Vorinostat and Mithramycin A in combination therapy as an interesting strategy for the treatment of Sézary T lymphoma: a transcriptomic approach.

SAHA (vorinostat) is a histone deacetylase inhibitor approved by the USA Food and Drug Administration (FDA) for treating advanced refractory cutaneous T cell lymphomas. As SAHA alters the expression of many genes under control of the Sp1 transcription factor, we examined the effect of its association with the FDA-approved anticancer antibiotic Mithramycin A (MTR, plicamycin), a competitive inhibitor of Sp1 binding to DNA. Sézary syndrome (SS) cells, expanded ex vivo from peripheral blood mononuclear cells of 4 patients, were tested for their sensitivity to the drugs regarding cytotoxicity and differential responsive gene expression. Multivariate statistical methods were used to identify genes whose expression is altered by SAHA, MTR, and the synergist effect of the two drugs. MTR, like SAHA, induced the apoptosis of SS cells, while the two drugs in combination showed clear synergy or potentiation. Expression data stressed a likely important role of additive or synergistic epigenetic modifications in the combined effect of the two drugs, while direct inhibition of Sp1-dependent transcription seemed to have only limited impact. Ontological analysis of modified gene expression suggested that the two drugs, either independently or synergistically, counteracted many intertwined pro-survival pathways deregulated in SS cells, resistance of these tumors to intrinsic and extrinsic apoptosis, abnormal adhesion migration, and invasive properties, as well as immunosuppressive behavior. Our findings provide preliminary clues on the individual and combined effects of SAHA and MTR in SS cells and highlight a potential therapeutic interest of this novel pair of drugs for treatment of SS patients.

RHD positive among C/E+ and D-negative blood donors in Tunisia.

PURPOSE OF THE STUDY: The aim of this study was to investigate RHD alleles among Tunisian blood donors with D-negative phenotype and positive for C and/or E antigen. PATIENTS AND METHODS: A total of 100 D-negative and C/E+ samples were analyzed by RHD genotyping using an initial test for RHD exon 10. In case of a positive reaction, further molecular investigations including real time quantitative PCR, allele specific PCR and nucleotide sequencing were done to elucidate the RHD involved mechanisms. RESULTS: Seventy-five percent of the studied samples lacked the RHD gene. Twenty-three percent carried the hybrid RHD-CE-D alleles (16 RHD-CE(3-7)-D, 5 RHD-CE(4-7)-D, 1 RHD-CE(4-8)-D, 1 RHD-CE(3-8)-D) and 2% were weak D (1 weak D type 1 and 1 weak D type 5). CONCLUSION: Our study proved the high frequency of RHD gene among serologically D-negative samples, positive for C and/or E antigen. Thus achieving systematically RHCE phenotyping in all transfusion centers on the Tunisian territory and considering blood donated from D-negative C/E+ persons as D-positive will be recommended to reduce anti-D allo-immunization.

Responder and nonresponder patients exhibit different peripheral transcriptional signatures during major depressive episode.

To date, it remains impossible to guarantee that short-term treatment given to a patient suffering from a major depressive episode (MDE) will improve long-term efficacy. Objective biological measurements and biomarkers that could help in predicting the clinical evolution of MDE are still warranted. To better understand the reason nearly half of MDE patients respond poorly to current antidepressive treatments, we examined the gene expression profile of peripheral blood samples collected from 16 severe MDE patients and 13 matched controls. Using a naturalistic and longitudinal design, we ascertained mRNA and microRNA (miRNA) expression at baseline, 2 and 8 weeks later. On a genome-wide scale, we detected transcripts with roles in various biological processes as significantly dysregulated between MDE patients and controls, notably those involved in nucleotide binding and chromatin assembly. We also established putative interactions between dysregulated mRNAs and miRNAs that may contribute to MDE physiopathology. We selected a set of mRNA candidates for quantitative reverse transcriptase PCR (RT-qPCR) to validate that the transcriptional signatures observed in responders is different from nonresponders. Furthermore, we identified a combination of four mRNAs (PPT1, TNF, IL1B and HIST1H1E) that could be predictive of treatment response. Altogether, these results highlight the importance of studies investigating the tight relationship between peripheral transcriptional changes and the dynamic clinical progression of MDE patients to provide biomarkers of MDE evolution and prognosis.

Molecular background of D-negative phenotype in the Tunisian population.

BACKGROUND: Most studies of the molecular basis of Rhesus D-negative phenotype have been conducted in Caucasian and African populations. A comprehensive survey of RHD alleles was lacking in people from North Africa (Tunisians, Moroccans and Algerians) which could be very efficient for managing donors and patients carrying an RHD molecular variant. We analyse the molecular background of D-negative population in Tunisia in the present study. MATERIALS AND METHODS: Blood samples were collected from native Tunisians. A total of 448 D-negative donors from different regions of Tunisia were analysed by RHD genotyping according to an adopted strategy using real-time PCR, ASP-PCR and sequencing. RESULTS: Among the 448 D-negative samples, 443 were phenotyped unequivocally as true D-negative including three molecular backgrounds which were RHD gene deletion (n = 437), RHDψ pseudogene (n = 2) and RHD-CE-D hybrid gene (n = 4) with the respective frequencies of 0·9900, 0·0023 and 0·0046. The remaining five samples, in discordance with the serological results, were identified as two weak D type 11, one weak D type 29, one weak D type 4·0 and one DBT-1 partial D. CONCLUSION: This study showed that the Tunisian population gets closer to Caucasians, given that the RHD gene deletion is the most prevalent cause of D-negative phenotype, but it is slightly different by the presence of the RHDψ pseudogene which was found with a very low frequency compared with that described in the African population. Nevertheless, the relative occurrence of weak D variants among studied serologically D-negative samples make necessary the adaptation of RHD genotyping strategy to the spectrum of prevalent alleles.

Development of a biochip-based assay integrated in a global strategy for identification of fusion transcripts in acute myeloid leukemia: a work flow for acute myeloid leukemia diagnosis.

Three major types of rearrangements are involved in acute myeloid leukemias (AML): t(8;21)(q22;q22), inv(16)(p13q22), and 11q23/MLL abnormalities. Their precise identification becomes essential for diagnosis, prognosis, and therapeutic choices. Resulting fusion transcripts (FT) are also powerful markers for monitoring the efficacy of treatment, the minimal residual disease (MRD) and could become therapeutic targets. Today, the challenge is to propose an individual follow-up for each patient even for those with a rare fusion event. In this study, we propose a biochip-based assay integrated in a global strategy for identification of rare FT in AML, after fluorescence in situ hybridization detection, as described by the World Health Organization classification. Using cell lines, we developed and validated a biochip-based assay called the AMLFusionChip that identifies every FT of AML1-ETO, CBFbeta-MYH11 as well as MLL-AF9, MLL-ENL, MLL-AF6, and MLL-AF10. The original design of our AMLFusionChip.v01 enables the identification of these FT wherever the breakpoint on the partner gene may be. In case of biochip negative result, our 3'RACE amplification strategy enables to clone and then sequence the new translocation partner. This AMLFusionChip strategy fits into the concept of personalized medicine for the largest number of patients.

Total and fetal cell-free DNA analysis in maternal blood as markers of placental insufficiency in intrauterine growth restriction.

OBJECTIVE: To compare total and fetal DNA levels in the maternal plasma in three groups: pregnancies with intrauterine growth restriction (IUGR) due to placental insufficiency (PI) and other causes, and in control pregnancies. METHODS: Total as well as fetal DNA was quantified in 78 maternal plasma samples. In 19 pregnancies, the fetus presented IUGR due to PI (group A), and in 31 pregnancies due to other causes (group B). The control group comprised 28 patients (group C). DNA quantification was done using real-time quantitative PCR with a standardized pool of plasmid calibrators. DNA concentrations of the three groups were compared using non-parametric tests (Kruskal-Wallis or Mann-Whitney tests). RESULTS: The three groups did not statistically differ regarding maternal age (mean +/- SD: 30.5 +/- 5.4 years), gestational age (30 +/- 5.3 weeks) or the proportion of male fetuses (48.2%). Plasma total DNA was significantly higher in group A compared to groups B and C (p = 0.001 for both). An increase in fetal DNA was only observed in group A for patients beyond 28 weeks of gestation. CONCLUSIONS: The plasma total DNA level is higher in patients with IUGR due to PI. These results suggest the presence of maternal endothelial damage independently of preeclampsia.

Outcome of treatment after first relapse in adults with acute lymphoblastic leukemia initially treated by the LALA-94 trial.

Fifty-four percent of adults with acute lymphoblastic leukemia (ALL) who entered the LALA-94 trial experienced a first relapse. We examined the outcome of these 421 adult patients. One hundred and eighty-seven patients (44%) achieved a second complete remission (CR). The median disease-free survival (DFS) was 5.2 months with a 5-year DFS at 12%. Factors predicting a better outcome after relapse were any transplant performed in second CR (P<0.0001), a first CR duration >1 year (P=0.04) and platelet level >100 x 10(9)/l at relapse (P=0.04). Risk groups defined at diagnosis and treatment received in first CR did not influence the outcome after relapse. The best results were obtained in a subset of patients who were eligible for allogeneic stem cell transplantation (SCT). Geno-identical allogeneic SCT was performed in 55 patients, and 3 patients received donor lymphocyte infusions. Forty-four transplantations were performed from an unrelated donor (of which four were cord blood). We conclude that most adult patients with recurring ALL could not be rescued using current available therapies, although allogeneic SCT remains the best therapeutic option.

Characterization of a reference material for BCR-ABL (M-BCR) mRNA quantitation by real-time amplification assays: towards new standards for gene expression measurements.

Monitoring of BCR-ABL transcripts has become established practice in the management of chronic myeloid leukemia. However, nucleic acid amplification techniques are prone to variations which limit the reliability of real-time quantitative PCR (RQ-PCR) for clinical decision making, highlighting the need for standardization of assays and reporting of minimal residual disease (MRD) data. We evaluated a lyophilized preparation of a leukemic cell line (K562) as a potential quality control reagent. This was found to be relatively stable, yielding comparable respective levels of ABL, GUS and BCR-ABL transcripts as determined by RQ-PCR before and after accelerated degradation experiments as well as following 5 years storage at -20 degrees C. Vials of freeze-dried cells were sent at ambient temperature to 22 laboratories on four continents, with RQ-PCR analyses detecting BCR-ABL transcripts at levels comparable to those observed in primary patient samples. Our results suggest that freeze-dried cells can be used as quality control reagents with a range of analytical instrumentations and could enable the development of urgently needed international standards simulating clinically relevant levels of MRD.

Quantification of mixed chimerism by real time PCR on whole blood-impregnated FTA cards.

This study has investigated quantification of chimerism in sex-mismatched transplantations by quantitative real time PCR (RQ-PCR) using FTA paper for blood sampling. First, we demonstrate that the quantification of DNA from EDTA-blood which has been deposit on FTA card is accurate and reproducible. Secondly, we show that fraction of recipient cells detected by RQ-PCR was concordant between the FTA and salting-out method, reference DNA extraction method. Furthermore, the sensitivity of detection of recipient cells is relatively similar with the two methods. Our results show that this innovative method can be used for MC assessment by RQ-PCR.

Allogeneic stem cell transplantation improves the outcome of adults with t(1;19)/E2A-PBX1 and t(4;11)/MLL-AF4 positive B-cell acute lymphoblastic leukemia: results of the prospective multicenter LALA-94 study.

Adult patients with acute lymphoblastic leukemia (ALL) and t(1;19)/E2A-PBX1 or t(4;11)/MLL-AF4 have a poor outcome. We have evaluated the impact of an intensified post-remission therapy using a high-dose chemotherapy course followed by allogeneic or autologous SCT on the outcome of 58 patients with t(1;19)/E2A-PBX1 (E2A group, n=24) or t(4;11)/MLL-AF4 (MLL group, n=34) treated in the LALA-94 multicenter prospective study. Patients in the MLL group had higher WBC counts and more frequent DIC. CR rates achieved by MLL and E2A groups were similar to other B-cell ALL (87, 82 and 86% respectively). While in CR, patients with a donor were assigned to alloSCT (n=22), the remaining patients with were randomized between autoSCT (n=15) or chemotherapy (n=8). Five-year overall survival was 31 and 45% for E2A and MLL groups, respectively. In both groups, DFS was higher in the alloSCT arm as compared to autoSCT and chemotherapy arms. The results of this study show that chemotherapy intensification did not overcome the poor prognosis of adults with t(1;19)/E2A-PBX1. Allogeneic SCT should thus be offered in first CR to patients with t(1;19)/E2A-PBX1 or t(4;11)/MLL-AF4. New therapeutic approaches are needed for patients without donor.

Autologous stem cell transplantation in adults with acute lymphoblastic leukemia in first complete remission: analysis of the LALA-85, -87 and -94 trials.

To evaluate the results of autologous stem cell transplantation (ASCT) in a large population of adults with acute lymphoblastic leukemia (ALL) in first complete remission (CR), we performed an individual data-based overview of the last three trials from the LALA group. Overall, 349 patients with ALL prospectively randomized in the consecutive LALA-85, -87, and -94 trials to receive either ASCT or chemotherapy as post-CR treatment were analyzed. Eligibility criteria were 15-50-year-old patients without sibling donors in both LALA-85/87 trials and 15-55-year-old patients with high-risk ALL and no sibling donors in the LALA-94 trial. Intent-to-treat analysis, which compared 175 patients from the ASCT arm to 174 patients from the chemotherapy arm, showed that ASCT was associated with a lower cumulative incidence of relapse (66 vs 78% at 10 years; P=0.05), without significant gain in disease-free or overall survival. Despite a possible lack of statistical power, a nested case-control analysis performed in 85 patient pairs adjusted for time to transplant and prognostic covariates confirmed these intent-to-treat results in patients actually transplanted. Of interest, the reduced relapse risk after ASCT translated in better disease-free survival in the 300 rapid responders who reached CR after the first induction course.

A diagnostic biochip for the comprehensive analysis of MLL translocations in acute leukemia.

Reciprocal rearrangements of the MLL gene are among the most common chromosomal abnormalities in both Acute Lymphoblastic and Myeloid Leukemia. The MLL gene, located on the 11q23 chromosomal band, is involved in more than 40 recurrent translocations. In the present study, we describe the development and validation of a biochip-based assay designed to provide a comprehensive molecular analysis of MLL rearrangements when used in a standard clinical pathology laboratory. A retrospective blind study was run with cell lines (n=5), and MLL positive and negative patient samples (n=31), to evaluate assay performance. The limits of detection determined on cell line data were 10(-1), and the precision studies yielded 100% repeatability and 98% reproducibility. The study shows that the device can detect frequent (AF4, AF6, AF10, ELL or ENL) as well as rare partner genes (AF17, MSF). The identified fusion transcripts can then be used as molecular phenotypic markers of disease for the precise evaluation of minimal residual disease by RQ-PCR. This biochip-based molecular diagnostic tool allows, in a single experiment, rapid and accurate identification of MLL gene rearrangements among 32 different fusion gene (FG) partners, precise breakpoint positioning and comprehensive screening of all currently characterized MLL FGs.

Evaluation of candidate control genes for diagnosis and residual disease detection in leukemic patients using 'real-time' quantitative reverse-transcriptase polymerase chain reaction (RQ-PCR) - a Europe against cancer program.

Real-time quantitative RT-PCR (RQ-PCR) is a sensitive tool to monitor minimal residual disease (MRD) in leukemic patients through the amplification of a fusion gene (FG) transcript. In order to correct variations in RNA quality and quantity and to calculate the sensitivity of each measurement, a control gene (CG) transcript should be amplified in parallel to the FG transcript. To identify suitable CGs, a study group within the Europe Against Cancer (EAC) program initially focused on 14 potential CGs using a standardized RQ-PCR protocol. Based on the absence of pseudogenes and the level and stability of the CG expression, three genes were finally selected: Abelson (ABL), beta-2-microglobulin (B2M), and beta-glucuronidase (GUS). A multicenter prospective study on normal (n=126) and diagnostic leukemic (n=184) samples processed the same day has established reference values for the CG expression. A multicenter retrospective study on over 250 acute and chronic leukemia samples obtained at diagnosis and with an identified FG transcript confirmed that the three CGs had a stable expression in the different types of samples. However, only ABL gene transcript expression did not differ significantly between normal and leukemic samples at diagnosis. We therefore propose to use the ABL gene as CG for RQ-PCR-based diagnosis and MRD detection in leukemic patients. Overall, these data are not only eligible for quantification of fusion gene transcripts, but also for the quantification of aberrantly expressed genes.

Standardization and quality control studies of 'real-time' quantitative reverse transcriptase polymerase chain reaction of fusion gene transcripts for residual disease detection in leukemia - a Europe Against Cancer program.

Detection of minimal residual disease (MRD) has proven to provide independent prognostic information for treatment stratification in several types of leukemias such as childhood acute lymphoblastic leukemia (ALL), chronic myeloid leukemia (CML) and acute promyelocytic leukemia. This report focuses on the accurate quantitative measurement of fusion gene (FG) transcripts as can be applied in 35-45% of ALL and acute myeloid leukemia, and in more than 90% of CML. A total of 26 European university laboratories from 10 countries have collaborated to establish a standardized protocol for TaqMan-based real-time quantitative PCR (RQ-PCR) analysis of the main leukemia-associated FGs within the Europe Against Cancer (EAC) program. Four phases were scheduled: (1) training, (2) optimization, (3) sensitivity testing and (4) patient sample testing. During our program, three quality control rounds on a large series of coded RNA samples were performed including a balanced randomized assay, which enabled final validation of the EAC primer and probe sets. The expression level of the nine major FG transcripts in a large series of stored diagnostic leukemia samples (n=278) was evaluated. After normalization, no statistically significant difference in expression level was observed between bone marrow and peripheral blood on paired samples at diagnosis. However, RQ-PCR revealed marked differences in FG expression between transcripts in leukemic samples at diagnosis that could account for differential assay sensitivity. The development of standardized protocols for RQ-PCR analysis of FG transcripts provides a milestone for molecular determination of MRD levels. This is likely to prove invaluable to the management of patients entered into multicenter therapeutic trials.