scholarly journals The Association between Clonal Hematopoiesis and Gout

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 595-595
Author(s):  
Mridul Agrawal ◽  
Abhishek Niroula ◽  
Pierre Cunin ◽  
Marie McConkey ◽  
Peter G. Kim ◽  
...  
Keyword(s):  
Immune Response ◽  
Mouse Models ◽  
Blood Cells ◽  
Research Funding ◽  
Hematopoietic Cells ◽  
Wild Type ◽  
Clonal Hematopoiesis ◽  
Increased Risk ◽  
Urate Crystals

Abstract Background: Gout is a highly prevalent arthritis associated with debilitating joint pain and functional impairment. It is caused by elevated serum uric acid levels (hyperuricemia) and triggered by precipitation of urate crystals in and around joints. Urate crystals are ingested by macrophages and provoke an innate immune response with subsequent secretion of inflammatory cytokines including interleukin 1 beta (IL-1B). Clonal hematopoiesis of indeterminate potential (CHIP) is a precursor to hematologic malignancies defined by somatic mutations in hematopoietic cells that drive clonal expansion and inflammation. Specifically, CHIP is associated with an increased risk of cardiovascular events and can accelerate atherosclerosis. Mutations in TET2, one of the most commonly mutated genes in CHIP, lead to increased expression of IL-1B through inflammasome activation. Here we investigate the role of CHIP in the development of gout using a combination of human genetic studies and mouse models of CHIP. Methods: To determine the clinical association between CHIP and gout, we analyzed exome sequencing and clinical data from >50,000 individuals included in the UK Biobank (UKB) and Mass General Brigham Biobank (MGBB). To test whether mutant blood cells can promote gout, Tet2- and Dnmt3a-deficient mouse models were used. Results: CHIP was more prevalent in individuals with gout than without gout (MGBB: 12.3% vs. 7.9%, P=0.017; UKB: 8.2% vs. 5.8%, P=0.011) and individuals with CHIP were at increased risk of developing gout (UKB: hazard ratio [HR], 1.59; 95% confidence interval [CI], 1.27-2.00; P<0.001). In multivariable analyses, CHIP with variant allele fraction (VAF) ≥10% was associated with higher risk of incident gout compared to no CHIP after adjusting for common gout risk factors (UKB: HR, 1.46; 95% CI, 1.07-2.01; P=0.019). To determine if somatically mutated blood cells directly contribute to the aberrant immune response in gout, we utilized a mouse model of MSU-mediated peritonitis. Compared to control animals, mice with hematopoietic-specific Tet2 deficiency demonstrated markedly increased IL-1B serum levels after injection with MSU (P<0.05). To study gene-specific contributions to joint tissue injury, we established an in vivo model that closely represents the clinical phenotype of gout. Following MSU treatment in situ, Tet2-deficient animals developed exacerbated paw edema compared to wild-type controls (P<0.05). We next generated bone-marrow derived macrophages (BMDM) from Tet2- and Dnmt3a-deficient mice to specifically investigate the MSU-induced cytokine profile in mutant macrophages. Consistent with our in vivo data, IL-1B was the most differentially secreted cytokine after MSU treatment in both Tet2-deficient and Dnmt3a-deficient BMDM compared to wild-type cells (P<0.05). RNA-sequencing confirmed a strong pro-inflammatory gene expression signature of MSU-treated Tet2- and Dnmt3a-deficient macrophages. Finally, we found that pharmacologic inhibition or genetic loss of inflammasome abrogated IL-1B secretion in Tet2- and Dnmt3a-deficient macrophages treated with MSU. Conclusion: CHIP is associated with an increased risk of having and developing gout in human cohorts and distinct mouse models confirm a direct influence of mutant hematopoietic cells on gout-induced inflammation and arthropathy. CHIP may provide a mechanistic explanation for the heterogeneity in clinical symptoms and inflammation due to gout. Our findings substantiate the biologic rationale for interventional strategies directed at CHIP-associated inflammatory conditions beyond cardiovascular disease and thereby define a path for clinical evaluation of targeted therapies for patients with CHIP-positive gout. Disclosures Miller: Foundation Medicine: Consultancy. Neuberg: Pharmacyclics: Research Funding; Madrigal Pharmaceuticals: Other: Stock ownership. Natarajan: Amgen: Research Funding; Apple: Consultancy, Research Funding; AstraZeneca: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Boston Scientific: Research Funding; Blackstone Life Sciences: Consultancy; Genentech: Consultancy; Foresite Labs: Consultancy. Rao: Janssen: Honoraria, Research Funding; Pfizer: Honoraria; Bristol-Myers Squibb: Honoraria, Research Funding; GlaxoSmithKline: Honoraria; Merck: Honoraria; Scipher Medicine: Honoraria.

PHI-101 Is a Potent Third-Generation FLT3 Inhibitor Developed to Overcome Resistance in Acute Myeloid Leukemia

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 28-28
Author(s):  
Ky-Youb Nam ◽  
Jeejin Im ◽  
June H-J H-J Han ◽  
Kyu-Tae Kim ◽  
Jeong-Hyeok Yoon ◽  
...  
Keyword(s):  
Oral Administration ◽  
Mouse Models ◽  
Research Funding ◽  
Third Generation ◽  
Wild Type ◽  
Private Company ◽  
Flt3 Inhibitor ◽  
Flt3 Inhibitors

Background: FMS-like tyrosine kinase 3 (FLT3), a member of the class III receptor tyrosine kinase family, plays a pivotal role in regulating cell growth and differentiation of hematopoietic cells. FLT3 is mutated in approximately 30% of AML patients either by internal tandem duplication (ITD) within the juxtamembrane portion or by point-mutations in the kinase domain (TKD). Thus, FLT3 inhibitors including quizartinib (AC220), midostaurin (PKC412) and gilteritinib (ASP2215) have been developed and undergone clinical testing for the treatment of AML. However, patients frequently relapse due to intrinsic and extrinsic resistance to these FLT3 inhibitors in spite of the initial clinical efficacy. We have developed a potent third-generation FLT3 inhibitor, PHI-101, capable of overcoming some of these mechanisms of resistance. Methods: Biochemical kinase assays for PHI-101 have been performed on 9 different FLT3 mutants and wild type FLT3. Cellular potencies of PHI-101 have also been assessed using various patient-derived AML cells as well as MV4-11, MOLM14 and BaF3 cell lines transformed with human FLT3 mutants including single mutations [FLT3(ITD), FLT3(D835Y)], double or triple mutations [FLT3(ITD/D835Y), FLT3(ITD/F691L), FLT3(ITD/F691L/D835Y)]. In order to evaluate in vivo efficacies of oral administration of PHI-101, xenograft mouse models and in vivo bioluminescence imaging have been utilized. Results: PHI-101 possessed excellent enzymatic potencies against FLT3 potential resistant mutants such as ITD/D835V and the gatekeeper ITD/F691L mutation, as well as against FLT3 single activating mutants that include ITD, D835V, D835H, and D835Y. PHI-101 inhibited the phosphorylation of FLT3 and downstream STAT5 and ERK1/2 more effectively than quizartinib and gilteritinib at equivalent doses. Moreover, oral administration of PHI-101 induced tumor regression in the xenograft mouse models developed by injection of BaF3 cells transformed with FLT3-ITD, FLT3-TKD or FLT3-ITD/TKD mutants in a dose-dependent fashion with no appreciable toxicities. In luciferase-bearing blood circulating mouse models with FLT3-double mutants (ITD/D835Y and ITD/F691L) or triple mutants (ITD/D835Y/F691L), oral administration (30 mpk, QD) of PHI-101 diminished more than 89% of bioluminescent intensity and reduced leukemic burden. PHI-101 also showed increased efficacy in extending the lifespan of xenograft mice compared to quizartinib. PHI-101 strongly suppressed proliferation and induced apoptosis in primary AML samples harboring FLT3/ITD and FLT3/TKD mutations with little effect on wild-type FLT3 samples. Conclusion: PHI-101, an orally bioavailable novel small molecule, is a potent third-generation FLT3 inhibitor able to overcome resistance to several resistance mutations based on in vitro and in vivo experiments. PHI-101 possesses excellent in vitro and in vivo activities against not only FLT3 single activating mutations (ITD or TKD mutants) but also FLT3 double (ITD/D835Y or ITD/F691L) and triple (ITD/D835Y/F691L) resistant mutations with no pronounced toxicities. Preclinical evaluation of PHI-101 showed clear evidence of antileukemic activity and improved efficacy in both in vitro and in vivo models. PHI-101 is currently under investigation in first-in-human clinical trials with relapsed or refractory AML patients. Disclosures Nam: Pharos I&BT Co., Ltd.: Current equity holder in private company. Im:Pharos I&BT Co., Ltd.: Current Employment. Han:Pharos I&BT Co., Ltd.: Current equity holder in private company. Kim:Pharos I&BT Co., Ltd.: Current Employment. Yoon:Pharos I&BT Co., Ltd.: Current equity holder in private company. Cho:Pharos I&BT Co., Ltd.: Research Funding. Choi:Pharos I&BT Co., Ltd.: Research Funding. Young:Pharos I&BT Co., Ltd.: Research Funding. Nguyen:Pharos I&BT Co., Ltd.: Research Funding. Zhu:Pharos I&BT Co., Ltd.: Research Funding. Li:Pharos I&BT Co., Ltd.: Research Funding. Small:Pharos I&BT Co., Ltd.: Consultancy, Research Funding. Sim:Pharos I&BT Co., Ltd.: Research Funding.

Dasatinib Exerts Differential Effects on Normal and BCR-ABL Positive Hematopoietic Cells in a Transgenic Mouse Model of Chronic Phase-CML

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 1885-1885
Author(s):  
Claudia Schubert ◽  
Nicolas Chatain ◽  
Till Braunschweig ◽  
Mirle Schemionek ◽  
Kristina Feldberg ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Flow Cytometry ◽  
Steady State ◽  
Mouse Model ◽  
Research Funding ◽  
Hematopoietic Cells ◽  
Transgenic Mouse Model ◽  
Wild Type ◽  
Dasatinib Treatment

Abstract The second generation tyrosine kinase inhibitor dasatinib is a clinically approved drug for chronic myeloid leukemia (CML) as well as Ph+ acute lymphoblastic leukemia. Dasatinib is a dual-specific inhibitor of ABL and SRC family kinases but shows a broad inhibitory effect on various kinases, including Kit, EGFR, FAK and BTK. In addition to its antileukemic effects, dasatinib was shown to impact on the immune system, including alterations in B-cell development, T-cell differentiation, as well as a transient activation of quiescent hematopoietic stem cells (HSCs) in the bone marrow of wild-type mice. In CML patients treated with dasatinib, the development of pleural effusions and large granular lymphocyte (LGL) lymphocytosis during dasatinib treatment was associated with a favorable response. Non-hematologic adverse events included pulmonary artery hypertension and gastrointestinal symptoms. We investigated the influence of dasatinib (5 or 20 mg/kg p.o.) on the cellular composition of immune cells in our tetracycline-controlled transgenic BCR-ABL mice in comparison to control mice. We analyzed dasatinib-induced effects by flow cytometry in the bone marrow (BM) and spleen under steady-state conditions as well as after bone marrow transplantation. Furthermore, we conducted flow cytometry analysis of stem- and progenitor cells in the BM of BCR-ABL expressing mice treated with dasatinib or vehicle control and performed histophathology to evaluate effects on the BM, spleen, lung and intestine. Our results demonstrated that dasatinib dose-dependently increased Gr1/CD11b positive myeloid cells in the BM of normal mice, while B220 positive B cells and Ter119 positive erythrocytic cells were reduced. NK1.1 positive NK cells were decreased in BM but increased in the spleen. Interestingly, the lower dose (5 mg/kg) induced an increase of the percentage of CD41 positive megakaryocytic cells in BM and B cells in the spleen, while higher doses (20 mg/kg) decreased both percentages. The BCR-ABL-induced phenotype was strongly reversed by dasatinib in BCR-ABL expressing transgenic animals under steady-state conditions and in a transplantation setting: the oncogene-induced upregulation of granulocytes, megakaryocytes, and the reduction of erythroid cells as well as of B-lymphocytes was antagonized by dasatinib. Concurrently, a strong decrease of Linneg Sca1+ c-kit+ (LSK) HSCs and an increase of MEPs together with a reduction of GMPs were observed. Although the overall lymphocyte population was reduced in the BCR-ABL-expressing mice and replaced by granulocytes, we observed an increase of the proportion of CD3+, CD4+ and CD8+T cells among lymphocytes, and this increase was reverted by dasatinib treatment. Conversely, dasatinib did not significantly alter NK1.1 cells in these mice. Our observations in BCR-ABL-positive animals are in part contrary to the findings in wild-type animals, but this may be explained by the reversion of BCR-ABL effects in addition to the effects of dasatinib on normal hematopoietic cells. In addition to the above-mentioned changes, we observed a reduction of BCR-ABL mediated granulocyte infiltration of the small intestine indicating a beneficial effect in attenuating inflammation of the bowel. There was no significant alteration of the bronchial epithelium or bronchial arteries. Altogether, dasatinib robustly reduced the CML phenotype in vivo in our transgenic mouse model, and this effect included stem and progenitor populations and was stronger than the effects we have previously described for imatinib in this model. Thus, our transgenic CML mouse model is well suited to examine dasatinib effects on normal and malignant hematopoietic cells in vivo. Interestingly, there was a differential effect on myeloid cells in normal vs. CML mice, suggesting different targets in these cells. (CS and NC contributed equally to this study) Disclosures Braunschweig: Bristol-Myers-Squibb: Honoraria; MSD Sharp & Dome: Honoraria. Brümmendorf:Pfizer: Consultancy, Honoraria; Ariad: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria; Novartis: Consultancy, Honoraria, Research Funding; Patent on the use of imatinib and hypusination inhibitors: Patents & Royalties. Mustjoki:Bristol-Myers Squibb: Honoraria, Research Funding; Ariad: Research Funding; Pfizer: Honoraria, Research Funding; Novartis: Honoraria, Research Funding. Koschmieder:Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel funding to conferences, Research Funding.

scholarly journals Expression of TCF3-ZNF384 in Human Hematopoietic Cells Induces Lineage Disruption in Vitro and Acute Leukemia in Vivo

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 550-550 ◽  
Author(s):  
Kirsten Dickerson ◽  
Hiroki Yoshihara ◽  
Laura Janke ◽  
Charles G. Mullighan
Keyword(s):  
Acute Leukemia ◽  
Blood Cells ◽  
Research Funding ◽  
Progenitor Cell ◽  
Wild Type ◽  
Hematopoietic Stem ◽  
Human Cd34 ◽  
Cord Blood Cells

Abstract Introduction: Rearrangement of ZNF384, a transcription factor of poorly characterized function, defines a subtype of acute leukemia that may manifest as either B-ALL with aberrant myeloid marker expression or B/myeloid mixed phenotype acute leukemia (MPAL). Such leukemias are characterized by chromosomal rearrangements that result in the fusion of a diverse group of partners, often transcription factors or epigenetic modifiers, to ZNF384. Our prior studies have shown that ZNF384 B-ALL and B/myeloid MPAL are genomically indistinguishable, and that the fusion may be identified in a subset of hematopoietic stem cells, suggesting that the acquisition of a ZNF384 fusion in a primitive progenitor directly perturbs hematopoietic differentiation. The goals of this study were to determine the effect of expression of ZNF384 rearrangements on human hematopoietic stem and progenitor cell differentiation in vitro and in vivo, using TCF3-ZNF384 as a commonly observed exemplar of this form of leukemia. Methods: For in vitro experiments, human CD34+ cord blood cells were sorted into stem and progenitor populations (hematopoietic stem cell (HSC), multipotent progenitor (MPP), common myeloid progenitor (CMP), granulocyte-macrophage progenitor (GMP), and megakaryocyte-erythroid progenitor (MEP)) and lentivirally infected with wild type ZNF384, TCF3-ZNF384, or vector control. Single cells were sorted onto an MS-5 stromal layer and the immunophenotype of colonies was determined 15 days later by flow cytometry. In vivo studies were performed by sorting human CD34+ cord blood cells into stem-enriched (CD34+CD38-) or progenitor-enriched (CD34+CD38+) populations and lentivirally infecting with wild type ZNF384, TCF3-ZNF384, or vector control. Cells were transplanted into sub-lethally irradiated NOD.Cg-Prkdcscid Il2rgtm1Wjl Tg(CMV-IL3,CSF2,KITLG)1Eav/MloySzJ (NSG-SGM3) mice. Results: Single-cell MS-5 stromal experiments revealed that expression of the fusion protein perturbed hematopoietic differentiation. In all stem and progenitor populations, cells expressing TCF3-ZNF384 lost the ability to differentiate into erythroid colonies. HSC, MPP, and CMP cells expressing the fusion most commonly form undifferentiated, CD45+, CD33+ colonies. Additionally, GMP and MEP cells expressing the fusion lost their ability to form colonies. Human CD34+ cells expressing TCF3-ZNF384 successfully initiate leukemia in NSG-SGM3 mice with a median latency of 123 days. Mice presented with anemia and pathological analysis using hematoxylin and eosin staining showed infiltration of leukemic cells into the bone marrow, spleen, liver, central nervous system, and ovary. Additionally, CD33, myeloperoxidase, and major basic protein staining confirmed myeloid leukemia with a subset of eosinophil differentiation. Conclusion: Our results demonstrate that hematopoietic lineage determination is altered by the expression of TCF3-ZNF384 in human stem and progenitor cell populations. Additionally, we have created the first model of TCF3-ZNF384 leukemia which mimics the complexity of lineage deregulation in ZNF384-rearranged leukemia. Disclosures Mullighan: Cancer Prevention and Research Institute of Texas: Consultancy; Amgen: Honoraria, Speakers Bureau; Loxo Oncology: Research Funding; Pfizer: Honoraria, Research Funding, Speakers Bureau; Abbvie: Research Funding.

Induction of an Antitumoral Immune Response by Wild-Type Adeno-Associated Virus Type 2 in an In Vivo Model of Pancreatic Carcinoma

Pancreas ◽  
2007 ◽  
Vol 35 (1) ◽  
pp. 63-72 ◽  
Author(s):  
Sven Eisold ◽  
Jan Schmidt ◽  
Eduard Ryschich ◽  
Michael Gock ◽  
Ernst Klar ◽  
...  
Keyword(s):  
Immune Response ◽  
Pancreatic Carcinoma ◽  
Virus Type ◽  
In Vivo Model ◽  
Wild Type ◽  
Adeno Associated Virus

FIX-Triple, a gain-of-function factor IX variant, improves haemostasis in mouse models without increased risk of thrombosis

2010 ◽  
Vol 104 (08) ◽  
pp. 355-365 ◽  
Author(s):  
Chung-Yang Kao ◽  
Chia-Ni Lin ◽  
I-Shing Yu ◽  
Mi-Hua Tao ◽  
Hua-Lin Wu ◽  
...  
Keyword(s):  
Mouse Models ◽  
Specific Activity ◽  
Factor Ix ◽  
Wild Type ◽  
Haemophilia B ◽  
Virus Particles ◽  
Thrombosis Risk ◽  
Increased Risk ◽  
Recombinant Factor Ix ◽  
Fold Excess

SummaryEngineered recombinant factor IX (FIX) with augmented clotting activity may prove useful for replacement therapy, but it has not been studied for risk of thrombosis. We used three mouse models to evaluate thrombosis risk associated with the FIX variant FIX-Triple, which has a 13-fold higher specific activity than wild-type FIX (FIX-WT). Protein infusion of FIX-Triple into haemophilia B mice was not thrombogenic, even at a dose of 13-fold higher than FIX-WT. Gene knock-in to generate mice that constitutively produce FIX-WT or FIX-Triple protein revealed that all mice expressed equal antigen levels. FIX-Triple knock-in mice that exhibited 10-fold higher FIX clotting activity did not show hypercoagulation. Adeno-associated viral (AAV) delivery of the FIX gene into mice was used to mimic gene therapy. Haemophilia B and inbred C57Bl/6 mice injected with different doses of virus particles carrying FIX-WT or FIX-Triple and expressing up to a nearly 13-fold excess (1289% of normal) of FIX clotting activity did not show increased risk of thrombosis compared with untreated wild-type mice in a normal haemostatic state. When challenged with ferric chloride (FeCl3), the mesenteric venules of AAV-treated C57Bl/6 mice that gave a nearly five-fold excess (474%) of FIX clotting activity were not thrombotic; however, thrombosis became obvious in FeCl3-challenged mice expressing extremely high FIX clotting activities (976–1289%) achieved by AAV delivery of FIX-Triple. These studies suggest that FIX-Triple is not thrombogenic at therapeutic levels and is a potential therapeutic substitute for FIX-WT.

Requirement of CREB in Normal and Malignant Hematopoiesis.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1168-1168
Author(s):  
Jerry C. Cheng ◽  
Deepa Shankar ◽  
Stanley F. Nelson ◽  
Kathleen M. Sakamoto
Keyword(s):  
Bone Marrow ◽  
Cell Proliferation ◽  
Western Blot ◽  
Blot Analysis ◽  
Hematopoietic Cells ◽  
Wild Type ◽  
Qrt Pcr ◽  
T315i Mutation

Abstract CREB is a nuclear transcription factor that plays an important role in regulating cellular proliferation, memory, and glucose homeostasis. We previously demonstrated that CREB is overexpressed in bone marrow cells from a subset of patients with acute leukemia at diagnosis. Furthermore, CREB overexpression is associated with an increased risk of relapse and decreased event-free survival in adult AML patients. Transgenic mice that overexpress CREB in myeloid cells developed myeloproliferative/myelodysplastic syndrome after one year. To further understand the role of CREB in leukemogenesis and in normal hematopoiesis, we employed RNA interference methods to inhibit CREB expression. To achieve sustained, CREB-specific gene knockdown in leukemia and normal hematopoietic cells, a lentiviral-based small hairpin (shRNA) approach was taken. Three CREB specific shRNAs were generated and tested for efficiency of gene knockdown in 293T cells. Knockdown efficiency approached 90 percent by Western blot analysis compared to vector alone and luciferase controls. Human myeloid leukemia cell lines, K562, TF1, and MV411, were then infected with CREB shRNA lentivirus, sorted for GFP expression, and analyzed using quantitative real time (qRT)-PCR, Western blot analysis, and growth and viability assays. Lentiviral CREB-shRNA achieved between 50 to 90 percent knockdown of CREB compared to control shRNAs at the protein and mRNA levels. To control for non-specific effects, we performed qRT-PCR analysis of the interferon response gene, OAS1, which was not upregulated in cells transduced with CREB shRNA constructs. Within 72 hours, cells transduced with CREB shRNA had decreased proliferation and survival. Similar results were obtained with murine leukemia cells (NFS60 and BA/F3 bcr-abl).To study the role of CREB in normal hematopoiesis, both primary murine and human hematopoietic cells were transduced with our shRNA constructs, and methylcellulose-based colony assays were performed. Primary hematopoietic cells infected with CREB shRNA lentivirus demonstrated a 5-fold decrease in colony number compared to control virus-infected cells (p<0.05). Bone marrow colonies consisted of myeloid progenitor cells that were mostly Mac-1+ by FACs analysis. Interestingly, there were fewer differentiated cells in the CREB shRNA transduced cells compared to vector control or wild type cells, suggesting that CREB is critical for both myeloid cell proliferation and differentiation. To study the in vivo effects of CREB knockdown on leukemia progression, we studied mice injected with BA/F3 cells that express both bcr/abl with the T315I mutation and a luciferase reporter gene. BA/F3 cells expressing the T315I mutation have a 2-fold increase in CREB overexpression compared to wild-type cells. Disease progression was monitored using bioluminescence imaging with luciferin. CREB knockdown was 90 percent after transduction and prior to injection into SCID mice. We observed improved survival of mice injected with CREB shRNA transduced BA/F3 bcr-abl (T315I) compared to vector control cells. To understand the mechanism of growth suppression resulting from CREB downregulation, we performed microarray analysis with RNA from CREB shRNA transduced K562 and TF1 cells. Several genes were downregulated using a Human Affymetrix chip. Most notable was Beclin1, a tumor suppressor gene often deleted in prostate and breast cancer that has been implicated in autophagy. Our results demonstrate that CREB is required for normal and leukemic cell proliferation both in vitro and in vivo.

The New CXCR4 Inhibitor MDX-1338 Exerts Anti-Tumor Activity in Multiple Myeloma

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 1844-1844 ◽  
Author(s):  
Aldo M Roccaro ◽  
Antonio Sacco ◽  
Michelle Kuhne ◽  
AbdelKareem Azab ◽  
Patricia Maiso ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Bone Marrow ◽  
Tumor Cells ◽  
Mouse Models ◽  
Research Funding ◽  
Therapeutic Agents ◽  
Dependent Manner ◽  
Apoptotic Pathways ◽  
Dose Dependent

Abstract Abstract 1844 Background. We have previously shown the SDF1/CXCR4 axis plays a major role in homing and trafficking of multiple myeloma (MM) to the bone marrow (BM), and disruption of the interaction of tumor cells with the BM leads to enhanced sensitivity to therapeutic agents. We hypothesize that the novel anti-CXCR4 antibody, BMS936564/MDX-1338, may prevent the homing and adhesion of MM cells to the BM and will sensitize them to therapeutic agents. Methods. Primary MM cells (CD138+); MM cell lines (MM.1S, RPMI.8226); and primary MM bone marrow stromal cells (BMSCs) were used. Migration towards SDF-1 and BMSCs has been evaluated. Cytotoxicity and DNA synthesis were measured by MTT and thymidine uptake, respectively. Cell signaling and apoptotic pathways were studied by Western Blot. Synergism was calculated using the Chou-Talalay method. In vivo MM tumor growth was evaluated with xenograft mouse models. Results. MDX-1338 inhibited migration of MM cells toward SDF-1a and primary MM BMSCs, in a dose-dependent manner. Adhesion of primary MM cells to BMSCs was also inhibited by BMS936564/MDX-1338 in a dose-dependent manner, while also inducing cytotoxicity on primary BM-derived CD138+ cells. BMS936564/MDX-1338 targeted MM cells in the context of BM milieu by overcoming BMSC-induced proliferation of tumor cells. In addition, BMS936564/MDX-1338 synergistically enhanced bortezomib-induced cytotoxicity in MM cells. BMS936564/MDX-1338-dependent activation of apoptotic pathways in MM cells was documented, as shown by cleavage of caspase-9 and PARP. SDF-1a-induced ERK-, Akt-, and Src-phosphorilation was inhibited by BMS936564/MDX-1338 in a dose-dependent manner. Importantly, BMS936564/MDX-1338 inhibited MM cell proliferation in vivo in xenograft mouse models. Conclusion. These studies therefore show that targeting CXCR-4 in MM by using BMS936564/MDX-1338 represents a valid therapeutic strategy in this disease. Disclosures: Roccaro: Roche:. Kuhne:BMS: Employment. Pan:Bristol-Myers Squibb: Employment. Cardarelli:Bristol-Myers Squibb: Employment. Ghobrial:Noxxon: Research Funding; Bristol-Myers Squibb: Research Funding; Millennium: Research Funding; Noxxon:; Millennium:; Celegene:; Novartis:.

Sqstm1 Is Required to Retain Hematopoietic Stem Cell/ Progenitors As a Negative Regulator of Macrophage-Dependent Inflammatory Signaling in the Bone Marrow Osteoblastic Niche

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 350-350
Author(s):  
Kyung-Hee Chang ◽  
Amitava Sengupta ◽  
Ramesh C Nayak ◽  
Angeles Duran ◽  
Sang Jun Lee ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Hematopoietic Stem Cells ◽  
Research Funding ◽  
Negative Regulator ◽  
Wild Type ◽  
Hematopoietic Stem ◽  
P Retention

Abstract In the bone marrow (BM), hematopoietic stem cells and progenitors (HSC/P) reside in specific anatomical niches. Among these niches, a functional osteoblast (Ob)-macrophage (MΦ) niche has been described where Ob and MΦ (so called "osteomacs") are in direct relationship. A connection between innate immunity surveillance and traffic of hematopoietic stem cells/progenitors (HSC/P) has been demonstrated but the regulatory signals that instruct immune regulation from MΦ and Ob on HSC/P circulation are unknown. The adaptor protein sequestosome 1 (Sqstm1), contains a Phox bemp1 (PB1) domain which regulates signal specificities through PB1-PB1 scaffolding and processes of autophagy. Using microenvironment and osteoblast-specific mice deficient in Sqstm1, we discovered that the deficiency of Sqstm1 results in macrophage contact-dependent activation of Ob IKK/NF-κB, in vitro and in vivo repression of Ccl4 (a CCR5 binding chemokine that has been shown to modulate microenvironment Cxcl12-mediated responses of HSC/P), HSC/P egress and deficient BM homing of wild-type HSC/P. Interestingly, while Ccl4 expression is practically undetectable in wild-type or Sqstm1-/- Ob, primary Ob co-cultured with wild-type BM-derived MΦ strongly upregulate Ccl4 expression, which returns to normal levels upon genetic deletion of Ob Sqstm1. We discovered that MΦ can activate an inflammatory pathway in wild-type Ob which include upregulation of activated focal adhesion kinase (p-FAK), IκB kinase (IKK), nuclear factor (NF)-κB and Ccl4 expression through direct cell-to-cell interaction. Sqstm1-/- Ob cocultured with MΦ strongly upregulated p-IKBα and NF-κB activity, downregulated Ccl4 expression and secretion and repressed osteogenesis. Forced expression of Sqstm1, but not of an oligomerization-deficient mutant, in Sqstm1-/- Ob restored normal levels of p-IKBα, NF-κB activity, Ccl4 expression and osteogenic differentiation, indicating that Sqstm1 dependent Ccl4 expression depends on localization to the autophagosome formation site. Finally, Ob Sqstm1 deficiency results in upregulation of Nbr1, a protein containing a PB1 interacting domain. Combined deficiency of Sqstm1 and Nbr1 rescues all in vivo and in vitro phenotypes of Sqstm1 deficiency related to osteogenesis and HSC/P egression in vivo. Together, this data indicated that Sqstm1 oligomerization and functional repression of its PB1 binding partner Nbr1 are required for Ob dependent Ccl4 production and HSC/P retention, resulting in a functional signaling network affecting at least three cell types. A functional ‘MΦ-Ob niche’ is required for HSC/P retention where Ob Sqstm1 is a negative regulator of MΦ dependent Ob NF-κB activation, Ob differentiation and BM HSC/P traffic to circulation. Disclosures Starczynowski: Celgene: Research Funding. Cancelas:Cerus Co: Research Funding; P2D Inc: Employment; Terumo BCT: Research Funding; Haemonetics Inc: Research Funding; MacoPharma LLC: Research Funding; Therapure Inc.: Consultancy, Research Funding; Biomedical Excellence for Safer Transfusion: Research Funding; New Health Sciences Inc: Consultancy.

scholarly journals Robotic QM/MM-driven maturation of antibody combining sites

2016 ◽  
Vol 2 (10) ◽  
pp. e1501695 ◽  
Author(s):  
Ivan V. Smirnov ◽  
Andrey V. Golovin ◽  
Spyros D. Chatziefthimiou ◽  
Anastasiya V. Stepanova ◽  
Yingjie Peng ◽  
...  
Keyword(s):  
Immune Response ◽  
In Vitro Selection ◽  
Single Point ◽  
Combinatorial Libraries ◽  
Single Point Mutation ◽  
Wild Type ◽  
Selection Of ◽  
Maturation Function

In vitro selection of antibodies from large repertoires of immunoglobulin (Ig) combining sites using combinatorial libraries is a powerful tool, with great potential for generating in vivo scavengers for toxins. However, addition of a maturation function is necessary to enable these selected antibodies to more closely mimic the full mammalian immune response. We approached this goal using quantum mechanics/molecular mechanics (QM/MM) calculations to achieve maturation in silico. We preselected A17, an Ig template, from a naïve library for its ability to disarm a toxic pesticide related to organophosphorus nerve agents. Virtual screening of 167,538 robotically generated mutants identified an optimum single point mutation, which experimentally boosted wild-type Ig scavenger performance by 170-fold. We validated the QM/MM predictions via kinetic analysis and crystal structures of mutant apo-A17 and covalently modified Ig, thereby identifying the displacement of one water molecule by an arginine as delivering this catalysis.

scholarly journals Gabarap Loss Mediates Immune Escape in High Risk Multiple Myeloma

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 891-891
Author(s):  
Annamaria Gulla ◽  
Eugenio Morelli ◽  
Mehmet K. Samur ◽  
Cirino Botta ◽  
Megan Johnstone ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cell ◽  
Clinical Outcome ◽  
Board Of Directors ◽  
Research Funding ◽  
Immune Escape ◽  
Publicly Traded ◽  
Advisory Committees

Abstract Immune therapies including CAR T cells and bispecific T cell engagers are demonstrating remarkable efficacy in relapsed refractory myeloma (MM). In this context, we have recently shown that proteasome inhibitor bortezomib (BTZ) results in immunogenic cell death (ICD) and in a viral mimicry state in MM cells, allowing for immune recognition of tumor cells. Induction of a robust anti-MM immune response after BTZ was confirmed both in vitro and in vivo: treatment of 5TGM1 MM cells with BTZ induced tumor regression associated with memory immune response, confirmed by ELISPOT of mouse splenocytes. We have confirmed the obligate role of calreticulin (CALR) exposure in phagocytosis and the ICD process, since BTZ-induced ICD is impaired in CALR KO MM cells both in vitro and in vivo. We further showed that the therapeutic efficacy of BTZ in patients was correlated with ICD induction: BTZ-induced ICD signature was positively correlated with OS (p=0.01) in patients enrolled in the IFM/DFCI 2009 study. Together, these studies indicate that ICD is associated with long-term response after BTZ treatment. In this work, we reasoned that genomic or transcriptomic alterations associated with shorter survival of MM patients after BTZ treatment may impair activation of the ICD pathway. To this aim, we performed a transcriptomic analysis of purified CD138+ cells from 360 newly diagnosed, clinically-annotated MM patients enrolled in the IFM/DFCI 2009 study. By focusing on genes involved in the ICD process, we found that low levels of GABA Type A Receptor-Associated Protein (GABARAP) were associated with inferior clinical outcome (EFS, p=0.0055). GABARAP gene locus is located on chr17p13.1, a region deleted in high risk (HR) MM with unfavorable prognosis. Remarkably, we found that correlation of low GABARAP levels with shorter EFS was significant (p=0.018) even after excluding MM patients with del17p; and GABARAP is therefore an independent predictor of clinical outcome. GABARAP is a regulator of autophagy and vesicular trafficking, and a putative CALR binding partner. Interestingly, among a panel of MM cell lines (n=6), BTZ treatment failed to induce exposure of CALR and MM cell phagocytosis by DCs in KMS11 cells, which carry a monoallelic deletion of GABARAP. This effect was rescued by stable overexpression of GABARAP. Moreover, CRISPR/Cas9-mediated KO of GABARAP in 3 ICD-sensitive cell lines (AMO1, H929, 5TGM1) abrogated CALR exposure and ICD induction by BTZ. GABARAP add-back by stable overexpression in KO clones restored both CALR exposure and induction of ICD, confirming GABARAP on-target activity. Similarly, pre-treatment of GABARAP KO cells with recombinant CALR restored MM phagocytosis, further confirming that GABARAP impairs ICD via inhibition of CALR exposure. Based on these findings, we hypothesized that GABARAP loss may alter the ICD pathway via CALR trapping, resulting in the ICD resistant phenotype observed in GABARAP null and del17p cells. To this end, we explored the impact of GABARAP KO on the CALR protein interactome, in the presence or absence of BTZ. Importantly, GABARAP KO produced a significant increase of CALR binding to stanniocalcin 1 (STC1), a phagocytosis checkpoint that mediates the mitochondrial trapping of CALR, thereby minimizing its exposure upon ICD. Consistently, GABARAP KO also affected CALR interactome in BTZ-treated cells, which was significantly enriched in mitochondrial proteins. Importantly, co-IP experiments confirmed GABARAP interaction with STC1. These data indicate a molecular scenario whereby GABARAP interacts with STC1 to avoid STC1-mediated trapping of CALR, allowing for the induction of ICD after treatment with ICD inducers; on the other hand, this mechanism is compromised in GABARAP null or del17p cells, and the STC1-CALR complex remains trapped in the mitochondria, resulting in ICD resistance. To functionally validate our findings in the context of the immune microenvironment, we performed mass Cytometry after T cell co-culture with DCs primed by both WT and GABARAP KO AMO1 clones. And we confirmed that treatment of GABARAP KO clones with BTZ failed to activate an efficient T cell response. In conclusion, our work identifies a unique mechanism of immune escape which may contribute to the poor clinical outcome observed in del17p HR MM patients. It further suggests that novel therapies to restore GABARAP may allow for the induction of ICD and improved patient outcome in MM. Disclosures Bianchi: Jacob D. Fuchsberg Law Firm: Consultancy; MJH: Honoraria; Karyopharm: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria. Richardson: AstraZeneca: Consultancy; Regeneron: Consultancy; Protocol Intelligence: Consultancy; Secura Bio: Consultancy; GlaxoSmithKline: Consultancy; Sanofi: Consultancy; Janssen: Consultancy; Takeda: Consultancy, Research Funding; AbbVie: Consultancy; Karyopharm: Consultancy, Research Funding; Celgene/BMS: Consultancy, Research Funding; Oncopeptides: Consultancy, Research Funding; Jazz Pharmaceuticals: Consultancy, Research Funding. Chauhan: C4 Therapeutics: Current equity holder in publicly-traded company; Stemline Therapeutics, Inc: Consultancy. Munshi: Legend: Consultancy; Karyopharm: Consultancy; Amgen: Consultancy; Janssen: Consultancy; Celgene: Consultancy; Oncopep: Consultancy, Current equity holder in publicly-traded company, Other: scientific founder, Patents & Royalties; Abbvie: Consultancy; Takeda: Consultancy; Adaptive Biotechnology: Consultancy; Novartis: Consultancy; Pfizer: Consultancy; Bristol-Myers Squibb: Consultancy. Anderson: Sanofi-Aventis: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Millenium-Takeda: Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; Scientific Founder of Oncopep and C4 Therapeutics: Current equity holder in publicly-traded company, Current holder of individual stocks in a privately-held company; AstraZeneca: Membership on an entity's Board of Directors or advisory committees; Mana Therapeutics: Membership on an entity's Board of Directors or advisory committees.

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