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

To evaluate the clinical relevance of multidrug resistance (MDR) phenotype, the intracellular daunorubicin accumulation (IDA) and P-glycoprotein (P-gp) expression were investigated in 87 adult patients with acute leukemia: 69 patients with de novo acute myeloid leukemia (AML), 10 with AML at relapse, and eight with secondary leukemia to myelodysplastic syndromes (MDS-AML). IDA and P-gp expression were determined by double-labeling flow cytometry analysis. Of 87 patients, 36 expressed P-gp (41%). P-gp expression was more frequently observed in AML at relapse and MDS-AML as compared with de novo AML (P = .0001). P-gp expression was significantly associated with CD34 expression (P = .0003) and chromosome 7 abnormalities (P = .027). A significantly reduced IDA was observed in P-gp+ as compared with P-gp- patients (P = .0007). Of the 87 patients, 51 achieved complete remission (CR). A reduced IDA was observed in patients in failure as compared with patients in CR (22% +/- 17% v 42% +/- 21%; P = 10(-4). Twelve of 36 P-gp+ patients as compared with 40 of 51 P-gp- patients achieved CR (33% v 78%; P = 10(-4). The prognostic value of IDA and P-gp expression was confirmed in multivariate analysis. These data suggest that the determination of IDA and P-gp expression may be useful in designing therapy for patients with AML.
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PMID:Predictive value for treatment outcome in acute myeloid leukemia of cellular daunorubicin accumulation and P-glycoprotein expression simultaneously determined by flow cytometry. 753 92

The c-mpl proto-oncogene which encodes a member of the hematopoietic cytokine receptor superfamily has been recently shown to be the receptor for thrombopoietin (TPO), which stimulates megakaryocyte progenitor expansion and differentiation. We studied c-mpl expression by Northern blot analysis, in a large series of 58 MDS. No expression was found in 14 patients with refractory anemia (RA) or with refractory anemia with ring sideroblasts (RARS). In contrast 11/26 (42%) patients with refractory anemia with excess of blasts (RAEB), or with RAEB in transformation (RAEBt), and 8/18 (44%) patients with chronic myelomonocytic leukemia (CMML) expressed c-mpl. In CMML patients, no correlation was found between c-mpl expression and any prognostic factor tested, nor with the course of the disease. In contrast, in RAEB and RAEBt, expression of c-mpl was correlated with high Bournemouth scoring (P < 0.005) and poor survival (P = 0.02) due to leukemic transformation. Forty-five per cent (5/11) of the c-mpl positive patients evolved towards AML with a mean follow-up of 10.5 months, while 13% (2/15) of the c-mpl negative patients developed a secondary leukemia, with a mean follow-up of 21.1 months. Moreover, in RAEB and RAEBt, a significant correlation was observed between c-mpl, CD34, megakaryocyte glycoprotein IIb (GPIIb) expression, and the presence of dysmegakaryopoiesis. These results indicate that patients with RAEB and RAEBt, with high expression of the c-mpl, CD34, and GPIIb genes, may identify a subgroup of patients with particularly poor prognosis, due to an increased risk of secondary leukemia. More aggressive therapy could be justified in these patients.
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PMID:Prognostic value of c-mpl expression in myelodysplastic syndromes. 753 13

The pericentric inversion of chromosome 16 [inv(16)(p13q22)] and t(16;16)(p13;q22) are chromosomal rearrangements frequently associated with AML FAB type M4Eo resulting in the production of a fusion gene CBFB/MYH11. We studied 17 patients with a chromosome 16 abnormality (eight M4Eo, two M1, one M2, three M4 without abnormal eosinophils, three MDS) for the presence of CBFB/MYH11 transcripts using an RT-PCR technique. 10 AML patients with inv(16) tested RT-PCR positive (eight at presentation, one in remission, one in remission and relapse). Three of these patients were originally reported by cytogenetic analysis to have del(16q22) but the positive RT-PCR results prompted a cytogenetic re-examination, resulting in the correction of the reports to inv(16). We show that although inv(16) is closely associated with AML M4Eo, it can also be detected in cases of AML M4 without abnormal eosinophils. Three cases of MDS with inv(16) were also RT-PCR positive. Four patients with other chromosome 16 abnormalities were RT-PCR negative. Four AML patients with inv(16) were studied in remission. All were RT-PCR positive, including one patient in remission for 108 months and one 22 months post allogeneic bone marrow transplant. In the latter two remission patients, RT-PCR evaluation was positive in bone marrow (BM) but not in peripheral blood, suggesting that BM may be the more informative. We conclude that this technique is valuable in the accurate molecular classification of AML, particularly as treatment options may be influenced by such information. Though RT-PCR is highly sensitive in detecting CBFB/MYH11 fusion transcripts during remission, monitoring of minimal residual disease in patients with inv(16) remains to be established.
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PMID:Detection of CBFB/MYH11 transcripts in patients with inversion and other abnormalities of chromosome 16 at presentation and remission. 757 15

Two major classes of therapy-related acute myeloid leukemias (t-AML) and myelodysplastic syndromes (t-MDS) have been described following the use of conventional doses of alkylating agents and epipodophyllotoxins. They are characterized by distinct clinical presentations and chromosomal abnormalities. We report 2 cases of t-AML and 1 case of t-MDS in 3 out of 36 women who underwent high-dose chemotherapy and attempted ABMT for breast cancer. Two patients developed t-AML 4 and 8 months following the initiation of high-dose chemotherapy with or without ABMT. The third patient developed t-MDS 23 months following dose-intensive chemotherapy and ABMT. Cytogenetic studies of the marrow metaphase chromosomes from the two patients who developed t-AML, including FISH analysis in 1 patient, showed a t(9;11)(p22ng,q23) abnormal chromosome 6 (ring chromosome). Neither patient had a preleukemic phase. Cytogenetic studies from the third patient who developed t-MDS showed abnormalities of chromosome 5 (-5) and a derivative of chromosome 17. The use of multiple chemotherapeutic agents in all 3 patients makes it difficult to attribute the development of these cases of t-MDS/t-AML to a single chemotherapeutic agent. The possible role of dose-intensive chemotherapy in the development of these secondary malignancies is discussed.
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PMID:Acute myeloid leukemia and myelodysplasia following intensive chemotherapy for breast cancer. 758 Nov 17

Abnormalities of chromosome 16 in AML include del(16q), inv(16) and t(16;16). These three groups have been categorized together and have been associated with high complete remission (CR) and survival rates following Ara-C-based chemotherapy. We have reviewed the 63 AML or MDS patients with an abnormality of chromosome 16 treated at MD Anderson Cancer Center (MDACC) over the past 18 years. Marked differences in survival and remission duration (RD) were noted between the inv(16) or t(16;16) patients and those with del(16q), whose outcome was no better than other M4 AML or MDS patients treated during the same period. Other differences characterizing del(16q) included a lack of CNS relapses, lower incidences of eosinophilia and M4 FAB subtype. Half the inv(16) patients had additional karyotypic abnormalities. The overall survival and remission duration for those patients were no different from those for patients with inv(16) alone, although the probability of remaining in first CR at 2 years was higher in the inv(16) alone group. There was no difference in overall survival for the 45 patients who received HDAC vs those who did not. The incidence of CNS relapse was, however, markedly reduced for the HDAC patients. Eosinophilia did not correlate with improved survival. We conclude that del(16q) confers a different prognosis from inv(16) and t(16;16) and for the purposes of prognostication or treatment recommendations should no longer be categorized with them. Additional karyotypic changes however, which accompany inv(16) in 50% of cases do not influence the overall outcome compared to patients with inv(16) alone.
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PMID:Cytogenetic and clinical correlates in AML patients with abnormalities of chromosome 16. 759 86

There is compelling evidence that leukemia arises via a multistep process. Molecular analysis of human leukemias, which are typically clonal, commonly shows multiple genetic lesions in a single leukemia including chromosomal translocations, gene amplification, and point mutations, and in several cases the mutational activation of an oncogene and the loss of a tumor suppressor gene have been found in the same leukemic cell. Accumulative evidences suggest that a number of oncogenes and tumor suppressor genes are involved in the hematopoietic tumorigenesis. These mutations can be utilized for molecular diagnosis of human hematopoietic tumors. Among them, detection of chimeric gene generated by chromosomal translocation is especially useful for molecular diagnosis. The t(3;21) (q26;q22) translocation is found usually in blastic crisis of CML and leukemias developed from MDS or hematopoietic proliferative diseases, but never in de novo acute myelocytic leukemia. This raises the possibility that the molecular event underlying the t(3;21) translocation has a critical role in progression from a preleukemic state to a leukemic state. The generation of AML1/EVI-1 chimeric gene has been demonstrated to be consistent in t(3;21)-carrying leukemias. Although target genes remain to be elucidated for both AML1 and EVI-1 as transcription factors, the AML1/EVI-1 fusion protein could work on different set of genes critical to the process of proliferation and differentiation of hematopoietic cells.
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PMID:[Diagnosis of hematological disorders by mutational analysis of oncogenes]. 760 95

Unbalanced translocations as well as interstitial deletions of the short arm of chromosome 12 [del(12p)] are found as recurring chromosomal changes in a broad spectrum of hematopoietic malignancies. These changes result in the hemizygous deletion of genetic material from 12p. We mapped a yeast artificial chromosome containing the TEL gene, a cosmid contig containing part of TEL and a P1 contig containing the KIP1 gene to 12p13. These probes were used for fluorescence in situ hybridization to analyze samples from 47 patients with various hematologic malignancies who had unbalanced translocations (25 patients) leading to loss of 12p or deletions (22 patients) involving 12p13. The patients had acute lymphoblastic leukemia (8 cases), myelodysplastic syndrome (MDS; 11 cases), acute myeloid leukemia (AML; 10 cases), myeloproliferative disorders (4 cases), therapy-related MDS or AML (7 cases), non-Hodgkin's lymphoma (2 cases), and other hematopoietic malignancies (5 cases). All three probes were hemizygously detected in 26 cases and were completely retained in only 9 cases. In 12 cases probes for one of the two genes were deleted, allowing us to map the smallest region of overlap of these deletions to a small genomic region that is bordered on the telomeric side by the TEL gene and on the centromeric side by KIP1. The genomic distance between TEL and KIP1 is estimated to be about 1 to 2 Mbp.
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PMID:TEL and KIP1 define the smallest region of deletions on 12p13 in hematopoietic malignancies. 763 60

Ten patients with acute leukemia after primary myelodysplastic syndrome (MDS-AL) were examined to clarify the biologic nature of the leukemic cells in comparison with that of de novo acute myelocytic leukemia (AML). The morphologic and cytochemical features of the leukemic cells from all these patients corresponded well to those of de novo AML, and they were diagnosed with MDS-AML. Phenotypically, the frequent expression of the lymphocyte activation antigens, CD25 and CD30, was characteristic in MDS-AML. The in vitro response of MDS-AML cells to various growth factors was similar to that of de novo AML cells. Transforming growth factor beta 1 (TGF beta 1) suppressed growth factor-dependent colony formation by normal bone marrow cells, MDS bone marrow cells, and de novo AML cells, but did not inhibit colony formation by MDS-AML cells. The number of TGF beta 1 high-affinity binding sites of MDS-AML samples (< 5 to 47 sites/cell) was markedly lower than that in de novo AML samples (120 to 221 sites/cell). Our results indicate that the reduced TGF beta 1 may represent disregulation of the proliferation system in MDS-AML cells. This is thought to occur during the MDS phase, and may be related to the poorer response shown to conventional chemotherapy of AML.
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PMID:Biologic characteristics of acute leukemia after myelodysplastic syndrome. 768 4

We compared immunogenotypic findings in 73 patients with de novo acute myeloid leukemia (AML) and 30 patients with AML developed in myelodysplastic syndrome (AML post MDS) to determine the biological difference between these hematopoietic neoplasias. Lymphoid-associated antigens were detected in 13 patients with de novo AML, four of whom exhibited rearrangement of the immunoglobulin heavy-chain (IgH) gene. T-cell receptor (TCR) gene rearrangements were detected in 10 patients with de novo AML who did not have lymphoid-associated antigens, none of whom carried rearranged IgH. This group included two AML patients with trilineage dysplasia. Neither lymphoid markers nor IgH rearrangement was detected in any of the 30 patients with AML post-MDS; TCR rearrangements were detected in eight out of 30 patients, TCR-beta rearrangements in six out of 30, and TCR-delta rearrangements in five out of 30. The TCR rearrangement without rearranged IgH in some AML post MDS patients might not be due to a common recombinase activity, and this alteration may link to genomic instability. Some patients with de novo AML also showed this pattern, suggesting a close biologic association between AML post MDS and some patients with de novo AML.
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PMID:Comparison between immunogenotypic findings in de novo AML and AML post MDS. 769 3

Allogeneic bone marrow transplantation is the treatment of choice for many childhood leukemias. The donor of choice-an HLA matched sibling-is only available about 30% of the time. Unrelated donors are an alternative choice. In this report, we describe the results of unrelated donor bone marrow transplants (BMT) in 50 children with leukemia (25 acute lymphoblastic leukemia [ALL], 3 acute myeloid leukemia [AML], 3 juvenile chronic myelogenous leukemia [JCML], 10 chronic myeloid leukemia [CML]) or myelodysplastic syndrome (MDS; 9). The median age of the 31 male and 19 female patients was 9 years (range 2 to 18). Only 13 patients were serologically matched at HLA-A, B, DR, and DQ with their donors; 6 of these were reactive in mixed lymphocyte culture. The other 37 patients were mismatched for one (36 patients) or more (1 patient) HLA antigens. Pretransplant conditioning included cytosine arabinoside, cyclophosphamide, fractionated total body irradiation (TBI) (with lung, liver, and more recently, kidney shielding), and methylprednisolone. High-risk patients also received busulfan. Graft-versus-host disease (GVHD) prophylaxis consisted of T-cell depletion with IgM monoclonal antibody T10B9 plus complement and posttransplant cyclosporine-A. Forty-nine patients (98%) engrafted. Median times to greater than 500 polymorphonuclear leukocytes (PMN)/microL and greater than 25,000 platelets/microL were 18 and 20 days, respectively. Acute GVHD > or = grade II occurred in 16 patients (33%); 13 (81%) of these died. Chronic GVHD developed in 30 of 40 patients at risk, but was extensive in only 5. Event-free survival (EFS) for all patients was 44% +/- 7% (median follow-up was 49 months), and overall survival was 50 +/- 7%. Patients with low-risk disease (ALL or AML in first or second remission and CML in chronic phase) had a better EFS than children with high-risk disease (60% v 34%, P = .07). There was no significant difference in EFS between patients who were serologically matched with their donors (46%) and those who were partially mismatched (43%) (P = .97). These data compare favorably with published reports for children transplanted with HLA-matched sibling donors and should encourage earlier consideration of unrelated donor BMT in children with leukemia or myelodysplasia.
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PMID:Unrelated bone marrow donor transplants for children with leukemia or myelodysplasia. 772 69


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