Climate impact of an optimised gas treatment on old landfills.

It is a well-established fact that the quality and quantity of landfill gas (LFG) start declining after a landfill is closed to further waste intake. Conventional gas treatment and utilisation systems such as flares and gas-driven engines require a certain quality of LFG: specifically, a sufficient methane concentration. Various measures are utilised to maintain the necessary quality of LFG, including a turn-down of gas extraction rates and a shutdown of low-quality gas wells, resulting in a decline of LFG production. This, however, does not have to be the case. The low calorific value (LCV) LFG capture and treatment technology developed by e-flox and referred to in this article as 'LCV LFG System' can significantly increase the collection rate and the amount of treated methane in an old landfill. This article introduces such new treatment measures, describes gas capture calculation methodologies and presents actual results based on a medium-sized landfill in Germany. The study demonstrates, among other things, that the LCV LFG system can reduce the CO2 avoidance costs to roughly 10 €/tCO2eq. We present this new technology as a quick and straightforward measure of dealing with the climate issues related to methane emissions of old landfills.

MLL insertion with MLL-MLLT3 gene fusion in acute leukemia: case report and review of the literature.

A new chromosomal insertion involving the MLL gene was detected by fluorescence in situ hybridization in a patient with acute myeloblastic leukemia (AML) and a t(9;11)(p21;q13). Genomic polymerase chain reaction confirmed the MLL-MLLT3 gene fusion. A review of the literature on MLL insertions shows that the opposite orientation of the genes involved in the fusion plays a role in the genesis of the rearrangement in most of the cases reported.

Transcriptional activation of the cardiac homeobox gene CSX1/NKX2-5 in a B-cell chronic lymphoproliferative disorder.

Homeobox containing transcription factors are frequently deregulated in human hematologic malignant diseases either indirectly through an abnormality of an upstream factor, or directly through rearrangement of the gene itself. Study of T-cell acute lymphoblastic leukemia identified the related non-clustered homeobox transcription factors, TLX1 and TLX3, as frequently ectopically expressed as a result of chromosomal translocations. We report the deregulation of a non-clustered homeobox gene in a new type of t(5;14)(q35;q11) translocation in a mature peripheral B-cell leukemia. This translocation results in the ectopic expression of the CSX1/NKX2-5 gene on chromosome 5q35 due to its juxtaposition to the TCR delta gene on chromosome 14q11. Expression of the CSX1/NKX2-5 protein conferred enhanced replating potential to transduced murine bone marrow cells. Our study establishes that deregulation of homeobox encoding genes is not restricted to acute leukemic proliferations, but is also observed in chronic malignant diseases.

High-throughput sequence analysis of the tyrosine kinome in acute myeloid leukemia.

To determine whether aberrantly activated tyrosine kinases other than FLT3 and c-KIT contribute to acute myeloid leukemia (AML) pathogenesis, we used high-throughput (HT) DNA sequence ana-lysis to screen exons encoding the activation loop and juxtamembrane domains of 85 tyrosine kinase genes in 188 AML patients without FLT3 or c-KIT mutations. The screen identified 30 nonsynonymous sequence variations in 22 different kinases not previously reported in single-nucleotide polymorphism (SNP) databases. These included a novel FLT3 activating allele and a previously described activating mutation in MET (METT1010I). The majority of novel sequence variants were stably expressed in factor-dependent Ba/F3 cells. Apart from one FLT3 allele, none of the novel variants showed constitutive phosphorylation by immunoblot analysis and none transformed Ba/F3 cells to factor-independent growth. These findings indicate the majority of these alleles are not potent tyrosine kinase activators in this cellular context and that a significant proportion of nonsynonymous sequence variants identified in HT DNA sequencing screens may not have functional significance. Although some sequence variants may represent SNPs, these data are consistent with recent reports that a significant fraction of such sequence variants are "passenger" rather than "driver" alleles and underscore the importance of functional assessment of candidate disease alleles.

NUP98-NSD1 fusion by insertion in acute myeloblastic leukemia.

A case of NUP98-NSD1 gene fusion resulting from the insertion of a subtelomeric part of chromosome 11p15.4 within the subtelomeric part of 5q35 was detected in a child with acute myeloblastic leukemia. This new case illustrates the importance of using fluorescence in situ hybridization followed by reverse transcriptase-polymerase chain reaction techniques to detect abnormalities involving subtelomeric chromosomal regions.

Identification of driver and passenger mutations of FLT3 by high-throughput DNA sequence analysis and functional assessment of candidate alleles.

Mutations in the juxtamembrane and kinase domains of FLT3 are common in AML, but it is not known whether alterations outside these regions contribute to leukemogenesis. We used a high-throughput platform to interrogate the entire FLT3 coding sequence in AML patients without known FLT3 mutations and experimentally tested the consequences of each candidate leukemogenic allele. This approach identified gain-of-function mutations that activated downstream signaling and conferred sensitivity to FLT3 inhibition and alleles that were not associated with kinase activation, including mutations in the catalytic domain. These findings support the concept that acquired mutations in cancer may not contribute to malignant transformation and underscore the importance of functional studies to distinguish "driver" mutations underlying tumorigenesis from biologically neutral "passenger" alterations.

Jumping translocations.

Jumping translocations (JT) are uncommon constitutional or acquired chromosome rearrangements involving one donor and several recipient chromosomes. They occur in various pathologic conditions and the mechanism of their formation remains elusive. A review of the literature showed that the major localizations of the breakpoints of JTs in human samples are nonrandomly located in pericentromeric and telomeric regions of chromosomes. Interestingly, comparison of the localization of the chromosomal breakpoints and of presence of interstitial DNA repeats showed differences between constitutional and acquired JTs suggesting differences in the mechanisms for the genesis of JTs and their consequences.

Gallium(III) and iron(III) complexes of alpha-N-heterocyclic thiosemicarbazones: synthesis, characterization, cytotoxicity, and interaction with ribonucleotide reductase.

A series of gallium(III) and iron(III) complexes with five different 4N-substituted alpha-N-heterocyclic thiosemicarbazones, viz., 2-acetylpyridine N,N-dimethylthiosemicarbazone (1), 2-acetylpyridine N-pyrrolidinylthiosemicarbazone (2), acetylpyrazine N,N-dimethylthiosemicarbazone (3), acetylpyrazine N-pyrrolidinylthiosemicarbazone (4), and acetylpyrazine N-piperidinylthiosemicarbazone (5), with the general formula [GaLCl2] (HL = 1 and 2) and [ML2][Y] (M = Ga, HL = 1-5, Y = PF6; M = Fe, HL = 1-5, Y = FeCl4 and PF6) were synthesized and characterized by elemental analysis, a number of spectroscopic methods (NMR, IR, UV-vis), mass spectrometry, and X-ray crystallography. The in vitro antitumor potency was studied in two human cancer cell lines (41M and SK-BR-3). The central metal ions exert pronounced effects in a divergent manner: gallium(III) enhances, whereas iron(III) weakens the cytotoxicity of the ligands. The capacity of ligand 1 and its Ga(III) and Fe(III) complexes to destroy the tyrosyl radical of the presumed target ribonucleotide reductase is reported.

Novel activating JAK2 mutation in a patient with Down syndrome and B-cell precursor acute lymphoblastic leukemia.

Activation of tyrosine kinase genes is a frequent event in human hematologic malignancies. Because gene activation could be associated with gene dysregulation, we attempted to screen for activating gene mutation based on high-level gene expression. We focused our study on the Janus kinase 2 (JAK2) gene in 90 cases of acute leukemia. This strategy led to the identification of a novel JAK2-acquired mutation in a patient with Down syndrome (DS) with B-cell precursor acute lymphoblastic leukemia (BCP-ALL). This mutation involves a 5-amino acid deletion within the JH2 pseudokinase domain (JAK2DeltaIREED). Expression of JAK2DeltaIREED in Ba/F3 cells induced constitutive activation of the JAK-STAT pathway and growth factor-independent cell proliferation. These results highlight the JAK2 pseudokinase domain as an oncogenic hot spot and indicate that activation of the JAK-STAT pathway may contribute to lymphoid malignancies and hematologic disorders observed in children with DS.

Preclinical characterization of anticancer gallium(III) complexes: solubility, stability, lipophilicity and binding to serum proteins.

The discovery and development of gallium(III) complexes capable of inhibiting tumor growth is an emerging area of anticancer drug research. A range of novel gallium coordination compounds with established cytotoxic efficacy have been characterized in terms of desirable chemical and biochemical properties and compared with tris(8-quinolinolato)gallium(III) (KP46), a lead anticancer gallium-based candidate that successfully finished phase I clinical trials (under the name FFC11), showing activity against renal cell cancer. In view of probable oral administration, drug-like parameters, such as solubility in water, saline and 0.5% dimethyl sulfoxide, stability against hydrolysis, measured as the rate constant of hydrolytic degradation in water or physiological buffer using a capillary zone electrophoresis (CZE) assay, and the octanol-water partition coefficient (logP) providing a rational estimate of a drug's lipophilicity, have been evaluated and compared. The differences in bioavailability characteristics between different complexes were discussed within the formalism of structure-activity relationships. The reactivity toward major serum transport proteins, albumin and transferrin, was also assayed in order to elucidate the drug's distribution pathway after intestinal absorption. According to the values of apparent binding rate constants determined by CZE, both KP46 and bis(2-acetylpyridine-4,4-dimethyl-3-thiosemicarbazonato-N,N,S)gallium(III) tetrachlorogallate(III) (KP1089) bind to transferrin faster than to albumin. This implies that transferrin would rather mediate the accumulation of gallium antineoplastic agents in solid tumors. A tendency of being faster converted into the protein-bound form found for KP1089 (due possibly to non-covalent binding) seems complementary to its greater in vitro antiproliferative activity.

HOX11L2/TLX3 is transcriptionally activated through T-cell regulatory elements downstream of BCL11B as a result of the t(5;14)(q35;q32).

The t(5;14)(q35;q32) chromosomal translocation is specifically observed in up to 20% of childhood T-cell acute lymphoblastic leukemia (T-ALL). It affects the BCL11B/CTIP2 locus on chromosome 14 and the RANBP17-TLX3/HOX11L2 region on chromosome 5. It leads to ectopic activation of TLX3/HOX11L2. To investigate the reasons of the association between t(5;14) and T-ALL, we isolated the translocation breakpoints in 8 t(5;14) patients. Sequence analyses did not involve recombinase activity in the genesis of the translocation. We used DNAse1 hypersensitive experiments to locate transcriptional regulatory elements downstream of BCL11B. By transient transfection experiments, 2 of the 6 regions demonstrated cis-activation properties in T cells and were also effective on the TLX3 promoter. Our data indicate that the basis of the specific association between t(5;14) and T-ALL lies on the juxtaposition of TLX3 to long-range cis-activating regions active during T-cell differentiation.

Overexpression of CEBPA resulting from the translocation t(14;19)(q32;q13) of human precursor B acute lymphoblastic leukemia.

Subtle variation in the expression or function of a small group of transcription factors can drive leukemogenesis. The CEBPA protein is known to regulate the balance between cell proliferation and differentiation during early hematopoietic development and myeloid differentiation. In human myeloid leukemia, CEBPA is frequently inactivated by mutation and indirect and posttranslational mechanisms, in keeping with tumor suppressor properties. We report that CEBPA is activated by juxtaposition to the immunoglobulin gene enhancer upon its rearrangement with the immunoglobulin heavy-chain locus in precursor B-cell acute lymphoblastic leukemia harboring t(14;19)(q32;q13). Overexpression of apparently normal CEBPA RNA or protein was observed in 6 patients. These data indicate that CEBPA may exhibit oncogenic as well as tumor suppressor properties in human leukemogenesis.

Transforming potential of the T-cell acute lymphoblastic leukemia-associated homeobox genes HOXA13, TLX1, and TLX3.

The importance of HOXA genes in T-cell acute lymphoblastic leukemia (T-ALL) has recently been recognized. We report a novel chromosomal translocation in a T-ALL patient that maps upstream of the HOXA13 gene and downstream of the BCL11B/CTIP2 locus. Analysis of HOXA gene transcription demonstrated massive expression of HOXA13, whereas the other HOXA genes were unaffected. A genomic rearrangement of the HOXA locus associated with exclusive expression of HOXA13 was observed in a second patient. This situation resembles chromosomal translocations activating genes of the TLX/HOX11 family in T-ALLs. To compare the leukemogenic properties of HOXA13 to that of TLX proteins, cohorts of lethally irradiated mice were transplanted with bone marrow transduced with a retroviral vector expressing TLX3 or HOXA13. Cells transduced with TLX3 or HOXA13 could not be detected in the peripheral blood of mice post-transplantation and none of the mice developed malignancies. Cotransduction of the HOX cofactor MEIS1 with TLX3 or HOXA13 did not alter this outcome. However, in a myeloid clonogenic assay HOXA13 and TLX3 extended the proliferation of progenitors similarly to what was observed for TLX1. Altogether, our results strongly suggest the absolute requirement for cooperative events in association with homeobox gene up-regulation to induce T-cell leukemogenesis.

Abnormalities of the long arm of chromosome 21 in 107 patients with hematopoietic disorders: a collaborative retrospective study of the Groupe Français de Cytogénétique Hématologique.

Chromosome 21 is frequently rearranged in hematopoietic malignancies. In order to detect new chromosomal aberrations, the Groupe Français de Cytogénétique Hématologique collected a series of 107 patients with various hematologic disorders and acquired structural abnormalities of the long arm of chromosome 21. The abnormalities were subclassified into 10 groups, according to the location of the 21q breakpoint and the type of abnormality. Band 21q22 was implicated in 72 patients (excluding duplications, triplications, and amplifications). The involvement of the RUNX1 gene was confirmed in 10 novel translocations, but the gene partners were not identified. Eleven novel translocations rearranging band 21q22 with bands 1q25, 2p21, 2q37, 3p21, 3p23, 4q31, 6p24 approximately p25, 6p12, 7p15, 16p11, and 18q21 were detected. Rearrangements of band 21q11 and 21q21 were detected in six novel translocations with 5p15, 6p21, 15q21, 16p13, and 20q11 and with 1p33, 3q27, 5p14, 11q11, and 14q11, respectively. Duplications, triplications, amplifications, and isodicentric chromosomes were detected in eight, three, eight, and three patients, respectively. The present study shows both the wide distribution of the breakpoints on the long arm of chromosome 21 in hematopoietic malignancy and the diversity of the chromosomal rearrangements and the hematologic disorders involved. The findings invite further investigation of the 21q abnormalities to detect their associated molecular rearrangements.

Deregulation of cyclin D2 by juxtaposition with T-cell receptor alpha/delta locus in t(12;14)(p13;q11)-positive childhood T-cell acute lymphoblastic leukemia.

OBJECTIVES: The t(12;14)(p13;q11)--a recurrent translocation in childhood T-cell acute lymphoblastic leukemia (T-ALL)--has very recently been molecularly characterized in one case, which displayed overexpression of the cyclin D2 gene (CCND2). PATIENTS AND METHODS: We have characterized two pediatric t(12;14)-positive T-ALLs using fluorescence in situ hybridization (FISH), cDNA microarray, and real-time polymerase chain reaction (PCR). RESULTS: FISH revealed breakpoints (BPs) in the T-cell receptor alpha/delta locus (14q11) and in the vicinity of the CCND2 gene at 12p13. To investigate the expression of genes in 12p13, cDNA microarray analysis was performed. Expression data for eight genes, including CCND2, surrounding the 12p BP were compared with those in other T-ALLs. The t(12;14)-positive T-ALL displayed an increased expression of CCND2 compared to the controls, whereas the expression of the other genes was similar in all T-ALLs. Expression of CCND2 and two additional genes (PARP11 and FGF23), close to the 12p BP, was investigated with real-time PCR of the two t(12;14)-positive cases and four controls. Neither PARP11 nor FGF23 displayed expression differences among the T-ALLs, whereas CCND2 was clearly overexpressed in both t(12;14)-positive cases as compared to the mean expression level in the controls. CONCLUSION: We have confirmed, in two additional cases, that the recurrent T-ALL-associated t(12;14) results in overexpression of cyclin D2. The t(12;14) is the first neoplasia-associated translocation shown to result in overexpression of cyclin D2. Furthermore, it is the first example of a T-cell neoplasm with a targeted deregulation of a member of a cyclin-encoding gene family.

Acute megakaryoblastic leukemia and loss of the RUNX1 gene.

Since the RUNX1 gene contributes to megakaryopoiesis and acquired trisomy 21 is the most frequent numerical chromosome anomaly in acute megakaryoblastic leukemia (AMLK), a systematic study of RUNX1 abnormalities was performed by fluorescence in situ hybridization in AMLK patients. Four abnormalities were detected among 15 patients. One copy of RUNX1 was completeley or partially lost in three patients and translocated onto Xq24 in the fourth. The possible consequences of RUNX1 haploinsufficiency are discussed.