[Loss-of-function of AML1/PEBP2 alpha B and leukemogenesis].
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Publications and source records attributed to N Asou.
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We report herein the clinical results of a multicenter trial of the Japan Adult Leukemia Study Group for cases of newly diagnosed acute promyelocytic leukemia (APL) treated with all-trans retinoic acid and chemotherapy (JALSG AML-92 study). Of 196 evaluable patients, 173 (88%) achieved complete remission (CR). Multivariate analysis showed that no or minor purpura at diagnosis and age less than 30 years were favorable factors for achievement of CR. There was a significant difference in the 4-year event-free survival between the AML-92 study (54%) and both the AML-87 (32%) and AML-89 (32%) studies which consisted of intensive chemotherapy. Since prognosis in patients with APL largely depends on chemotherapy, it is important to consider more effective chemotherapy during induction and consolidation therapy.
We report 2 paroxysmal nocturnal hemoglobinuria (PNH) patients who were initially diagnosed with aplastic anemia and sequentially developed PNH, myelodysplastic syndromes (MDS), and leukemia. Flow cytometry and cytogenetic analysis showed the initial appearance and expansion of PNH clones, gradual replacement of PNH clones by MDS clones with monosomy 7, and then expansion of MDS clones or their subclones with additional chromosomal abnormalities. In relation to these developments, expression increased of the Wilms' tumor gene WT1, a marker for leukemic progression. These patients not only shared bone marrow failure but also might have harbored a hematopoietic environment favorable for the emergence of abnormal clones leading to leukemogenesis.
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 the FLT3 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 +/- 10(9)/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 the FLT3 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.
The AML1 gene encoding the DNA-binding alpha-subunit in the Runt domain family of heterodimeric transcription factors has been noted for its frequent involvement in chromosomal translocations associated with leukemia. Using reverse transcriptase-polymerase chain reaction (RT-PCR) combined with nonisotopic RNase cleavage assay (NIRCA), we found point mutations of the AML1 gene in 8 of 160 leukemia patients: silent mutations, heterozygous missense mutations, and biallelic nonsense or frameshift mutations in 2, 4, and 2 cases, respectively. The mutations were all clustered within the Runt domain. Missense mutations identified in 3 patients showed neither DNA binding nor transactivation, although being active in heterodimerization. These defective missense mutants may be relevant to the predisposition or progression of leukemia. On the other hand, the biallelic nonsense mutants encoding truncated AML1 proteins lost almost all functions examined and may play a role in leukemogenesis leading to acute myeloblastic leukemia.
We identified a novel human long fatty acyl CoA synthetase 2 gene, ACS2, as a new ETV6 fusion partner gene in a recurrent t(5;12)(q31;p13) translocation in a patient with refractory anemia with excess blasts (RAEB) with basophilia, a patient with acute myelogenous leukemia (AML) with eosinophilia, and a patient with acute eosinophilic leukemia (AEL). ACS2 is expressed in the brain and bone marrow and is highly conserved in man and rats. The resulting ETV6/ACS2 fusion transcripts showed an out-frame fusion of exon 1 of ETV6 to exon 1 of ACS2 in the AEL case, an out-frame fusion of exon 1 of ETV6 to exon 11 of ACS2 in the AML case, and a short in-frame fusion of ETV6 exon 1 to the 3' untranslated region of ACS2 in the RAEB case. Reciprocal ACS2/ETV6 transcripts were identified in two of the cases. Fluorescence in situ hybridization (FISH) analysis with ETV6 cosmids on 12p13, and BACs and P1s on 5q31, demonstrated that the 5q31 breakpoints of the AML and AEL cases involved the 5' portion of the ACS2 gene, and that the 5q31, breakpoint of the RAEB case involved the 3' portion of the ACS2 gene. None of the resulting chimeric transcripts except for the ACS2/ETV6 transcript in the RAEB case led to a fusion protein. Disruption of the second ETV6 allele by t(12;19) was detected in the AML case by FISH analysis. These observations suggest that the disruption of ETV6 and/or ACS2 may lead to the pathogenesis of hematologic malignancies with t(5;12)(q31;p13).
Relapse is a major cause of treatment failure in acute myeloid leukaemia (AML), and is usually accompanied by resistance to chemotherapy. To study whether relapse is accompanied by genetic alterations, we compared N-ras, p53 and FLT3 gene mutations in paired samples obtained at initial diagnosis and first relapse. 28 patients with relapsed AML were studied, and their duration of complete remission ranged from 133 to 989 d (mean 318 d). Karyotype changes were observed at relapse in 11 patients. Point mutations of the N-ras gene were positive at both stages (+/+) in three patients, positive at initial diagnosis and negative at relapse (+/-) in three patients, and negative at initial diagnosis and positive at relapse (-/+) in two patients. Internal tandem duplications of the FLT3 gene (FLT3/ITD) were +/+ in five patients, +/- in one patient, and -/+ in six patients. The p53 gene mutations were +/+ in two patients, +/- in one patient, and -/- in 25 patients. FLT3/ITD and mutant p53 at relapse were associated with short survival after relapse. These results indicate that relapse is frequently accompanied by molecular alterations that include the loss and/or acquisition of mutations. Thus relapse can be understood as clonal shift or collateral succession rather than clonal progression.
The prevalence of Borna disease virus (BDV)-specific antibodies among patients with psychiatric disorders and healthy individuals has varied in several reports using several different serological assay methods. A reliable and specific method for anti-BDV antibodies needs to be developed to clarify the pathological significance of BDV infections in humans. We developed a new electrochemiluminescence immunoassay (ECLIA) for the antibody to BDV that uses two recombinant proteins of BDV, p40 and p24 (full length). Using this ECLIA, we examined 3,476 serum samples from humans with various diseases and 917 sera from blood donors in Japan for the presence of anti-BDV antibodies. By ECLIA, 26 (3.08%) of 845 schizophrenia patients and 9 (3.59%) of 251 patients with mood disorders were seropositive for BDV. Among 323 patients with other psychiatric diseases, 114 with neurological diseases, 75 with chronic fatigue syndrome, 85 human immunodeficiency virus-infected patients, 50 with autoimmune diseases including rheumatoid arthritis and systemic lupus erythematosis and 17 with leprosy, there was no positive case except one case each with alcohol addiction, AIDS, and dementia. Although 19 (1.36%) of 1,393 patients with various ocular diseases, 10 (1.09%) of 917 blood donors, and 3 (4.55%) of 66 multitransfused patients were seropositive for BDV-specific antigen, high levels of seroprevalence in schizophrenia patients and young patients (16 to 59 years old) with mood disorders were statistically significant. The immunoreactivity of seropositive sera could be verified for specificity by blocking with soluble p40 and/or p24 recombinant protein. Anti-p24 antibody was more frequent than p40 antibody in most cases, and in some psychotic patients antibody profiles showed only p40 antibody. Although serum positive for both p40 and p24 antibodies was not found in this study, the p40 ECLIA count in schizophrenia patients was higher than that of blood donors. Furthermore, we examined 90 sera from Japanese feral horses. Antibody profiles of control human samples are similar to that of naturally BDV-infected feral horses. We concluded that BDV infection was associated in some way with psychiatric disorders.
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To assess the efficacy of etoposide added to the standard remission induction therapy for acute myeloid leukemia (AML), newly diagnosed adult AML patients were randomized to receive either daunorubicin (40 mg/m2/day x 4 or more), behenoyl cytarabine (200 mg/m2/day x 10 or more), and 6-mercaptopurine (70 mg/m2/day x 10 or more) (BHAC-DM), or the same three drugs plus etoposide (100 mg/m2/day x 5) (BHAC-EDM) for response-oriented individualized induction therapy. The patients achieving complete remission (CR) received the same 3 courses of consolidation therapy followed by 6 courses of maintenance/intensification therapy. M3 patients were excluded because all-trans retinoic acid was used. Of 667 patients registered, 655 were evaluable. The median age was 49 (range 15 to 85). CR rates were 77% in the BHAC-DM group and 75% in the BHAC-EDM group. In 173 M4 patients, CR rates were 86% and 69% (P = 0.009), and in 32 M5 patients, 80% and 77% (P = 0.810) in the BHAC-DM and the BHAC-EDM groups, respectively. The predicted 6-year overall survival rates were 30% and 38% (P = 0.925) for the BHAC-DM and BHAC-EDM groups, and the disease-free survival rates of CR patients were 25% and 35% (P = 0.352), respectively. Nonhematological toxicities after the first course of induction therapy were almost equal among the two groups, with the exception of a greater loss of hair (P = 0.024) and more frequent diarrhea (P = 0.013) in the BHAC-EDM group. We concluded that in the present study, the addition of etoposide to the standard individualized induction therapy showed no advantage in adult AML, even among M4 and M5 patients.
The Japan Adult Leukemia Study Group analyzed infectious episodes in 577 patients with acute myeloid leukemia during remission induction therapy between 1987 and 1991. 542 patients (93.9%) experienced at least one infectious episode, 121 (21.0%) had microbiologically documented infection; there was clinically documented infection in 184 (31.9%) and unexplained fever in 237 (41.1%). Among 121 microbiologically documented infections, bacteremia/fungemia was observed in 68, pneumonia in 33, and other types of infections in 20. Among the bacteremia/fungemia, gram-negative bacteria accounted for 41.2% (Pseudomonas aeruginosa was the most common), gram-positive bacteria for 39.7%, fungi for 16.2% (Candida spp. being most frequent), and polymicrobial for 2.9%. The most frequent isolates among pneumonia were Pseudomonas aeruginosa and Aspergillus. A total of 70 patients (12.1%) died during remission induction. Mortality of 68 patients with bacteremia/fungemia was 26.5%; in these patients, mortality with concomitant pneumonia increased to 41.4%; without pneumonia, mortality was 15.4% (P < 0.05). Mortality according to the isolated microbes was 17.2% for gram-negative bacteria, 25% for gram-positive bacteria, and 54.5% for fungi. Mortality of 113 patients with pneumonia (33 microbiologically documented and 80 clinically documented), 20 with other microbiologically documented infections, 104 with other clinically documented infections, and 237 with unexplained fever was 25.7%, 5.0%, 5.8%, and 5.1%, respectively.
To evaluate the long-term effectiveness of interferon-alpha (IFN-alpha) therapy in patients with chronic myelogenous leukemia (CML) in chronic phase, we examined the updated outcomes of 159 patients who had been enrolled between 1988 and 1991 into a randomized trial comparing IFN-alpha with busulfan. At a median follow-up of 73 months, the median survival was 71 months in the IFN-alpha group and 55 months in the busulfan group (P=0.0563), and the median time of remaining in chronic phase was 58 months in the IFN-alpha group and 39 months in the busulfan group (P=0.4676). Landmark analysis showed a significant advantage in survival (P=0.009) and duration of chronic phase (P=0.0001) in patients with any cytogenetic response among the IFN-alpha group. About half patients were discontinued IFN-alpha administration in spite of cytogenetic response in this study. It appears that continuation of IFN-alpha might possibly confer a survival advantage. Pretreatment factors associated with cytogenetic response included high hemoglobin level, low percentage of peripheral basophils and low leukocyte counts. Multivariate analysis identified lower percentage of bone marrow basophilia (P=0.007) for survival advantage. If a group with a very good prognosis is predicted by a new prognostic model, it might be an option to wait for bone marrow transplantation.
Adult patients with acute lymphoblastic leukemia (ALL) were treated according to the ALL90 study, the second prospective study for ALL of the Japan Adult Leukemia Study Group (JALSG). Its characteristics included response-oriented individualized induction therapy with six drugs (doxorubicin, mitoxantrone, vincristine, prednisolone, [corrected] cyclophosphamide and L-asparaginase), and a prospective comparison between allogeneic bone marrow transplantation (allo-BMT) and chemotherapy alone in patients below 45 years of age. The protocol consisted of one or two courses of induction, four courses of consolidation, and three courses of intensification including 12 month maintenance and six times of central nervous system (CNS) prophylaxis. Of 180 evaluable patients (median age, 43), 125 (69%) achieved complete remission (CR). Predicted overall survival (OAS), event-free survival and disease-free survival (DFS) were 15, 10 and 14%, respectively at the median follow-up period of 62 months. No specific toxicities were observed. Leukocytes < 30,000/microliter, normal karyotype, and blasts < 10% in bone marrow at day 15 of induction therapy were significantly favorable prognostic factors for the achievement of CR, DFS and OAS by univariate analysis. Multivariate analysis showed leukocytes < 30,000/microliter and blasts < 10% on day 15 was a significant factor for the achievement of CR, DFS and OAS. Ph-chromosome was found in 28% (36/130) of patients examined and was one of the worst prognostic factors. All Ph positive patients were predicted to die within 600 days. Allo-BMT was not significantly superior to chemotherapy with respect to DFS (P = 0.226). The overall results were inferior to those of the former ALL87 protocol. As reasons, the older median age of 43 years old (vs. 38 years old) and lower dose intensity, especially of l-asparaginase, etc. were suggested. However, patients with good prognostic factors (leukocyte < 30,000/microliter and age < 30 years old) showed better survival than others (P < 0.0001), and the result was similar to that of older children, the high risk group of childhood ALL, suggesting that ALL could be a disease of single entity, showing higher resistance to chemotherapy as patients become older.
The Japan Adult Leukemia Study Group conducted the ALL-87 study to determine whether response-oriented induction therapy and intensive consolidation and maintenance/intensification therapies could increase complete remission (CR) rate and survival in adult acute lymphoblastic leukemia (ALL). Of 121 patients registered, 116 were evaluated. Patients' ages ranged from 15 to 72 years (median, 38 years). Induction therapy, which consisted of doxorubicin, vincristine, cyclophosphamide, L-asparaginase and prednisolone, was given in a response-oriented individualized fashion. Patients were randomly allocated either to receive or not, intrathecal chemotherapy on day 8 of the induction therapy. Complete remission (CR) was obtained in 97 (83.6%) patients (90.2%) in patients of less than 50 years of age and 67.6% in patients 50 years of age or older). At a median follow-up period of 65 months, the predicted 6-year overall survival and event free survival (EFS) rates of 116 patients were 23.4 and 20.0%, respectively. Predicted 6-year survival and disease-free survival (DFS) rates of 97 CR patients were 28.2 and 24.5%, respectively. By multivariate analysis, patients under 40 years of age (P = 0.002) or those with a platelet count of more than 100,000/microliters (P = 0.004) were significant favorable prognostic factors for obtaining CR, and days to CR less than 50 (P = 0.003), patients under 50 years of age (P = 0.005) were significant favorable factors for longer DFS. There was no significant difference in CR rates and DFS between the two randomized groups according to the intrathecal chemotherapy on day 8. Response-oriented induction therapy produced a high CR rate, but fairly intensive consolidation and maintenance/intensification chemotherapies resulted in only a marginal effect on DFS in adult ALL. Although age is one of the most important prognostic factors in ALL, the outcome was unsatisfactory even in younger adult patients using chemotherapeutic regimen employed in this study.
PURPOSE: We conducted a multicenter study of differentiation therapy with all-trans retinoic acid (ATRA) followed by intensive chemotherapy in patients with newly diagnosed acute promyelocytic leukemia (APL) and analyzed the prognostic factors for predicting complete remission (CR), event-free survival (EFS), and disease-free survival (DFS). PATIENTS AND METHODS: All patients received ATRA until CR. If patients had an initial leukocyte count greater than 3.0 x 10(9)/L, they received daunorubicin (DNR) and behenoyl cytarabine (BHAC). During therapy, if patients showed blast and promyelocyte counts greater than 1.0 x 10(9)/L, they received additional DNR and BHAC. After achieving CR, patients received three courses of consolidation and six courses of maintenance/intensification chemotherapy. RESULTS: Of 198 registered, 196 were assessable (age range, 15 to 86 years; median, 46) and 173 (88%) achieved CR. Multivariate analysis showed that no or minor purpura at diagnosis (P = .0046) and age less than 30 years (P = .0076) were favorable factors for achievement of CR. Predicted 4-year overall survival and EFS rates were 74% and 54%, respectively, and the 4-year predicted DFS rate for 173 CR patients was 62%. Multivariate analysis showed that age less than 30 years (P = .0003) and initial leukocyte count less than 10 x 10(9)/L (P = .0296) were prognostic factors for longer EFS, and initial leukocyte count less than 10.0 x 10(9)/L was a sole significant prognostic factor for longer DFS (P = .0001). CONCLUSION: Our results show that age, hemorrhagic diathesis, and initial leukocyte count are prognostic factors for APL treated with ATRA followed by intensive chemotherapy.
As recurrent chromosome abnormalities in leukemia are highly associated with particular subtypes, the genetic events of specific chromosome alteration must be associated with leukemogenesis and characteristics of the disease. The chromosomal breakpoints involved in inv(16) and t(16;16) have been shown to generate the fusion gene PEBP2beta(CBFbeta)/MYH11. The PEBP2beta/MYH11 fusion transcripts in all 8 patients with M4Eo, 2 of 18 with M4, and one CML in the blastic phase were detected by using RT-PCR and Southern blotting. We demonstrated the marked expression of CD34 and c-KIT (CD117) antigens in myelomonoblastic leukemia cells from all patients carrying this fusion gene, which was in contrast to the patients with M4 but without the fusion gene. These results indicate that immunophenotypic analysis is useful for detection of leukemia with the fusion gene, and that the PEBP2beta/MYH11 fusion gene is involved in immature cells expressing CD34 and c-KIT antigens.
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