scholarly journals The Volume-Regulated Anion Channel in Glioblastoma

Cancers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 307 ◽  
Author(s):  
Martino Caramia ◽  
Luigi Sforna ◽  
Fabio Franciolini ◽  
Luigi Catacuzzeno
Keyword(s):  
Cell Migration ◽  
Cell Volume ◽  
Signal Transduction Pathway ◽  
Anion Channel ◽  
Serum Levels ◽  
High Serum ◽  
Human Brain Tumor ◽  
Original Cell ◽  
The Impact

Malignancy of glioblastoma multiforme (GBM), the most common and aggressive form of human brain tumor, strongly depends on its enhanced cell invasion and death evasion which make surgery and accompanying therapies highly ineffective. Several ion channels that regulate membrane potential, cytosolic Ca2+ concentration and cell volume in GBM cells play significant roles in sustaining these processes. Among them, the volume-regulated anion channel (VRAC), which mediates the swelling-activated chloride current (IClswell) and is highly expressed in GBM cells, arguably plays a major role. VRAC is primarily involved in reestablishing the original cell volume that may be lost under several physiopathological conditions, but also in sustaining the shape and cell volume changes needed for cell migration and proliferation. While experimentally VRAC is activated by exposing cells to hypotonic solutions that cause the increase of cell volume, in vivo it is thought to be controlled by several different stimuli and modulators. In this review we focus on our recent work showing that two conditions normally occurring in pathological GBM tissues, namely high serum levels and severe hypoxia, were both able to activate VRAC, and their activation was found to promote cell migration and resistance to cell death, both features enhancing GBM malignancy. Also, the fact that the signal transduction pathway leading to VRAC activation appears to involve GBM specific intracellular components, such as diacylglicerol kinase and phosphatidic acid, reportedly not involved in the activation of VRAC in healthy tissues, is a relevant finding. Based on these observations and the impact of VRAC in the physiopathology of GBM, targeting this channel or its intracellular regulators may represent an effective strategy to contrast this lethal tumor.

scholarly journals POS0329 GASTROINTESTINAL INVOLVEMENT IN SYSTEMIC SCLEROSIS: PATHOGENETIC ROLE OF GUT MICROBIOME, CYTOKINES AND ADIPOKINES

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 392.1-392
Author(s):  
E. Pigatto ◽  
M. Schiesaro ◽  
M. Caputo ◽  
M. Beggio ◽  
P. Galozzi ◽  
...  
Keyword(s):  
Systemic Sclerosis ◽  
Gut Microbiome ◽  
Serum Levels ◽  
High Serum ◽  
Healthy Population ◽  
Gastrointestinal Involvement ◽  
Degrading Bacteria ◽  
Gi Symptoms ◽  
Low Levels ◽  
The Impact

Background:Gastrointestinal (GI) involvement is very common in patients with Systemic Sclerosis (SSc). The pathophysiology of GI manifestations has not yet been defined. Cell-mediated immunological reactions appear to lead to endothelial damage resulting in fibrosis. The risk of developing malnutrition reinforces the need to better understand GI pathophysiology in these patients.Objectives:The study aimed to evaluate GI symptoms (GIT 2.0) and malnutrition status (MUST) and to determine specific bacterial changes in gut microbiome by investigating the possible presence of positive hot spots in bacterial species in SSc patients and their potential role in the disease progression. We also evaluated serum levels of adipokines and cytokines involved in the pathogenesis of SSc and their role, in addition to gut microbiome, in predicting the onset of GI involvement and malnutrition in SSc patients.Methods:We enrolled 25 scleroderma patients (EULAR/ACR 2013 criteria). UCLA-SCTC GIT 2.0 questionnaire to evaluate GI symptoms and MUST to investigate the risk of malnutrition were used. Gut microbiome was analyzed and the samples were subjected to extraction for the 16S rRNA gene (Earth Microbiome Project and the NIH-Human Microbiome Project). The microbiome was investigated at phenotypic and genotypic level. Serum levels of cytokines and adipokines (adiponectin and leptin) were evaluated by ELISA.Results:79.9% of patients had GERD and 63.5% abdominal distension at GIT 2.0 questionnaires. 48% of patients had moderate risk of malnutrition (MUST=2) and 12% had high risk (MUST=3). Gut microbioma: 19 patients (76%) had low similarity and 11 (44%) low diversity compared to the healthy population. The prevailing enterotypes of gut microbiome was Bacteroides (80%) and Prevotella (20%). The genotypic evaluation showed a reduced concentration of: gluten-digesting (Lactobacillus); lactose-digesting (Faecalibacterium); vitamin K-producing (Enterococcus, Desulfovibrio and Veillonella); acetaldehyde-degrading bacteria. 24 patients (96%) showed a reduction in bacteria devoted to maintaining weight control (Bifidobacterium and Ruminococcus). The patients had an altered intestinal permeability with less mucolytic bacteria (Bacteroides) and reduced production of LPS (Enterobacter and Escherichia). Low levels of butyrate (Eubacterium and Clostridium), acetate and propionate were found for SCFA-producing bacteria. Potentially pathogenic bacteria were also investigated: Salmonella was found in 14 (56%), Klebsiella in 9 (36%) and Enterococcus Faecalis in 3 (12%) patients. 11 (44%) patients had elevated serum levels of IL10 and IL12; 4 (16%) had high value of leptin. Correlation was found in patients who had a reduced concentration of gluten-digesting bacteria and MUST. Elevated MUST was correlated with serological increase in IL17A and IFN-α. Serum levels of IL12 and IL10 were found to correlate with specific bacteria alterations: high concentration of acetaldehyde-producing bacteria and low levels of acetaldehyde-degrade bacteria (also correlated with high serum levels of IL6), mucolytic bacteria and producers of hydrogen sulphide, acetate and propionate. Finally, reduced levels of mucolytic bacteria and acetate producing bacteria correlated with high serum leptin levels.Conclusion:The relationship between the gut microbiome and SSc seems to be multifactorial. In our study genotypic changes of gut microbioma might play a role in damaging the permeability of the mucosa and increasing risk of malnutrition. The evaluation of gut microbiome and cytokine profile is probably going to be of value in the follow-up of SSc. However, further studies are needed to clarify the impact of GI dysbiosis on the immune system in SSc.References:[1]Patrone V. et al. Gut microbiota profile in systemic sclerosis patients with and without clinical evidence of gastrointestinal involvement, Sci Rep. 2017; 7: 14874Disclosure of Interests:None declared

scholarly journals A Versatile Macromer-Based Glycosaminoglycan (sHA3) Decorated Biomaterial for Pro-Osteogenic Scavenging of Wnt Antagonists

Pharmaceutics ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 1037
Author(s):  
Mathis Gronbach ◽  
Franziska Mitrach ◽  
Stephanie Möller ◽  
Sandra Rother ◽  
Sabrina Friebe ◽  
...  
Keyword(s):  
Serum Levels ◽  
Bone Defects ◽  
High Serum ◽  
Qualitative And Quantitative Analysis ◽  
Negative Effects ◽  
Bone Defect Healing ◽  
2D System ◽  
Surface Decoration ◽  
The Impact ◽  
Regeneration Of Bone

High serum levels of Wnt antagonists are known to be involved in delayed bone defect healing. Pharmaceutically active implant materials that can modulate the micromilieu of bone defects with regard to Wnt antagonists are therefore considered promising to support defect regeneration. In this study, we show the versatility of a macromer based biomaterial platform to systematically optimize covalent surface decoration with high-sulfated glycosaminoglycans (sHA3) for efficient scavenging of Wnt antagonist sclerostin. Film surfaces representing scaffold implants were cross-copolymerized from three-armed biodegradable macromers and glycidylmethacrylate and covalently decorated with various polyetheramine linkers. The impact of linker properties (size, branching) and density on sHA3 functionalization efficiency and scavenging capacities for sclerostin was tested. The copolymerized 2D system allowed for finding an optimal, cytocompatible formulation for sHA3 functionalization. On these optimized sHA3 decorated films, we showed efficient scavenging of Wnt antagonists DKK1 and sclerostin, whereas Wnt agonist Wnt3a remained in the medium of differentiating SaOS-2 and hMSC. Consequently, qualitative and quantitative analysis of hydroxyapatite staining as a measure for osteogenic differentiation revealed superior mineralization on sHA3 materials. In conclusion, we showed how our versatile material platform enables us to efficiently scavenge and inactivate Wnt antagonists from the osteogenic micromilieu. We consider this a promising approach to reduce the negative effects of Wnt antagonists in regeneration of bone defects via sHA3 decorated macromer based macroporous implants.

scholarly journals Alpha 1-antichymotrypsin contributes to stem cell characteristics and enhances tumorigenicity of Glioblastoma

2020 ◽  
Author(s):  
Montserrat Lara-Velazquez ◽  
Natanael Zarco ◽  
Anna Carrano ◽  
Jordan Phillipps ◽  
Emily S Norton ◽  
...  
Keyword(s):  
Stem Cell ◽  
Cell Migration ◽  
Brain Tumor ◽  
Primary Cultures ◽  
Cellular Migration ◽  
Tumor Initiating Cells ◽  
The Impact

Abstract Background Glioblastomas (GBMs) are the most common primary brains tumors in adults with almost 100% recurrence rate. Patients with lateral ventricle proximal GBMs (LV-GBMs) exhibit worse survival compared to distal locations for reasons that remain unknown. One potential explanation is the proximity of these tumors to the cerebrospinal fluid (CSF) and its contained chemical cues that can regulate cellular migration and differentiation. We therefore investigated the role of CSF on GBM gene expression and the role of a CSF-induced gene, SERPINA3, in GBM malignancy in vitro and in vivo. Methods We utilized patient-derived CSF and primary cultures of GBM brain tumor initiating cells (BTICs). We determined the impact of SERPINA3 expression in glioma patients using TCGA database. SERPINA3 expression changes were evaluated at both the mRNA and protein levels. The effects of knockdown (KD) and overexpression (OE) of SERPINA3 on cell behavior were evaluated by transwell assay (for cell migration), and alamar blue and Ki67 (for viability and proliferation respectively). Stem cell characteristics on KD cells were evaluated by differentiation and colony formation experiments. Tumor growth was studied by intracranial and flank injections. Results GBM CSF induced a significant increase in BTIC migration accompanied by upregulation of the SERPINA3 gene. In patient samples and TCGA data we observed SERPINA3 to correlate directly with brain tumor grade and indirectly with GBM patient survival. Silencing of SERPINA3 induced a decrease in cell proliferation, migration, invasion, and stem cell characteristics, while SERPINA3 overexpression increased cell migration. In vivo, mice orthotopically-injected with SERPINA3 KD BTICs showed increased survival. Conclusions SERPINA3 plays a key role in GBM malignancy and its inhibition results in a better outcome using GBM preclinical models.

Gvhd Severity Is Regulated by the Adoptive Transfer Low Numbers of NKT Cells by a Mechanism Distinct From CD4+CD25+ Regulatory T Cells.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 229-229
Author(s):  
Dennis Leveson-Gower ◽  
Janelle Olson ◽  
Emanuela I Sega ◽  
Jeanette Baker ◽  
Robert Zeiser ◽  
...  
Keyword(s):  
T Cells ◽  
Regulatory T Cells ◽  
Adoptive Transfer ◽  
Conflicts Of Interest ◽  
Serum Levels ◽  
Nkt Cells ◽  
Donor Type ◽  
Ifn Γ ◽  
The Impact

Abstract Abstract 229 NKT cells, a subset of which are CD1d reactive, play an important immunoregulatory role in suppressing dysfunctional immune reactions, including graft-versus-host disease (GVHD). To explore the biological activity and mechanism of donor-type NKT in suppression of GVHD, we utilized highly purified (>95%) populations of donor (C57Bl6; H-2b) NKT (DX5+TCR+CD4+) cells adoptively transferred into lethally irradiated recipient (Balb/c; H-2d) animals with T cell depleted bone marrow (TCD-BM). Highly purified (>95%) NKT cells (5.5×105) from luciferase positive (luc+) C57BL/6 mice were infused into lethally irradiated Balb/c recipients with TCD-BM(5×106) from wild-type (WT) C57BL/6 mice, and the animals were monitored by bioluminescence imaging (BLI). By day 4 after transfer, an NKT derived signal was observed in spleen and lymph node (LN) sites, and between days 7 and 10, NKT had also migrated to the skin. Total photons emitted peaked near day 25 after transplantation, followed by a steady decline. To assess the impact of donor-type NKT cells on GVHD induction by conventional CD4+ and CD8+ T cells (Tcon), we co-transferred various doses of highly purified WT NKT at day 0 with TCD-BM, followed by 5×105 luc+Tcon/animal on day 2. As few as 2.5×104 NKT cells significantly improved survival of mice receiving 5×105 Tcon. Animal survival with Tcon only was 20% and for Tcon with NKT cells was 74%(p=0.0023). In contrast to what is observed with CD4+CD25+FoxP3+ regulatory T cells (Treg), the NKT cells did not suppress Tcon proliferation assayed by both in vivo BLI and in a mixed-leukocyte reaction. Analysis of serum cytokines with or without 2.5×104 NKT, following HCT with TCD-BM and Tcon, indicated the addition of NKT cells resulted in elevated levels of INF-γ, IL-5, and IL-6 in serum; significant differences were not observed in serum levels of IL-2, IL-4, IL-10, IL-17, or TNF-α. Intracellular levels of cytokines in Tcon were analyzed from the same groups. At 8 days after HCT, mice receiving NKT had fewer TNFα-positive cells in LNs (CD4: 45% to 27%; CD8 36% to 24%); by day 11, however, TNFαa levels between groups were equivalent. IFN-γ levels, which were high in both NKT treated and untreated groups at day 8 (85%-95%), decreased significantly in NKT treated mice by day 11 (CD4: 40%; CD8: 43%), but were abundant in Tcon only mice (CD4: 78%; CD8: 80%) (p=.0001). No significant changes were found in the intracellular levels of IL-2, IL-4, IL-5, IL-10, or IL-17 of Tcon in the presence or absence of NKT cells. NKT from both IL-4 -/- and IFN-γ -/- mice were less effective at suppressing GVHD than WT NKT, implicating these cytokines in the suppressive mechanism. Finally, we found that NKT do not have a major impact on the graft-versus-tumor effect of Tcon against a luc+ BCL-1 tumor. These studies indicate that NKT persist in vivo upon adoptive transfer and suppress GVHD, even at extremely low cell numbers, which is important given the relative paucity of this cell population. The mechanisms of GVHD suppression appear to be distinct to those of Treg and involve the production of IL-4 and IFN-γ by NKT resulting in a decrease in Tcon, which produce pro-inflamatory cytokines. Disclosures: No relevant conflicts of interest to declare.

scholarly journals High serum levels of CML are associated with poor coronary collateralization in type 2 diabetic patients with chronic total occlusion of coronary artery

2022 ◽  
Author(s):  
Le Ying Li ◽  
Ying Shen ◽  
Shuai Chen ◽  
Fei Fei Li ◽  
Zhi Ming Wu ◽  
...  
Keyword(s):  
Coronary Artery ◽  
Roc Curve ◽  
Chronic Total Occlusion ◽  
Serum Levels ◽  
High Serum ◽  
Diabetic Patients ◽  
Type 2 Diabetic Patients ◽  
Total Occlusion

Abstract Background: The formation of advanced glycation end-products (AGEs) is a crucial risk factor for the pathogenesis of cardiovascular diseases. We investigated whether N-e-carboxy-methyl-lysine (CML), a major form of AGEs in vivo, was associated with poor coronary collateral vessel (CCV) formation in patients with type 2 diabetes mellitus (T2DM) and chronic total occlusion (CTO) of coronary artery.Methods: This study consisted of 242 T2DM patients with angiographically documented CTO. Blood samples were obtained and demographic/clinical characteristics were documented. The collateralization of these patients was defined according to Rentrop score. Receiver operating characteristic (ROC) curve and multivariable regression analysis were performed.Results: 242 patients were categorized into poor CCV group (Rentrop score 0 and 1)(n = 107) and good CCV group (Rentrop score 2 and 3)(n = 135). Serum CML levels were significantly higher in poor CCV group (110.0 ± 83.35 ng/ml) than in good CCV group (62.95 ± 58.83 ng/ml, P<0.001). Moreover, these CML levels were also significantly different across the Rentrop score 0, 1, 2 and 3 groups (P <0.001). In ROC curve for ascertaining poor CCV, AUCs were 0.70 (95% CI 0.64-0.77) for CML. In multivariable logistic regression, CML levels (P<0.001) remained independent determinants of poor CCV after adjustment of traditional risk factors. Conclusions: This study suggests that higher CML levels are associated to poor CCV in T2DM patients with CTO. Inhibition of AGEs including CML is a strategy in antagonizing poor CCV in diabetic patients.

scholarly journals Anion channel sensitivity to cytosolic organic acids implicates a central role for oxaloacetate in integrating ion flux with metabolism in stomatal guard cells

2011 ◽  
Vol 439 (1) ◽  
pp. 161-170 ◽  
Author(s):  
Yizhou Wang ◽  
Michael R. Blatt
Keyword(s):  
Plasma Membrane ◽  
Organic Acids ◽  
Organic Acid ◽  
Stomatal Closure ◽  
Anion Channel ◽  
Guard Cells ◽  
Solute Flux ◽  
Stomatal Guard Cells ◽  
The Impact

Stomatal guard cells play a key role in gas exchange for photosynthesis and in minimizing transpirational water loss from plants by opening and closing the stomatal pore. The bulk of the osmotic content driving stomatal movements depends on ionic fluxes across both the plasma membrane and tonoplast, the metabolism of organic acids, primarily Mal (malate), and its accumulation and loss. Anion channels at the plasma membrane are thought to comprise a major pathway for Mal efflux during stomatal closure, implicating their key role in linking solute flux with metabolism. Nonetheless, little is known of the regulation of anion channel current (ICl) by cytosolic Mal or its immediate metabolite OAA (oxaloacetate). In the present study, we have examined the impact of Mal, OAA and of the monocarboxylic acid anion acetate in guard cells of Vicia faba L. and report that all three organic acids affect ICl, but with markedly different characteristics and sidedness to their activities. Most prominent was a suppression of ICl by OAA within the physiological range of concentrations found in vivo. These findings indicate a capacity for OAA to co-ordinate organic acid metabolism with ICl through the direct effect of organic acid pool size. The findings of the present study also add perspective to in vivo recordings using acetate-based electrolytes.

scholarly journals SARS-CoV-2 Induces Lymphocytopenia by Promoting Inflammation and Decimates Secondary Lymphoid Organs

2021 ◽  
Vol 12 ◽  
Author(s):  
Qun Xiang ◽  
Zeqing Feng ◽  
Bo Diao ◽  
Chao Tu ◽  
Qinghua Qiao ◽  
...  
Keyword(s):  
Serum Levels ◽  
High Serum ◽  
Human Spleen ◽  
Angiotensin Converting Enzyme 2 ◽  
Reactive Protein ◽  
Secondary Lymphoid Organs ◽  
Severe Tissue

While lymphocytopenia is a common characteristic of coronavirus disease 2019 (COVID-19), the mechanisms responsible for this lymphocyte depletion are unclear. Here, we retrospectively reviewed the clinical and immunological data from 18 fatal COVID-19 cases, results showed that these patients had severe lymphocytopenia, together with high serum levels of inflammatory cytokines (IL-6, IL-8 and IL-10), and elevation of many other mediators in routine laboratory tests, including C-reactive protein, lactate dehydrogenase, α-hydroxybutyrate dehydrogenase and natriuretic peptide type B. The spleens and hilar lymph nodes (LNs) from six additional COVID-19 patients with post-mortem examinations were also collected, histopathologic detection showed that both organs manifested severe tissue damage and lymphocyte apoptosis in these six cases. In situ hybridization assays illustrated that SARS-CoV-2 viral RNA accumulates in these tissues, and transmission electronic microscopy confirmed that coronavirus-like particles were visible in the LNs. SARS-CoV-2 Spike and Nucleocapsid protein (NP) accumulated in the spleens and LNs, and the NP antigen restricted in angiotensin-converting enzyme 2 (ACE2) positive macrophages and dendritic cells (DCs). Furthermore, SARS-CoV-2 triggered the transcription of Il6, Il8 and Il1b genes in infected primary macrophages and DCs in vitro, and SARS-CoV-2-NP+ macrophages and DCs also manifested high levels of IL-6 and IL-1β, which might directly decimate human spleens and LNs and subsequently lead to lymphocytopenia in vivo. Collectively, these results demonstrated that SARS-CoV-2 induced lymphocytopenia by promoting systemic inflammation and direct neutralization in human spleen and LNs.

Lysine-Specific Histone Demethylase, LSD1, (KDM1A) As a Novel Therapeutic Target in Myeloproliferative Neoplasms

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 601-601 ◽  
Author(s):  
Maria Kleppe ◽  
Kaitlyn Shank ◽  
Papalexi Efthymia ◽  
Hugh Riehnhoff ◽  
Ross L. Levine
Keyword(s):  
Mutant Allele ◽  
Myeloproliferative Neoplasms ◽  
Serum Levels ◽  
Advisory Committees ◽  
Allele Burden ◽  
Circulating Cells ◽  
Cell Counts ◽  
White Blood Cell Counts ◽  
The Impact

Abstract Among BCR-ABL-negative myeloproliferative neoplasms (MPN), primary myelofibrosis (PMF) and post PV/ET myelofibrosis (MF) are associated with the highest degree of morbidity and mortality, including progressive bone marrow (BM) fibrosis and resultant BM failure. Although the JAK inhibitor ruxolitinib is now approved for the treatment of MF-associated splenomegaly and systemic symptoms, JAK inhibitor therapy does not reduce the proportion of JAK2-mutant cells in MPN patients. The limited ability of JAK inhibition to induce molecular or clinicopathologic responses in the majority of MPN patients underscores the need for the development of more effective therapies for JAK kinase-dependent malignancies. Recent studies have shown that the lysine-specific histone demethylase, LSD1 (KDM1A), participates in the balance between proliferation and differentiation in vivo by influencing state-specific gene expression patterns. In physiologic hematopoiesis, LSD1 is essential for normal myeloid differentiation affecting the erythroid, megakaryocytic and granulocytic lineages. Small molecule inhibitors of LSD1 have shown promising results in preclinical models of acute myeloid leukemia (AML) and solid cancers and have recently entered clinical trials in AML. However, the role and requirement for LSD1 in the pathogenesis of MPNs and the therapeutic targeting of LSD1 in MPN has not been investigated. In this study, we first tested the effects of IMG-98, a potent, selective LSD1 inhibitor, in the MPLW515L-driven ET/MF mouse model. After disease was established, mice were treated with IMG-98 or vehicle for 28 days. LSD1 inhibition in mice markedly suppressed myeloproliferation reducing granulocyte counts and spleen weights compared to mice treated with vehicle thus establishing therapeutic efficacy (Fig. 1a). Pathologic analysis of BM and spleen confirmed a marked reduction in myeloproliferation as well as a reversal of extramedullary hematopoiesis (EMH). Most notably, we observed a marked reduction in reticulin fibrosis with IMG-98 treatment (Fig. 1b). We next investigated the impact of IMG-98 therapy on inflammatory cytokine signaling; in contrast to the broad anti-cytokine effects of JAK1/2 inhibition, we observed a more specific anti-cytokine effect of IMG-98, a significant reduction in the secretion of the inflammatory cytokine Cxcl5 (Fig. 1c), a key participant in pathologic inflammatory states. We then investigated the in vivo impact of IMG-98 therapy on mutant disease burden. IMG-98 therapy reduced mutant allele burden to a degree not seen with JAK1/2 inhibitor therapy: whereas 74.6% of circulating cells in mice treated with vehicle were GFP-positive cells, only 43.2% of circulating cells were GFP-positive in IMG-98-treated mice (Fig. 1d). Flow cytometry analysis of spleen and BM revealed reduced numbers of CD11b/Gr1-positive myeloid cells and CD41-positive megakaryocytes. The numbers of mutant GFP-positive myeloid cells and megakaryocytes in these tissues were also significantly reduced by IMG-98 treatment. Studies of the impact of LSD1 inhibition on MPN stem cell function and on epigenetic regulation in MPN cells will be presented in detail. In summary, the LSD1 inhibitor IMG-98 had a highly significant therapeutic effect in an established preclinical model of ET/MF. LSD1 inhibition in diseased mice reduced JAK-STAT-driven myeloproliferation, markedly reversed EMH and BM fibrosis, and reduced the mutant clone burden. These data suggest LSD1 is a valid target in MPN and that clinical studies of LSD1 inhibitor IMG-98 alone and in combination with JAK inhibitors are warranted. Figure 1. a, b) LSD1 inhibition results in reduced white blood cell counts (WBC) and platelet counts (PLT). (a), and in near-complete elimination of BM fibrosis (b). c) Profound reduction of Cxcl5 serum levels in IMG-98 treated mice compared to vehicle treated mice. d) Significantly lower mutant allele burden in the peripheral blood of IMG-98 treated mice. * P<0.05, n =5. Figure 1. a, b). LSD1 inhibition results in reduced white blood cell counts (WBC) and platelet counts (PLT). (a), and in near-complete elimination of BM fibrosis (b). c) Profound reduction of Cxcl5 serum levels in IMG-98 treated mice compared to vehicle treated mice. d) Significantly lower mutant allele burden in the peripheral blood of IMG-98 treated mice. * P<0.05, n =5. Disclosures Riehnhoff: Imago: Employment, Equity Ownership. Levine:Loxo Oncology: Membership on an entity's Board of Directors or advisory committees; CTI BioPharma: Membership on an entity's Board of Directors or advisory committees; Foundation Medicine: Consultancy.

scholarly journals SCIDOT-06. TOWARDS EXCLUSIVELY LOCAL THERAPY OF GLIOBLASTOMA - ENGINEERING IL-12Fc WITH SUPERIOR TISSUE RETENTION AND MINIMAL SYSTEMIC EXPOSURE AFTER CNS ADMINISTRATION

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi273-vi273
Author(s):  
Michal Beffinger ◽  
Linda Schellhammer ◽  
Stanislav Pantelyushin ◽  
Iwan Zimmermann ◽  
Pascal Egloff ◽  
...  
Keyword(s):  
Local Treatment ◽  
Systemic Exposure ◽  
Local Therapy ◽  
Serum Levels ◽  
Therapeutic Window ◽  
Convection Enhanced Delivery ◽  
Interaction Interface ◽  
Heavy Chain Constant Region ◽  
The Impact

Abstract Intratumoral application of IL-12 overrides the prevailing glioblastoma (GB) associated immunosuppression and can trigger efficient anti-tumor responses. With clinical studies currently testing local expression of IL-12 in brain tumors, concerns on IL-12 systemic toxicity via leakage resurface. The fusion to an immunoglobulin heavy chain constant region (“Fc tag”) should increase tissue retention of IL-12. However, export of IL-12Fc into the blood via the neonatal Fc receptor (FcRn) could nevertheless lead to systemic exposure. Subsequent systemic recycling via FcRn could lead to gradually increasing and eventually toxic serum concentrations. We analysed the effect of the Fc-tag on IL-12 tissue retention and evaluated whether FcRn also is involved in brain export and systemic recycling of IL-12Fc upon local delivery. Human or murine IL-12Fc was delivered in GB-bearing or naïve wt or FcRn-humanized mice (mFcRn-/- hFcRn tg) continuously via mini osmotic pumps or as bolus via convection-enhanced delivery (CED). Brain and blood concentration levels were assessed via ELISA. FcRn affinity of IL-12Fc mutants was assessed via ELISA and surface plasmon resonance. We observed much higher tissue retention of IL-12Fc compared to unmodified IL-12, but also an FcRn-dependent gradual increase of IL-12Fc serum levels. Testing a battery of amino acid substitutions at the FcRn interaction interface, we discovered unique substitutions that largely abolish brain export and systemic accumulation while preserving IL-12Fc functionality, leading to an over 100-fold higher brain to blood ratio than unmodified IL-12. We currently test the impact on efficacy of local IL-12Fc and checkpoint brain tumor treatment in vivo. Achieving high local concentrations at low to absent systemic exposure is an important prerequisite for a large therapeutic window for local treatment of neurologic diseases. The novel Fc-modifications present a promising platform for reducing systemic leakage of Fc-containing therapeutics in the context of continuous or intermittent CNS delivery beyond brain cancer therapy.

Sign in / Sign up

Export Citation Format

Share Document