor cell growth and bone resorption by targeting immunosuppressive myeloid cells and inhibiting c-MYC expression in multiple myeloma

Background Immunotherapy emerged as a promising treatment option for multiple myeloma (MM) patients. However, therapeutic efficacy can be hampered by the presence of an immunosuppressive bone marrow microenvironment including myeloid cells. S100A9 was previously identified as a key regulator of myeloid cell accumulation and suppressive activity. Tasquinimod, a small molecule inhibitor of S100A9, is currently in a phase Ib/IIa clinical trial in MM patients (NCT04405167). We aimed to gain more insights into its mechanisms of action both on the myeloma cells and the immune microenvironment.Methods We analyzed the effects of tasquinimod on MM cell viability, cell proliferation and downstream signaling pathways in vitro using RNA sequencing, real-time PCR, western blot analysis and multiparameter flow cytometry. Myeloid cells and T cells were cocultured at different ratios to assess tasquinimod-mediated immunomodulatory effects. The in vivo impact on immune cells (myeloid cell subsets, macrophages, dendritic cells), tumor load, survival and bone disease were elucidated using immunocompetent 5TMM models.Results Tasquinimod treatment significantly decreased myeloma cell proliferation and colony formation in vitro, associated with an inhibition of c-MYC and increased p27 expression. Tasquinimod-mediated targeting of the myeloid cell population resulted in increased T cell proliferation and functionality in vitro. Notably, short-term tasquinimod therapy of 5TMM mice significantly increased the total CD11b+ cells and shifted this population toward a more immunostimulatory state, which resulted in less myeloid-mediated immunosuppression and increased T cell activation ex vivo. Tasquinimod significantly reduced the tumor load and increased the trabecular bone volume, which resulted in prolonged overall survival of MM-bearing mice in vivo.Conclusion Our study provides novel insights in the dual therapeutic effects of the immunomodulator tasquinimod and fosters its evaluation in combination therapy trials for MM patients

Developing Engineering-oriented Educational Workshops Within a Student Branch

The development of two educational workshops, one on energy efficiency and one on human-machine interfaces, is detailed and discussed. Attraction to engineering is not created as much as lost at early ages through current education methods. Through positive, hands-on experiences with engineering in K-12 education, this trend can be turned. IEEE student branches have as part of their mission the education and creation of quality educational resources for the public. After searching in vain for suitable inexpensive material, the IEEE student branch Leuven decided to design and create two workshops on engineering topics for an audience of 10-12 year olds. Handling this as a repeatable project, the student branch found partners to create a low budget project for the attendees. Using the skillset of the specific partners and organizers optimally on the subtasks, a successful repeatable cooperation is realized. This paper discusses the environment in which the project is realized, the steps to it, and how it (indirectly) benefits the organizing student branch.status: publishe