Significance of chromosomal aberrations in CLL.
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Chromosome Aberrations↗
Biomedical subjects
L Bergmann
Publications and source records attributed to L Bergmann.
Identification of novel polymorphisms in intron 7 of the human p53 gene in acute myeloid leukemia and healthy donors.
Screening for mutations by PCR-SSCP in exons 5 to 9 of the p53 gene in 38 bone marrow or peripheral blood specimens of patients with acute myeloid leukemia (AML) showed abnormal shifts in 9 cases. One reflected a mutation in exon 8, whereas in the other cases there were no exonic mutations identified by sequencing. As PCR primers were chosen annealing in the introns flanking the exon region, following sequencing of the encompassing introns identified 5 base substitutions at various sites in intron 7. Two of them have been described previously [1] and 3 novel polymorphisms could be identified. To determine whether these polymorphisms are linked to the pathogenesis of AML, we screened peripheral blood specimens of 26 healthy controls. We found identical base substitutions in 6 out of 26 controls. Our data suggest that these polymorphisms are not related to the pathogenesis of AML.
Acute Disease↗
[Aromatase inhibitors: anastrozole versus tamoxifen as first-ine therapy for advanced postmenopausal breast cancer].
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Aged↗
The Wilms' tumor gene product (WT1) modulates the response to 1,25-dihydroxyvitamin D3 by induction of the vitamin D receptor.
The Wilms' tumor gene (wt1) encodes a transcription factor involved in urogenital development, in particular in renal differentiation, and in hematopoietic differentiation. Differentiation of a number of solid tumor and leukemic cells lines can be mediated by 1,25-dihydroxyvitamin D(3). This is predominantly mediated by the nuclear receptor for 1,25-dihydroxyvitamin D(3), the vitamin D receptor (VDR). In initial experiments addressing a possible link between WT1 and VDR, we observed a correlated expression of WT1 and VDR mRNA in samples from renal tissues. HT29 colon carcinoma cells, stably transfected to express WT1, exhibited elevated endogenous VDR levels compared with control cells transfected with a control construct. Elevated VDR expression was found in wt1-transfected human embryonic kidney 293 cells, as well. In transient cotransfection experiments, we observed an activation of a vdr promoter reporter by WT1 through a WT1 recognition element, indicating transcriptional regulation of the vdr gene expression by WT1. The responsive sequence element was specifically bound by wild-type, but not by mutated WT1, in electrophoretic mobility shift assays. HT29 colon carcinoma cells, which respond to 1,25-dihydroxyvitamin D(3) with slow induction of growth arrest, were investigated for the influence of WT1 on 1,25-dihydroxyvitamin D(3)-mediated growth suppression. Although HT29 cells transfected with a control construct responded moderately to 1,25-dihydroxyvitamin D(3), the response of HT29 cells expressing WT1 was strikingly enhanced. Stimulation with dihydroxyvitamin D(3) caused an up to 3-fold reduction in the growth rate of different HT29 clones expressing WT1 as compared with control cells lacking WT1 expression. Thus, induction of VDR by WT1 leads to an enhanced response to 1,25-dihydroxyvitamin D(3). We conclude that the vitamin D receptor gene is a target for transcriptional activation by WT1, suggesting a possible physiological role of this regulatory pathway.
Base Sequence↗
Targeting the Ras signaling pathway: a rational, mechanism-based treatment for hematologic malignancies?
A series of alterations in the cellular genome affecting the expression or function of genes controlling cell growth and differentiation is considered to be the main cause of cancer. These mutational events include activation of oncogenes and inactivation of tumor suppressor genes. The elucidation of human cancer at the molecular level allows the design of rational, mechanism-based therapeutic agents that antagonize the specific activity of biochemical processes that are essential to the malignant phenotype of cancer cells. Because the frequency of RAS mutations is among the highest for any gene in human cancers, development of inhibitors of the Ras-mitogen-activated protein kinase pathway as potential anticancer agents is a very promising pharmacologic strategy. Inhibitors of Ras signaling have been shown to revert Ras-dependent transformation and cause regression of Ras-dependent tumors in animal models. The most promising new class of these potential cancer therapeutics are the farnesyltransferase inhibitors. The development of these compounds has been driven by the observation that oncogenic Ras function is dependent upon posttranslational modification, which enables membrane binding. In contrast to many conventional chemotherapeutics, farnesyltransferase inhibitors are remarkably specific and have been demonstrated to cause no gross systemic toxicity in animals. Some orally bioavailable inhibitors are presently being evaluated in phase II clinical trials. This review presents an overview on some inhibitors of the Ras signaling pathway, including their specificity and effectiveness in vivo. Because Ras signaling plays a crucial role in the pathogenesis of some hematologic malignancies, the potential therapeutic usefulness of these inhibitors is discussed. (Blood. 2000;96:1655-1669)
Alkyl and Aryl Transferases↗
Intensive chemotherapy with idarubicin, ara-C, etoposide, and m-AMSA followed by immunotherapy with interleukin-2 for myelodysplastic syndromes and high-risk Acute Myeloid Leukemia (AML).
Intensive chemotherapy followed by treatment with interleukin-2 (IL-2) was evaluated in a prospective, randomized, multicenter trial including 18 patients with refractory anemia with excess of blasts in transformation (RAEB-T), 86 patients with acute myeloid leukemia (AML) evolving from myelodysplastic syndromes, and six patients with secondary AML after previous chemotherapy. Median age was 58 years (range: 18-76 years). Forty-nine patients (45%) achieved a complete remission (CR) after two induction cycles with idarubicin, ara-C, and etoposide, 52% of them aged </=60 years and 35% aged >60 years (p=0.06). After two consolidation courses, patients were randomized to four cycles of either high- or low-dose IL-2. Patients aged up to 55 years with an HLA-identical sibling donor were eligible for allogeneic bone marrow transplantation. The median relapse-free survival was 12.5 months, with a probability of ongoing CR at 6.5 years of 19%. Overall survival of all patients was 8 months, and 21 months for the CR patients. Median survival was significantly longer among patients aged </=60 years than among the older patients (16 vs 6 months, p<0.001). Median duration of survival and relapse-free survival were not statistically different in the two IL-2 treatment arms.
Acute Disease↗
Simultaneous expression of different immunogenic antigens in acute myeloid leukemia.
Identification of immunogenic leukemia-associated antigens as target structures is mandatory for specific immunotherapy of leukemia. Here, we define acute myeloid leukemia (AML) antigens eliciting a humoral immune response in the autologous host. We applied the method of serologic screening of cDNA expression libraries with autologous serum (SEREX). To date, this technique has been used to characterize antigen structures in solid tumors. The mRNA expression pattern of these newly in AML isolated antigens and previously described leukemia antigens (PRAME, MAGE-1, and Wt-1) was evaluated by reverse transcriptase polymerase chain reaction. For Wt-1, Western blotting also was performed. Screening of a cDNA expression library prepared from a patient with AML FAB M2 using autologous and allogeneic sera, followed by sequencing of positive clones, yielded three autoantigens (Prp1p/Zer1p, L19H1, and one without homology to previously described genes) and two antigens reactive with allogeneic sera (MAZ, PINCH). PRAME mRNA was expressed in 47% of 34 AML patients, but not in 13 CD34(+) cell samples or in peripheral blood mononuclear cells of 13 healthy volunteers. mRNA expression of MAZ was detected in 44% of AML patients, but only in 8% of healthy donors. Humoral responses to MAZ were detected in 35%. More than 80% of the screened AML patients showed simultaneous expression of two or more of these antigens.Differential expression in AML patients vs healthy volunteers suggests that the immunogenic antigens PRAME and MAZ are potential candidates for immunotherapy in AML.
Adaptor Proteins, Signal Transducing↗
CD34+ selected cells in mismatched stem cell transplantation: a single centre experience of haploidentical peripheral blood stem cell transplantation.
Over the past 3 years we have performed 10 haploidentical peripheral blood stem cell transplants in patients with incurable haematological malignancies and no prospect of a matched unrelated donor within an adequate time period. Conditioning consisted of ATG, TBI, thiotepa, cyclophosphamide and additional radioimmunotherapy in five patients. All patients received G-CSF mobilized peripheral blood stem cell grafts. GVHD prophylaxis consisted of T cell depletion by CD34+ selection; no post-transplant immunosuppression was given in nine patients. Stable engraftment was achieved in nine patients; one case of acute graft rejection was observed. Seven patients developed grade I acute GVHD, and six patients have developed chronic GVHD. Infections were the most significant clinical problem post transplant. Two patients have suffered a relapse of their disease and two further patients have died of transplant-related complications. After a median follow-up of 13 months (range 5-37 months) six patients are surviving in remission. We conclude that haploidentical PBSCT is a reasonable alternative to a MUD transplant.
Adult↗
Non-infectious lung complications are closely associated with chronic graft-versus-host disease: a single center study of incidence, risk factors and outcome.
Non-infectious lung complications (NILC) are frequent, influencing morbidity and mortality of patients after allogeneic BMT. Although the term NILC encompasses a number of different entities, an association with GVHD has been noted for almost all of them. Our study was directed towards assessing the incidence and risk factors for developing NILC, as well as the response to treatment and long-term outcome. Forty (14.7%) out of 272 patients surviving for more than 3 months after allogeneic BMT, developed lung complications fulfilling the criteria for NILC. The evaluation was based on clinical investigation, radiologic imaging, lung function tests, broncho-alveolar lavage and biopsies. Risk factors were assessed by univariate and multiple statistical regression models, where chronic GVHD proved to be the only significant risk factor for the development of NILC (P = 0.011). In three patients NILC developed in direct association with donor lymphocyte infusions. The majority of patients responded well to treatment with corticosteroids and immunosuppressive drugs. NILC had no adverse effect on survival. The frequency of NILC was low in autologous (5%) as compared with allogeneic transplants (14.7%) but this difference was not statistically significant. Bone Marrow Transplantation (2000) 25, 1263-1268.
Bone Marrow Transplantation↗
No impact of high-dose cytarabine on the outcome of patients transplanted for acute myeloblastic leukaemia in first remission. Acute Leukaemia Working Party of the European Group for Blood and Marrow Transplantation (EBMT).
High-dose cytarabine is currently used in combination with anthracycline in the treatment of acute myeloblastic leukaemia (AML). Moreover, high-dose cytarabine has been reported to produce long-term disease-free survival in a proportion of patients, especially in certain subtypes of AML. However, it remains unknown whether the outcome of patients undergoing allogeneic or autologous stem cell transplantation is influenced by previous treatment with high-dose cytarabine. To this end, 1672 patients with AML in first remission who were reported to the Acute Leukaemia Working Party registry of the European Group for Blood and Marrow Transplantation (EBMT) and who were transplanted between 1980 and 1995 were analysed according to the dose intensity of cytarabine given at induction and/or consolidation. Autologous stem cell transplantation (ABMT) was performed in 846 patients and allogeneic bone marrow transplantation (BMT) in 826 patients. This study shows that the dose of cytarabine (Ara-C) given at induction and/or consolidation did not influence the relapse incidence in patients subsequently allografted or autografted. In addition, it did not give any advantage in terms of overall outcome. Therefore, high-dose (HD) Ara-C may not be needed for patients who have a planned stem cell transplantation (SCT) as post-remission therapy. Nevertheless, HD Ara-C may be utilized in certain subtypes of AML that are believed to be curable by chemotherapy alone.
Adolescent↗
Is there a graft-versus-leukaemia effect in the absence of graft-versus-host disease in patients undergoing bone marrow transplantation for acute leukaemia?
During a 13-year period, 5200 autografts, 1039 HLA-identical sibling transplants without acute or chronic graft-vs.-host disease (GVHD) and 67 twins were reported to the European Group for Blood and Marrow Transplantation EBMT. Follow-up time was a median of 32 months. Diagnoses were acute myeloid leukaemia (AML, 4521) and acute lymphoblastic leukaemia (ALL, 1785) in first complete remission. The probability of relapse at 5 years was 51 +/- 1% in the autografts, 45 +/- 8% in the twins and 34 +/- 2% among the HLA-identical siblings (auto vs. sibs, P < 0.0001). In multivariate analyses, the following factors were significantly associated with an increased risk of relapse: ALL vs. AML M3 [relapse rate (RR) 2.29, P < 0.0001], AML non-M3 vs. AML M3 (RR 1.8, P < 0.0001), autograft vs. sibling transplant (RR 1.76, P < 0.0001), interval diagnosis to transplantation < 261 d (RR 1.45, P < 0.001) and other conditioning vs. total body irradiation (RR 1.16, P = 0.001). Transplant-related mortality was the same in the three groups at approximately 10% at 2 years. Five-year leukaemia-free survival was 42 +/- 1% in the autografts, 44 +/- 8% in the twins and 58 +/- 2% among the siblings (auto vs. sibs, P < 0.0001). The factors significant for relapse were also significant in multivariate analyses for leukaemia-free survival. In addition, children had a significantly better leukaemia-free survival than adults (RR 0.82, P < 0.0001). Recipients of bone marrow from HLA-identical siblings without GVHD had a lower risk of relapse and a better leukaemia-free survival than recipients of autografts. This may be as a result of a graft-vs.-leukaemia effect in the absence of GVHD.
Acute Disease↗
Normal structure of NFKB2, C-REL and BCL-3 gene loci in lymphoproliferative and myeloproliferative disorders.
NF-kappaB/rel transcription factors are crucial regulators of development, differentiation and apoptosis of both lymphoid and myeloid lineages. There is increasing evidence for an involvement of NF-kappaB/rel proteins in lymphomagenesis and resistance of lymphoid tumors to the induction of apoptosis. Structural alterations of the NF-kappaB/rel genes NFkappaB2, c-rel and bcl-3 have been shown to result in increased NF-kappaB/rel activity. Because we observed strong constitutive NF-kappaB/rel binding activity in chronic lymphocytic leukemia of the B-cell type (B-CLL) which may contribute to resistance against cytotoxic drugs we studied the genomic organisation of NFkappaB2, c-rel and bcl-3 gene loci in a panel of lymphoproliferative disorders (n=81) with an emphasis on B-CLL (n=47). The method of genomic Southern blotting using cDNAs of the respective genes was used. In spite of the role of NF-kappaB/rel in myeloid maturation there is no data available as to the occurrence of NF-kappaB/rel rearrangements in chronic myeloproliferative syndromes (cMPS). For this reason we included a small panel of cMPS patients (n=16). Southern Blotting revealed a germline configuration of NFkappaB2, c-rel and bcl-3 loci in all NHL and cMPS patients examined. Our results demonstrate that structural alterations of NFkappaB2, c-rel and bcl-3 genes at the Southern Blotting level are rare events that do not contribute to lymphoid or myeloid transformation in the majority of NHL or cMPS patients.
B-Cell Lymphoma 3 Protein↗
Serum erythropoietin and thrombopoietin levels in patients with essential thrombocythaemia.
In 40 patients with essential thrombocythaemia (ET) serum erythropoietin (EPO) and thrombopoietin (TPO) concentrations were determined and compared with the EPO and TPO values of a healthy control group. The mean EPO serum concentration for 24 control patients was 9.4 mU/ml +/- 3.7 (range 2-17.9), for 32 untreated ET patients at diagnosis 6.6 mU/ml +/- 7.6 (range 0.5-44.3) and for 8 ET patients treated with cytoreduction 14.1 mU/ml +/- 8.0 (range 4.5-26.1). Serum EPO levels in untreated ET patients at diagnosis were significantly lower compared with serum EPO levels in healthy control patients (p=0.002). Serum EPO levels in treated ET patients were not different from serum EPO levels in healthy controls (p=0.13) but were significantly higher compared with untreated ET patients (p=0.003). Serum TPO levels were determined in 18 of 40 ET patients, the mean TPO serum concentration was 211 pg/ml +/- 109 (range 62,5-345). The mean TPO serum concentration for 10 untreated ET patients at diagnosis was 162 pg/ml +/- 87 (range 62,5-302) and for 8 ET patients who had received cytoreductive treatment 272 pg/ml +/- 106 (range 96-345), respectively (p=0.04). Both serum TPO levels for treated and untreated ET patients were significantly higher (p<0.001) compared with serum TPO levels for healthy controls. The results of our study suggest a difference in the regulation of serum EPO and TPO in patients with ET. While the mean serum EPO level is decreased in untreated ET patients, the corresponding mean serum TPO level is increased. Treatment with cytoreduction, results in normalisation of the mean serum EPO level, whereas the mean TPO serum level remains elevated.
Adolescent↗
Radioimmunotherapy for the intensification of conditioning before stem cell transplantation: differences in dosimetry and biokinetics of 188Re- and 99mTc-labeled anti-NCA-95 MAbs.
UNLABELLED: A new concept is the intensification of preparative regimens for patients with advanced leukemia using monoclonal antibodies (MAbs) with an affinity for beta emitter-labeled bone marrow. 188Re is a high-energy beta emitter that has therapeutic promise. Our first aim was to clarify whether the therapeutic application of 188Re-MAb against nonspecific cross-reacting antigen 95 (NCA-95) can be predicted from biokinetic data derived from 99mTc-labeled NCA-95. Our second aim was to show that a radiation absorbed dose of > or =12 Gy in the bone marrow can be achieved using 188Re-MAb. METHODS: Dosimetric data were obtained for both radiotracers from multiple planar whole-body scans (double-head gamma camera), blood samples, and urine measurements from 12 patients with advanced leukemia. Radiation absorbed doses were calculated using MIRDOSE 3 software. RESULTS: Radiation absorbed doses to bone marrow, liver, spleen, lung, and kidney were 2.24, 0.50, 1.93, 0.05, and 0.90 mGy/MBq, respectively, using 99mTc-MAb and 1.45, 0.43, 1.32, 0.07, and 0.71 mGy/MBq, respectively, using 188Re-MAb. These differences were statistically significant for bone marrow, spleen, and kidney. The main differences were less accumulation of 188Re-MAb in bone marrow (31%+/-13% compared with 52%+/-13%) and faster elimination through urine (25%+/-3% compared with 15%+/-5% after 24 h). On the basis of these data, a mean marrow dose of 14+/-7 Gy was achieved in 12 patients suffering from leukemia after application of approximately 10+/-2 GBq 188Re-MAb. CONCLUSION: Myeloablative radiation absorbed doses can easily be achieved using 188Re-MAb. 99mTc- and 188Re-MAb showed similar whole-body distributions. However, direct prediction of radiation absorbed doses from the 99mTc-MAb, assuming identical biokinetic behavior, is not valid for the 188Re-MAb in a single patient. Therefore, individual dosimetry using 188Re-MAb is needed to calculate therapeutic activity.
Adult↗
Increased platelet surface expression of P-selectin and thrombospondin as markers of platelet activation in essential thrombocythaemia.
Essential thrombocythaemia (ET) is a clonal myeloproliferative disorder associated with an increased risk of both thromboembolic and bleeding complications. Platelet activation plays a crucial role in the pathogenesis of prethrombotic conditions. The platelet surface expression of p-selectin (CD62p) and thrombospondin (TSP) has been shown to correlate with platelet activation. In the present study, we used a flow cytometric assay to study whether the fraction of platelets expressing CD62p and TSP is increased in newly diagnosed ET. Thirty-four patients with newly diagnosed ET and 25 healthy control subjects were investigated. The proportion of platelets expressing the activation-dependent antigens CD62p and TSP was higher in patients with ET (CD62p: 14.7+/-15.0%; TSP: 12.4+/-9.9%) as compared with healthy control subjects (CD62p: 3.0+/-4.0%; TSP: 3.2+/-3.2%; p< 0.001). In ET, there was a linear correlation between platelet surface expression of CD62p and TSP (p<0.0001, r=0.83). At diagnosis of ET, 20 patients were symptomatic and 14 asymptomatic. Compared with asymptomatic ET patients there was no difference in the expression of CD62p (18.3+/-16.2% vs. 14.5+/-13.4%) and TSP (14.4+/-9.8% vs. 12.8+/-9.5%) in symptomatic ET patients. In conclusion, increased expression of platelet neoantigens is present at the diagnosis of ET. Both activation-dependent epitopes CD62p and TSP are increasingly expressed on the platelet surface in newly diagnosed ET patients.
Aspirin↗
[Stem cell supported high dose chemotherapy (HDCT) in primary treatment of advanced ovarian carcinoma].
The standard treatment for ovarian cancer consists of staging laparotomy with aggressive debulking, a pelvic and paraaortal lymphadenectomy if indicated and a postoperative chemotherapy. A reappraisal of primary high dose chemotherapy in advanced ovarian cancer seems warranted because of high remission rates of such schedules in palliative situations. For a nation-wide interdisciplinary phase I/II multi-center-study 49 patients were recruited. Induction for stem cell mobilization consists of two cycles of cyclophosphamide and taxol. Three high dose cycles follow with a steady dose-escalation of carboplatin by a factor of 4, this is contrast to a conventionally dosed chemotherapy. During the first two cycles taxol is added, during the third etoposide and melphalane. The plan of primary sequential high dose therapy proved feasible in this study. In a prospective randomized follow-up study primary high dose therapy is compared to conventional chemotherapy (AGO-Ovar-5-study). It results will answer the question whether primary high dose chemotherapy with stem cell support improves the course of ovarian cancer compared to conventional treatment.
Adult↗
Association between structural and numerical chromosomal aberrations in acute myeloblastic leukemia: a study by RT-PCR and FISH in 447 patients with de-novo AML.
We analyzed 447 patients with de novo AML using alpha-satellite probes for the chromosomes 7, 8, X, and Y and RT-PCR for t(8;21), t(15;17) and inv(16). In 130/447 patients (29%) chromosomal aberrations were found. Thirty-three patients (7%) had a t(8;21); 11 of these had the additional loss of a sex chromosome (p<0.001) and two a trisomy 8. Twenty-nine patients (6%) had a t(15;17); four of these had a trisomy 8. Sixteen patients (4%) displayed an inv(16); four of these had a trisomy 8. Twenty-two patients (5%) had a sole trisomy 8 and one patient the combination of trisomy 8 and trisomy X. Five patients (1%) displayed the loss of a Y-chromosome as the sole abnormality and two patients had a sole trisomy X. In 22 patients (5%) a monosomy 7 was found, and in none of these patients were additional chromosomal aberrations detected by RT-PCR (p < 0.05). In conclusion, trisomy 8 and the loss of a gonosome are frequently associated with structural chromosomal aberrations with a significant association of -X/Y and t(8;21). The absence of these genomic lesions in AMLs with monosomy 7 suggests that the monosomy 7 has a specific role in the development of these leukemias and their clinical course.
Adolescent↗
The tyrosine kinase NPM-ALK, associated with anaplastic large cell lymphoma, binds the intracellular domain of the surface receptor CD30 but is not activated by CD30 stimulation.
The heterogenous group of anaplastic large cell lymphomas (ALCLs) is characterized by expression of the Ki-1/CD30 antigen, a member of the tumor necrosis factor receptor superfamily. About 40 to 50% of cases diagnosed as ALCL contain a specific chromosomal rearrangement, t(2;5)(p23;q35), resulting in expression of the chimeric tyrosine kinase NPM-ALK. As NPM-ALK-positive lymphomas define a distinct subtype within the group of ALCL, the chimeric protein might be responsible for certain pathogenetic and clinicopathologic characteristics. To better elucidate the function of NPM-ALK, we investigated a possible mechanism for regulation of its activity. We demonstrate that NPM-ALK specifically binds to the intracellular domain of the cytokine receptor CD30. In vitro binding assays revealed that the ALK portion of NPM-ALK mediates interaction of the two proteins. Stimulation of the CD30 receptor by cross-linking with immobilized anti-CD30 antibody results in complete growth inhibition of Karpas 299, an NPM-ALK-positive ALCL cell line, but does not alter proliferation of HDLM-2, a Hodgkin's lymphoma-derived cell line lacking t(2;5). Western blot analysis of coimmunoprecipitated CD30 and NPM-ALK proteins from stimulated Karpas 299 cells showed that the interaction of the proteins is not modified by stimulation. Activation of CD30 neither enhanced NPM-ALK activity measured by autophosphorylation of the chimeric tyrosine kinase nor phosphorylation of phospholipase C-gamma, an NPM-ALK substrate. We conclude that NPM-ALK is not stimulated by CD30 activation, but exists as a constitutively hyperactivated protein. Interaction with CD30 may extend the subcellular localization of NPM-ALK to the microenvironment of membrane-associated proteins.
Enzyme Activation↗