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Genetic changes associated with Acute Lymphoblastic Leukaemia (ALL) provide diagnostic and prognostic information with a direct impact on patient management. We report the cytogenetic analysis of 298 Tunisian patients with ALL, including 183 children and 115 adults. Chromosome abnormalities have been detected in 68.2% of our patients associating clonal numerical and/or structural rearrangements. Some chromosomal abnormalities especially hyperdiploidy, 19p13 abnormalities, 8q24 translocations, 12p, 6q deletions and TCR rearrangements occur at a lower incidence compared to that reported in other populations. ALL cases (5.7%) had miscellaneous clonal abnormalities. We also found in our Tunisian series a higher incidence for T-lineage ALL more than usually described. Among structural chromosomal abnormalities, t(9;22)(q34;q11) resulting in the BCR/ABL fusion and the t(12;21)(p13;q22) resulting in the TEL/AML1 fusion were studied by FISH providing additional diagnostic and prognostic information. We conclude that although the incidence of our cytogenetic results are slightly different, their clinical significance is similar to that described in the literature.

The commonly deleted region (CDR) for the 5q- syndrome has been identified as a 1.5-megabase interval on human chromosome 5q32. We studied, by real-time reverse-transcription (RT)-PCR, the expression of 33 genes within the CDR that are known to be expressed in CD34+ hematopoietic stem cells. Genes in the 5q- samples that showed the most pronounced decrease in expression compared to non-5q- samples were: solute carrier family 36, member 1 (SLC36A1; 89% downregulated), Ras-GTPase-activating protein SH3 domain-binding (G3BP; 79%), antioxidant protein 1 (ATOX1; 76%), colony-stimulating factor-1 receptor precursor (CSF1R; 76%), ribosomal protein S14 (RPS14; 74%), platelet-derived growth factor receptor-beta (PDGFRB; 73%), Nef-associated factor 1 (TNIP1; 72%), secreted protein, acidic and rich in cysteine (SPARC; 71%), annexin VI (ANAX6; 69%), NSDT (66%) and TIGD (60%). We further studied the hematopoietic system in SPARC-null mice. These mice showed significantly lower platelet counts compared to wild-type animals (P=0.008). Although hemoglobin, hematocrit and mean corpuscular volume (MCV) were lower in mice lacking SPARC, differences were not statistically significant. SPARC-null mice showed a significantly impaired ability to form erythroid burst-forming units (BFU-E). However, no significant differences were found in the formation of erythroid colony-forming units (CFU-E), granulocyte/monocyte colony-forming units (CFU-GM) or megakaryocyte colony-forming units (CFU-Mk) in these animals. We conclude that many of the genes within the CDR associated with the 5q- syndrome exhibit significantly decreased expression and that SPARC, as a potential tumor suppressor gene, may play a role in the pathogenesis of this disease.

The demethylating 5-aza-2'deoxycytidine (DAC) and the histone deacetylase inhibitor (HDACi) suberoyl anilide bishydroxamide (SAHA) possess potent antitumorigenic properties in myeloid disorders. However, the transcriptome alterations mediated by these drugs are poorly understood. We analyzed the transcriptional effects of DAC and SAHA in the AML cell line KG-1. Microarray analyses revealed 76 genes expressed in normal CD34+ cells, absent in KG-1 cells but whose expression was induced after drug treatment. A total of 39 of these genes harbored CpG islands in their promoters. We examined the expression level of these genes in 120 AML patient samples representing diverse karyotpyes. Gas2l1, tfIIs, ehd3, enolase 2, mx1, dral, astml and pxdn were diminished across all AML karyotypes examined. Ehd3 was methylated in 63% of AML patients examined. This methylation was lost upon complete remission, and not observed in normal CD34+ cells. CD34+ cells expressed ehd3 at approximately 10-fold higher levels than AML samples. Another highlighted gene, alpha-catenin, is located at q31 of chromosome 5. Analyses of 29 5q- AML/myelodysplastic syndrome (MDS) samples revealed marked decreases in expression of alpha-catenin, compared to non-5q- MDS samples (6.6+/-9-fold). However, no methylation was detected, suggesting indirect effects of these drugs on the expression of alpha-catenin.

Background: ZAP-70, after being considered as a potential surrogate for VH mutational status, has seen its own prognostic value emerge. We aimed at standardizing a simple, fast, and reproducible flow cytometry method., Methods: AntiZAP-70 antibody 2F3.2 was used with indirect labeling and secondary anti-IgG2a antibody. The reference values for the expression of the results were determined on 45 normal blood samples. ZAP-70 protein expression was investigated in 192 CLL samples. The indirect technique was compared with FITC-conjugated 2F3.2 clone, and with clone 1E7.2-FITC, -PE or -AlexaFluor 488., Results: Using FITC or PE-conjugated antibodies, 2F3.2 and 1E7.2 clones allowed a much less adequate discrimination between positive and negative cells and discordant cases were most likely true negative cases. Using the AlexaFluor 488 conjugated 1E7.2 clone, the discordant cases were mostly negative with the conjugated antibody and positive with the 2F3.2 clone but Western blotting or RNA microarray confirmed discordant cases were false negative with the conjugated antibody. Subsequently, recommendations were used by 13 centers participating in an interlaboratory quality control protocol. The use of MFI ratio appeared to be more reliable., Conclusions: Results suggested that slight differences in the procedure had little impact on the interpretation in characteristic cases; however, careful interpretation was required for values close to threshold., ((c) 2006 International Society for Analytical Cytology.)

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.

Some Shiga toxin-producing Escherichia coli strains (STEC), and in particular E. coli O157:H7, are known to cause severe illness in humans. STEC have been responsible for large foodborne outbreaks and some of these have been linked to dairy products. The aim of the present study was to determine the dissemination and persistence of STEC on 13 dairy farms in France, which were selected out of 151 randomized dairy farms. A total of 1309 samples were collected, including 415 faecal samples from cattle and 894 samples from the farm environment. Bacteria from samples were cultured and screened for Shiga toxin (stx) genes by polymerase chain reaction (PCR). STEC isolates were recovered from stx-positive samples after colony blotting, and characterized for their virulence genes, serotypes and XbaI digestion patterns of total DNA separated by pulsed-field gel electrophoresis (PFGE). Stx genes were detected in 145 faecal samples (35%) and 179 (20%) environmental samples, and a total of 118 STEC isolates were recovered. Forty-six percent of the STEC isolates were positive for stx1, 86% for stx2, 29% for intimin (eae-gene) and 92% for enterohemolysin (ehx), of which 16% of the STEC strains carried these four virulence factors in combination. Furthermore, we found that some faecal STEC strains belonged to serotypes involved in human disease (O26:H11 and O157:H7). PFGE profiles indicated genetic diversity of the STEC strains and some of these persisted in the farm environment for up to 12 months. A large range of contaminated samples were collected, in particular from udders and teats. These organs are potential sources for contamination and re-contamination of dairy cattle and constitute an important risk for milk contamination.

For the first time, a combined genome-wide transcriptome and metabolic analysis was performed with a dairy Lactococcus lactis subsp. lactis biovar diacetylactis strain under dynamic conditions similar to the conditions encountered during the cheese-making process. A culture was grown in skim milk in an anaerobic environment without pH regulation and with a controlled temperature downshift. Fermentation kinetics, as well as central metabolism enzyme activities, were determined throughout the culture. Based on the enzymatic analysis, a type of glycolytic control was postulated, which was shared by most of the enzymes during the growth phase; in particular, the phosphofructokinase and some enzymes of the phosphoglycerate pathway during the postacidification phase were implicated. These conclusions were reinforced by whole-genome transcriptomic data. First, limited enzyme activities relative to the carbon flux were measured for most of the glycolytic enzymes; second, transcripts and enzyme activities exhibited similar changes during the culture; and third, genes involved in alternative metabolic pathways derived from some glycolytic metabolites were induced just upstream of the postulated glycolytic bottlenecks, as a consequence of accumulation of these metabolites. Other transcriptional responses to autoacidification and a decrease in temperature were induced at the end of the growth phase and were partially maintained during the stationary phase. If specific responses to acid and cold stresses were identified, this exhaustive analysis also enabled induction of unexpected pathways to be shown.

The EVI1 gene plays important roles in development and leukemogenesis. Recently, human EVI1 has been shown to give rise to at least six different mRNA variants with alternative 5'-ends, only some of which are conserved in mice. In order to gain a basic understanding of the regulation and potential biological importance of these alternative transcripts, we confirmed their expression by Northern blot, and, using real time quantitative RT-PCR, compared their abundance and stability under different conditions. The general expression patterns of the EVI1 5'-end variants in a panel of 20 human tissues were similar, but particularly high or low levels of some of them were noted in certain tissues. Pronounced differences in the expression of the 5'-end variants were noted in response to all-trans retinoic acid: in a human teratocarcinoma cell line, only the EVI1 transcript variants containing alternative exons 1a and 1b were upregulated in response to this agent. This induction required transcriptional activity of RNA polymerase, but was also associated with a substantial increase in the stability of these mRNA variants.

Three Annonaceous acetogenins exhibited in vitro antimalarial activities on a chloroquine-resistant Plasmodium falciparum strain, with IC50s ranging from 5 to 10 microM. Structure-activity relationships showed that maximal antimalarial activity occurred in the presence of at least one tetrahydrofuran moiety and a synergistic action with chloroquine was observed. These acetogenins partially inhibited the P. falciparum adenylate translocase.

Cytogenetic abnormalities in myelodysplastic syndromes (MDS) are complex and heterogeneous. The most frequent rearrangements (gains or losses of genetic material) vary from patient to patient, and within the same patient. The prognostic value of these rearrangements has been extensively studied. They allowed the definition of a risk based classification system for MDS (the International Scoring System for evaluating Prognosis, IPSS), proven to be a highly useful method for evaluating prognosis in MDS patients. Despite recent progress in mapping and definition of minimally deleted chromosomal regions, the primary critical genetic events remain to be determined. The recurrent cytogenetic abnormalities associated with MDS are likely to be secondary events contributing to but not initiating the neoplastic phenotype of the disease.

The calcination and natural sintering of calcium deficient hydroxyapatite powders Ca(10-x)(PO4)(6-x)(HPO4)x(OH)(2-x) (with 0 < or = x < or = 1) were studied. For temperature below 700 degrees C, particle coalescence occurs without densification. The particle coalescence is associated with a reduction of the specific surface area. This surface decreases all the more as the Ca/P molar ratio of the powder is small. The mechanism agrees with a transfer of matter occurring by superficial diffusion, which is enhanced by the augmentation of vacancies in the apatitic structure (i.e. by a decrease of the Ca/P ratio). The sintering of compacted powders begins at 700 degrees C. At the same temperature, the calcium deficient hydroxyapatites dissociate into biphasic mixtures of hydroxyapatite and tricalcium phosphate. The sintering is slowed down when the content of TCP in the biphasic mixture increases. In parallel, the grain size increases. This result relates to the augmentation of the coalescence of particles at low temperature.

Single phased apatitic calcium phosphate powders Ca(10-x)(PO4)(6-x)(HPO4)x(OH)(2-x) with Ca/P molar ratio ranging from 1.5 to 1.667 (0 < or = x < or = 1) were synthesised using wet method. Outside this compositional range the powders were biphasic mixtures composed of a calcium phosphate apatite and CaHPO4 (Ca/P < 1.5) or Ca(OH)2 (Ca/P > 1.667). Temperature and pH of synthesis were the preponderant parameters for the control of the precipitate composition. The precise determination of the chemical composition requires the use of several complementary techniques and thermal treatments of powders. These techniques include high resolution and high temperature X-ray diffractometry and FTIR spectroscopy and show that very small variations of the Ca/P molar ratio of the powder lead to great changes in powder composition and characteristics after thermal treatment.

Calcium deficient hydroxyapatite powders Ca(10-x)(PO4)(6-x)(HPO4)x(OH)(2-x) (0 < or = x < or = 1) were hot pressed to produce dense hydroxyapatite-tricalcium phosphate (HAP/TCP) biphasic materials. Ceramics hot pressed at 1000 degrees C were composed of an homogeneous distribution of the HAP and beta-TCP grains with an average size of 0.2 microm. Grain growth was observed for TCP loading > 70 wt%. The strength exhibited a maximum of sigma(f) = 150 MPa for 90/10 (w/w) HAP/TCP and it dropped for smaller and greater amounts of TCP. This value was twice that of pure HAP. When placed in Ringer's solution, only the surface of biphasic compounds was degraded after 60 days of immersion with a preferential etching of the TCP phase. After hot pressing at 1200 degrees C, grain growth was observed and the mechanical properties were decreased. This was explained by the allotropic transformation alpha/beta of TCP.

Polycrystalline hydroxyapatite was densified by hot pressing. The dissolution process in aqueous solution and the effects of environment on dynamic fatigue resistance of the resulting HAP ceramics were investigated. Pure water or Ringer's solution strongly enhances subcritical crack growth. The crack propagation exponent decreases from 22.5+/-2 in air to 10+/-4 in Ringer's solution for materials densified at 98% of the theoretical value. The residual porosity ratio is also very detrimental for the mechanical reliability. Both fatigue resistance and immediate fracture strength are decreased, with values of only 14+/-4 for the propagation exponent and 40 MPa for the tensile strength (compared to 90 MPa at 98% relative density) for materials densified at 94% tested in air. The degradation in solution appears to be governed by uniform physico-chemical dissolution of crystalline HAP phase at the surface of the material. This dissolution is accompanied by a decohesion of grains located around residual pores which leads to the growth of local surface defects., (Copyright 1998 Chapman & Hall)

Translocations in hematologic disease of myeloid or lymphoid origin with breakpoints at chromosome band 12p13 frequently result in rearrangements of the Ets variant gene 6 (ETV6). As a consequence either the ETS DNA-binding domain or the Helix-Loop-Helix (HLH) oligomerization domain of ETV6 is fused to different partner genes. We show here that a t(9;12)(p24;p13) in a case of early pre-B acute lymphoid leukemia and a t(9;15;12)(p24;q15;p13) in atypical chronic myelogenous leukemia in transformation involve the ETV6 gene at 12p13 and the JAK2 gene at 9p24. In each case different fusion mRNAs were found, with only one resulting in an open reading frame for a chimeric protein consisting of the HLH oligomerization domain of ETV6 and the protein tyrosine kinase (PTK) domain of JAK2. The cloning of the complete human JAK2 coding and genomic sequences and of the genomic junction fragments of the translocations allowed a characterization of the different splice events leading to the various mRNAs. JAK2 plays a central role in non-protein tyrosine kinase receptor signaling pathways, which could explain its involvement in malignancies of different hematologic lineages. Besides hop in Drosophila no member of the JAK family has yet been implicated in tumorigenesis.

The presence of ETV6 deletions was investigated in 215 children with acute lymphoblastic leukemia (ALL) using the loss of heterozygosity (LOH) approach. We used four intragenic or juxtagenic microsatellite markers to detect allelic deletions. In this series of unselected patients, LOH of ETV6 markers was found in 23% of cases (6% of T-ALL and 26% of B lineage ALL) confirming that chromosome 12p12-13 deletions represent a major genetic alteration in childhood ALL, frequently missed by cytogenetic analysis. The presence of a t(12;21)(p13;q22) was studied by RT-PCR and/or FISH in a total of 134 patients (125 B lineage ALL, nine T-ALL) including 42 cases with LOH. Thirty-four out of 44 patients (77%) for whom a t(12;21) was observed displayed LOH of the ETV6 markers. When associated with a t(12;21), ETV6 is very likely to be the target of deletions as indicated by the detection of intragenic deletions in three patients. Although deletion of ETV6 and t(12;21) were associated in most patients, in eight cases (six B lineage and two T-ALL) LOH was detected at the ETV6 locus without ETV6-AML1 hybrid RNA. FISH studies conducted in five of these eight patients confirmed the absence of translocation involving ETV6. In such patients, the other allele of ETV6 could be disrupted by either a small deletion, a point mutation, or an epigenetic modification and it will be of interest to study the structure and expression of the remaining allele of ETV6 in these cases. Alternatively, a tumor suppressor gene located close to ETV6 and CDKN1B could be the target of deletions.

We report an infant born with a cutaneous nodular eruption and neutropenia. Skin biopsy specimens revealed an immature dermal infiltrate suggestive of leukemia cutis, but repeated peripheral blood and bone marrow examinations failed to demonstrate malignant cells. The eruption resolved spontaneously. At the age of 3 months, a second occurrence of maculopapular skin lesions led to discovery of an acute monoblastic leukemia with (9;11)(p21-22;q23) translocation. Congenital acute leukemia is a rare disease associated with skin infiltration in 25% to 30% of patients. Usually the diagnosis is easily made by peripheral blood examination and/or bone marrow aspirate. However, skin involvement may precede acute leukemia by several weeks. Although very rare, this event must be kept in mind.

We have identified a new recurrent reciprocal translocation between chromosome 3 and 12 with breakpoints at bands 3q26 and 12p13, t(3;12)(q26;p13) in the malignant cells from five patients with acute transformation of myelodysplastic syndrome or blast crisis of chronic myelogenous leukemia. t(3;12)(q26;p13) appears as a rare but nonrandom event present in various myeloid leukemia subtypes, which is frequently associated with dysplasia of megakaryocytes, multilineage involvement, short duration of any blastic phase, and a very poor prognosis. Here, we report the molecular cytogenetic analysis of the t(3;12). Fluorescence in situ hybridization results indicate that the 3q26 breakpoints are quite heterogeneous and occur 5' of MDS1, 3' of EVI1, or between MDS1 and EVI1. Our results are very similar to those observed in other 3q26 rearrangements in which breakpoints were shown to occur over considerable distances 5' and 3' of EVI1. Fluorescence in situ hybridization investigations proved that, in three myelodysplastic syndrome cases with t(3;12)(q26;p13), the 12p 13 breakpoint occurred within the TEL gene.

Fluorescence in situ hybridization (FISH) was performed on bone marrow cells thought to contain a t(7;11)(p22;q13) from a patient with chronic myelomonocytic leukemia in transformation. FISH analysis using a panel of 10 probes previously mapped to 11q13 revealed a cytogenetically undetected complex rearrangement that involved chromosomes 7 and 11 as well as a chromosome 3 at band p24. Two distinct translocation breakpoints, both proximal to the BCL1 locus, were found in chromosome 11 that perforce separate it into three subregions. The two breakpoints appear distinct from the two previously described ones which involved the FAU and GSTP1 genes. Our observations add to the involvement of proximal 11q13 in myeloid malignancies.

We have undertaken the cytogenetic monitoring of 39 adult patients treated for de novo acute myeloid leukemia (AML) by intensive chemotherapy. We describe this monitoring in seven patients in continuous complete clinical and morphologic remission (CR) of AML. Although in CR, these patients exhibit the emergence of cytogenetically abnormal clones. Abnormalities observed include monosomy 7, del(20)(q11), partial trisomy 1q, and 6p12-22 rearrangements. They correspond to well-known chromosomal rearrangements commonly found in myelodysplasia (MDS), and myeloproliferative syndromes (MPS), as well as AML. Present as the sole detected chromosomal change, they preceded by months the onset of overt leukemia or MDS. In some cases, the abnormal clone showed a proliferative advantage (some patients exhibited up to 100% of abnormal bone marrow metaphases in subsequent analyses). AML relapse, when it occurred, was associated with a different chromosomal modification. Altogether the question arises, whether the abnormalities pointed out in our study (monosomy 7, del(20)(q11), partial trisomy for the long arm of chromosome 1 (q21qter), 6p12-22 rearrangements), and seen after chemotherapy, mark preleukemic cells or not, and whether they participate indirectly, or not at all in the leukemic process.

We have analyzed the BCL1 locus in a series of 24 B-cell tumors and cell lines with rearrangements of 11q13 (mostly t(11;14)(q13;q32) translocations). Using Southern hybridization and/or fluorescence in situ hybridization (FISH) on metaphase chromosomes, we have not only confirmed the scattering of the breakpoints between the BCL1 locus and the cyclin D1 gene (CCND1), but also shown that some of the breakpoints could be as far as 500 kb on either side of the latter. Expression of CCND1 was not restricted to cases with t(11;14)(q13;q32), but was also associated with other 11q13 rearrangements, such as a t(8;11)(p22;q13). Whatever the alteration at 11q13, a correlation was observed between the expression of CCND1 and the presence of a breakpoint within 150 kb upstream of the gene. On the contrary, three samples, including a bona fide t(11;14) translocation and two cases with breakpoints located outside the BCL1-CCND1 area, did not exhibit detectable levels of CCND1 transcripts. Our results raise the possibility that several discrete molecular events can take place at 11q13 in B-cell malignancies.

In order to document a possible involvement of structural alterations of FGF (Fibroblast Growth Factor)-like genes in human oncogenesis, we have screened a large series of human tumors for amplification of five FGF-related genes (Basic-FGF, INT2, HST, FGF5 and FGF6). None of 37 hematopoietic neoplasms, one out of 13 melanomas (8%), three out of 43 bladder tumors (7%) and 41 out of 238 breast carcinomas (17%) contained amplified FGF-related sequences, namely HST and INT2. Only these two genes, both located on band q13 of chromosome 11 have been found amplified. In all cases they were co-amplified and in only one instance did amplification extend to the ETS1 locus at position 11q23. INT2 and HST RNA could be evidenced by RNA/RNA in situ hybridization in breast carcinomas. Our results indicate a correlation between RNA expression and gene amplification in the case of HST but not of INT2. Although evaluation of the clinical significance of HST amplification and expression must await long-term follow-up of the patients, we suggest that HST gene product could play a role in development and/or progression of human breast cancer.

A cytogenetic prenatal diagnosis due to maternal age led us to find a male fetus with a (X;Y) translocation. This translocation is found in the mother, who presents no phenotypic abnormalities or mental retardation. The 22 cases described in the literature indicate that among male carriers of an (X;Y) translocation, half the cases present mental retardation and 2/3 phenotypic anomalies. These findings led us to give a genetic counselling of therapeutic abortion. Post mortem histological examination revealed no morphodysplasia.

Data obtained on 88 patients with refractory anemia or preleukemia, without previous cytotoxic treatment, showed medullar chromosomal abnormalities in 32%. In 45% of the cases, the disease had progressed to acute nonlymphocytic leukemia. A high frequency of acute transformation (78%) was observed in patients with abnormal clones. These results are different from those of the Second International Workshop on chromosomes in Leukemia. The discrepancies may be related to the difference between the cases selected for submission to the workshop and those of this study. Serial studies on 28 patients with abnormal karyotypes showed that two different populations of patients were investigated: one with a terminal smoldering phase of leukemia and the other with true preleukemic disease. In the latter group, no predictive karyotype evolution was seen.

A new case of a variant form of the translocation (8;21) in an AML-M2, including in addition involvement of chromosome #15 is reported. The selection of two abnormal lines, probably resulting from two successive rearrangements of the (8;15) translocated segment, is observed. It is suggested that these rearrangements change the cellular morphology and seem to play a part similar to additional autosomal abnormalities in the course of the disease, such as those found in CML.