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ABSTRACT: Application of five-color staining may improve quantification of minimal residual disease by multiparameter flow cytometry in acute myeloid leukemia. We analysed bone marrow samples in 139 cases using a comprehensive antibody panel with five-color combinations. Sensitivity was estimated by quantification of leukemia-associated aberrant immunophenotype (LAIP)-positive cells for each LAIP in 18 normal bone marrow (BM) samples. The logarithmic difference (LD) in LAIP-positive cells between leukemic and normal BM amounted to a median of 3.32 (range 1.76 - 4.89). Skipping one color resulted in an increase of LAIP-positive normal bone marrow cells while percentages of LAIP-positive leukemic cells changed only marginally (median gain in LD = 0.54; maximum gain = 3.30). Because regenerating bone marrow has not been used as control data are most important to post-therapy checkpoints. In 32 patients with clinical follow-up, a LD higher than the median (3.25) at the follow-up checkpoint corresponded to a longer event-free survival. These data suggest that the application of five-color staining significantly improves the sensitivity and accuracy of the method.
Leukemia and Lymphoma 02/2007; 48(1):80-8. · 2.58 Impact Factor
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Leukemia 01/2007; 20(12):2195-7. · 9.56 Impact Factor
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ABSTRACT: AML1-ETO collaborates with further genetic abnormalities to induce acute myeloid leukaemia (AML). We analysed 99 patients with an AML1-ETO rearrangement for additional aberrations. Frequent genetic abnormalities were, loss of a sex chromosome (56/99, 56.5%) and del(9)(q22) (24/99, 24.2%). The most frequent molecular aberrations were mutations of KITD816 (3/23, 13%) and NRAS (8/89, 8.9%). Further molecular abnormalities were FLT3 mutations (3/87, 3.4%), AML1 (1/26, 3.8%) and PU1 (1/14, 7.1%). MLL-PTD, KRAS and CEBPA mutations were not found. These clinical findings support the model that AML1-ETO collaborates with other genetic alterations, such as mutations of receptor tyrosine kinases, to induce AML.
British Journal of Haematology 10/2006; 134(6):616-9. · 4.94 Impact Factor
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C Meyer,
B Schneider,
S Jakob,
S Strehl,
A Attarbaschi,
S Schnittger, C Schoch,
M W J C Jansen,
J J M van Dongen,
M L den Boer, [......],
A Biondi,
E Delabesse,
E Macintyre,
M Stanulla,
M Schrappe,
O A Haas,
T Burmeister,
T Dingermann,
T Klingebiel,
R Marschalek
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ABSTRACT: Chromosomal rearrangements of the human MLL gene are a hallmark for aggressive (high-risk) pediatric, adult and therapy-associated acute leukemias. These patients need to be identified in order to subject these patients to appropriate therapy regimen. A recently developed long-distance inverse PCR method was applied to genomic DNA isolated from individual acute leukemia patients in order to identify chromosomal rearrangements of the human MLL gene. We present data of the molecular characterization of 414 samples obtained from 272 pediatric and 142 adult leukemia patients. The precise localization of genomic breakpoints within the MLL gene and the involved translocation partner genes (TPGs) was determined and several new TPGs were identified. The combined data of our study and published data revealed a total of 87 different MLL rearrangements of which 51 TPGs are now characterized at the molecular level. Interestingly, the four most frequently found TPGs (AF4, AF9, ENL and AF10) encode nuclear proteins that are part of a protein network involved in histone H3K79 methylation. Thus, translocations of the MLL gene, by itself coding for a histone H3K4 methyltransferase, are presumably not randomly chosen, rather functionally selected.
Leukemia 06/2006; 20(5):777-84. · 9.56 Impact Factor
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M-C Béné,
G Castoldi,
A Derolf,
R Garand,
T Haas,
T Haferlach,
W Knapp,
E Kuhlein,
P Lemez,
W-D Ludwig,
I Marinov,
E Matutes,
K Michalová,
A Porwit-MacDonald,
A Orfao, C Schoch,
P Talmant,
M B Van't Veer,
Z Zemanová,
M Zühlsdorf
Leukemia 05/2006; 20(4):725-8. · 9.56 Impact Factor
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ABSTRACT: Standardized procedures were developed to compare quantitatively the toxic and transforming effects of ten environment-related polycyclic aromatic hydrocarbons (PAH's) using early passage mixed cultures of fetal Syrian golden hamster lung cells. Evaluation of toxicity was attempted by applying a linear regression to the relative number of surviving colonies. Transformation data were fitted satisfactorily to the one-hit model. Used as a monitor compound in each subexperiment, benzo[a]pyrene (BaP) showed dose-related colony reduction (0.01–0.5 μg ml−1). Benzo[b]fluoranthene (BbF), indeno[1,2,3-cd]pyrene (IcdP), benzo[k]fluoranthene (BkF) and benzo[e]pyrene (BeP) were generally colony enhancing at dose ranges up to 1.0 μg ml−1. Fluoranthene (FLT), pyrene (PYR), chrysene (CHR), benzo[ghi]perylene (BghiPL) and benz[a]anthracene (BaA) were neither stimulatory nor inhibitory to colony formation. For transformation induction, BaP was over 14-fold more effective than BbF, IcdP or BaA. The other PAH's showed no transformation.
Journal of Applied Toxicology 02/2006; 2(3):167 - 171. · 2.48 Impact Factor
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Blood 01/2006; 108(11):150A-150A. · 9.90 Impact Factor
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Bone Marrow Transplantation 01/2006; 36(11):1017-8. · 3.75 Impact Factor
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Leukemia 01/2006; 19(12):2366-8. · 9.56 Impact Factor
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W Hiddemann,
K Spiekermann,
C Buske,
M Feuring-Buske,
J Braess,
T Haferlach, C Schoch,
W Kern,
S Schnittger,
W Berdel,
B Wörmann,
A Heinecke,
C Sauerland,
Th Büchner
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ABSTRACT: Genetic and molecular techniques have provided increasing insights into the biology of acute myeloid leukemia (AML). These investigations showed that AML is not a homogeneous disease but a heterogeneous group of biologically different subentities. These subentities are currently primarily defined by cytogenetics by which three main subgroups can be discriminated: AML with balanced translocations, AML with unbalanced aberrations and AML without cytogenetically detectable aberrations. Within the latter group molecular alterations are identified in more than half of cases such as NPM mutations, FLT3 mutations, MLL duplications and mutations of CEBP-alpha. The clinical meaning of these findings is illustrated by substantial differences in response to therapy and long-term outcome. As demonstrated by the recent multicenter trial of the German AML Cooperative Group (AMLCG) and other studies intensification of induction therapy may improve the results in distinct subtypes but fails to do so in others. Therefore, new strategies need to be explored which incorporate the knowledge about the biology of AML to develop biology adapted treatment strategies. This process has just begun and is predominantly determined by the availability of new agents and their evaluation in clinical phase I and II studies. A variety of targets are currently explored and some trials have yielded promising results already. The step towards a biology adapted treatment of AML is long and requires the combined efforts of researchers, clinicians and the pharmaceutical industry. The first steps towards this goal have been taken and give rise to the hope for more effective and more specific therapies of AML.
Critical Reviews in Oncology/Hematology 12/2005; 56(2):235-45. · 4.41 Impact Factor
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ABSTRACT: In search for general PCR targets for minimal residual disease (MRD) studies in acute myeloid leukemia (AML), Wilms' tumor gene 1 (WT1) expression was assessed by real-time RT-PCR relative to the control gene ABL in 569 archived samples of AML patients (pts). Pts were analyzed at diagnosis (n=116) and during follow-up (n=105, median 4 times, range 2--17). Median follow-up time was 258 days (range 16--1578 days). In 66 pts, the WT1 expression was analyzed in comparison to a second PCR marker or to multiparameter flow cytometry. Quantitative WT1 levels correlated to the clinical course or a second marker in 83-96% of the cases. Prognostic significance of WT1 levels was analyzed at diagnosis and three intervals: (1) days 16--60, (2) days 61--120, and (3) days 121--180 after start of chemotherapy. Higher levels of WT1 expression were associated with shorter overall survival (OS) and event-free survival (EFS) within intervals 2 and 3 but not at diagnosis or interval 1. In addition, within these intervals, WT1/ABL levels <or=0.4% were associated with improved OS and EFS. An increase of WT1 levels was detected in 16/44 cases, which subsequently relapsed within a median of 38 days (range 8--180 days). In conclusion, quantification of WT1 may be used for MRD studies and for prognostification in AML.
Leukemia 09/2005; 19(8):1416-23. · 9.56 Impact Factor
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ABSTRACT: We performed microarray analyses in AML with trisomies 8 (n=12), 11 (n=7), 13 (n=7), monosomy 7 (n=9), and deletion 5q (n=7) as sole changes to investigate whether genomic gains and losses translate into altered expression levels of genes located in the affected chromosomal regions. Controls were 104 AML with normal karyotype. In subgroups with trisomy, the median expression of genes located on gained chromosomes was higher, while in AML with monosomy 7 and deletion 5q the median expression of genes located in deleted regions was lower. The 50 most differentially expressed genes, as compared to all other subtypes, were equally distributed over the genome in AML subgroups with trisomies. In contrast, 30 and 86% of the most differentially expressed genes characteristic for AML with 5q deletion and monosomy 7 are located on chromosomes 5 or 7. In conclusion, gain of whole chromosomes leads to overexpression of genes located on the respective chromosomes. Losses of larger regions of the genome translate into lower expression of the majority of genes represented by only one allele. The reduced expression of these genes is the most characteristic difference in gene expression profiles between AML with monosomy 7 and AML with deletion 5q, respectively, and other AML subtypes. Therefore, these data provide evidence that gene dosage effects gene expression in AML with unbalanced karyotype abnormalities. Losses of specific regions of the genome determine the gene expression profile more strongly than the gain of whole chromosomes.
Leukemia 08/2005; 19(7):1224-8. · 9.56 Impact Factor
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C Walz,
A Chase, C Schoch,
A Weisser,
F Schlegel,
A Hochhaus,
R Fuchs,
A Schmitt-Gräff,
R Hehlmann,
N C P Cross,
A Reiter
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ABSTRACT: The 8p11 myeloproliferative syndrome (EMS) also known as stem cell leukemia-lymphoma syndrome (SCLL) is associated with translocations that disrupt FGFR1. The resultant fusion proteins are constitutively active tyrosine kinases, and different FGFR1 fusions are associated with subtly different disease phenotypes. We report here a patient with a t(8;17)(p11;q23) and an unusual myelodysplastic/myeloproliferative disease (MDS/MPD) characterized by thrombocytopenia due to markedly reduced size and numbers of megakaryocytes, with elevated numbers of monocytes, eosinophils and basophils. A novel mRNA fusion between exon 32 of the myosin XVIIIA gene (MYO18A) at chromosome band 17q11 and exon 9 of FGFR1 was identified. Partial characterization of the genomic breakpoints in combination of bubble-PCR with fluorescence in situ hybridization revealed that the t(8;17) arose from a three-way translocation with breaks at 8p11, 17q11 and 17q23. MYO18A-FGFR1 is structurally similar to other fusion tyrosine kinases and is likely to be the causative transforming lesion in this unusual MDS/MPD.
Leukemia 07/2005; 19(6):1005-9. · 9.56 Impact Factor
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ABSTRACT: Rearrangements of the MLL gene occur in both acute lymphoblastic and acute myeloid leukemias (ALL, AML). This study addressed the global gene expression pattern of these two leukemia subtypes with respect to common deregulated pathways and lineage-associated differences. We analyzed 73 t(11q23)/MLL leukemias in comparison to 290 other acute leukemias and demonstrate that 11q23 leukemias combined are characterized by a common specific gene expression signature. Additionally, in unsupervised and supervised data analysis algorithms, ALL and AML cases with t(11q23) segregate according to the lineage they are derived from, that is, myeloid or lymphoid, respectively. This segregation can be explained by a highly differing transcriptional program. Through the use of novel biological network analyses, essential regulators of early B cell development, PAX5 and EBF, were shown to be associated with a clear B-lineage commitment in lymphoblastic t(11q23)/MLL leukemias. Also, the influence of the different MLL translocation partners on the transcriptional program was directly assessed. Interestingly, gene expression profiling did not reveal a clear distinct pattern associated with one of the analyzed partner genes. Taken together, the identified molecular expression pattern of MLL fusion gene samples and biological networks revealed new insights into the aberrant transcriptional program in 11q23/MLL leukemias.
Leukemia 07/2005; 19(6):953-64. · 9.56 Impact Factor
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Leukemia 04/2005; 19(3):460-3. · 9.56 Impact Factor
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ABSTRACT: Allogeneic bone marrow or stem cell transplantation is a curative therapeutic option for chronic myelogenous leukemia. In order to decrease the toxicity of the procedure, the dosage of total body irradiation was reduced from 12 to 8 Gy and subsequently the dose of cyclophosphamide from 120 to 80 mg/kg. The purine analogue fludarabine, ATG, cyclosporine A and a short course of methotrexate were given for immune suppression. So far, 35 elderly CML patients with sibling and unrelated donors have been transplanted. Transplant-related mortality at day + 100 was 11%. After engraftment, all patients achieved a complete cytogenetic remission. Relapse occurred in 14% of the patients. The risk of relapse was significantly higher in those patients transplanted in second chronic or accelerated phase (P = 0.048). After a median follow-up of 30 months (range 12-62), 63% of the patients are alive. Those patients transplanted within the first year from diagnosis had an overall survival of 79% (P = 0.049), emphasizing the benefit of early transplantation. Stepwise reduction of conditioning intensity resulted in stable engraftment, low relapse rates and encouraging overall survival in this high-risk patient group.
Bone Marrow Transplantation 01/2005; 34(12):1083-8. · 3.75 Impact Factor
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Leukemia 01/2005; 18(12):2050-3. · 9.56 Impact Factor
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Leukemia 10/2004; 18(9):1551-3. · 9.56 Impact Factor
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ABSTRACT: We report on a 21-year-old man with a mediastinal germ cell tumor (MGCT) who developed a myelodysplastic syndrome (MDS) (refractory anemia with ringed sideroblasts, RARS) 10 months after the start of successful treatment with cisplatin, etoposide, ifosfamide, and paclitaxel. A very rare early occurrence of a therapy-related MDS was suspected. Cytogenetic analysis of the bone marrow revealed an aberrant karyotype, showing a deletion in 12p, an isochromosome 5p, as well as gain of an isochromosome 12p. Isochromosome 12p is a specific aberration frequently observed in MGCT. It also was described in patients who developed hematological transformation of a mediastinal germ cell tumor. In this report the association between mediastinal germ cell tumors and hematological malignancies including the possibility of a common genetic origin is discussed.
Annals of Hematology 07/2004; 83(6):386-9. · 2.62 Impact Factor
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ABSTRACT: Although interphase fluorescence in situ hybridization (FISH) is routinely used in chronic lymphocytic leukemia (CLL), differences in the chromosomal pattern with respect to morphological subtypes of CLL (typical CLL, CLL/PL, PLL) are still under debate. We studied 153 patients with CLL and correlated cytomorphology on peripheral blood stains with FISH analysis and other prognostic markers. The percentage of prolymphocytes was calculated as a continuous variable and followed published thresholds in parallel while being correlated to FISH analysis. Higher percentages of prolymphocytes were associated significantly with deletion of 17p13. Deletion of 17p13 was most frequently observed in patients with more than 30% prolymphocytes. Trisomy 12 was found mainly in cases with 6-30% prolymphocytes. The percentage of prolymphocytes did not correlate with deletions of 11q23 or with 13q14 abnormalities. In conclusion, we suggest that further research focus on the percentage of prolymphocytes in CLL. Doing so, biologically relevant thresholds for the percentages of prolymphocytes in the peripheral blood and their association to underlying genetic markers could be investigated together with other biologically and especially prognostic markers.
Annals of Hematology 07/2004; 83(6):349-55. · 2.62 Impact Factor
