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PubMed2003

AML-1, PU.1, and Sp3 regulate expression of human bactericidal/permeability-increasing protein.

Bactericidal/permeability-increasing protein (BPI) is an antimicrobial protein in neutrophils, stored in azurophil granules. Expression of BPI is absent in neutrophils of newborns and patients with secondary granule deficiency (SGD), possibly contributing to dysfunction of neutrophils. We report two alternative transcription start sites at 52 and 22bp upstream of the translation start. A proximal 222bp promoter conferring expression in myeloid cells was identified, and critical cis-acting sites for myeloid expression were contained within the 159bp upstream of translation start. Within this region, direct binding and transactivation by AML-1, PU.1, and Sp3 were demonstrated, as judged by electrophoretic mobility shift analysis. Moreover, transient transfections of C/EBPalpha or C/EBPepsilon to HeLa cells resulted in increased promoter activity, indicating a direct or indirect role for C/EBP. In conclusion, we provide evidence for AML-1, PU.1, and Sp3 cooperatively and directly mediating BPI-expression during myeloid differentiation.

Antimicrobial Cationic Peptides↗

PubMed2006

How good is allogeneic transplantation for high-risk patients with AML?

Patients with acute myeloid leukemia (AML) may differ significantly in their response to therapy and long-term outcome. A number of risk factors have been identified that characterize patients at diagnosis as well as during their clinical course. At diagnosis these parameters include age, cytogenetic configuration, hemopoietic elements, and a previous history of myelodysplasia or cytoreductive therapy for a preexisting malignancy. They are complemented by the response to induction therapy and subsequent treatments as well as by the duration of response. More recently, gene expression profiling of leukemic cells has added a new dimension to simultaneously assess biological risk factors that may ultimately lead to individualization of therapy. This presentation will review data to address the question of whether or not allogeneic transplants are effective in the management of patients with AML presenting with adverse cytogenetics and older age, showing a poor response to induction therapy, and relapsing after achieving a remission.

Age Factors↗

PubMed2005

NUP98 is fused to HOXA9 in a variant complex t(7;11;13;17) in a patient with AML-M2.

The t(7;11)(p15;p15.4) has been reported to fuse the NUP98 gene (11p15), a component of the nuclear pore complex, with the class-1 homeobox gene HOXA9 at 7p15. This translocation has been associated with myeloid leukemias, predominantly acute myeloid leukemia (AML) M2 subtype with trilineage myelodysplastic features, and with a poor prognosis. The derived fusion protein retains the FG repeat motif of NUP98 N-terminus and the homeodomain shared by the HOX genes, acting as an oncogenic transcription factor critical for leukemogenesis. We report here a new complex t(7;11)-variant, i.e., t(7;11;13;17)(p15;p15;p?;p1?2) in a patient with AML-M2 and poor prognosis. The NUP98-HOXA9 fusion transcript was detected by RT-PCR, suggesting its role in the malignant transformation as it has been postulated for other t(7;11)-associated leukemias. No other fusion transcripts involving the NUP98 or HOXA9 genes were present, although other mechanisms involving several genes on chromosomes 13 and 17 may also be involved. To our knowledge, this is the first t(7;11) variant involving NUP98 described in hematological malignancies.

Aged↗

PubMed2005

Purging of peripheral blood stem cell transplants in AML: a predictive model based on minimal residual disease burden.

OBJECTIVE: Minimal residual disease (MRD) present in peripheral blood stem cell (PBSC) products of AML patients may contribute to relapse. Our goal was to 1) predict leukemia recurrence based on the frequency of MRD present in PBSC products, 2) establish the efficacy of different purging procedures, and 3) integrate this into a model that enables to predict whether or not to purge. METHODS: Minimal residual disease was measured with flow cytometry using leukemia-associated phenotypes as established at diagnosis. Toxicity of purging procedures was established using clonogenic assays. Purging procedures used were cryopreservation, hyperthermia, ether lipid ET-18-OCH3, and combinations. RESULTS: Minimal residual disease in PBSC products correlated significantly with relapse-free survival (n=24, p=0.003). At a cut-off value of 0.05% MRD the relative risk of relapse was 4.6 times lower in the group with less than 0.05% MRD. As measured in 54 PBSC products, the MRD level was less than 0.05% in 17 of 54 cases, between 0.05% and 0.5% in 19 of 54 cases, and higher than 0.5% in 18 of 54 cases. Based on the MRD cut-off of 0.05%, the log tumor reduction needed to achieve this threshold is zero for the 17 of 54 cases in which MRD was below 0.05%, less than or equal to 1 log in 19 of 54 cases, and greater than 1-2 log in 18 of 54 cases. When applying purging with 25 mug/mL ET-18-OCH3 combined with cryopreservation at 10% DMSO and hyperthermia at 42 degrees C combined with cryopreservation at 10% or 4% DMSO, there was greater than or equal to 1 log depletion of AML blasts. CONCLUSION: This study establishes (1) a threshold level for MRD above which prognosis is worse, (2) that stem cell products from 69% of patients have higher than this "safe" MRD level, and (3) that ET-18-OCH3 and hyperthermia may be used to purge products in part of these patients.

Acute Disease↗

PubMed2006

Clinical grade expansion of CD45RA, CD45RO, and CD62L-positive T-cell lines from HLA-compatible donors: high cytotoxic potential against AML and ALL cells.

OBJECTIVE: Identification of a clinical grade method for the ex vivo generation of donor-derived T cells cytotoxic against both myeloid and lymphoblastic cells still remains elusive. We investigated rapid generation and expansion of donor derived-allogeneic T-cell lines cytotoxic against patient leukemic cells. MATERIALS AND METHODS: Acute myelogenous leukemia (AML) and acute lymphoblastic leukemia (ALL) blasts were cultured 5 days in Stem Span, granulocyte macrophage colony-stimulating factor, interleukin-4, and calcium ionophore. All B-precursor ALL (N22) and AML (N13), but not T-cell ALL (N3), differentiated into mature leukemia-derived antigen-presenting cells (LD-APC). All but one LD-APC generated cytotoxic T lymphocyte (CTL) from adult human leukocyte antigen (HLA)-identical (N8) or unrelated donors (N2). RESULTS: Upon in vitro culture, donor-derived CTL acquired a memory T phenotype, showing concomitant high CD45RA, CD45RO, CD62L expression. CD8(+) cells, but not CD4(+) cells, were granzyme, perforine, and interferon-gamma-positive. Pooled CD4(+) and CD8(+) cells were cytotoxic against leukemic blasts (32%, 30:1 E:T ratio), but not against autologous or patient-derived phytohemagglutinin blasts. LD-APC from five ALL patients were used to generate CTL from cord blood. A mixed population of CD4(+) and CD8(+) cells was documented in 54% of wells. T cells acquired classical effector memory phenotype and showed a higher cytotoxicity against leukemia blasts (47%, 1:1 E:T ratio). Adult and cord blood CTL showed a skewing from a complete T-cell receptor repertoire to an oligo-clonal/clonal pattern. CONCLUSIONS: Availability of these cells should allow clinical trials for salvage treatment of leukemia patients relapsing after allogeneic stem cell transplantation.

Adolescent↗

PubMed2006

Dendritic cells pulsed or fused with AML cellular antigen provide comparable in vivo antitumor protective responses.

OBJECTIVE: To investigate whether syngeneic BM-derived DCs generated in vitro and fused with syngeneic C1498 tumor cells (murine AML line) could induce a better antitumor protective effect compared to similarly generated DCs pulsed with C1498 lysate with or without co-injection of a class B CpG oligodeoxynucleotide (CpG 7909) in vivo. METHODS: DCs were pulsed with C1498 lysate prior to intravenous administration 14 and 7 days prior to tumor challenge. Separate cohorts received DCs electrically fused to irradiated C1498 cells. Cohorts were administered DCs that were lysate-pulsed or fused with tumor cells on days 14 and 7 prior to tumor injection. Some cohorts were co-injected with CpG 7909 at the time of DC administration. RESULTS: All DC vaccines significantly improved survival (p < 0.01) vs nonvaccinated controls. There was no difference in the antitumor protective response between mice that received pulsed vs fused DCs (47% vs 45% survival). Both DC vaccines generated a fivefold increase in splenic tumor-reactive cytotoxic T-lymphocyte precursor cells and significantly (p < 0.05) higher mean frequencies of IFN-gamma-producing splenocytes compared to controls. CpG 7909 improved the survival of mice receiving the fused DCs (p < 0.05) but not the pulsed DCs. Surviving mice were rechallenged and found to be resistant to lethal tumor injection. CONCLUSIONS: DC vaccine strategies may be effective in generating anti-AML responses. No advantage was observed between lysate-pulsed and tumor cell-fused DCs. CpGs may provide an adjuvant effect depending on the type of DC vaccine administered.

Adjuvants, Immunologic↗

PubMed2005

The anti-angiogenesis agent, AG-013736, has minimal activity in elderly patients with poor prognosis acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS).

AG-013736 is an oral anti-angiogenesis agent with activity against a variety of receptor tyrosine kinases, including VEGFR-1, VEGFR-2, VEGFR-3, c-kit, and PDGFR-beta. A phase 2 study was conducted in patients with poor prognosis AML or MDS. Twelve patients (six AML; six MDS) were treated with AG-013736 at a dose of 10mg orally daily for a median of 56 days (range, 1-248 days). Median age was 80 years (range, 58-88 years). Grade 3 or 4 drug-related toxicities included hypertension (42%), mucositis (8%) and deep venous thrombosis (8%). No objective responses occurred; two patients with MDS had stable disease for 8.3 and 6.2 months, respectively. Bone marrow expression of VEGFR-1 and VEGFR-2 was observed in 11% and 0% of patients, respectively. Sustained decreases in soluble VEGFR-2 plasma levels with concomitant elevation in plasma VEGF and placental growth factor levels were obtained during the course of therapy with AG-013736. AG-01736 had minimal biologic or clinical activity in this elderly patient population.

Acute Disease↗

PubMed2006

Phase II trial of subcutaneous recombinant human interleukin 11 with subcutaneous recombinant human granulocyte-macrophage colony stimulating factor in patients with acute myeloid leukemia (AML) receiving high-dose cytarabine during induction: ECOG 3997.

Randomized trials of substituting high-dose cytarabine (HiDAC) for standard dose cytarabine (SDAC) during induction therapy for newly diagnosed AML have not demonstrated an improvement in the complete remission (CR) rate. Phase II trials of the scheduled administration of HiDAC after SDAC suggest an improved outcome. The hematological complications of intensification are considerable. GM-CSF after chemotherapy improved the survival of older patients in a randomized trial. Recombinant human interleukin 11, a thrombopoietic cytokine, reduced the incidence of chemotherapy-induced thrombocytopenia in patients with solid tumors. Therefore, 34 patients were treated, with newly diagnosed AML less than 56 years of age, with daunorubicin 45 mg/m2 on days 1-3, cytarabine 100mg/m2 days 1-7 and cytarabine 2g/m2 for 12 h on days 8-10 (7+3+3). rhIL-11 (50 microg/kg/day,) and GM-CSF (250 microg/kg/day) were administered subcutaneously from day 11 until recovery. The complete remission rate was 59% (90% C.I. 43-73%). The median time to recovery of neutrophils to >500 and platelets to > or =20,000 microl(-1) was 27 days (95% C.I. 27-30 days) and 25 days (95% C.I. 24-29 days), respectively. The trial does not confirm the high CR rate observed in phase II trials, despite optimal supportive care.

Acute Disease↗

PubMed2006

Geographic differences in the incidence of cytogenetic abnormalities of acute myelogenous leukemia (AML) in Spain.

The incidence of chromosomal abnormalities in acute myeloid leukemia (AML) differs according to geographical regions in Spain. We analyse 1,271 consecutive patients diagnosed of AML between 1995 and 2002 in three different regions of Spain: northern, central and southern. There were 624 males (55%) and 505 females (45%). Age ranged between 1 month and 94 years with a median of 61 years. Abnormal karyotypes were observed in 64% of cases. Numerical abnormalities as sole cytogenetic changes were detected in 15% of patients, while structural aberrations were present in 28% of cases, and both abnormalities were found in 22% of patients. A significantly higher proportion of t(15;17) was observed in the south of Spain (21.6%) than in the central (17%) or northern regions (12.6%) (p=0.03). By contrast, patients from the south of Spain showed lower incidence of t(8;21) (0%, compared to 1.6% and 3.6% in central and northern areas, respectively, p=0.04). These differences were maintained in the age-adjusted analysis. Trisomy 8 showed similar incidence in southern and central areas, while the incidence in the northern area was lower (14% and 10%, respectively, p=0.04). Other chromosomal abnormalities, such as inv(16) or 11q23 rearrangements, were found at similar frequencies in the three regions.

Adolescent↗

PubMed2006

Phosphoproteomic analysis of AML cell lines identifies leukemic oncogenes.

STAT5 is constitutively phosphorylated in leukemic cells in approximately 70% of acute myeloid leukemia (AML) patients. To identify kinase candidates potentially responsible for STAT5 phosphorylation, we used liquid chromatography-tandem mass spectrometry (LC-MS/MS) mass spectrometry to detect phosphoproteins in AML cell lines. We established TEL-ARG and BCR-ABL fusion proteins as the mechanism underlying STAT5 phosphorylation in HT-93 and KBM-3 cells, respectively. In addition, we identified a JAK2 pseudokinase domain mutation in HEL cells and using siRNA downregulation, established JAK2 as the kinase responsible for phosphorylating STAT5. This study illustrates the benefit of LC-MS/MS mass spectrometry and siRNA for the identification of novel targets and mutations.

Carcinogens↗

PubMed2006

Lifelong persistence of AML associated MLL partial tandem duplications (MLL-PTD) in healthy adults.

AML-associated MLL-PTD contribute to leukemogenesis by a gain of function and confer an unfavorable prognosis. Like other leukemia associated aberrations they are also present in healthy adults. To delineate the leukemogenic mechanism we tracked down MLL-PTD in normal hematopoiesis and investigated cord blood samples. MLL-PTD were observed in 56/60 (93%) of all cord bloods. In contrast to AML, the transcript frequency in cord blood was four log scales lower as determined by real-time PCR. The CD34+ progenitor cell, CD33+ myeloid, CD19+ B-lymphoid and CD3+ T-lymphoid subfractions were positive. The ubiquitous presence of MLL-PTD in cord blood implicates a lifelong exposure, not an accumulation during lifetime. Since also present in the stem cell subfraction, these factors seem not to be major determinants in MLL-PTD leukemogenesis.

Adult↗

PubMed2006

Stress-induced in vitro apoptosis of native human acute myelogenous leukemia (AML) cells shows a wide variation between patients and is associated with low BCL-2:Bax ratio and low levels of heat shock protein 70 and 90.

Spontaneous in vitro apoptosis reflects a true biological heterogeneity between patients which has to be considered when in vitro models are used to study regulation of apoptosis in native human AML cells. Even though the balance between pro- and anti-apoptotic signaling seems to have a prognostic impact in AML, the possible clinical relevance of spontaneous apoptosis remains to be clarified. High apoptosis/low viability was associated with low levels of heat shock proteins 70 and 90 as well as low Bcl-2:Bax ratio for patients heterogeneous with regard to morphology, membrane molecule expression, genetic abnormalities and response to therapy.

Adult↗

PubMed2006

Successful treatment of relapsed AML after allogeneic stem cell transplantation with azacitidine.

Therapeutic options for patients with relapse of MDS or high risk AML after allogeneic stem cell transplantation are limited. We here present the case of a 64-year-old female patient with MDS, who received peripheral blood stem cells from her HLA-identical brother after a non-myeloablative conditioning regimen. Two months after allogeneic transplantation she suffered from a relapse, now fulfilling WHO criteria for AML with a bone marrow blast count of 91%. We then decided to treat her with azacitidine, a DNA methyltransferase inhibitor with proven antileukemic activity. The patient achieved a complete haematological response after two cycles and full donor chimerism after a single dose of donor lymphocytes. We postulate that azacitidine acts through a direct reduction of malignant cells and may in addition augment the immunologic effects of donor lymphocyte infusions.

Acute Disease↗

PubMed2006

Double loading of dendritic cell MHC class I and MHC class II with an AML antigen repertoire enhances correlates of T-cell immunity in vitro via amplification of T-cell help.

Therapeutic vaccination with dendritic cells presenting tumor-specific antigens is now recognized as an important investigational therapy for the treatment of neoplastic disease. Dendritic cell cross-presentation is credited with the ability of tumor lysate-loaded dendritic cells to prime both CD4 and CD8-specific T-lymphocyte responses, enabling the generation of cancer specific CTL activity without the loading of the classical MHC class I compartment. Recently, however, several reports have raised doubts as to the efficiency of cross-presentation as a mechanism for CTL priming in vivo. To examine this issue, we have doubly-loaded human dendritic cells with both AML-specific tumor lysate and AML-specific tumor mRNA. Our results show that these doubly-loaded dendritic cells can mediate superior primary, recall, and effector lytic responses in vitro in comparison to those of dendritic cells loaded with either tumor lysate or tumor mRNA alone. Enhanced recall responses appeared to be influenced by CD40/CD40L signaling, underscoring the importance of T-cell help in the generation and perpetuation of the adaptive immune response.

Antigens, Neoplasm↗

PubMed2001

Exposure to armament wastes and leukemia: a case-control study within a cluster of AML and CML in Germany.

An unusually high incidence of acute myeloid leukemia (AML) and chronic myeloid leukemia (CML) concentrated in a specific locality of a region in Germany motivated a descriptive incidence study in that region which showed a near 10-fold increased risk of CML among males but not among females (Kolb G, Becker N, Scheller S, Zugmaier G, Pralle H, Wahrendorf J, Havemann K. Increased risk of acute myelogenous leukemia (AML) and chronic myelogenous leukemia (CML) in a County of Hesse, Germany, Soc Prev Med 1993;38:190-195). Since a serious environmental contamination of areas in this locality with armament wastes containing toluene-derivatives has been known for a long time, the hypothesis arose that TNT production and the related severe contamination of soil and water might be responsible for the observed higher risk. We carried out a case-control study within the cluster to test this hypothesis. Overall, the results do not confirm the hypothesis. There is an indication of a relationship of an increased odds ratio with the exposure for a small group of persons who lived at a particular site in one of the two communities involved during the peak phase of TNT production during the 1940s. However, this finding is spurious and cannot explain the large majority of cases which occurred in that area in the 1980s. At the moment, no other explanation can be given for the increased risk of leukemias in that area.

Adult↗

PubMed2002

Potential mechanisms of resistance to cytarabine in AML patients.

To determine whether the human equilibrative nucleoside transporter 1 (hENT1), deoxycytidine kinase (dCK), cytoplasmic 5'-nucleotidase (5NT), cytidine deaminase (CDD), topoisomerase I (TOPO I) and topoisomerase II alpha (TOPO II) are involved in clinical resistance to cytarabine (ara-C), we analyzed the level of expression of these parameters by reverse transcriptase polymerase chain reaction (rt-PCR), at diagnosis in the blast cells of 77 acute myeloid leukemia (AML) patients treated with ara-C, including 31 for whom samples were collected at first relapse. By univariate and/or multivariate analyses, patients with expression of 5NT or hENT1 deficiency at diagnosis had significantly shorter disease-free survival (DFS) and overall survival (OS). These results suggest that expression of 5NT and reduced hENT1 in leukemic blasts at diagnosis are correlated with clinical outcome and may play a role in resistance mechanisms to ara-C in patients with AML.

5'-Nucleotidase↗

PubMed2003

Different effects of metabolic inhibitors and cyclosporin A on daunorubicin transport in leukemia cells from patients with AML.

The objective of this study was to determine the role of transport proteins in daunorubicin (Dnr) accumulation and efflux in leukemia cells from 36 patients with acute myeloid leukemia (AML). Mononuclear cells were isolated and incubated with 1 microM Dnr with/without addition of 3 microM cyclosporin A (CyA) or metabolic inhibitors (MI). Cellular Dnr concentration in leukemia blast cells was measured with flow cytometry. After washing and reincubation of the cells in drug-free medium, Dnr efflux was followed with/without addition of CyA or MI. Levels of mRNA expression for mdr1, multidrug resistance associated protein (mrp) and lung resistance protein (lrp) were determined with reverse transcriptase-polymerase chain reaction (RT-PCR). MI enhanced cellular Dnr accumulation to a higher extent than CyA whereas CyA reduced Dnr efflux more efficiently than MI (P<0.001). There was a significant difference in Dnr accumulation between samples with low and high mdr1 mRNA levels but only in the presence of MI or CyA. Our results imply that other factors than P-glycoprotein (Pgp) are of major importance for in vitro Dnr accumulation in AML blasts and that the role of Pgp as a drug efflux pump is not conclusive.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2003

Empirical examination of the neutrophil criterion (>1500 microl(-1)) currently needed to declare CR in AML.

Currently, NCI guidelines require that the neutrophil count exceed 1500 before complete remission (CR) may be declared in acute myeloid leukemia (AML). We tested the empirical validity of this formulation by comparing event-free survival (EFS) in CR in (a). 305 patients who met the NCI criteria for CR and (b). 36 patients who met all the criteria for CR except that the neutrophil count at what we considered CR was 1000-1499 (lower neutrophil group) at which time they began post-remission therapy. EFS was statistically identical in both groups. We extended these findings to 752 patients, who met the NCI criteria for CR except that some may have had circulating blasts at "CR"; 82 of the 752 were in the lower neutrophil group. These data suggest that the minimum needed to declare CR in AML be changed from 1500 to 1000.

Acute Disease↗