Although FLT3 mutations are essentially found in myeloid-lineage leukemia cells, a high level of FLT3 expression was recently observed in MLL gene-rearranged acute lymphoblastic leukemia without FLT3 ...mutations. Here, we analyzed the biologic and clinical significance of the FLT3 transcript level in comparison with several gene alterations in 181 de novo acute myeloid leukemia (AML) cases. The mean expression level in AML was higher than that in normal mononuclear cells, whereas the range varied widely. A high level of FLT3 is related to internal tandem duplication of the FLT3 gene (FLT3/ITD), the mutations within the activation loop of FLT3 (FLT3/D835Mt), and tandem duplication of the MLL gene (MLL-TD) but not to p53 or N-RAS gene mutations. Furthermore, a high expression level in AML cases with FLT3 mutations was not related to MLL-TD. Overexpressed FLT3 revealed autophosphorylation and had the same sensitivity to the FLT3 inhibitor as FLT3/ITD. Overexpression of FLT3 (more than 200 000 copies/μgRNA) was an unfavorable prognostic factor for overall survival in 91 AML cases without FLT3/ITD. These results indicated that FLT3 overexpression may distinguish a novel disease entity in AML without FLT3 mutations and serve as a therapeutic target for FLT3 inhibitors.
The present study investigates the regulatory mechanisms involved in the cooperation between IFN-gamma and TNF-alpha to promote transcription from IFN regulatory factor-1 (IRF-1). A transient ...transfection analysis revealed that the region between -218 and -144, where +1 is the transcription start site, as well as previously reported downstream elements, ppkappaB and IFN-gamma activation site/kappaB, were required for the optimal response to the two cytokines. A subsequent DNase I footprint analysis showed that the region between -171 and -144 was inducibly protected with stimulation by TNF-alpha, and this protection was significantly enhanced with the combination of IFN-gamma and TNF-alpha. In an EMSA with the protected region as a probe, a TNF-alpha-inducible complex (C1) and an IFN-gamma-inducible complex (C2), but no synergy-specific DNA-protein complexes, were recognized. The C1 complex consisted of a pre-existing factor (p65/p50), whereas the C2 complex consisted of a newly synthesized IRF-1-related factor. A methylation interference assay revealed the critical G residues (from -167 to -151) for the DNA-protein complex formation specific to the cytokine response, and within this region the novel kappaB sequence, the promoter distal kappaB (pdkappaB) element (5'-GGGGAAG TAC-3'), was identified. Because the base substitutions over the pdkappaB region (from -171 to -144) affected not only the TNF-alpha-response but also that of IFN-gamma, this region might contribute to the cooperative action of the NF-kappaB subunits with the IRF-1-related factor. Finally, we demonstrated that none of the cis-acting elements, ppkappaB, pdkappaB, or IFN-gamma activation site/kappaB, is dispensable for the optimal synergism in response to IFN-gamma and TNF-alpha.
Myeloid leukemia in this series corresponds to the myeloid neoplasms of the 4th WHO classification of pathology and genetics of tumor of haematopoietic and lymphoid tissue. The myeloid neoplasms are ...composed of six categories, which are 1) myeloproliferative neoplasms (MPN), a new category of 2) myeloid and lymphoid neoplasms with eosinophilia and abnormalities of PDGFRA, PDGFRB or FGFR1, 3) myelodysplastic syndrome (MDS)/MPN, 4) MDS, 5) acute myeloid leukemia (AML) and related precursor neoplasms, and 6) acute leukemias of ambiguous lineage. In MPNs without chronic myelogenous leukemia, the genetic marker of JAK2 V617F is added to the diagnostic criteria for polycythemia vera, essential thrombocythemia and primary myelofibrosis. MDS has the new subtype of refractory cytopenia with unilineage dysplasia composed of refractory anemia, refractory neutropenia and refractory thrombocytopenia. AML with t(9; 11) (p22;q23); MLLT3-MLL, AML with t(6;9) (p23; q34); DEK-NUP214, AML with inv(3) (q21q26.2) or t(3; 3) (q21 ; q26.2); RPN1-EVI1 and AML (megakaryoblastic) with t(1; 22) (p13; q13); RBM15-MKL1 are added to the subtype of AML with recurrent genetic abnormalities, and AML with gene mutations of NPM1 and CEBPA are also added as provisional entities of it. The myeloid neoplasms of the 4th WHO classification are comprehensive and seem to be dynamic by incorporating the results of leukemia researches.
A morphological review system of the Japan Adult Leukemia Study Group has developed from the AML-87 through the AML-92 experience. We reviewed 1427 (90%) of 1592 cases enrolled in the AML-87, -89, or ...-92 protocols for morphology; 1408 (88%) were eligible. The rate of diagnostic concordance between each institute and the Committee on Morphological Diagnosis ranged from 76% to 80%. Acute myeloid leukemia (AML) subtypes were as follows: AML M0, 27 (2%); M1, 179 (13%); M2, 472 (34%); M3, 358 (25%); M4, 265 (19%); M5, 57 (4%); M6, 39 (3%); and M7, 11 (1%). The reason for the high number of patients with AML M3 is that many M3 patients were enrolled in the AML-92 protocol, which contained all-trans-retinoic acid. AML M0, M6 and M7 belonged to the poor prognostic groups. Auer bodies were found in 284 (53%) of 538 patients who survived significantly longer than those without Auer bodies in AML-87/-89. In AML-92 except for AML M3, 259 (43%) of 602 cases were Auer+ and also showed better survival rates. The survival of patients with >50% myeloperoxidase (MPO)-positive blast cells was better than those with < or =50% MPO+ blast cells in AML-87/-89. This trend was also seen in AML-92 excluding M3. AML with trilineage dysplasia (AML/TLD) is characterized as a subtype of de novo AML that shows morphological dysplasia of mature hematopoietic cells on a background of leukemic blast cells The number of patients with AML/TLD was 89 (16.5%) of 545 patients reviewed in AML-87/-89. AML-92, except for M3, showed a higher rate of patients with TLD (161 cases; 27.6%) because there were no patients with TLD in the AML M3 group. Survival rates for AML/TLD were worse than those for AML/non-TLD in both the AML-87/-89 and -92 protocols. Eighty percent of all cases (793/986) entered in AML-92 were analyzed cytogenetically. Fifty-one cases were not available for karyotyping because of a lack of mitoses or inappropriate preparations. The most frequent karyotype was normal, which accounted for 34.2%. The t(15;17), t(8;21), and inv(16) karyotypes, which are regarded as good risk factors, were 23.8%, 9.2%, and 1.6%, respectively. Abnormal chromosomes 5, 7, t(9;22), and t(6;9) were considered to be poor or intermediate risk factors As a new system of karyotyping begins in the ongoing AML protocol, useful chromosomal data will be obtained in the near future.
Internal tandem duplication of the FLT3 gene and point mutations of the N-RAS gene are the most frequent somatic mutations causing aberrant signal-transduction in acute myeloid leukemia (AML). ...However, their prognostic importance is unclear. In this study, their prognostic significance was analyzed in 201 newly diagnosed patients with de novo AML except acute promyelocytic leukemia. Three patients had mutations in both genes, 43 had only theFLT3 gene mutation, 25 had only the N-RAS gene mutation, and 130 had neither. These mutations seemed to occur independently. Both mutations were related to high peripheral white blood cell counts, and the FLT3 gene mutation was infrequently observed in the French-American-British (FAB)-M2 type. AML cases with wild FLT3/mutant N-RAS had a lower complete remission (CR) rate than those with wild FLT3/wild N-RAS, whereas the presence of mutant FLT3 did not affect the CR rate. Univariate analysis showed that unfavorable prognostic factors for overall survival were age 60 years or older (P = .0002), cytogenetic data (P = .002), FAB types other than M2 (P = .002), leukocytosis over 100 ± 109/L (P = .003), and the FLT3 gene mutation (P = .004). However, the N-RAS gene mutation was only a marginal prognostic factor (P = .06). For the subjects under 60 years old, multivariate analysis showed that theFLT3 gene mutation was the strongest prognostic factor (P = .008) for overall survival. The FLT3 gene mutation, whose presence is detectable only by genomic polymerase chain reaction amplification and gel electrophoresis, might serve as an important molecular marker to predict the prognosis of patients with AML.
We searched for trisomy 11 in acute myelogenous leukemia (AML) patients using the Japan Adult Leukemia Study Group (JALSG) AML-92 and -95 databases to clarify the clinical and hematologic features of ...a rare numerical chromosome abnormality. Among the sequentially registered patients of JALSG AML-92 (655 patients) and JALSG AML-95 (531 patients), chromosome findings were obtained for 1074 patients (90.6%); we found 5 patients with trisomy 11 as the sole abnormality. The patients were 4 women and 1 man with trisomy 11 AML, all aged more than 45 years (median, 52 years), with 4 M1 morphologies and 1 M2. No patients manifested hepatosplenomegaly or lymph node enlargement, and no central nervous system leukemia or extramedullary lesions were detectable. All showed positivity for CD13 (5/5), CD33 (5/5), CD34 (3/3), CD38 (2/2), and HLA-DR (5/5). Except for 1 patient, all achieved complete remission after 1 course of induction chemotherapy, but 2 relapsed after discontinuation of chemotherapy. A third case of relapse occurred during intensification of chemotherapy, and the patient underwent allogenic bone marrow transplantation but died from interstitial pneumonia.
Abstract 4594
B-chronic lymphocytic leukemia (B-CLL) is rare in Japan. Therefore, only a few data are available on the clinical characteristics of B-CLL for Japanese patients (pts). We reported that ...the rate of atypical CLL appeared to be higher in Japanese pts than that of Caucasians.
This nation-wide study was performed from Oct. 2003 to March 2008, and was supported by Japanese Elderly Leukemia and Lymphoma Study Group. The study was conducted in accordance with the Declaration of Helsinki and was approved by the Institutional Review Boards of the core members’ hospitals. The pts with CLL and CLL-like disease were registered. Precursor leukemia and adult T-cell leukemia/lymphoma were excluded. The smears of peripheral blood and bone marrow of all the registered pts were examined by the Diagnosis Committee by using the 4th edition of WHO classification and FAB classification. FAB classification defines typical CLL as prolymphocytes≤10% and atypical CLL including CLL/PLL as 11%≤prolymphocyte<55% and CLL mixed as prolymphocytes<10% and pleomorphic lymphocyte>15%. Mantle cell lymphoma was excluded by means of cytogenetics, fluorescent in situ hybridization of CCND1-IGH, and immunohistochemistry of CCND1.
One hundred and thirty-one evaluable pts were registered. There were 96 pts with B-CLL, 2 SLL, 1 B-PLL, 3 hairy cell leukemia, 16 leukemic phase of other B-cell lymphomas. Thirteen pts had NK or T cell leukemia/lymphoma with 7 T-LGL, 4 T-PLL, 1 NK-LGL, and 1 Sezary syndrome. Among B-CLL, there were 62 pts with typical morphology (typical CLL), 18 with atypical morphology (atypical CLL), 16 with intermediate morphology between typical and atypical CLL (intermediate CLL). The differences among 3 subgroups are shown in Table. No differences were found between the 3 morphological subgroups for age, sex, stage (modified Rai and Binet classification), hemoglobin level, platelet counts, the presence of hepatomegaly, splenomegaly and lympoadenopathy, ECOG-PS and the rate of treatment requirement. However, the incidence of CD5 and CD23 expression was higher in typical CLL than in atypical/intermediate morphology groups (P<0.001), i.e. 7% of the pts with atypical CLL showed co-expression of CD5 and CD23. The overall survival (OS) of typical CLL pts was lower than that of intermediate or atypical CLL pts (Figure).
Morphological atypia was more frequent in Japanese B-CLL pts, partly because of the low incidence of typical CLL. The atypical/intermediate CLLs were associated with atypical immunophenotype (absence of CD5 and/or CD23) and favorable prognosis. Prospective study is ongoing to evaluate other prognositic factors including the implication of IgVH gene mutation status and ZAP-70 expression in Japan.
TableTypicalIntermediateAtypicalPPatients No.621618Age, median6765670.50Sex (male/female)1.301.292.60.47CD20+98.4%100%88.9%0.16CD5+98.4%81.30%77.8%0.003CD5+23+86.5%50.0%7.0%<0.001No treatment45%50%61%0.49Outcome(died)29.8%0%12.5%0.018 Display omitted
No relevant conflicts of interest to declare.
Acute myeloid leukemia (AML) is a heterogeneous disorder of hematopoietic progenitor cells. The World Health Organization (WHO) classification of the myeloid neoplasm incorporates genetic, ...immunophenotypic, biologic and clinical features. Although the WHO classification recognizes several chromosomal translocations they are frequently seen in AML patients, for categorizing the AML with recurrent genetic abnormalities, a number of other genetic alterations such as point mutations and gene rearrangements have not been included. To date, several genetic alterations, which are involved in the pathogenesis of AML and associated with prognosis of patients, have been documented. Therefore, it is required to establish the detailed classification of AML according to the genetic status. In this study, we comprehensively analyzed the genetic alterations and in de nove AML patients and investigated the association with mutational status, cytogenetic status and clinical features in comparison with the WHO classification. The study population included 144 newly diagnosed de nove AML patients consisting of 38 recurrent genetic abnormalities (RGA), 34 multilineage dysplasia (MLD) and 72 not otherwise categorized (NOC) according to WHO subcategories. Bone marrow samples were obtained from the patients after obtaining informed consent for banking and molecular analyses. Mutations in FLT3, cKIT, NPM1, N-RAS, TP53, C/EBPA, AML1, WT1 and MLL/PTD were analyzed as previously described. In consistent with previous reports, FLT3 (24%), cKIT (5%), NPM1 (20%), N-RAS (8%), C/EBPA (12%), AML1 (2%), MLL-PTD (9%), WT1 (3%) and TP53 (8%) mutations were frequently observed. No significantly different distribution was found in the prevalence of FLT3, N-RAS, C/EBPA, AML1 and MLL-PTD mutations among the WHO categories. However, the skewed prevalence was found in cKIT, NPM1 and TP53 mutations: cKIT mutation was frequently found in AML-RGA, NPM1 mutation was not found in AML-RGA, and TP53 mutation was preferentially found in AML-MLD. N-RAS, C/EBPA, AML1 and WT1 mutations were not identified in AML-RGA, though their distributions were not statistically significant among the WHO categories. It is notable that 9 of 12 (75%) patients who have TP53 mutation are categorized in AML with MLD and 8 of the 9 have complex-karyotype. Importantly, 8 of 9 (88.9%) showed complex karyotype, and 5 of them deleted chromosome 17. In this study, we found 2 additional patients harboring TP53 mutation in the other categories, while they did not show the complex karyotype and chromosome 17 abnormality. Furthermore, complex karyotype was found in 14 of the 144 entire AML patients, while 10 of them were categorized in AML-MLD. The remaining 4 patients were categorized in AML-NOC. Three of them showed del(17) or del(17p), though TP53 mutation was not identified. The genotype consisting of complex karyotype and TP53 mutation was, therefore, specifically found in AML-MLD. Thus TP53 mutation and complex-karyotype AML are significantly correlated and associated with the presence of multi-lineage dysplasia (P= .000 and P= .000, respectively). Moreover, these patients have significantly inferior induction rate and overall survival in AML with MLD. These results suggest that TP53 mutation and complex-karyotype AML distinguish a disease entity in AML with MLD.
PDF
