Jean-Pierre Marie

Oncologic Trogocytosis of an Original Stromal Cells Induces Chemoresistance of Ovarian Tumours

Background The microenvironment plays a major role in the onset and progression of metastasis. Epithelial ovarian cancer (EOC) tends to metastasize to the peritoneal cavity where interactions within the microenvironment might lead to chemoresistance. Mesothelial cells are important actors of the peritoneal homeostasis; we determined their role in the acquisition of chemoresistance of ovarian tumours. Methodology/Principal Findings We isolated an original type of stromal cells, referred to as “Hospicells” from ascitis of patients with ovarian carcinosis using limiting dilution. We studied their ability to confer chemoresistance through heterocellular interactions. These stromal cells displayed a new phenotype with positive immunostaining for CD9, CD10, CD29, CD146, CD166 and Multi drug resistance protein. They preferentially interacted with epithelial ovarian cancer cells. This interaction induced chemoresistance to platin and taxans with the implication of multi-drug resistance proteins. This contact enabled EOC cells to capture patches of the Hospicells membrane through oncologic trogocytosis, therefore acquiring their functional P-gp proteins and thus developing chemoresistance. Presence of Hospicells on ovarian cancer tissue micro-array from patients with neo-adjuvant chemotherapy was also significantly associated to chemoresistance. Conclusions/Significance This is the first report of trogocytosis occurring between a cancer cell and an original type of stromal cell. This interaction induced autonomous acquisition of chemoresistance. The presence of stromal cells within patients tumour might be predictive of chemoresistance. The specific interaction between cancer cells and stromal cells might be targeted during chemotherapy.

High Id1 expression is associated with poor prognosis in 237 patients with acute myeloid leukemia

Inhibitors of differentiation (Id) are a group of dominant inhibitors of basic helix-loop-helix transcriptional factors, which promote excessive proliferation, and also protect cells against drug-induced apoptosis in mammalians. Recently, Id1 has been identified as a common downstream target of several constitutively activated oncogenic tyrosine kinase, such as FLT3 internal tandem duplication, in leukemia cells. We analyzed Id1 expression as possible prognostic factor in 237 acute myeloid leukemia (AML) patients. High Id1 expression was associated with older age (P = .009) and with FLT3 internal tandem duplication (P = .003). However, 61% of the patients in the group of FLT3(-) AML were Id1(+), suggesting that other tyrosine kinases are involved. In whole population, high Id1 expression independently predicted shorter disease-free survival (P = .05) and overall survival (P = .003). In young patients (age <OR= 60 years) with normal cytogenetics, Id1(+) was, in multivariate analysis, associated with lower complete remission rates (P = .02), shorter disease-free survival (P = .02), and overall survival (P = .006). In conclusion, our data provide a new molecular marker for refining the risk classification of AML, especially in young patients with normal cytogenetic. Id1(-) patients with normal cytogenetic should be classified as favorable-risk leukemia. Id1, as a downstream target of constitutively activated tyrosine kinase, could be a suitable candidate for targeted therapy.

P-gp activity is a critical resistance factor against AVE9633 and DM4 cytotoxicity in leukaemia cell lines, but not a major mechanism of chemoresistance in cells from acute myeloid leukaemia patients

BackgroundAVE9633 is a new immunoconjugate comprising a humanized monoclonal antibody, anti-CD33 antigen, linked through a disulfide bond to the maytansine derivative DM4, a cytotoxic agent and potent tubulin inhibitor. It is undergoing a phase I clinical trial. Chemoresistance to anti-mitotic agents has been shown to be related, in part, to overexpression of ABC proteins. The aim of the present study was to investigate the potential roles of P-gp, MRP1 and BCRP in cytotoxicity in AVE9633-induced acute myeloid leukaemia (AML).MethodsThis study used AML cell lines expressing different levels of P-gp, MRP1 or BCRP proteins and twenty-five samples from AML patients. Expression and functionality of the transporter protein were analyzed by flow cytometry. The cytotoxicity of the drug was evaluated by MTT and apoptosis assays.ResultsP-gp activity, but not MRP1 and BCRP, attenuated AVE9633 and DM4 cytotoxicity in myeloid cell lines. Zosuquidar, a potent specific P-gp inhibitor, restored the sensitivity of cells expressing P-gp to both AVE9633 and DM4. However, the data from AML patients show that 10/25 samples of AML cells (40%) were resistant to AVE9633 or DM4 (IC50 > 500 nM), and this was not related to P-gp activity (p-Value: 0.7). Zosuquidar also failed to re-establish drug sensitivity. Furthermore, this resistance was not correlated with CD33 expression (p-Value: 0.6) in those cells.ConclusionP-gp activity is not a crucial mechanism of chemoresistance to AVE9633. For patients whose resistance to conventional anthracycline AML regimens is related to ABC protein expression, a combination with AVE9633 could be beneficial. Other mechanisms such as microtubule alteration could play an important role in chemoresistance to AVE9633.

JC-1, a sensitive probe for a simultaneous detection of P-glycoprotein activity and apoptosis in leukemic cells.

JC‐1 probe has been successfully used for the analysis of either apoptosis or P‐glycoprotein (P‐gp) activity. Therefore, we wanted to see if JC‐1 could also simultaneously assess both, P‐gp activity and apoptosis, in acute myeloid leukemia (AML) cells.

Outcome of 40 adults aged from 18 to 55 years with acute lymphoblastic leukemia treated with double-delayed intensification pediatric protocol

Adolescents ALL have a better outcome when treated with pediatric protocol compared to adult protocol. We have tested the feasibility of pediatric protocol to treat 40 consecutive adults ALL. DFS and OS were 73±7%, and 72±7%, and were significantly longer in patients under 40 yo (81±9% vs 51±15%, p=0.05 [DFS] and 83±7.8% vs 45±15%, p=0.003 [OS], respectively) or cortico/chemo-sensitive (86±9% vs 36±16%, p=0.001 [DFS] and 95±4.4% vs 28±13%, p<0.0001 [OS]) than in other patients. Overall tolerance was acceptable. We have shown the feasibility of using this unmodified pediatric protocol to treat adult with ALL up to 40 years.

The detection of CD14 and CD16 in paraffin-embedded bone marrow biopsies is useful for the diagnosis of chronic myelomonocytic leukemia

Histopathological study of bone marrow biopsy (BMB) in chronic myelomonocytic leukemia (CMML) is often difficult and might benefit from an immunohistochemical approach. We immunostained 15 cases of CMML, focusing at two new antibodies staining for CD14 and CD16 on paraffin-embedded tissues. CD68 (KP1), CD68 (PG-M1), and CD163 were not differentially expressed between CMML and chronic myelogenous leukemia (CML). In CMML BMB, we found a significant increase in the number of CD14+ monocytes. This increase was made of dispersed cells in the interstitium, often exhibiting bilobated nuclei, and being difficult to differentiate from neutrophils. There was no expansion of CD16+ monocyte-like cells. However, we found a significant decrease in the number of granulocytes expressing CD16, MPO, and CD15 in CMML compared to CML and control BMB, probably related to dysgranulopoiesis. Indeed, BMB immunohistochemistry can be helpful in CMML by identifying both the monocyte expansion with CD14 and the dysgranulopoiesis with CD16.

A new model of cell dynamics in Acute Myeloid Leukemia involving distributed delays

Abstract In this paper we propose a refined model for the dynamical cell behavior in Acute Myeloid Leukemia (AML) compared to (Ozbay et al , 2012) and (Adimy et al , 2008). We separate the cell growth phase into a sequence of several sub-compartments. Then, with the help of the method of characteristics, we show that the overall dynamical system of equations can be reduced to two coupled nonlinear equations with four internal sub-systems involving distributed delays.

Soluble endothelial protein C receptor (sEPCR) is likely a biomarker of cancer-associated hypercoagulability in human hematologic malignancies.

Elevated plasma level of soluble endothelial protein C receptor (sEPCR) may be an indicator of thrombotic risk. The present study aims to correlate leukemia‐associated hypercoagulability to high level plasma sEPCR and proposes its measurement in routine clinical practice. EPCR expressions in leukemic cell lines were determined by flow cytometry, immunocytochemistry, and reverse transcription polymerase chain reaction (RT‐PCR). EPCR gene sequence of a candidate cell line HL‐60 was also determined. Plasma samples (n = 76) and bone marrow aspirates (n = 72) from 148 patients with hematologic malignancies and 101 healthy volunteers were analyzed by enzyme‐linked immunosorbent assay (ELISA) via a retrospective study for sEPCR and D‐dimer. All leukemic cell lines were found to express EPCR. Also, HL‐60 EPCR gene sequence showed extensive similarities with the endothelial reference gene. All single nucleotide polymorphisms (SNPs) originally described and some new SNPs were revealed in the promoter and intronic regions. Among these patients 67% had plasma sEPCR level higher than the controls (100 ± 28 ng/mL), wherein 16.3% patients had experienced a previous thrombotic event. These patients were divided into: group‐1 (n = 45) with amount of plasmatic sEPCR below 100 ng/mL, group‐2 (n = 45) where the concentration of sEPCR was between 100 and 200, and group‐3 (n = 20) higher than 200 ng/mL. The numbers of thrombotic incidence recorded in each group were four, six, and eight, respectively. These results reveal that EPCR is expressed not only by a wide range of human malignant hematological cells but also the detection of plasma sEPCR levels provides a powerful insight into thrombotic risk assessment in cancer patients, especially when it surpasses 200 ng/mL.

Analysis of a New Model of Cell Population Dynamics in Acute Myeloid Leukemia

A new mathematical model of the cell dynamics in Acute Myeloid Leukemia (AML) is considered which takes into account the four different phases of the proliferating compartment. The dynamics of the cell populations are governed by transport partial differential equations structured in age and by using the method of characteristics, we obtain that the dynamical system of equation can be reduced to two coupled nonlinear equations with four internal sub-systems involving distributed delays. Equilibrium and local stability analysis of this model are performed and several simulations illustrate the results.

Endothelial cell markers' kinetics following umbilical cord blood transplantation

Assistance Publique–Hôpitaux de Paris, Département d’Hématologie et Oncologie Médicale, Hôtel-Dieu; 1, Place du parvis Notre-Dame, 75004 Paris, France; Université Descartes, Paris 5, France, Centre de Recherches des Cordeliers U872 team 18, Université Pierre et Marie Curie, Paris 6, INSERM, Université Paris Descartes, Paris, France, UMR7131 UPMC Paris Universitas/CNRS, 102, Rue Didot, 75014 Paris, France, Assistance Publique–Hôpitaux de Paris; Service d’Hématologie Biologique, Hôtel-Dieu, 1, Place du parvis Notre-Dame, 75004 Paris, France, and Assistance Publique–Hôpitaux de Paris; Service d’Hématologie Biologique, Hôpital Tenon, 4, rue de la Chine, 75020 Paris, France