Biology subjects

Cartron, G.

Publications and source records attributed to Cartron, G..

10 recordsLinked to original sources

bioRxiv2024

The SUMOylation inhibitor TAK-981 (Subasumstat) triggers IFN-I-dependent activation of Natural Killer cells against Acute Myeloid Leukemias.

Natural Killer (NK) cells play a pivotal role in mounting an anti-cancer immune response. Patients with diminished NK cells number and activity face less favorable prognosis. Promising therapeutic strategies include the adoptive transfer of NK cells or the reactivation of patients own NK cells. TAK-981, a first-in-class inhibitor of SUMOylation undergoing phase I/II clinical trials for cancer, is emerging as an immunomodulatory drug. Here, we demonstrate that TAK-981 activates NK cells from healthy donors and patients with Acute Myeloid Leukemia (AML), a cancer with very poor prognosis. TAK-981 heightens their degranulation capacity, secretion of inflammatory cytokines (IFN-{gamma}, TNF-, FasL), and cytotoxicity against AML cells. In vivo, TAK-981 also enhances the anti-leukemic activity of ex-vivo expanded human NK cells. At the molecular level, TAK-981 first induces IFNB1 gene in NK cells, leading to the secretion of type I Interferon (IFN-I), which binds to the Interferon receptor IFNAR. This induces Interferon-Stimulated Genes (ISG) and activates NK cells in vitro and in vivo. Finally, TAK-981 stimulates IFN-I secretion by monocytes, which contributes to the activation of NK cells in trans. Altogether, targeting SUMOylation could be a promising strategy to reactivate AML patients NK cells and enhance the efficiency of NK cells-based therapies. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=109 SRC="FIGDIR/small/580882v1_ufig1.gif" ALT="Figure 1"> View larger version (20K): org.highwire.dtl.DTLVardef@1a5fd47org.highwire.dtl.DTLVardef@974336org.highwire.dtl.DTLVardef@bdb99dorg.highwire.dtl.DTLVardef@1e4fe15_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗

bioRxiv2022

SUMOylation controls the rapid transcriptional reprogramming induced by anthracyclines in Acute Myeloid Leukemias

Genotoxicants have been used for decades as front-line therapies against cancer on the basis of their DNA-damaging actions. However, some of their non-DNA-damaging effects are also instrumental for killing dividing cells. We report here that the anthracycline Daunorubicin (DNR), one of the main drugs used to treat Acute Myeloid Leukemia (AML), induces broad transcriptional changes in AML cells before cell death induction. The regulated genes are particularly enriched in genes controlling cell proliferation and death, as well as inflammation and immunity. These transcriptional changes are preceded by DNR-dependent deSUMOylation of chromatin proteins, which limits both the positive and negative effects of DNR on transcription. Quantitative proteomics shows that proteins that are deSUMOylated in response to DNR are mostly transcription factors, transcriptional co-regulators and chromatin organizers. Among them, the CCCTC-binding factor CTCF is highly enriched at SUMO-binding sites found in cis-regulatory regions. This is notably the case at the promoter of the DNR-induced NFKB2 gene. Its induction is preceded by a SUMO-dependent reconfiguration of chromatin loops engaging its CTCF- and SUMO-bound promoter with distal cis-regulatory regions. Altogether, our work suggests that one of the earliest effects of DNR in AML cells is a SUMO-dependent transcriptional reprogramming.

molecular biology↗

bioRxiv2022

Arginine-dependent hypusination of the eukaryotic translation initiation factor (eIF)5A drives erythroid lineage differentiation

Metabolic programs contribute to hematopoietic stem and progenitor cell (HSPC) fate but it is not known whether the metabolic regulation of protein synthesis controls HSPC differentiation. We discovered that SLC7A1/CAT1-dependent arginine uptake and its catabolism to spermidine control the erythroid specification of HSPCs via activation of eukaryotic translation initiation factor 5A (eIF5A). eIF5A activity is dependent on the metabolism of spermidine to hypusine and inhibiting hypusine synthesis abrogates erythropoiesis and diverts EPO-stimulated HSPCs to a myeloid fate. Proteomic profiling reveals mitochondrial translation to be a critical target of hypusinated eIF5A and induction of mitochondrial function partially rescues erythropoiesis in the absence of hypusine. Within the hypusine network, ribosomal proteins are highly enriched and we identify defective eIF5A hypusination in erythroid pathologies caused by abnormal ribosome biogenesis. Thus, eIF5A-dependent protein synthesis is critical in the branching of erythro-myeloid differentiation and attenuated eIF5A activity characterizes ribosomal protein-linked disorders of ineffective erythropoiesis.

physiology↗

bioRxiv2021

Human Cytomegalovirus modifies placental small extracellular vesicle secretion and composition towards a proviral phenotype to enhance infection of fetal recipient cells

Although placental small extracellular vesicles (sEVs) are extensively studied in the context of pregnancy, little is known about their role during human cytomegalovirus (hCMV) congenital infection, especially at the beginning of pregnancy. In this study, we examined the consequences of hCMV infection on sEVs production, composition and function using an immortalized human cytotrophoblast cell line derived from first trimester placenta. By combining complementary approaches of biochemistry, electron microscopy and quantitative proteomic analysis, we showed that hCMV infection increases the yield of sEVs produced by cytotrophoblasts and modifies their protein content towards a proviral phenotype. We further demonstrate that sEVs secreted by hCMV-infected cytotrophoblasts potentiate infection in naive recipient cells of fetal origin, including human neural stem cells. Importantly, these functional consequences are also observed with sEVs prepared from either an ex vivo model of infected histocultures from early placenta or from the amniotic fluid of patients naturally infected by hCMV at the beginning of pregnancy. Based on these findings, we propose that placental sEVs could be key actors favoring viral dissemination to the fetal brain during hCMV congenital infection. Significance StatementHuman cytomegalovirus (hCMV) infection is a major issue during pregnancy, affecting 1% of births in western countries. Despite extensive research, the pathophysiology of this congenital infection remains unclear. Recently, increasing evidence point to the key role of placental small extracellular vesicles (sEVs) in materno-fetal communication during pregnancy. Here, we examined the impact of hCMV infection on the protein composition and function of placental sEVs. We observe that hCMV infection leads to major changes in placental sEV protein content. Functional studies show the ability of sEVs produced by placental infected cells to facilitate further infection of naive recipient fetal cells, notably human neural stem cells. Our study demonstrates that placental sEVs are key players of hCMV pathophysiology during congenital infection.

cell biology↗

bioRxiv2021

Nonclassical monocytes are prone to migrate into tumor in diffuse large B-cell lymphoma

Absolute count of circulating monocytes has been proposed as an independent prognostic factor in diffuse large B-cell lymphoma (DLBCL). However, monocyte nomenclature includes various subsets with pro-, anti-inflammatory, or suppressive functions, and their clinical relevance in DLBCL has been poorly explored. Herein, we broadly assessed circulating monocyte heterogeneity in 91 DLBCL patients. Classical- (cMO, CD14pos CD16neg) and intermediate- (iMO, CD14pos CD16pos) monocytes accumulated in DLBCL peripheral blood and exhibited an inflammatory phenotype. On the opposite, nonclassical monocytes (ncMO, CD14low CD16pos) were decreased in peripheral blood. Tumor-conditioned monocytes presented similarities with ncMO phenotype from DLBCL and were prone to migrate in response to CCL3, CCL5, and CXCL12, and presented similarities with DLBCL-infiltrated myeloid cells, as defined by mass cytometry. Finally, we demonstrated the adverse value of an accumulation of nonclassical monocytes in 2 independent cohorts of DLBCL. Key pointsO_LINonclassical monocytes are prone to migrate to DLBCL tumor C_LIO_LIHigh count of circulating nonclassical monocytes is an independent adverse event in DLBCL C_LI

immunology↗

bioRxiv2021

The NADPH oxidase NOX2 is a marker of adverse prognosis involved in chemoresistance of Acute Myeloid Leukemias

Resistance to chemotherapeutic drugs is a major cause of treatment failure in Acute Myeloid Leukemias (AML). To better characterize the mechanisms of chemoresistance, we first identified genes whose expression is dysregulated in AML cells resistant to daunorubicin (DNR) or cytarabine (Ara-C), the main drugs used for the induction therapy. The genes found activated are mostly linked to immune signaling and inflammation. Among them, we identified a strong up-regulation of the NOX2 NAPDH oxidase subunit genes (CYBB, CYBA, NCF1, NCF2, NCF4 and RAC2). The ensuing increase in NADPH oxidase activity, which is particularly strong in DNR-resistant cells, participates in the acquisition and/or maintenance of resistance to DNR. In addition, analyzing gp91phox (CYBB-encoded Nox2 catalytic sub-unit) expression at the surface of leukemic blasts from 74 patients at diagnosis showed that NOX2 is generally more expressed and active in leukemic cells from the FAB M4/M5 subtypes compared to FAB M0-M2 ones. Using a gene expression-based score we demonstrate that high NOX2 subunit genes expression is a marker of adverse prognosis, independent of the cytogenetic-based risk classification, in AML patients.

cancer biology↗

bioRxiv2020

Consequences of human cytomegalovirus infection on small extracellular vesicles isolated from first trimester placental histocultures

Currently, research on the use of non-invasive biomarkers as diagnosis and prognosis tools during pathological pregnancies is in full development. Among these, placenta-derived small extracellular vesicles (sEVs) are considered as serious candidates, since their composition is modified during many pregnancy pathologies. Moreover, sEVs are found in maternal serum and can thus be easily purified from a simple blood sample. In this study, we describe the isolation of sEVs from a histoculture model of first trimester placental explants. Using bead-based multiplex cytometry and electron microscopy combined with biochemical approaches, we characterized these sEVs and defined their associated markers and ultrastructure. We next examined the consequences of infection by human cytomegalovirus on sEVs secretion and characteristics. We observed that infection led to increased levels of expression of several surface markers, without any impact on the secretion and integrity of sEVs. Our findings open the prospect for the identification of new predictive biomarkers for the severity and outcome of this congenital infection early during pregnancy, which are still sorely lacking.

cell biology↗

bioRxiv2019

Ubiquitin and SUMO conjugation as biomarkers of Acute Myeloid Leukemias response to chemotherapies

Ubiquitin and the ubiquitin-like SUMO are covalently conjugated to thousands of proteins to modulate their function and fate. Many of the enzymes involved in their conjugation are dysregulated in cancers and involved in cancer cells response to therapies. We describe here the identification of biomarkers of the activity of these enzymes and their use to predict Acute Myeloid Leukemias (AML) response to standard chemotherapy (daunorubicine-DNR and cytarabine-Ara-C). We compared the ability of extracts from chemosensitive and chemoresistant AML cells to conjugate ubiquitin or SUMO-1 on 9000 proteins spotted on protein-arrays. We identified 122 proteins whose conjugation by these post-translational modifiers marks AML resistance to DNR and/or Ara-C. Based on this modifomic signature, we defined a statistical score able to predict AML patient response to standard chemotherapy. We finally developed a miniaturized assay to easily assess the modification level of the selected biomarkers and validated it in patient cell extracts. Thus, our work identifies a new type of ubiquitin-based biomarkers that could be used to predict cancer patients response to treatments.\n\nSummary blurbThis study describes the identification of a new class of biomarkers of cancer response to therapies based on protein modification by Ubiquitin and SUMO and provides the tools to analyze them in Acute Myeloid Leukemia patient samples.

cancer biology↗

bioRxiv2019

Targeting the methyltransferase SETD8 impairs tumor cell survival and overcomes drug resistance independently of p53 status in multiple myeloma

Multiple myeloma (MM) is a malignancy of plasma cells that largely remains incurable. The search for new therapeutic targets is therefore essential. Here we show that a higher expression of the lysine methyltransferase SETD8, which is responsible for histone H4K20 mono-methylation, is an adverse prognosis factor associated with a poor outcome in two cohorts of newly diagnosed patients. Remarkably, primary malignant plasma cells are particularly addicted to SETD8 activity. Indeed, pharmacological inhibition of this enzyme by the chemical compound UNC0379 demonstrated a significantly higher toxicity in MM cells compared to normal cells from the bone marrow microenvironment. Moreover, RNA sequencing and functional studies revealed that SETD8 inhibition induces a mature non-proliferating plasma cell signature and an activation of the p53 canonical pathway, which together leads to an impairment of myeloma cell proliferation and survival. However, UNC0379 treatment triggers a deadly level of replicative stress in p53 deficient MM cells, indicating that the cytotoxicity associated with SETD8 inhibition is independent of the p53 status. Consistent with this, the combination of UNC0379 with the conventional cytotoxic agent melphalan strongly enhances DNA damage and overcomes drug resistance in myeloma cells. Thus, targeting SETD8 could be of therapeutic interest to improve MM treatment in high-risk patients independently of the p53 status.

cancer biology↗

bioRxiv2018

Targeting the SUMO pathway primes all-trans-retinoic acid-induced differentiation of non promyelocytic Acute Myeloid Leukemias

Differentiation therapies using All-trans-retinoic acid (ATRA) are highly efficient at treating Acute Promyelocytic Leukemia (APL), a minor subtype of Acute Myeloid Leukemias (AML). However, their efficacy, if any, is very limited in the case of non-APL AMLs. We report here that the inhibition of SUMOylation, a post-translational modification related to ubiquitinylation, restores the pro-differentiation and anti-proliferative activities of retinoids in non-APL AMLs. Controlled inhibition of SUMOylation with pharmacological inhibitors (2-D08 or anacardic acid), or via overexpression of SENP desumoylases, strongly enhances the ATRA-induced expression of key genes involved in differentiation, proliferation and apoptosis in non-APL AML cells. This activates ATRA-induced terminal myeloid differentiation and reduces cell proliferation and viability, including in AML cells resistant to chemotherapeutic drugs. Conversely, enhancement of SUMOylation by overexpressing the SUMO-conjugating enzyme Ubc9 dampens the expression of ATRA-responsive genes and prevents differentiation. Thus, inhibition of the SUMO pathway is a promising strategy to sensitize non-APL AML patients to retinoids and improve the treatment of this poor prognosis cancer, which has not significantly changed over the past 40 years.

cancer biology↗