Biomedical subjects

Ollivier Legrand

Publications and source records attributed to Ollivier Legrand.

13 recordsLinked to original sources

PubMed2006

Flt3 internal tandem duplication and P-glycoprotein functionality in 171 patients with acute myeloid leukemia.

PURPOSE: Patients with adult acute myeloid leukemia (AML) with intermediate cytogenetics remain a heterogeneous group with highly variable individual prognoses. New molecular markers could help to refine cytogenetic stratification. EXPERIMENTAL DESIGN: We assessed P-glycoprotein (Pgp) activity and Flt3 internal tandem duplication (ITD+) because of their known prognostic value and because they might lead to targeted therapy. We did a multivariate analysis on 171 patients with adult AML treated in the European Organization for Research and Treatment of Cancer protocols. RESULTS: ITD+ and high Pgp activity (Pgp+) were found in 26 of 171 (15%) and 55 of 171 (32%) of all patients, respectively. ITD and Pgp activities were negative in 94 of 171 (55%, Pgp-ITD- group), mutually exclusive in 73 of 171 (43%, Pgp-ITD+ and Pgp+ITD- groups), and only 4 of 171 (2%, Pgp+ITD+ group) patients were positive for both. In multivariate analyses, Pgp+ITD+ (P < 0.0001) and age (P = 0.0022) were independent prognostic factors for the achievement of complete remission (CR). Overall survival (OS), CR achievement (P < 0.0001), WHO performance status (P = 0.0007), and Pgp+ITD+ status (P = 0.0014) were also independent prognostic factors. In 95 patients with intermediate cytogenetics, the CR rates of ITD+ patients were 40% versus 62% for ITD- (P = 0.099) and 41% versus 67% (P = 0.014) for Pgp+ versus Pgp- patients. In the Pgp-ITD- group (41 of 95), CR rates were 70% versus 44% for others (P = 0.012), OS achieved 48% versus 16% (P < 0.0001) and disease-free survival was 56% versus 27% (P = 0.024), respectively. Furthermore, the OS curves of the intermediate cytogenetics-Pgp-ITD- group were not significantly different from the favorable cytogenetic group. CONCLUSION: Flt3/ITD and Pgp activity are independent and additive prognostic factors which provide a powerful risk classification that can be routinely used to stratify the treatment of patients with intermediate cytogenetic AML. ITD+ and Pgp+ patients should be considered for targeted therapy.

ATP Binding Cassette Transporter, Subfamily B↗

PubMed2006

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

BACKGROUND: 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. METHODS: P-gp activity was measured using JC-1 and compared to the results of the Rhodamine 123 (Rh 123) assay in P-gp negative and P-gp positive cell lines, and 12 AML samples. For apoptosis, spontaneous apoptosis, as well as, apoptosis induced by Cytosine Arabinosine and Homoharringtonine were analyzed. Both mitochondrial red fluorescence and cytoplasmic green fluorescence of JC-1 with and without a P-gp inhibitor (Cyclosporine A : CsA) were used for the identification of apoptotic cells, and this was compared to Annexin V/PI staining. RESULTS: (1) We found a good correlation between JC-1 and Rh 123 in viable cells. Even in a small population of viable cells, P-gp positive cells emitting low red fluorescence, gained on red fluorescence after P-gp inhibition with CsA permitting an evaluation of P-gp activity. (2) We found a good correlation between the Annexin V/PI staining and JC-1 (P < 0.0001) in the assessment of apoptotic cells. Most importantly, the apoptotic cells could be distinguished by the loss of red fluorescence and the increase of green fluorescence without any change after P-gp inhibition with CsA. CONCLUSIONS: JC-1 can simultaneously evaluate two important parameters involved in drug resistance in AML cells, P-gp activity and apoptosis.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2006

Semisynthetic homoharringtonine induces apoptosis via inhibition of protein synthesis and triggers rapid myeloid cell leukemia-1 down-regulation in myeloid leukemia cells.

Semisynthetic homoharringtonine (ssHHT) is now being evaluated in phase II clinical trials for the treatment of chronic myelogenous leukemia and acute myelogenous leukemia patients. Here, we examined the mechanism of the apoptosis induced by ssHHT in myeloid leukemia cells. First, we have shown that ssHHT induces apoptosis in HL60 and HL60/MRP cell lines in a time- and dose-dependent manner, and independently of the expression of Bax. The decrease of mitochondrial membrane potential and the release of cytochrome c were observed in the apoptotic cells induced by ssHHT. To unveil the relationship between ssHHT and the mitochondrial disruption, we have shown that ssHHT decreased myeloid cell leukemia-1 (Mcl-1) expression and induced Bcl-2 cleavage in HL60 and HL60/MRP cell lines. The Bcl-2 cleavage could be inhibited by the Z-VAD.fmk caspase inhibitor. However, Mcl-1 turnover was very rapid and occurred before caspase activation. The Mcl-1 turnover was only induced by ssHHT and cycloheximide, but not by daunorubicin and cytosine arabinoside, and could be restored by proteasome inhibitors. Second, we confirmed that ssHHT rapidly induced massive apoptosis in acute myelogenous leukemia patient cells. We have also confirmed the release of cytochrome c and a rapid turnover of Mcl-1 in these patient cells, taking place only in apoptotic cells induced by ssHHT but not in cells undergoing spontaneous apoptosis. Finally, we have shown that ssHHT inhibits protein synthesis in both cell line and patient cells. We suggest that the inhibition of protein synthesis and resulting Mcl-1 turnover play a key role in the apoptosis induced by ssHHT. Our results encourage further clinical trials for the use of ssHHT in acute myelogenous leukemia.

Antineoplastic Agents, Phytogenic↗

PubMed2005

MRP3, BCRP, and P-glycoprotein activities are prognostic factors in adult acute myeloid leukemia.

PURPOSE: P-Glycoprotein (Pgp) is associated with poor outcome in acute myeloid leukemia (AML). We have investigated other ATP-binding cassette proteins such as BCRP, MRP1, MRP2, MRP3, and MRP5 for their potential implication in chemoresistance. EXPERIMENTAL DESIGN AND RESULTS: Eighty five AML patient samples were analyzed in this study. First, MRP3 function was higher in patients which had a high level of leukocytes (P = 0.01), a M5 FAB subtype (P = 0.04), and an intermediate or poor cytogenesis (P = 0.05). BCRP activity was not correlated with clinical or biological variables, but high Pgp activity was correlated with the following variables: CD34 expression (P = 0.002), FAB subtype (P = 0.002), intermediate or poor cytogenesis (P = 0.02), and elderly patients (P = 0.03). Second, Pgp, MRP3, and BCRP activities were correlated with complete remission (P = 0.02, P = 0.04, and P = 0.04, respectively), disease-free survival (P = 0.02, P = 0.03, and P = 0.25, respectively), and overall survival (P = 0.04, P = 0.04, and P = 0.05, respectively) in multivariate analysis. The patient samples expressing one or none of these Pgp, MRP3, or BCRP functional proteins have a better prognosis than the patients expressing two or three of these functional proteins (complete remission, P = 0.02; disease-free survival, P = 0.01; overall survival, P < 0.001). CONCLUSIONS: BCRP and MRP3 may also be involved in chemoresistance in AML, especially MRP3 in patients with M5 FAB. Additional modulation of BCRP or MRP3 to Pgp modulation may be necessary in some patients in order to improve the treatment outcome.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2005

Acute myeloid leukemia in the elderly: etoposide when anthracyclins are contraindicated.

We investigated whether etoposide might be a suitable alternative to anthracyclins for the treatment of elderly patients with acute myeloid leukemia (AML) in whom anthracyclins are contraindicated. In total, 88 patients over 60 years old were treated in our department between 1988 and 2000 for de novo or secondary AML. Of these 88 patients, 21 had severe cardiac disease and received a combination of etoposide and cytosine arabinoside (group A). They were compared with 23 patients who received daunorubicin plus cytosine arabinoside (group B) and 44 patients who received mitoxantrone, cytosine arabinoside and etoposide (group C). In group A, the complete remission (CR) rate was 33% (7/21), median disease-free survival (DFS) was 365 days and median overall survival (OS) was 214 days. These results were not statistically different from those for the anthracyclin-based regimens (CR 43%, DFS 210 days, OS 150 days for group B and CR 47%, DFS 216, OS 295 days for group C). Moreover, there was no significant difference in the number of treatment-related toxic events and deaths in the 3 treatment groups. Etoposide combined with a standard dose of cytosine arabinoside is relatively safe and effective in elderly patients with AML and offers an alternative approach to patients with cardiac contraindications to anthracyclin treatment.

Aged↗

PubMed2005

Prognosis of patients with acute myeloid leukaemia admitted to intensive care.

This retrospective study assessed the prognostic factors associated with early and long-term outcome in consecutive patients with acute myeloid leukaemia (AML) admitted to the intensive care unit (ICU) over a 9-year period. A total of 83 patients were studied (age 48 +/- 16 years), among whom 60% were neutropenic on admission. For 68%, admission occurred within the first month following diagnosis of AML. The main reason for ICU admission was an acute respiratory disease in 82% of cases. Mechanical ventilation (MV) was required in 57% of patients. In-ICU mortality was 34%. Among patients discharged alive from ICU, 49% died within a year after discharge. Factors significantly associated with in-ICU death in multivariate analysis were simplified acute physiology score II and need for invasive MV (IMV). Age, performance status, AML3 subtype and complete remission were significantly associated with 1-year survival. Patients with acute respiratory failure initially supported with non-invasive MV had significantly better ICU outcome than patients initially supported with IMV. In conclusion, ICU admission is justified for selected patients with AML. The ICU mortality rate is highly predictable by the acute illness severity score. A 1-year survival is predicted by haematological prognostic factors.

Acute Disease↗

PubMed2005

Reticulated platelets: a reliable measure to reduce prophylactic platelet transfusions after intensive chemotherapy.

BACKGROUND: Reticulated platelets (RPs) are the youngest circulating platelets (PLTs). The aim of our study was to predict PLT recovery with RP percentage (RP%) and therefore to identify PLT transfusions that could be avoided after autologous peripheral blood progenitor cell (PBPC) transplantation. STUDY DESIGN AND METHODS: With a whole-blood dual-labeling flow cytometric method, RP% was prospectively assessed in 47 patients who received myeloablative chemotherapy followed by autologous PBPC transplantation. Retrospective analysis of RP evolution identified three time points: nadir of the RP% (NRP), imminent PLT recovery (IPR) corresponding to an RP% of greater than 7 percent, and PLT transfusion autonomy (PTA). RESULTS: Median occurrences of NRP, IPR, and PTA were on Days +5, +8, and +12 after transplantation, respectively. The RP% value at NRP (4%) was significantly lower compared to the IPR (15%) and PTA (14%). Thirty patients (64%) achieved PTA within 4 days after IPR. On Day +8, if RP% was greater than 7 percent, positive and negative predictive values for PTA within 4 days, specificity, and sensitivity were 79, 63, 66, and 76 percent, respectively. Fever between IPR and PTA was the only factor found to negatively influence PLT recovery (p = 0.02). All patients required at least one PLT transfusion. Among patients with rapid PLT recovery (IPR-PTA interval < 4 days; n = 30), half of them received one PLT transfusion after RP increase, which could be avoided. CONCLUSION: These encouraging results may allow us to reduce the prophylactic PLT transfusion according to patients RP% increase.

Adult↗

PubMed2004

Breast cancer resistance protein and P-glycoprotein in 149 adult acute myeloid leukemias.

PURPOSE: Recently, a new ABC protein, breast cancer resistance protein (BCRP), was described. But its prognosis is not known in acute myeloid leukemia (AML). In addition, the prognosis of P-glycoprotein (Pgp) and BCRP in patients treated homogeneously by the same anthracycline (daunorubicin, idarubicin, or mitoxantrone) during all of the treatment with aracytine is not known. Therefore, we have evaluated the relationship between drug resistance phenotype, in vitro anthracene sensitivity, and the relation to treatment outcome. EXPERIMENTAL DESIGN: We have analyzed 149 AML treated according to protocol of the European Organization for Research and Treatment of Cancer group. The prognostic value of BCRP and Pgp were analyzed in the whole population and according to intercalating agent. RESULTS: BCRP was a prognostic factor, for achievement of complete remission (43% in positive patients and 69% in negative patients, P = 0.005), the 4-year disease-free survival (12% versus 33%, P = 0.03), and the 4-year overall survival (19% versus 38%, P = 0.003). When BCRP expression and Pgp function were categorized in three groups, +/+, +/- or -/+, and -/-, the achievement of complete remission was 45%, 66%, and 90% (P = 0.0003), the 4-year disease-free survival was 8%, 26%, and 40% (P = 0.01), and the 4-year overall survival was 16%, 37%, and 48% (P = 0.001), respectively. Pgp function was a prognostic factor in patients treated by daunorubicin and idarubicin but not by mitoxantrone. In contrast, BCRP expression was a prognostic factor in patients treated by daunorubicin and mitoxantrone but not by idarubicin. CONCLUSIONS: BCRP would be implicated in the resistance to chemotherapies in AML. But these are the patients expressing both BCRP and Pgp who have the poorest prognosis.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2004

Absence or low expression of fas-associated protein with death domain in acute myeloid leukemia cells predicts resistance to chemotherapy and poor outcome.

In acute myeloid leukemia (AML), coexpression of death receptors and ligands of the tumor necrosis factor (TNF) receptor/TNF-alpha superfamily on leukemic cells after chemotherapy is not always accompanied by apoptosis, suggesting that the apoptotic death receptor signaling pathway is disrupted. Because Fas-associated protein with death domain (FADD) is the main adaptor for transmitting the Fas, TNF-related apoptosis-inducing ligand receptors, and TNF receptor 1 death signal, expression of FADD was analyzed by Western blot and immunocytochemistry in leukemic cells of 70 de novo AML patients treated with the European Organization of Research and Treatment of Cancer AML-10 randomized trial before initiation of induction chemotherapy. Thirty seven percent of patients (17 of 46) with FADD negative/low (FADD(-/low)) leukemic cells had a primary refractory disease compared with 12% of FADD(+) patients (3 of 24; P = 0.05). FADD(-/low) expression was significantly associated with a worse event-free survival [EFS (P = 0.04)] and overall survival (P = 0.04). In multivariate analysis, FADD(-/low) protein expression was independently associated with a poor EFS and overall survival (P = 0.002 and P = 0.026, respectively). Importantly, FADD(-/low) protein expression predicted poor EFS even in patients with standard- or good-risk AML (P = 0.009). Thus, we identified low or absent expression of the FADD protein in leukemic cells at diagnosis as a poor independent prognostic factor that can predict worse clinical outcome even for patients with standard- or good-risk AML.

Adaptor Proteins, Signal Transducing↗

PubMed2004

Evaluation and comparison of MRP1 activity with three fluorescent dyes and three modulators in leukemic cell lines.

MRP1 activity was evaluated and compared in 11 cell lines with different levels of MRP1 expression using functional assays of calcein acetoxymethyl ester (calcein-AM), carboxyfluorescein diacetate (CFDA) and Rhodamine 123 (Rh123) in combination with the modulators cyclosporin A (CsA), probenecid and MK571. A good correlation was found between MRP1 expression and the modulatory effect of MK571 on calcein-AM uptake (P = 0.01 and probenecid effect on CFDA uptake (P = 0.02). Additionally, the combined modulatory effect of MK571 and probenecid on CFDA uptake (P < 0.0001) and on calcein-AM uptake (P = 0.0001) were highly significant. No correlation was found between MRP1 expression and the effects of three modulators on Rh123 uptake or efflux. In conclusion, calcein-AM and CFDA uptake assays are the best choices to probe MRP1 activity and combination of two modulators may improve the efficiency of these assays.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2004

P-glycoprotein and multidrug resistance associated protein-1 activity in 132 acute myeloid leukemias according to FAB subtypes and cytogenetics risk groups.

BACKGROUND AND OBJECTIVES: We studied the function of both Pgp and MRP1 to identify subgroups of patients who could benefit from Pgp reversion, and to clarify in different FAB subtypes and in cytogenetic risk groups their expression and function. DESIGN AND METHODS: We examined 132 adults with de novo acute myeloid leukemia (AML) for Pgp and MRP1 expression and function. We correlated our finding with the FAB subtypes and the cytogenetics, and clinical data of our patients. RESULTS: Among FAB subtypes and cytogenetic subgroups, patients with good risk cytogenetics have a low expression and activity of Pgp and MRP1 except patients with inv(16) who have a higher activity of MRP1 than t(8;21) and t(15;17) (p=0.05). All other AML patients, except M5, have a high expression and activity of Pgp. In contrast, M5 have a high expression, but a low activity of Pgp. In this subgroup, M5 with MLL gene rearrangement did not express an active Pgp. Others patients with M5 AML did not have a functional Pgp. Monosomy 7, 11q2.3 gene rearrangement and complex cytogenetic have a higher activity of MRP1 than other cytogenetic (p=0.03). INTERPRETATION AND CONCLUSIONS: Resistance mechanism in M5 was not mediated by Pgp. In contrast, MRP1 may play a role in patients who have a 11q2.3 gene rearrangement, or in M4E with inv(16). Thus trials that modulate Pgp are likely to achieve limited success in AML with low activity of Pgp, i.e., M5 and, AML with good risk cytogenetics.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2003

Comparison of flow cytometry and enzyme cytochemistry for the detection of myeloperoxydase in acute myeloid leukaemia: interests of a new positivity threshold.

Following the recommendations of the European Group for the Immunological Characterization of Leukaemias (EGIL) in 1995, few reports have been published comparing enzyme cytochemistry (EC) and flow cytometry (FC) for the detection of myeloperoxydase (MPO) in acute myeloid leukaemia (AML). The EGIL guidelines defined MPO positivity in FC, by the presence of this enzyme in 10% or more of the blast cells. We studied 136 adult patients with the systematic use of both EC and FC, using a 3% threshold for positivity for EC, and 10% and 3% consecutively for FC. FC was less sensitive than EC using the currently recommended threshold of 10%, but a 3% cut-off showed more sensitivity and was superior to EC. The joint use of both techniques identified 14 discordant patients (positive in FC/negative in EC or vice versa), all of whom displayed at least one poor-prognosis biological factor, which correlated with a mediocre clinical result. In conclusion, we recommend that the cut-off for a positive MPO value should be lowered to 3%, and suggest that the concomitant use of FC and EC is a fast clinically relevant prognostic tool.

Acute Disease↗

PubMed2002

[Update on malignant hemopathies].

The beginning of this century was marked, in our specialty as in other, by two revolutions: the routine use of molecular biology tools for a better prognosis of the disease (flt3 receptor duplication in AML, mutational profile of Ig genes in CLL, gene expression profile with ARN chips in aggressive lymphomas.), and the discovery of "intelligent" molecules, targeting the tumoral cell. In this category, the most appealing is the STI571 (Gleevec , Novartis), targeting the molecular abnormality of the cells expressing bcr-abl protein: CML, ALL Ph1(+). Other molecules targeting signal transduction proteins (ras farnesylation inhibitors for example) are already in clinical trials. The increasing therapeutic use of monoclonal antibodies is also to be cited, with a special mention concerning the rituximab, used in several B lymphoid pathologies, from lymphoma to autoimmune diseases. His very good tolerance permits his use in ambulatory patients, and his combination with chemotherapy or his linkage with radioactive elements render this molecule indispensable. The other side of these molecules is their incredibly high cost, explaining the uncontrolled expenses in 2001 of hospitals hosting hematology as well as oncology activities.

Acute Disease↗