Pathogenic complexity of gastric B-cell lymphoma.
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Chromosome Aberrations↗
Biomedical subjects
Hartmut Döhner
Publications and source records attributed to Hartmut Döhner.
Prognostic significance of partial tandem duplications of the MLL gene in adult patients 16 to 60 years old with acute myeloid leukemia and normal cytogenetics: a study of the Acute Myeloid Leukemia Study Group Ulm.
PURPOSE: To evaluate the incidence and clinical significance of partial tandem duplications (PTDs) of the mixed lineage leukemia (MLL) gene in a large series of newly diagnosed adult patients (16 to 60 years old) with acute myeloid leukemia (AML) intensively treated within the multicenter treatment trials AML-HD93 and AML-HD98A. PATIENTS AND METHODS: Identification of MLL PTD was performed centrally using Southern blot analysis in pretreatment samples from 525 of 683 assessable patients. PTD was confirmed by polymerase chain reaction (PCR) and sequencing of the PCR products. RESULTS: MLL PTD was identified in none of the 129 patients with t(8;21), inv(16), and t(15;17); in 19 (7.7%) of 247 patients with normal karyotype; and in 10 (8.5%) of 119 patients with all other abnormalities, with 30 cases of t(11q23) excluded. In the group of patients with a normal karyotype, there was no difference in the presenting clinical features between the PTD-positive and the PTD-negative cases. Sixteen (89%) of the 18 assessable PTD-positive patients and 158 (78%) of the 203 PTD-negative patients achieved a complete remission. After a median follow-up time of 19 months, 11 of the 16 PTD-positive patients relapsed compared with 54 of the 158 PTD-negative patients; the median remission durations of the PTD-positive and the PTD-negative groups were 7.75 months and 19 months, respectively (P <.001). Multivariate analysis identified the MLL PTD status as the single prognostic factor for remission duration. CONCLUSION: Within the subgroup of young adult AML patients with normal karyotype, MLL PTD is associated with short remission duration.
Adolescent↗
Evidence for distinct pathomechanisms in B-cell chronic lymphocytic leukemia and mantle cell lymphoma by quantitative expression analysis of cell cycle and apoptosis-associated genes.
The B-cell lymphoproliferative malignancies B-cell chronic lymphocytic leukemia (B-CLL) and mantle cell lymphoma (MCL) share characteristics, including overlapping chromosomal aberrations with deletions on chromosome bands 13q14, 11q23, 17p13, and 6q21 and gains on chromosome bands 3q26, 12q13, and 8q24. To elucidate the biochemical processes involved in the pathogenesis of B-CLL and MCL, we analyzed the expression level of a set of genes that play central roles in apoptotic or cell proliferation pathways and of candidate genes from frequently altered genomic regions, namely ATM, BAX, BCL2, CCND1, CCND3, CDK2, CDK4, CDKN1A, CDKN1B, E2F1, ETV5, MYC, RB1, SELL, TFDP2, TNFSF10, and TP53. Performing real-time quantitative reverse transcription polymerase chain reaction in a panel of patients with MCL and B-CLL and control samples, significant overexpression and underexpression was observed for most of these genes. Statistical analysis of the expression data revealed the combination of CCND1 and CDK4 as the best classifier concerning separation of both lymphoma types. Overexpression in these malignancies suggests ETV5 as a new candidate for a pathogenic factor in B-cell lymphomas. Characteristic deregulation of multiple genes analyzed in this study could be combined in a comprehensive picture of 2 distinctive pathomechanisms in B-CLL and MCL. In B-CLL, the expression parameters are in strong favor of protection of the malignant cells from apoptosis but did not provide evidence for promoting cell cycle. In contrast, in MCL the impairment of apoptosis induction seems to play a minor role, whereas most expression data indicate an enhancement of cell proliferation.
Adult↗
Down-regulation of candidate tumor suppressor genes within chromosome band 13q14.3 is independent of the DNA methylation pattern in B-cell chronic lymphocytic leukemia.
Loss of genomic material from chromosomal band 13q14.3 is the most common genetic imbalance in B-cell chronic lymphocytic leukemia (B-CLL) and mantle cell lymphoma, pointing to the involvement of this region in a tumor suppressor mechanism. From the minimally deleted region, 3 candidate genes have been isolated, RFP2, BCMS, and BCMSUN. DNA sequence analyses have failed to detect small mutations in any of these genes, suggesting a different pathomechanism, most likely haploinsufficiency. We, therefore, tested B-CLL patients for epigenetic aberrations by measuring expression of genes from 13q14.3 and methylation of their promotor region. RB1, CLLD7, KPNA3, CLLD6, and RFP2 were down-regulated in B-CLL patients as compared with B cells of healthy donors, with RFP2 showing the most pronounced loss of expression. To test whether this loss of gene expression is associated with methylation of CpG islands in the respective promotor regions, we performed methylation-sensitive quantitative polymerase chain reaction analyses and bisulfite sequencing on DNA from B-CLL patients. No difference in the methylation patterns could be detected in any CpG island of the minimally deleted region. Down-regulation of genes within chromosomal band 13q14.3 in B-CLL is in line with the concept of haploinsufficiency, but this tumor-specific phenomenon is not associated with DNA methylation.
Base Sequence↗
Comparison of cytogenetic and molecular cytogenetic detection of chromosome abnormalities in 240 consecutive adult patients with acute myeloid leukemia.
PURPOSE: To prospectively compare cytogenetic and molecular cytogenetic analysis for the detection of the most relevant chromosome abnormalities in a large series of patients with acute myeloid leukemia (AML). PATIENTS AND METHODS: Two hundred forty consecutive adult patients with AML entered onto the multicenter treatment trial AML HD93 were studied. Chromosome banding and fluorescence in situ hybridization (FISH) applying a comprehensive set of genomic DNA probes were performed in a single reference laboratory. RESULTS: Two cases of inv(16), three cases of t(11q23), and three cases of t(8;21)var were only detected by molecular cytogenetics. By FISH, aberrations were identified in three cases with normal karyotypes: inv(16), -Y (in a patient with low metaphase yield on chromosome banding) and a 12p microdeletion. Additional aneuploidies, in particular +8q and +11q, were diagnosed by FISH; however, virtually all these aberrations occurred in patients with complex karyotypes or as an additional abnormality in leukemias with an AML-specific translocation. Finally, aberrations were detected by FISH in eight of 14 patients with no assessable metaphases. CONCLUSION: In most cases of AML, conventional cytogenetic study reliably detects chromosomal abnormalities, and this method should not be replaced by FISH. FISH should be used as a complementary method for the detection of more subtle abnormalities, such as inv(16) and t(11q23), in all patients with newly diagnosed AML and for suspected t(8;21)var. Furthermore, molecular cytogenetics using this comprehensive set of DNA probes provides a valuable diagnostic tool for patients with poor chromosome morphology, low or no yields of metaphase cells, or both.
Acute Disease↗
Up-front randomization and common standard arm: a proposal for comparing AML treatment strategies between different studies.
Most multicenter randomized AML studies use randomizations of patients early or later in complete remission which necessarily occur with exclusions and positive selection of patients included. Since the exclusion criterias are regimen related and do not follow common standards, incomparabilities between treatment results across different studies are produced by these late randomizations. In order to overcome this problem, we here propose a cooperation of studies on the basis of a general up-front randomization with attribution of 10% patients from each study to a common standard arm. A validation of complete treatment strategies according to intent-to-treat against the standard arm and thus also across the studies is provided by this inter-group model which may contribute to accelerate the therapeutic progress in AML.
Acute Disease↗
Receptor for hyaluronan acid-mediated motility (RHAMM) is a new immunogenic leukemia-associated antigen in acute and chronic myeloid leukemia.
OBJECTIVE: Identification of leukemia-associated antigens (LAA) eliciting an immune response in patients is a prerequisite for specific immunotherapy of leukemias. To identify new LAA, we used the method of serologic screening of cDNA expression libraries (SEREX). MATERIALS AND METHODS: A SEREX library of the cell line K562 was subjected to allogeneic screening with sera from patients with acute myeloid leukemia (AML) or chronic myeloid leukemia (CML) vs sera from healthy volunteers. RESULTS: The receptor for hyaluronan acid-mediated motility (RHAMM) involved in cell growth and metastasis was identified as a new LAA. Serologic responses to RHAMM were observed in patients with AML (42%), CML (31%), melanoma (83%), renal cell carcinoma (40%), breast cancer (67%), and ovarian carcinoma (50%), but not in HV or patients with autoimmune diseases. RHAMM mRNA was detectable in peripheral blood mononuclear cells (PBMN) of 60% of newly diagnosed AML patients. Western blotting stained positive for RHAMM protein in 70% of AML patients. mRNA expression of RHAMM also was found in patients with CML (40%), renal cell carcinoma (73%), breast carcinoma (60%), and ovarian carcinoma (50%). In melanoma, RHAMM mRNA expression was detected in metastases (80%) but not in primary tumors. RHAMM is differentially expressed: significant mRNA expression was not found in normal tissues, except from testis, placenta, and thymus, or in PBMN- and CD34-separated cell samples of healthy volunteers. CONCLUSIONS: RHAMM is an immunogenic antigen in leukemias and solid tumors and might be a potential target structure for cellular immunotherapies and antibody therapies.
Acute Disease↗
Automated screening for genomic imbalances using matrix-based comparative genomic hybridization.
Genome-wide screening for chromosomal imbalances using comparative genomic hybridization (CGH) revealed a wealth of data on previously unrecognized tumor-specific genomic alterations. CGH to microarrays of DNA, an approach termed matrix-CGH, allows detection of genomic imbalances at a much higher resolution. We show that matrix CGH is also feasible from small tissue samples requiring universal amplification of genomic DNA. Because widespread application of matrix-CGH experiments using large numbers of DNA targets demands a high degree of automation, we have developed a protocol for a fully automated procedure. The use of specialized instrumentation for the generation of DNA chips, their hybridization, scanning, and evaluation required numerous alterations and modifications of the initial protocol. We here present the elaboration and testing of automated matrix-CGH. A chip consisting of 188 different genomic DNA fragments, cloned in bacterial artificial chromosome (BAC) or P1-derived artificial chromosome (PAC) vectors and immobilized in replicas of 10, was used to assess the performance of the automated protocol in determining the gene dosage variations in tumor cell lines COLO320-HSR, HL60, and NGP. Although ratios of matrix-CGH were highly concordant with results of chromosomal CGH (85%), the dynamic range of the matrix-CGH ratios was highly superior. Investigation of the two amplicons on 8q24 in COLO320-HSR and HL60, containing the MYC gene, revealed a homogeneous amplicon in COLO320-HSR but a heterogeneous amplification pattern in HL60 cells. Although control clones for normalization of the signal ratios can be predicted in cases with defined chromosomal aberrations, in primary tumors such data are often not available, requiring alternative normalization algorithms. Testing such algorithms in a primary high-grade B-cell lymphoma, we show the feasibility of this approach. With the matrix-CGH protocol presented here, robust and reliable detection of genomic gains and losses is accomplished in an automated fashion, which provides the basis for widespread application in tumor and clinical genetics.
Chromosome Aberrations↗
Myeloablative radioimmunotherapy with Re-188-anti-CD66-antibody for conditioning of high-risk leukemia patients prior to stem cell transplantation: biodistribution, biokinetics and immediate toxicities.
BACKGROUND: Stem cell transplantation (SCT) is potentially curative for high-risk leukemia patients. Conditioning regimens affect relapse rate and treatment-related mortality. We evaluated biodistribution, radiation absorbed organ doses and immediate toxicities of myeloablative radioimmunotherapy with marrow selective 188rhenium (188Re)-labeled anti-CD66 monoclonal antibody (mAb). METHODS: Fifty high-risk leukemia patients were treated 14 +/- 2 days prior to SCT. Dosimetric measurements were performed at 1.5, 3, 20, 26, and 44 hours after about 1 GBq of 188Re followed by radioimmunotherapy with about 10 GBq 188Re. Standard conditioning consisted of high-dose chemotherapy and 12 Gy total-body irradiation. Forty-six patients received allogenic, and four received autologous, stem cell grafts. RESULTS: The mean radiation absorbed doses (in Gy) were: marrow, 13.9 +/- 4.6; liver, 5.7 +/- 2.7; spleen, 22.6 +/- 25.5; kidneys, 6.8 +/- 2.6; lungs, 0.8 +/- 0.7; total body, 1.4 +/- 0.3. The tumor-to-organ-ratios were 2.4 for liver, 0.6 for the spleen, 2.0 for the kidneys and 17.8 for the lungs. Type of leukemia did not affect radiation absorbed doses of marrow, lungs, kidneys and liver. Mean marrow dose of transplanted patients in complete remission was 1.37 +/- 0.43 Gy/GBq, compared with 1.34 +/- 0.29 Gy/GBq for patients with leukemic blast marrow infiltration of 5-25%. Immediate side effects were moderate. All patients showed primary engraftment. After a median follow-up of 11.0 +/- 7.4 months 28/50 patients (56%) are in ongoing complete remission. Nine patients (5%) have relapsed, seven (4%) of them have died. Another 13 patients (7%) died of treatment-related causes. CONCLUSIONS: Due to its biodistribution, radiation absorbed organ doses, low toxicity and clinical data, myeloablative radioimmunotherapy with 188Re-labeled anti-CD66 mAb seems to be a promising method for improving standard conditioning of high-risk leukemia patients prior to SCT.
Adolescent↗
p53 gene deletion predicts for poor survival and non-response to therapy with purine analogs in chronic B-cell leukemias.
Conventional cytogenetic analysis in B-cell chronic lymphocytic leukemia (B-CLL) has been very difficult, and the prognostic significance of specific chromosome aberrations is under discussion. Recent improvements in fluorescence in situ hybridization (ISH) techniques have provided an alternative approach for the detection of chromosome aberrations. Here, an interphase cytogenetic study was performed to analyze the incidence and prognostic significance of a p53 gene deletion in B-CLL and related disorders. We studied mononuclear cells from 100 patients with chronic B-cell leukemias [B-CLL, 90 patients; B-prolymphocytic leukemia (B-PLL), 7; Waldenström's macroglobulinemia (WM), 3] by fluorescence ISH with a genomic p53 DNA probe. In a subset of patients, additional G-banding analysis and single strand conformation polymorphism (SSCP) analysis was performed. Seventeen of the 100 patients [17%; B-CLL, 11 of 90 (12%); WM, 1 of 3; B-PLL, 5 of 7] exhibited a monoallelic p53 gene deletion by ISH. G-banding analysis demonstrated abnormalities of chromosome 17 in 13 of these 17 patients, all leading to loss of band 17p13. SSCP analysis showed aberrant bands in 9 of 14 patients with a p53 gene deletion. None of 12 patients with a p53 gene deletion compared with 20 of 36 patients (56%) without a deletion responded to therapy with fludarabine or pentostatin (P < .001). The difference in survival probabilities from the time of diagnosis and from the start of treatment with purine analogs between the two groups was highly significant (P < .001). In multivariate analysis, p53 gene deletion was the strongest prognostic factor for survival. In conclusion, p53 gene deletion predicts for non-response to therapy with purine analogs and for poor survival in chronic B-cell leukemias.
Adult↗