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Current autologous cell therapies, with blockbuster products on the market, have been leading for a decade to unprecedented clinical successes in patients with hematological malignancies. However, these patient-derived T-cell therapies are facing many challenges. The use of GMP iPSC lines to produce immune effector cells will reduce the complexity of the manufacturing process and will provide an unlimited source of starting material. The goal of the EVOcells Oncology platform is to offer a truly allogeneic cell therapy platform to treat a broad number of cancer patients with consistent quality and scalability of the final product. Besides, the versatility of our platform to produce different immune cell types combined to customized genetic engineering strategies will bring cell therapy to the level of personalized medicine. Our “off-the-shelf” cell therapy platform has already validated two pillars: iPSC-derived NK cells (iNK) and iPSC-derived Macrophages (iMACs). Through multiple genetic engineering strategies specific to each immune cell type, we are developing a comprehensive portfolio of cell therapy products to address specific tumor escape mechanism in liquid and solid tumors. Our initial effort aimed to develop these two innate immune cell types to propose efficacious cell therapies with an increased safety profile as they have low risk of graft-versus-host disease (GvHD) or CRS (Cytokine Release Syndrome). Thanks to the expression of a broad pattern of activatory receptors, iNK cells form Immunological Synapses with tumor cells leading in turn to efficient killing with and without addition of a CAR construct. Besides, we demonstrated the possibility to combine “naked” iNK cells with marketed therapeutic monoclonal antibodies (mAb) to further improve their efficacy. At the end of the differentiation process, iMACs are showing a M0 like phenotype with high plasticity allowing the in vitro differentiation of the cells towards either a M1 or a M2 polarization in response to the appropriate stimulations. iMACs produce key macrophages cytokines and are able to kill tumor cells via ADCP (Antibody-Dependent-Cell-Phagocytosis) mechanism when combined to a therapeutic mAb. Thanks to our collaboration with clinicians at the IUCT-Oncopole (Toulouse Cancer Hospital), we were able to identify appropriate cancer indications and further demonstrate in a translational fashion that both iNK and iMACs are able to kill primary resistant tumor cells which were isolated from patient’ samples. Taken together, these results are showing the versatility and the breadth of our EVOcells Oncology platform to produce a true arsenal of cell therapies and its potential for future clinical development. Citation Format: Michael Esquerré, Audrey Holtzinger, Nadja Wagner, Monika Braun, Mélanie Pichery, Stefanie Pfaender, Stephanie Sontag, Kathrin Haake, Michela Mirenda, Michael Paillasse, Davide Grandolfo, Chloé Beuraud, Mandy Richter, Philip Hublitz, Julien Bousquet, Marion Fabre, Mylène Gador, Daniel Sommermeyer, Tanja Schneider, Oriane Bombarde, Camille Esquerré, Loic Ysebaert, Fabien Despas, Matthias Austen, Andreas Scheel, Markus Dangl. EVOcells Oncology: Tailored genetic engineering of iPSC-derived immune effector cells and combination with the right biologic therapeutics result in optimal killing of primary tumor cells from patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3203.

The KIT D816V mutation is found in >80% of patients with systemic mastocytosis (SM) and is key to neoplastic mast cell (MC) expansion and accumulation in affected organs. Therefore, KIT D816V represents a prime therapeutic target for SM. Here, we generated a panel of patient-specific KIT D816V induced pluripotent stem cells (iPSCs) from patients with aggressive SM and mast cell leukemia to develop a patient-specific SM disease model for mechanistic and drug-discovery studies. KIT D816V iPSCs differentiated into neoplastic hematopoietic progenitor cells and MCs with patient-specific phenotypic features, thereby reflecting the heterogeneity of the disease. CRISPR/Cas9n-engineered KIT D816V human embryonic stem cells (ESCs), when differentiated into hematopoietic cells, recapitulated the phenotype observed for KIT D816V iPSC hematopoiesis. KIT D816V causes constitutive activation of the KIT tyrosine kinase receptor, and we exploited our iPSCs and ESCs to investigate new tyrosine kinase inhibitors targeting KIT D816V. Our study identified nintedanib, a US Food and Drug Administration–approved angiokinase inhibitor that targets vascular endothelial growth factor receptor, platelet-derived growth factor receptor, and fibroblast growth factor receptor, as a novel KIT D816V inhibitor. Nintedanib selectively reduced the viability of iPSC-derived KIT D816V hematopoietic progenitor cells and MCs in the nanomolar range. Nintedanib was also active on primary samples of KIT D816V SM patients. Molecular docking studies show that nintedanib binds to the adenosine triphosphate binding pocket of inactive KIT D816V. Our results suggest nintedanib as a new drug candidate for KIT D816V–targeted therapy of advanced SM.

Clinical epigenetics 14, 29 (2022). doi:10.1186/s13148-022-01245-3, Published by BioMed Central, [Erscheinungsort nicht ermittelbar]

Classical Philadelphia chromosome-negative myeloproliferative neoplasms (MPN) are a heterogeneous group of hematopoietic malignancies including polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF). The JAK2V617F mutation plays a central role in these disorders and can be found in 90% of PV and ~50-60% of ET and PMF. Hypoxia-inducible factor 1 (HIF-1) is a master transcriptional regulator of the response to decreased oxygen levels. We demonstrate the impact of pharmacological inhibition and shRNA-mediated knockdown (KD) of HIF-1α in JAK2V617F-positive cells. Inhibition of HIF-1 binding to hypoxia response elements (HREs) with echinomycin, verified by ChIP, impaired growth and survival by inducing apoptosis and cell cycle arrest in Jak2V617F-positive 32D cells, but not Jak2WT controls. Echinomycin selectively abrogated clonogenic growth of JAK2V617F cells and decreased growth, survival, and colony formation of bone marrow and peripheral blood mononuclear cells and iPS cell-derived progenitor cells from JAK2V617F-positive patients, while cells from healthy donors were unaffected. We identified HIF-1 target genes involved in the Warburg effect as a possible underlying mechanism, with increased expression of Pdk1, Glut1, and others. That was underlined by transcriptome analysis of primary patient samples. Collectively, our data show that HIF-1 is a new potential therapeutic target in JAK2V617F-positive MPN.

Clinical chemistry 68(5), 646-656 (2022). doi:10.1093/clinchem/hvac006, Published by Oxford University Press, Oxford

TheKITD816V mutation is found in more than 80% of patients with systemic mastocytosis (SM) and is key to neoplastic mast cell (MC) expansion and accumulation in affected organs.KITD816V therefore represents a prime therapeutic target for SM. Here we generated a panel of patient-specificKITD816V induced pluripotent stem cells (iPSCs) from patients with aggressive SM (ASM) and mast cell leukemia (MCL) to develop a patient-specific SM disease model for mechanistic and drug discovery studies.KITD816V iPSCs differentiated into neoplastic hematopoietic progenitor cells and MCs with patient-specific phenotypic features, thereby reflecting the heterogeneity of the disease. CRISPR/Cas9n-engineeredKITD816V human embryonic stem cells (ESCs), when differentiated into hematopoietic cells, recapitulated the phenotype observed forKITD816V iPSC hematopoiesis.KITD816V causes constitutive activation of the KIT tyrosine kinase receptor and we exploited our iPSCs and ESCs to investigate new tyrosine kinase inhibitors targeting KIT D816V. Our study identified nintedanib as a novel KIT D816V inhibitor. Nintedanib selectively reduced the viability of iPSC-derivedKITD816V hematopoietic progenitor cells and MCs in the nanomolar range. Nintedanib was also active on primary samples of KIT D816V SM patients. Molecular docking studies show that nintedanib binds to the ATP binding pocket of inactive KIT D816V. Our results suggest nintedanib as a new drug candidate for KIT D816V targeted therapy of advanced SM.

Stem cell research 55, 102490 (2021). doi:10.1016/j.scr.2021.102490, Published by Elsevier, Amsterdam [u.a.]

Supplemental Digital Content is Available in the Text. Human sodium channel NaV1.7 in induced pluripotent stem cell–derived sensory neurons sets the action potential threshold but does not support subthreshold depolarizations., The chronic pain syndrome inherited erythromelalgia (IEM) is attributed to mutations in the voltage-gated sodium channel (NaV) 1.7. Still, recent studies targeting NaV1.7 in clinical trials have provided conflicting results. Here, we differentiated induced pluripotent stem cells from IEM patients with the NaV1.7/I848T mutation into sensory nociceptors. Action potentials in these IEM nociceptors displayed a decreased firing threshold, an enhanced upstroke, and afterhyperpolarization, all of which may explain the increased pain experienced by patients. Subsequently, we investigated the voltage dependence of the tetrodotoxin-sensitive NaV activation in these human sensory neurons using a specific prepulse voltage protocol. The IEM mutation induced a hyperpolarizing shift of NaV activation, which leads to activation of NaV1.7 at more negative potentials. Our results indicate that NaV1.7 is not active during subthreshold depolarizations, but that its activity defines the action potential threshold and contributes significantly to the action potential upstroke. Thus, our model system with induced pluripotent stem cell–derived sensory neurons provides a new rationale for NaV1.7 function and promises to be valuable as a translational tool to profile and develop more efficacious clinical analgesics.

Background Differentiation of induced pluripotent stem cells (iPSCs) toward hematopoietic progenitor cells (HPCs) raises high hopes for disease modeling, drug screening, and cellular therapy. Various differentiation protocols have been established to generate iPSC-derived HPCs (iHPCs) that resemble their primary counterparts in morphology and immunophenotype, whereas a systematic epigenetic comparison was yet elusive. Results In this study, we compared genome-wide DNA methylation (DNAm) patterns of iHPCs with various different hematopoietic subsets. After 20 days of in vitro differentiation, cells revealed typical hematopoietic morphology, CD45 expression, and colony-forming unit (CFU) potential. DNAm changes were particularly observed in genes that are associated with hematopoietic differentiation. On the other hand, the epigenetic profiles of iHPCs remained overall distinct from natural HPCs. Furthermore, we analyzed if additional co-culture for 2 weeks with syngenic primary mesenchymal stromal cells (MSCs) or iPSC-derived MSCs (iMSCs) further supports epigenetic maturation toward the hematopoietic lineage. Proliferation of iHPCs and maintenance of CFU potential was enhanced upon co-culture. However, DNAm profiles support the notion that additional culture expansion with stromal support did not increase epigenetic maturation of iHPCs toward natural HPCs. Conclusion Differentiation of iPSCs toward the hematopoietic lineage remains epigenetically incomplete. These results substantiate the need to elaborate advanced differentiation regimen while DNAm profiles provide a suitable measure to track this process. Electronic supplementary material The online version of this article (10.1186/s13148-019-0617-1) contains supplementary material, which is available to authorized users.

The aim of the current study was to estimate total intake and dietary sources of eicosapentaenoic acid (EPA), docosapentanoic (DPA), and docosahexaenoic acid (DHA) and compare DHA intakes with the recommended intakes in a cohort of pregnant and lactating women. Twenty-four–hour dietary recalls and supplement intake questionnaires were collected from 600 women in the Alberta Pregnancy Outcomes and Nutrition (APrON) cohort at each trimester of pregnancy and 3 months postpartum. Dietary intake was estimated in 2 ways: by using a commercial software program and by using a database created for APrON. Only 27% of women during pregnancy and 25% at 3 months postpartum met the current European Union (EU) consensus recommendation for DHA. Seafood, fish, and seaweed products contributed to 79% of overall n-3 long-chain polyunsaturated fatty acids intake from foods, with the majority from salmon. The estimated intake of DHA and EPA was similar between databases, but the estimated DPA intake was 20%–30% higher using the comprehensive database built for this study. Women who took a supplement containing DHA were 10.6 and 11.1 times more likely to meet the current EU consensus recommendation for pregnancy (95% confidence interval (CI): 6.952–16.07; P < 0.001) and postpartum (95% CI: 6.803–18.14; P < 0.001), respectively. Our results suggest that the majority of women in the cohort were not meeting the EU recommendation for DHA during pregnancy and lactation, but taking a supplement significantly improved the likelihood that they would meet recommendations.

Induced pluripotent stem cells (iPS cells) are engineered stem cells, which exhibit properties very similar to embryonic stem cells (ES cells; Takahashi and Yamanaka, 2016). Both iPS cells and ES cells have an extraordinary self-renewal capacity and can differentiate into all cell types of our body, including hematopoietic stem/progenitor cells and dendritic cells (DC) derived thereof. This makes iPS cells particularly well suited for studying molecular mechanisms of diseases, drug discovery and regenerative therapy ( Grskovic et al., 2011 ; Bellin et al., 2012 ; Robinton and Daley, 2012). DC are the major antigen presenting cells of the immune system and thus they are key players in modulating and directing immune responses ( Merad et al., 2013 ). DC patrol peripheral and interface tissues (e.g., lung, intestine and skin) to detect invading pathogens, and upon activation they migrate to lymph nodes to activate and prime lymphocytes. DC comprise a phenotypically heterogeneous family with functionally specialized subsets (Schlitzer and Ginhoux, 2014). Generally, classical DC (cDC) and plasmacytoid DC (pDC) are distinguished, exhibiting a classical and plasma cell-like DC morphology, respectively. cDC recognize a multitude of pathogens and secrete proinflammatory cytokines upon activation, while pDC are specialized to detect intracellular pathogens and secrete type I interferons ( Merad et al., 2013 ; Schlitzer and Ginhoux, 2014). cDC are further divided into cross-presenting cDC1 and conventional cDC2, in the human system referred to as CD141(+) Clec9a(+) cDC1 and CD1c(+) CD14- cDC2. Human pDC are characterized as CD303(+) CD304(+) ( Jongbloed et al., 2010 ; Joffre et al., 2012 ; Swiecki and Colonna, 2015). To investigate subset specification and function of human DC, we established a protocol to generate cDC1, cDC2 and pDC in vitro from human iPS cells (or ES cells) ( Sontag et al., 2017 ). Therefore, we differentiated iPS cells (or ES cells), via mesoderm commitment and hemato-endothelial specification, into CD43(+) CD31(+) hematopoietic progenitors. Subsequently, those were seeded onto inactivated OP9 stromal cells with FLT3L, SCF, GM-CSF and IL-4 or FLT3L, SCF and GM-CSF to specify cDC1 and cDC2, or cDC1 and pDC, respectively.

Stem cells 35(4), 898-908 (2017). doi:10.1002/stem.2565, Published by Wiley-Blackwell, Hoboken, NJ

Myeloproliferative neoplasms (MPN) are a heterogeneous group of malignancies including polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF). The JAK2V617F mutation can be found in 90% of PV and approximately 50% of ET and PMF patients. Hypoxia-inducible factors (HIFs) are master transcriptional regulators of the response to decreases in cellular oxygen levels. Unveiling the function of deregulated HIF-1 signaling in normal and malignant hematopoiesis was the aim of several recent publications, highlighting the importance of HIF-1 for the maintenance of leukemic stem cells (LSCs) in acute and chronic myeloid leukemia (AML/CML). In a JAK2V617F knock-in mouse model and in patients, JAK2V617F was shown to induce the accumulation of reactive oxygen species (ROS) in the hematopoietic stem cell compartment, leading to a stabilization of HIF-1α protein. Further, aberrant STAT5 and PI3K/AKT/mTOR signaling induced HIF-1α expression on the transcriptional and translational level. Ruxolitinib treatment inhibited growth and reduced the expression of HIF-1α and its target gene VEGF in the JAK2V617F human erythroleukemia cell line HEL. In several leukemic cell lines constitutive expression of HIF-1α was reported, even under normoxic conditions. However, it still remains unknown whether HIF-1α plays a role in JAK2V617F positive MPN. In this study, we investigated the role HIF-1α signaling in JAK2V617F positive MPN in vitro. We retrovirally transduced the murine bone marrow cell line 32D with JAK2V617F or JAK2WT. Western blot analysis revealed significant increases in HIF-1α protein levels in JAK2V617F positive cells compared to JAK2WT controls after cultivation in normoxic conditions and this effect was abrogated by treatment with the JAK1/JAK2 inhibitor ruxolitinib. Inhibition of HIF-1, binding to hypoxia response elements (HRE), by low doses of echinomycin (1 nM), significantly impaired proliferation and survival. Using an Annexin-V/7-AAD flow cytometry assay apoptosis was found to be selectively induced in JAK2V617F positive, but not JAK2WT cells after echinomycin treatment. Additionally, BrdU/7-AAD cell cycle analysis revealed that only JAK2V617F positive cells were significantly arrested in G0/1 phase. These findings were consistent with shRNA-mediated knockdown (KD) of HIF-1α in JAK2V617F transduced 32D cells in presence but not the absence of HIF-2 antagonist 2. Inhibition of HIF-2 was necessary due to a compensatory increase of HIF-2α protein levels, shown by Western Blot analysis, counteracting HIF-1α-KD mediated effects. We isolated PBMCs and BMMNCs from JAK2V617F positive patients or healthy controls using Ficoll density gradient centrifugation. Echinomycin significantly abrogated the colony formation ability alone and in combination with ruxolitinib. In vitro treatment with echinomycin significantly decreased cell number and viability of 8 JAK2V617F positive BMMNC samples (4 PV, 3 PMF, 1 preMF; p[1nM]=0.0169, p[5nM]=0.0009) and 7 PBMC samples (6 PV, 1 PMF; p[1nM]=0.0156, p[5nM]=0.0156) in a dose-dependent manner. In contrast, PBMCs from 6 healthy donors were unaffected by the treatment. The same effect was observed in heterozygous and homozygous iPS cell-derived progenitors from JAK2V617F positive PV patients, whereas JAK2WT cells were unaffected by the treatment. Collectively, our data indicate that targeting HIF-1 might represent a novel therapeutic approach in classical Philadelphia-chromosome-negative MPN. Disclosures Brümmendorf: Pfizer: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Janssen: Consultancy; Merck: Consultancy; Takeda: Consultancy.

PLoS one 10(4), e0123476 (2015). doi:10.1371/journal.pone.0123476, Published by PLoS, Lawrence, Kan.

Human induced pluripotent stem cells (iPS cells) resemble embryonic stem cells and can differentiate into cell derivatives of all three germ layers. However, frequently the differentiation efficiency of iPS cells into some lineages is rather poor. Here, we found that fusion of iPS cells with human hematopoietic stem cells (HSCs) enhances iPS cell differentiation. Such iPS hybrids showed a prominent differentiation bias toward hematopoietic lineages but also toward other mesendodermal lineages. Additionally, during differentiation of iPS hybrids, expression of early mesendodermal markers-Brachyury (T), MIX1 Homeobox-Like Protein 1 (MIXL1), and Goosecoid (GSC)-appeared with faster kinetics than in parental iPS cells. Following iPS hybrid differentiation there was a prominent induction of NODAL and inhibition of NODAL signaling blunted mesendodermal differentiation. This indicates that NODAL signaling is critically involved in mesendodermal bias of iPS hybrid differentiation. In summary, we demonstrate that iPS cell fusion with HSCs prominently enhances iPS cell differentiation.

Introduction Next-Generation Sequencing holds the promise of comprehensive analysis of molecular aberrations in human malignancies and therapeutic approaches individually tailored to each patient. Methods We investigated the use of a multiplex-PCR (TruseqAmplicon Cancer Panel, Illumina) of 212 amplicons covering genomic mutational hotspots in 48 cancer-related genes to identify mutations in a cohort of patients with myeloproliferativeneoplasms (MPN). After signed informed consent, samples from 59 patients with MPN (19 MF [8 PMF, 11 post-PV/ET-MF], 14 PV, 10 ET, 10 CML, 4 HES, and 2 SM), two patients with reactive erythrocytosis, and two anonymized healthy controls as well as six myeloid cell lines (K562, HEL, HMC1, SUPB15, HL60, U937) were analyzed on a Miseq sequencer (Illumina), using 250 ng of genomic DNA from peripheral blood -derived cells. Results Altogether, the quality of the sequencing runs was very good, with Q30 values above 90%. 151 bidirectional cycles were performed, yielding between 2 and 6 Gigabases of sequencing data.Healthy donor and reactive erythrocytosis samples showed several SNPs but no known pathogenic mutation. Sequencing of the cell lines confirmed the presence of a TP53 frameshift mutation (c.405_406insC; in 98% of transcripts) in K562, JAK2 V617F (100%) and TP53 M133K (99%) mutations in HEL, two heterozygous KIT mutations (V560G in 51% and D816V in 52%) and a TP53 C277F (16%) mutation in HMC1, while SUP-B15, HL60, and U937 showed no abnormality in the tested gene set.JAK2 V617F was present in all PV, 4 of 10 ET, and 14 of 19 MF patients.The JAK2 V617F allele burden was significantly higher in MF than ET (p=0.026) but not PV (71+/-27% vs. 33+/-22% vs. 55+/-29%, respectively). Further analysis detected a previously described G12V NRAS mutation (13% of transcripts) in a patient with JAK2 V617F negative PMF and an additional IDH1 R132H mutation (24%) in a JAK2 V617F positive (46%) MF patient with 20% basophils and hyperhistaminemia. Another JAK2 V617F positive (31%) MF sample showed an E255G ABL mutation (10%). One patient with JAK2 V617F negative ET showed an ERBB2 A847D sequence variant (50%). Moreover, an S935N CSF1R mutation (17%) and a V125G IDH1 mutation (9%) were each detected in one case of PV, but the biological relevance remains unclear so far. Four patients with CML-CP (n=3) or –AP (n=1) showed subclones with sequence variants in the HNF1A gene, with two S304P changes (9 and 10% of transcripts) and two 872delC mutations (6 and 5%), the latter of which have already been implicated in colon cancer. Two patients with CML-CP showed KIT mutations (a V532I mutation and a known oncogenic mutation V530I). This latter patient also harbored the known E255K ABL mutation – leading to imatinib resistance. Interestingly, this patient showed a good response to dasatinib (which is also active against KIT) but not to bosutinib (which has no activity against KIT). These data suggest that HNF1A and KIT may play a role in CML pathogenesis. One patient with lymphoid BC/Ph+ ALL who had a T315I ABL mutation and was treated with ponatinib, was found to harbor a newly acquired V216M TP53 mutation (12% of transcripts) when becoming resistant to ponatinib. Ponatinib had led to a decrease of ABL T315I positive transcripts from 47% before ponatinib treatment to 16% at the time of ponatinib resistance in this patient, suggesting that both TP53 and ABL mutations were present in the same clone and that the newly acquired TP53 mutation may have caused ponatinib resistance in this patient. Additionally, other not yet defined aberrations may have been responsible for the observed resistance. Finally, while both SM patients were negative for KIT D816V, one of them harbored a KRAS 436G>A(146A>T) mutation (34%) which is a known oncogene in colorectal cancer and may thus also play a role in SM pathogenesis. We are currently generating induced pluripotent stem cells from patients harboring selected mutations described above in order to better be able to study the functional properties of genetically unstable malignant stem cell populations. Conclusion Amplicon-based next-generation sequencing may uncover additional oncogenic mutations in patients with MPN, potentially explaining therapy resistance and opening new therapeutic options for individual patients. Disclosures: Off Label Use: Two individual patients mentioned that were treated with ponatinib or bosutinib within compassionate use trials before these drugs were approved for the indication. Bruemmendorf:Bristol-Myers Squibb: Consultancy, Honoraria, Membership on an entity’s Board of Directors or advisory committees; Pfizer: Consultancy, Honoraria, Membership on an entity’s Board of Directors or advisory committees, Speakers Bureau; Novartis: Consultancy, Honoraria, Membership on an entity’s Board of Directors or advisory committees, Research Funding; Ariad: Consultancy, Honoraria. Koschmieder:Bristol-Myers Squibb: Consultancy, Honoraria, Membership on an entity’s Board of Directors or advisory committees, Research Funding; Pfizer: Consultancy, Honoraria, Membership on an entity’s Board of Directors or advisory committees; Novartis: Consultancy, Honoraria, Membership on an entity’s Board of Directors or advisory committees, Research Funding.

PLoS one 8(5), e65324 (2013). doi:10.1371/journal.pone.0065324, Published by PLoS [u.a.], Lawrence, Kan.