Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0023467 (acute myeloid leukemia)
 35,200 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Patients with Fanconi anemia (FA) have an extraordinary predisposition to acute myelogenous leukemia (AML). The genetic mechanisms underlying the neoplastic transformation of FA hematopoietic cells are unknown. In this study, we have investigated the molecular features of hematopoiesis in the course of FA at different stages of the disease, including aplastic anemia, myelodysplastic syndrome (MDS), and AML. The analysis focused on defining the clonality status of FA hematopoiesis as well as the putative involvement of N-ras, a dominantly acting oncogene, and p53, a tumor suppressor gene, which are known to play a role in human hematopoietic tumors. Clonality of hematopoiesis was assessed by testing X-chromosome inactivation at the DXS255 locus, which displays different methylation patterns according to the activation status of the corresponding X homolog. Five out of seven FA cases analysed for clonality displayed monoclonal hematopoiesis, including one case at the aplastic anemia stage, three cases with MDS and one with AML. Mutations of the N-ras and p53 genes were studied by a combination of single strand conformation polymorphism (SSCP) analysis and direct sequencing of the PCR product in the bone marrow and/or peripheral blood of 18 FA patients (seven with aplastic anemia, seven with MDS, four with AML). Only normal N-ras and p53 sequences were detected in all cases analyzed. These results suggest that monoclonal hematopoiesis is a frequent finding in the course of FA and may precede the onset of neoplasia in some cases. The genetic mechanisms underlying FA-associated leukemogenesis appear to be independent of N-ras and p53 mutations, which are relatively frequent events in myeloid tumors associated with other hematologic disorders.
 ...
PMID:Clonality studies and N-ras and p53 mutation analysis of hematopoietic cells in Fanconi anemia. 805 73

We analyzed data from 388 subjects with Fanconi anemia reported to the International Fanconi Anemia Registry (IFAR). Of those, 332 developed hematologic abnormalities at a median age of 7 years (range, birth to 31 years). Actuarial risk of developing hematopoietic abnormalities was 98% (95% confidence interval, 93% to 99%) by 40 years of age. Common hematologic abnormalities were thrombocytopenia and pancytopenia. These were often associated with decreased bone marrow (BM) cellularity (75% of cases studied). Clonal cytogenetic abnormalities developed in 23 of 68 persons with BM failure who had adequate studies. Actuarial risk of clonal cytogenetic abnormalities during BM failure was 67% (47% to 87%) by 30 years of age. Fifty-nine subjects developed myelodysplastic syndrome (MDS) or acute myelogenous leukemia (AML). Actuarial risk of MDS or AML was 52% (37% to 67%) by 40 years of age. Risk was higher in persons with than in those without a prior clonal cytogenetic abnormality (3% [0% to 9%] v 35% [0% to 79%]; P = .006). One hundred twenty persons died of hematologic causes including BM failure, MDS or AML and treatment related complications. Actuarial risk of death from hematologic causes was 81% (67% to 90%) by 40 years of age.
 ...
PMID:Hematologic abnormalities in Fanconi anemia: an International Fanconi Anemia Registry study. 784 7

Thirty-one patients (19 males and 12 females; mean age 23.9 years, range 4-41 years) were treated with bone marrow transplantation (BMT) after intensive chemoradiotherapy. Their diagnoses were as follows: chronic myeloid leukemia (CML) in 13, acute myeloid leukemia (AML) in seven, acute lymphocytic leukemia (ALL) in six, myelodysplastic syndrome (MDS) in two, aplastic anemia (AA) in two, and Fanconi anemia (FA) in one. Allogeneic BMT was performed in 28 cases (17 donors were of like sex, 11 were of unlike sex), one patient received syngenic transplant, and one received transplant of cells obtained from an unrelated donor through a computerized international registry in London. Autologous BMT was performed in three patients. BM cells were analyzed cytogenetically at diagnosis, before and serially after BMT (three to nine times). Follow-up ranged from 2 to 55.5 months. Cytogenetic examination was a very useful method for monitoring posttransplantation course in patients with CML or in those who received BM cells of unlike sex. Results of concomitant cytogenetic examinations are reported in detail.
 ...
PMID:Sequential cytogenetic study of patients after bone marrow transplantation. 811 42

This review summarizes both historical and more recent data on the clinical, cellular and genetic features of Fanconi anemia (FA), a rare autosomal recessive disorder. FA patients are characterized by pancytopenia, congenital malformations, growth delay and an increased susceptibility to the development of malignancies, particularly acute myelogenous leukemia. FA cells show chromosomal fragility, slow growth and increased sensitivity to DNA crosslinking agents. FA can be caused by defects in any one of at least four genes. Two general hypotheses have been proposed to explain the underlying defect: loss of a DNA repair function or of a step in the defense toward oxygen toxicity. After many attempts to clone the FA genes, the first one, that defective in group C, has been cloned by complementation of the increased sensitivity of FA(C) cells to mitomycin C and diepoxybutane. This gene (FACC) codes for a novel protein and is ubiquitously expressed. Mutations in various FA(C) patients that cause loss of function have been identified. The review concludes by suggesting directions for future research in FA.
 ...
PMID:Fanconi anemia revisited: old ideas and new advances. 819 59

Fanconi anemia is an autosomal recessive disease characterized by a high risk of developing bone marrow (BM) failure and acute myelogenous leukemia. We studied growth of hematopoietic progenitor cells in long-term BM culture (LTBMC) in 8 persons with Fanconi anemia and BM failure. Although LTBMC were initiated with very few BM cells, an adherent layer formed in cultures from 7 persons. In these cultures, the number of nonadherent cells increased for 10 to 15 days. Cell growth continued until cultures were terminated at day 35 to 40. During the first 2 weeks of culture, most nonadherent cells were differentiated myeloid cells. By days 35 to 40, the adherent layer contained cells able to initiate secondary LTBMCs. These data indicate that hematopoietic precursors cells able to proliferate and differentiate in vitro are present in the BM of persons with Fanconi anemia and BM failure. They suggest that mechanisms other than absent precursor cells are responsible for BM failure in Fanconi anemia.
 ...
PMID:Long-term bone marrow culture in persons with Fanconi anemia and bone marrow failure. 828 33

We report the clonal chromosome abnormalities of five patients with Fanconi anemia (FA). In one with myelodysplastic syndrome (MDS), an abnormal clone was present in the bone marrow (BM): 47,XY,trp(1)(q32q44), + mar. Two had acute myeloblastic leukemia (AML), one with monosomy 7 and the other with 46,XY,add(1)(p34),del(7)(p13). In the two others without signs of MDS or AML, pseudodiploidy with 46,XX,-5, +8 and 46,XX, +5, -21 were present, respectively. The significance of these abnormalities is discussed.
 ...
PMID:Chromosome abnormalities in bone marrow of Fanconi anemia patients. 843 15

Preparative regimens containing busulfan (BU) followed by allogeneic bone marrow transplantation (BMT) were used in 27 consecutive patients with myelodysplastic syndromes (MDS). The median age was 33 years (range, 4 to 54). Ten were female and 17 male. Sixteen patients had primary MDS, 11 other patients had antecedent hematologic diseases or developed MDS after cytotoxic and/or radiation therapy. Six patients had leukemic transformation and received antileukemic therapy before BMT. Pre-BMT cytogenetic studies showed complex chromosomal abnormalities in 13 patients, a simple abnormality in 5 patients, and normal chromosome in 8 patients. Three BU-based preparative regimens were used: 1 patient received BU 4 mg/kg orally (PO) daily for 4 days and cyclophosphamide (CY) 50 mg/kg intravenously (IV) daily for 4 days (BUCY-4); 24 patients received BU 4 mg/kg PO daily for 4 days, cytosine arabinoside (ara-C) 2 g/m2 IV every 12 hours for 4 doses, and CY 60 mg/kg IV daily for 2 days (BAC); and 2 patients with preceding Fanconi anemia received BU 2 mg/kg PO daily for 4 days followed by total lymphoid irradiation of 5 Gy. Seventeen of 27 patients are alive with no evidence of disease. Ten patients have died: 2 from hepatic veno-occlusive disease, 3 from sepsis, 1 from a cerebral bleed, 1 from a massive gastrointestinal (GI) bleed associated with acute graft-versus-host disease, 1 from hemolytic uremic syndrome with adult respiratory distress syndrome, 1 from bronchiolitis obliterans, and the only patient who did not engraft died from acute myeloid leukemia. Regimen-related toxicities (RRT) include GI tract (diarrhea, 14; stomatitis, 11), liver (9), cardiac (1), and skin (5). Patients who received a genotypically matched marrow graft had a significantly better disease-free survival (DFS) than patients who received a nongenotypic marrow graft (P = .02). The Kaplan-Meier analysis projects an overall DFS of 56% +/- 13% and 78% +/- 10% for patients who received a genotypically matched marrow graft. With the exception of a child who did not engraft, there was no relapse of MDS or leukemia. Excellent DFS, acceptable RRT, and the ease of administration are advantages of this regimen.
 ...
PMID:Busulfan-based regimens and allogeneic bone marrow transplantation in patients with myelodysplastic syndromes. 847 79

Cytogenetic analysis of bone marrow cells of a 63-year-old male Caucasian patient with polycythemia vera (PV) who developed anemia, thrombocytopenia, and increased granulocytic immaturity revealed a 47, X,der(Y) t(Y;1)(q12;q12),+9 karyotype. The breakpoint in chromosome 1 appeared to map to q12 and not to q21, as has been described in previous reports without FISH confirmation. In the 4 years before this transition the patient was polycythemic and, accordingly, treated with phlebotomy and three short courses of busulfan. The cytogenetic picture observed has been described before in seven patients: three with PV, three with myelodysplasia, and one with Fanconi anemia. In 5/7 cases, like in our patient, the abnormality was observed during transition of the disease into either myelodysplasia or AML.
 ...
PMID:Derivative (y)t(Y;1)(q12;q12),+9 in a patient with polycythemia vera during transition into myelodysplasia. 863 Sep 87

Patients with Fanconi anemia (FA) commonly develop bone marrow failure, which may evolve to myelodysplasia or acute myeloid leukemia (AML). Treatment of these patients is complicated by their marked hypersensitivity to DNA cross-linking agents. In this report we describe the results of allogeneic unrelated donor bone marrow transplantation in seven FA patients, using a low-dose cyclophosphamide (40 mg/kg) and TBI (400-450 cGy) conditioning regimen. Two patients had bone marrow failure with normal chromosomes and no dysplasia prior to transplant. The remaining five had clonal chromosomal abnormalities. One patient had refractory anemia with excess blasts in transformation and two had early AML with 20 and 25% blasts, respectively. Two patients died early (before day 28) without hematological evidence of engraftment, one of veno-occlusive disease and one of infection (fungal). Four of the remaining five patients achieved sustained engraftment after the first marrow infusion; one patient had secondary graft failure requiring repeat marrow infusion but subsequently achieved engraftment. Of five evaluable patients, three had mild (grades I-II) acute GVHD and two had grade IV GVHD, which was fatal in both cases. Two of three evaluable surviving patients have chronic GVHD controlled with immunosuppression. Three patients survive 9 months to 3 years post-unrelated donor BMT: two who had early leukemia and one with severe aplasia at the time of transplant. These data indicate that unrelated donor BMT can be performed successfully in FA patients using cyclophosphamide 40 mg/kg and TBI 400 to 450 cGy, even after evolution to early leukemia. However, significant problems with both GVHD and engraftment remain. Future studies will evaluate the role of T cell depletion in improving the results of unrelated donor marrow transplantation in FA patients.
 ...
PMID:Unrelated donor bone marrow transplantation for Fanconi anemia. 867 53

Fanconi anemia (FA) is a complex autosomal recessive disease with hematologic manifestations characterized by a progressive hypoplastic anemia, hypersensitivity to clastogenic agents, and an increased incidence of acute myelogenous leukemia. The cDNA that corrects one of four FA complementation subtypes, named Fanconi anemia Type C (FAC) has recently been identified. We constructed a a simplified recombinant retrovirus (vMFGFAC) encoding only the FAC cDNA, and tested its ability to correct the FAC defect in a lymphocytic cell line and primary mobilized blood progenitor cells. In addition, the gene transfer efficiency using a clinically applicable gene transfer protocol into normal primitive hematopoietic progenitor cells, high proliferating potential colony forming cells (HPP-CFC), derived from CD34+ purified cord blood cells was examined. The gene transfer efficiency was significantly enhanced when cells were transduced with supernatant while adherent to a 30/35 KD fragment of fibronectin, FN30/35, and was similar to efficiency obtained by coculture with retrovirus packaging cells. Transduction of an FAC deficient lymphoid cell line with vMFGFAC supernatant resulted in an enhanced cell viability, and G-CSF mobilized peripheral blood cells from an FAC-deficient patient transduced with the vMFGFAC virus demonstrated enhanced progenitor cell colony formation. These data indicate that the vMFGFAC virus allows functional complementation of FAC in lymphoblasts and primary hematopoietic progenitors, and that primitive cord blood hematopoietic stem/progenitor cells can be transduced at an efficiency comparable to protocols using cocultivation if adherent to FN 30/35 fragment.
 ...
PMID:Correction of Fanconi anemia type C phenotypic abnormalities using a clinically suitable retroviral vector infection protocol. 872 7


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>