Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0023473 (chronic myeloid leukemia)
 18,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

M195, a mouse monoclonal antibody reactive with the early myeloid antigen CD33, has been shown to target leukemia cells in patients and to reduce large leukemic burdens when labeled with 131I. A complementarity-determining region-grafted, humanized version (HuM195) has demonstrated similar targeting of leukemia cells without immunogenicity. We have studied two applications of therapy with 131I-M195. First, to intensify therapy prior to bone marrow transplantation (BMT), we combined 131I-M195 with busulfan and cyclophosphamide. Fifteen patients received first BMT for relapsed or refractory acute myelogenous leukemia or accelerated or blastic chronic myelogenous leukemia; four received second BMT for relapsed chronic or accelerated chronic myelogenous leukemia. Doses of 131I-M195 ranged from 120 to 230 mCi/m2. Few toxicities could be attributed to 131I-M195 therapy, and all patients engrafted. Eighteen patients achieved complete remission. Among those patients receiving first BMT, three have remained in unmaintained remission for 18+ to 29+ months. Six patients relapsed, including one with isolated central nervous system disease 32 months after BMT. Ten patients died in complete remission of transplant-related complications. Second, we studied whether 131I-M195 could reduce minimal residual disease and prolong remission and survival durations safely in patients with relapsed acute promyelocytic leukemia after they attained remission with all-trans-retinoic acid. Seven patients were treated with either 50 or 70 mCi/m2 131I-M195. Toxicity was limited to myelosuppression. As a measure of minimal residual disease, we monitored PML/RAR-alpha mRNA by reverse transcription PCR. Six patients had positive reverse transcription PCR assays prior to receiving 131I-M195; two converted transiently to negative. Median disease-free survival and overall survival of the seven patients were 8 (range, 3-14.5) months and 28 (range, 5.5-43+) months, respectively. This regimen compares favorably with others for relapsed acute promyelocytic leukemia. In an effort to avoid nonspecific cytotoxicity associated with 131I in future trials for minimal residual disease, we have conjugated short-range, alpha particle-emitting radioisotopes to HuM195 using a bifunctional chelate, 2-(p-isothiocyanatobenzyl)-cyclohexyldiethyl-enetriaminep entaacetic acid, with high efficiency and specific activities. 212Bi-HuM195 has demonstrated dose- and specific activity-dependent killing of HL60 cells in vitro. Injection of 213Bi-HuM195 into healthy BALB/c mice produced no effects on weight or viability.
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PMID:Radiolabeled anti-CD33 monoclonal antibody M195 for myeloid leukemias. 749 68

The WT 1 gene has been isolated as a tumor suppressor gene of Wilms' tumor. Using reverse transcriptase-polymerase chain reaction (RT-PCR), relative levels of the WT 1 gene expression was examined in 87 patients with acute leukemia, 25 with chronic myelogenous leukemia (CML), and 24 with non-Hodgkin's lymphoma (NHL). Significant levels of the WT 1 gene were expressed in all leukemia patients, and for CML the levels increased as the clinical phase progressed. No point mutations were found in the WT 1 gene when samples from 15 acute leukemia patients were subjected to PCR single-strand conformation polymorphism analysis. In striking contrast to acute leukemia, the levels of WT1 gene expression for NHL were significantly low or even undetectable. The levels of WT 1 gene expression inversely correlated with the prognosis of acute leukemia. The quantification of the WT 1 gene expression made it possible to detect minimal residual disease (MRD) in acute leukemia regardless of the presence of absence of tumor-specific DNA markers. Simultaneous monitoring of MRD by RT-PCR using primers for specific DNA markers in four patients (two AML-M3 with PML/RAR-alpha, one AML-M2 with AML1/ETO, and one CML with bcr/abl) detected MRD comparable to that obtained from quantitation of WT 1 gene expression. In a patient with acute promyelocytic leukemia, the limits of leukemic cell detection by RT-PCR using either WT 1 or PML/RAR-alpha gene primers were 10(-3)-10(-4) and 10(-4) for bone marrow, and 10(-5) and 10(-4) for peripheral blood, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[WT 1 and leukemia]. 764 50

The very rapid development of techniques based on use of the polymerase chain reaction (PCR) for characterizing molecular lesions in leukaemia and lymphoma mow offers the opportunity for monitoring residual disease at a sensitivity of one malignant cell in 10(5) or 10(6) normal cells. Maximal specificity is achieved when the DNA sequences amplified are truly leukaemia-specific (i.e. BCR/ABL in CML, PML/RAR-alfa in APL, AML1/ETO in t(8; 21) AML and CBFB/MYH1 in inv(16) AML). A good level of sensitivity may also be achieved by using immunoglobin heavy chain (IGH) and T-cell receptor (TCR) gene rearrangements if a clonospecific probe can be generated. For clinical purposes the crucial issues are the following: can PCR techniques be used for confirmation of diagnosis and evaluation of extent of disease? Can PCR data obtained be developed to quantitate the PCR product and thereby increase its predictive value? These and other issues are still a matter of debate and several studies are presently in progress to address these points.
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PMID:Minimal residual disease detection in human leukemias: biologic and clinical significance. 765 31

Molecularly defined specific chromosomal translocation in leukemia allows detection of minimal residual leukemia cells by the reverse transcription-polymerase chain reaction (RT-PCR). However, the positivity of the specific fusion transcripts in chronic myelogenous leukemia and acute myelogenous leukemia with t(8;21) is reportedly not directly correlated with the predictability of relapse. We analyzed seven patients with acute promyelocytic leukemia (APL) in hematological remission for PML-retinoic acid receptor alpha (PML-RAR alpha) fusion transcripts by RT-PCR with the sensitivity level of one APL cell in 10(5) bone marrow mononuclear cells. Two of the four patients with chemotherapy-induced remission had detectable PML-RAR alpha only before treatment. In the other two patients with chemotherapy-induced remission, the PML-RAR alpha was detectable when their remission was first confirmed and became negative after consolidation chemotherapy. Two patients were resistant to chemotherapy and achieved remission by all-trans-retinoic acid; PML-RAR alpha was detectable in them for a few months during consolidation chemotherapy. Two patients whose PML-RAR alpha had become continuously positive had relapse 2 and 8 months later, but the other five patients with continuously negative or only transiently positive PML-RAR alpha remained in remission during follow-up for 11 to 35 months. These findings suggest the relevance of detectable PML-RAR alpha by RT-PCR to the predictability of relapse in acute promyelocytic leukemia.
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PMID:PML-RAR alpha fusion transcripts by RNA PCR in acute promyelocytic leukemia in remission and its correlation with clinical outcome. 785 39

With the recent advances in molecular technology, diagnostic procedures of the diseases at a DNA level have been introduced in hematological fields. The diagnostic methods used are Southern blotting to detect gene rearrangements, Northern blotting to find gene expressions, RT-PCR (reverse transcriptase-polymerase chain reaction) to identify transcribed fusion messages, and PCR-SSCR (single strand conformation polymorphism) to detect mutated genes. Rearrangements within major Bcr (breakpoint cluster region) were observed in almost all cases in chronic myelogenous leukemia, and breakpoint were found within minor Bcr in Philadelphia-positive leukemia. The rearrangements within the second intron of the retinoic acid receptor-alpha and sixth intron (bcr 1), third intron (bcr 3) and sixth exon (bcr 2) of the PML gene were detected in all cases with acute promyelocytic leukemia. In malignant lymphoma, the rearrangements of immunoglobulin and T-cell receptor genes, and new genes such as Bcl-1, Bcl-2, Bcl-5, Tal-1, and Tal-2 were also reported and rearrangements of the Bcl-5 gene were found in this study using Bcl-5 specific probe which we have cloned. Point mutations and deletions of the genes involved in the coagulation and fibrinolysis system have been reported. One base insertion resulting in elongation of carboxy terminal region and one amino acid deletion in alpha 2-plasmin inhibitor gene were found in two cases of its deficiency. Further study revealed that mutated proteins were retained in the endoplasmic reticulum in the cells. With the development of the PCR method, identification of gene mutation is gradually carried out as a routine work.
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PMID:[Molecular study of hematological diseases]. 791 42

This paper describes the treatment of promyelocytic blast crisis of chronic myelogenous leukemia with all-trans-retinoic acid (ATRA). The patient, a 22-year-old male, was diagnosed to have APL and had been treated with busulfan and then with three and half years interferon (IFN) alpha in the chronic phase. A cytogenetic study of blast cells showed the t(1;17) (p11;q11) translocation as the second chromosomal abnormality without morphological abnormality of chromosome 15. Molecular analysis showed cells to have a chimera gene consisted of PML and retinoic acid receptor alpha genes. Though maturation and differentiation of leukemic cells were seen after ATRA therapy, hematological complete remission did not occur. The ineffectiveness of ATRA may be dut to different pathological conditions from de novo APL, or progressive reduction in plasma ATRA concentration as reported by Muindi et al. When our case was compared with a similar case reported by Wiernick et al., both cases were treated with IFN alpha in the chronic phases, had no t(15;17) translocation involving No.1 chromosome abnormality and did not develop complete remission after ATRA therapy.
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PMID:[Treatment of promyelocytic blast crisis of chronic myelogenous leukemia with all-trans-retinoic acid]. 813

We performed clonality studies of hemopoietic reconstitution in 24 female patients (pts) with leukemias characterized by specific tumor markers. Thirteen pts had Acute Promyelocytic Leukemia (APL) with rearrangements of the RAR-a and PML genes, 8 BCR rearranged (BCR+)/Ph+ Chronic Myeloid Leukemia (CML) and 3 BCR+/Ph+ Acute Lymphoid Leukemia (ALL). Bone marrow (BM) DNA samples were obtained at diagnosis and at remission after Southern blot documented suppression of specific markers. The clonal or non-clonal nature of hemopoietic reconstitution was assessed by hybridizing the same DNAs with the M27 beta probe, in order to detect methylation differences at the X-linked DXS255 locus. Twenty four pts showed a polyclonal methylation pattern at remission, whereas in 3 cases an apparently clonal pattern was observed despite no evidence of specific gene rearrangement. In 2 of these 3 cases, however, DNAs derived from non-affected tissues (T lymphocytes, skin and BM fibroblasts) revealed the presence of the same DXS255 unmethylated allele detected at diagnosis, while in the third case we found the same apparently clonal pattern in blood mononuclear cells obtained from her healthy female BM donor. These data indicate that polyclonal hematopoiesis occur in APL and CML pts after therapy induced suppression of specific tumor markers, and that unbalanced or aberrant X chromosome methylation patterns are observed in some cases, most likely reflecting constitutional features.
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PMID:Polyclonal hemopoiesis in leukemia patients following molecularly documented remission. 815 81

Hybrid fusion genes are specific tumor markers of several leukemic subtypes. The use of reverse transcription-polymerase chain reaction (RT-PCR) to amplify chimeric cDNAs allows sensitive detection of the neoplastic clone for diagnostic and monitoring studies in these leukemias. Nonetheless, the clinical relevance of minimal residual disease (MRD) evaluation by PCR remains controversial. In this study, 9 patients (pts) with acute promyelocytic leukemia (APL) in long-term remission for 4 to 12 years were analyzed for the presence of MRD by RT-PCR amplification of the specific PML/RAR-alpha fusion gene. Seven pts had been treated with conventional chemotherapy (CHT) alone, 1 had undergone allogeneic bone marrow transplantation (BMT), and 1 autologous BMT as consolidation therapy after CHT. In 8 cases, the presence of the t(15;17) rearrangement could be documented in diagnostic BM specimens by cytogenetic and/or molecular analysis. A two-rounds "nested" RT-PCR assay with sensitivity levels of 1 in 10(5) was used to analyze BM samples collected at 32 to 141 months from the achievement of complete remission (CR). In no cases were residual PML/RAR-alpha transcripts detectable in these remission controls. All patients are in unmaintained CR at 48 to 154 months from CR and at 6 to 17 months from PCR evaluation. These results suggest that long-term survival of APL is associated with eradication of cells carrying the specific PML/RAR-alpha rearrangement, indicating that PCR negativity should be considered the therapeutic goal in these patients. Our findings further strengthen the clinical relevance of PCR monitoring studies in APL, as opposite to other leukemic subtypes (chronic myeloid leukemia and acute myeloid leukemia-M2) in which the prognostic significance of PCR evaluation is unclear.
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PMID:Absence of reverse transcription-polymerase chain reaction detectable residual disease in patients with acute promyelocytic leukemia in long-term remission. 826 Jun 93

RT-PCR assays used to detect acute promyelocytic leukemia (APL) are generally considered less sensitive than those for other hematological malignancies, such as CGL. Most patients with APL express del(17q)-derived RAR alpha-PML transcripts as well as the putative leukemogenic PML-RAR alpha associated with add(15q). We have found that a nested RT-PCR for RAR alpha-PML affords greater sensitivity than that for PML-RAR alpha, particularly in patients with the commonest breakpoint pattern. Therefore, we have evaluated both assays in parallel to monitor a group of 12 de novo APL patients who relapsed despite treatment with both all-trans retinoic acid (ATRA) and chemotherapy. 5' (bcr 3) breakpoints in PML were over represented among the group and three patients had complex cytogenetic abnormalities suggesting both factors may increase the risk of relapse. The RAR alpha-PML assay changed the PCR status of two patients in morphological remission; in both cases disease contamination of bone marrow harvest specimens was detected. Although parallel assessment of PML-RAR alpha and RAR alpha-PML can enhance minimal residual disease detection in APL, this study demonstrates that treatment strategies involving determination of PCR status post-consolidation, even using RAR alpha-PML in addition to the more conventional PML-RAR alpha assay will fail to identify all patients at risk of relapse. Whether the duration of PCR positivity is a helpful prognostic indicator in those patients who ultimately become PCR negative is being addressed by
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PMID:Minimal residual disease detection in acute promyelocytic leukemia by reverse-transcriptase PCR: evaluation of PML-RAR alpha and RAR alpha-PML assessment in patients who ultimately relapse. 855 40

Fluorescent in situ hybridization (FISH) is a rapid, sensitive and reliable method for the identification of complete chromosomes, or segments of them, during metaphase or nuclear interphase. The present study shows the results of the analysis of 32 bone marrow aspirates from patients with malignant hematological diseases (11 AML, 7 ALL, 12 CML and 2 CLL), referred to the Medical Genetics Unit of the Faculty of Medicine, Zulia University, Maracaibo, Venezuela between 1994 and 1996. All samples were studied by conventional and molecular techniques (FISH), using probes of total chromosomes, alpha-satellites and locus specific. In patients with AML and ALL and FISH technique detected clonal chromosomal abnormalities, that were not found by the conventional cytogenetic technique. Furthermore, the PML-alpha RARA complex was identified in the promyelocytic acute leukemias. The presence of the molecular complex ABL-BCR was also demonstrated in CML. The present study demonstrates the usefulness of the FISH technique in the detection of clonal chromosomal abnormalities, which are important when considering the clinical care of patients with these pathologies.
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PMID:[Clonal chromosome abnormalities in malignant hematological diseases using fluorescence in situ hybridization]. 970 20


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