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)

Gene transfer or gene therapy has advantages in the treatment of a variety of disorders due to its selective expression within specific mammalian cells. Interferon-alpha (IFN-alpha) has been used in the management of leukemia but its diverse adverse activities with multiple potential side effects, possibly unrelated to therapeutic targets, may negatively influence the ability of IFN-alpha to treat this disorder. Therefore, we examined the ability of adenovirus (Ad)-IFN-alpha gene construct to transfect normal (CD34+ cells) and chronic myelogenous leukemia (CML) bone marrow mononuclear cells (BMMNC) and the transient overexpression of IFN-alpha in these cells. Ad-cytomegalovirus promoter driven IFN-alpha (AdCMV-IFN-alpha) at multiple doses was assessed to transfect highly purified CD34+ cells in liquid culture, and optimal transduction of CD34+ cells was achieved using 120 plaque forming units. Flow cytometric determinations revealed that there was no significant difference in cell viability for the 4 h or 24 h transfection periods. Immunoassay of IFN-alpha produced by CD34+ cells shows that IFN-alpha levels increased several fold in transfected cells. Transient expression of the IFN-alpha gene did not suppress proliferation of CD34+ progenitors as indicated by BFU-E or colony forming units-granulocyte-macrophage (CFU-GM) growth. Reverse transcriptase/polymerase chain reaction analysis of RNA from CD34+ harvested CFU-GM progenitor cells demonstrated transient IFN-alpha mRNA expression. Similarly, CML BMMNC were transfected with AdCMV-IFN-alpha under similar conditions as described for CD34+ cells. BMMNC cells exposed to adenovirus for 24 h and 48 h were found to express IFN-alpha at a substantial level. This in vitro data suggest that Ad-mediated gene transfer of IFN-alpha into hematopoietic stem cells can be achieved and that the IFN-alpha gene can be translated into its specific mRNA in CD34 progenitor cells.
 ...
PMID:Adenovirus mediated alpha interferon (IFN-alpha) gene transfer into CD34+ cells and CML mononuclear cells. 2739 20

For the great majority of patients with chronic myeloid leukaemia (CML), the Philadelphia (Ph) chromosome is a specific marker of the malignant clone. The standard method to assess the quality of remission in these patients is cytogenetic analysis of bone marrow derived metaphases. However, the molecular definition of the t(9;22) and its consequences has enabled other tests to be developed that can specifically detect CML cells. Fluorescence in situ hybridization (FISH) analyses chromosomes to detect either the juxtaposition of BCR and ABL sequences or the disruption of these genes; Southern blotting analyses genomic DNA to determine whether the BCR gene is rearranged; reverse-transcriptase polymerase chain reaction (RT-PCR) analyses RNA to determine the presence or absence of BCR-ABL transcripts; Western blotting analyses cell lysates to determine the presence or absence of BCR-ABL protein. Each of these techniques has particular advantages and pitfalls but in general they may be used to replace or at least to reduce the frequency of conventional cytogenetic analysis. Partly because of economic factors and the lack of standardization or effective quality control, these assays are still largely restricted to research laboratories. The sensitivity with which residual leukaemia can be detected suggests that FISH, Southern blotting and Western blotting are likely to be most useful in assessing patient response to interferon-alpha or other forms of treatment that typically induce partial remission. RT-PCR is by far the most sensitive assay and is probably most appropriate for monitoring patients who are in complete remission.
 ...
PMID:Assessing residual leukaemia. 937 71

Philadelphia (Ph) chromosome-positive leukemias, with the bcr-abl gene translocation, have a dismal prognosis. The identification of Ph-positive patients is vitally important because only aggressive therapeutic approaches, such as allogeneic bone marrow transplantation, may result in long-term disease-free survival. Routine diagnostic methods, such as Southern blot analysis and cytogenetics, may lead to false-negative results. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis is considered the most sensitive tool for the detection of the bcr-abl translocation, and it is widely used alone or in combination with karyotyping or Southern blot analysis to identify Ph-positive cases. In this study, we used fluorescence in situ hybridization (FISH) with BCR and ABL double-color probes for detecting Ph-positive leukemias. The FISH results were compared with the results of cytogenetic and RT-PCR analyses in 75 patients with leukemia or other myeloproliferative syndromes (chronic myeloid leukemia, 30; acute lymphoblastic leukemia, 24; acute myelogenous leukemia, 6; essential (hemorrhagic) thrombocythemia, 12; chronic myelomonocytic leukemia, 2; and polycythemia vera, 1). FISH analysis proved to be simple, extremely reliable and sensitive; bcr-abl fusion detection was successful in the presence of all types of molecular junctions i.e., (b2a2, b3a2, and e1a2). Furthermore, a Ph-positive case that proved fusion negative by RT-PCR was identified as positive by FISH. The sensitivity of RT-PCR and FISH related to Ph-positive cases were 97% and 100%, respectively. Regarding specificity, in 4 (5%) of 75 patients, RT-PCR provided false-positive results. Cross-contamination was identified because a new specimen was harvested and reanalyzed when FISH, cytogenetics, and RT-PCR results were contradictory. We believe FISH is an optimal diagnostic method to detect bcr-abl translocation that can be used alone or to validate the results of RT-PCR analysis.
 ...
PMID:A comparative analysis of FISH, RT-PCR, and cytogenetics for the diagnosis of bcr-abl-positive leukemias. 942 14

Fas-R is expressed constitutively in CD34(+) cells of patients with chronic myelogenous leukemia (CML); Fas-R triggering results in decreased proliferation rate due to apoptosis of clonogenic cells. We have already shown that alpha-interferon (IFN-alpha) enhances Fas-R expression on CML progenitor cells, thus increasing their sensitivity to Fas-R agonists. Although it appears that IFN-alpha can prime CML cells for the effects of Fas, the response to IFN-alpha in vivo is not a constant feature in CML patients. We studied the mechanisms of Fas-mediated apoptosis in 11 patients suffering from CML in chronic phase and tried to see whether there was a correlation between in vitro inducibility of apoptosis in CD34(+) CML cells after Fas-R triggering and the clinical response to IFN-alpha. After priming with IFN-alpha, Fas triggering resulted in in vitro suppression of hematopoietic cell growth in seven of eight patients who had optimal hematologic response to IFN-alpha; in the same conditions, no inhibitory response to Fas-R agonist was observed in cells from three of three patients who proved to be poor responders to IFN-alpha. In responders to IFN-alpha, Fas-R agonist induced dose-dependent apoptosis of CD34(+) cells; this effect was associated with a decrease in the bcr/abl protein level. In cells derived from patients with a poor response to IFN-alpha, the rate of apoptosis in culture remained unchanged in the presence of Fas-R agonist and no bcr/abl downmodulation was observed. Finally, we measured bcr/abl mRNA by quantitative reverse-transcriptase polymerase chain reaction (RT-PCR) and found that decreased bcr/abl protein after Fas triggering was not associated with decreased amounts of specific mRNA, a finding which is consistent with a posttranscriptional regulation of the bcr/abl protein expression. It appears that Fas-mediated downmodulation of p210 bcr/abl restores susceptibility to apoptosis of CML cells; in addition, in vitro studies on CML cells may predict response to IFN-alpha treatment.
 ...
PMID:Fas-mediated modulation of Bcr/Abl in chronic myelogenous leukemia results in differential effects on apoptosis. 968 Mar 67

A 40-year-old man had chronic myeloid leukemia (CML) and an apparently normal karyotype. Fluorescence in situ hybridization with a BCR/ABL1-S probe, which is formatted to display a BCR/ABL fusion signal on chromosome 22, gave a positive fusion signal on a chromosome 9. Therefore this patient has a BCR/ABL fusion gene on chromosome 9. The BCR/ABL1-D probe, formatted to display a fluorescent signal for both the reciprocal products of a 9/22 rearrangement, gave a positive fusion signal on the derivatives 9 and 22. These findings favor either a cryptic reciprocal exchange between BCR and ABL loci or the reversal of a Philadelphia translocation. An insertion of BCR next to ABL is ruled out. The reverse-transcriptase polymerase chain reaction provided molecular evidence that a typical CML chimeric product resulting from a fusion of BCR exon 2 with C-ABL exon II, a2b2, is present.
 ...
PMID:A Philadelphia-negative chronic myeloid leukemia with a BCR/ABL fusion gene on chromosome 9. 980 34

The two matrix metalloproteinases (MMPs) Mr 72,000 type IV collagenase (MMP-2, gelatinase A) and Mr 92,000 type IV collagenase (MMP-9, gelatinase B) play key roles in tissue remodeling and tumor invasion by digestion of extracellular matrix barriers. We have investigated the production of these two enzymes as well as the membrane-type MMP (MT1-MMP) and the tissue inhibitors of metalloproteinases (TIMPs) TIMP-1 and TIMP-2 in the bone marrow mononuclear cells (BM-MNCs) of patients with acute myeloid leukemia (AML; n = 24), chronic myeloid leukemia (CML; n = 17), myelodysplastic syndromes (MDS; n = 8), and healthy donors (n = 5). Zymographic analysis of BM-MNC-conditioned medium showed that a Mr 92,000 gelatinolytic activity, identified as MMP-9 by Western blotting, was constitutively released from cells of all patients and healthy individuals examined in this study. In contrast, MMP-2 secretion was found to be absent in all samples from healthy donors but present in 8 of 11 (73%) of the samples from patients with primary AML, 7 of 8 (88%) with secondary AML, and only 1 of 5 (20%) cases with AML in remission, indicating MMP-2 to be produced by the leukemic blasts. MMP-2 release was not detected in CML cell-conditioned medium with the exception of two cases, both patients either being in or preceding blast crisis. In MDS, MMP-2 was found in three of eight (38%) of the patients, two of them undergoing progression of disease within 12 months. Quantitative Northern blot analysis in freshly isolated BM-MNCs showed a relatively low constitutive expression of TIMP-1 in all samples, whereas MMP-9 gene transcription was higher in healthy donors and CML samples, than in AML and MDS. Reverse transcriptase-PCR analysis revealed the presence of TIMP-2 mRNA in the majority of MMP-2-releasing BM-MNCs. MT1-MMP expression was present in most samples of patients with MDS or AML but absent in those with secondary AML and CML. Thus, we have shown that BM-MNCs continuously produce MMP-9 and TIMP-1 and demonstrated that leukemic blast cells additionally secrete MMP-2 representing a potential marker for dissemination in myeloproliferative malignancies.
 ...
PMID:Matrix metalloproteinase production by bone marrow mononuclear cells from normal individuals and patients with acute and chronic myeloid leukemia or myelodysplastic syndromes. 1035 46

Philadelphia (Ph) or BCR/ABL-negative cells with immature phenotype (CD34-positive, DR-negative) can be recovered from patients with chronic myeloid leukemia (CML) in chronic phase. We used the technique described by Berardi et al (Science 1995; 267: 104-108) to select stem cells from marrow or blood of CML patients at diagnosis or during treatment with alpha-interferon. Mononuclear cells (MNC), and in some experiments CD34+ cells, were maintained for 7 days in the presence of 5-fluorouracil (5-FU), stem cell factor and interleukin-3. The number of viable cells recovered after culture was between 7.4 and 70.2 for 10(6) cells plated. These cells exhibited the following phenotype: CD34+, CD117+, CD38-, lineage-, and were able to generate cobblestone areas and secondary colonies in long-term culture (LTC), with a frequency similar to that of cells selected from normal marrow. Study by fluorescence in situ hybridization of LTC cells or secondary colonies showed no evidence of BCR/ABL rearrangement. Reverse transcriptase polymerase chain reaction studies on pooled LTC cells or secondary colonies were also negative. By contrast, LTC cells or secondary colonies obtained from CML CD34+ cells without culture in the presence of 5-FU were always positive for BCR/ABL rearrangement. Finally, 5-FU selected cells were able to engraft NOD/SCID mouse, as human cells were detected in blood and marrow 10 weeks post transplantation, which were BCR/ABL negative by RT-PCR. This method of culture makes it possible to select constantly BCR/ABL-negative cells with capacities of development in LTC assay and of NOD/SCID mouse engraftment.
 ...
PMID:Selection of BCR/ABL-negative stem cells from marrow or blood of patients with chronic myeloid leukemia. 1040 Apr 13

We encountered a 44-year-old woman with suspected chronic myelocytic leukemia (CML) in the acute phase that was difficult to be differentiate from Philadelphia chromosome (Ph)-positive acute lymphoblastic leukemia (ALL). At disease onset, her bone marrow showed an increase in blasts that were negative for myeloperoxydase (MPO) and Positive for CD10, 19, 34, and HLA.DR. Standard type Ph was detected by chromosome analysis, and both major and minor BCR/ABL m-RNA were detected by reverse-transcriptase polymerase chain reaction (RT-PCR) methods. Neutrophil alkaliphosphatase (NAP) score was normal, and neither eosinophilia nor basophilia was observed in peripheral blood. Under a presumptive diagnosis of Ph-positive ALL (L2), the patient was given AdVP (doxorubicin, vincristine, and prednisolone) therapy followed by a regimen of LMVP (L-asparaginase, mitoxantrone, and VP), and obtained a complete remission 2 months later. At that time, FISH analyses of her bone marrow and blood cells no longer detected bone marrow Ph or BCR/ABL fusion gene. A month later, however, the leukemia relapsed with an increase in MPO-positive blasts in bone marrow, and the patient died soon thereafter. We finally concluded that her leukemia was not Ph-positive ALL, but CML in the acute phase at disease onset.
 ...
PMID:[Blast crisis of chronic myelocytic leukemia that was difficult to differentiate from Ph+ acute lymphoblastic leukemia]. 1062 28

Elevated leukotriene (LT)C(4) synthase activity was observed in peripheral blood granulocyte suspensions from patients with chronic myeloid leukemia (CML). Magnetic cell sorting (MACS) with CD16 monoclonal antibodies (mAbs), which were used to fractionate granulocytes from CML patients and healthy individuals, yielded highly purified suspensions of CD16(+) neutrophils. The purity of these cell fractions was verified by extensive morphologic examination. Reverse transcriptase-polymerase chain reaction (RT-PCR) analyses, demonstrating the absence of interleukin-4 messenger RNA (IL-4 mRNA), further confirmed the negligible contamination of eosinophils in these fractions. Notably, purified CML CD16(+) neutrophils from all tested patients transformed exogenous LTA(4) to LTC(4). These cells also produced LTC(4 )after activation with ionophore A23187 or the chemotactic peptide fMet-LeuPhe (N-formylmethionyl-leucyl-phenylalanine). Subcellular fractionation revealed that the enzyme activity was exclusively distributed to the microsomal fraction. Expression of LTC(4) synthase mRNA in CML CD16(+) neutrophils was confirmed by RT-PCR. Furthermore, Western blot analyses consistently demonstrated expression of LTC(4) synthase at the protein level in CML CD16(+) neutrophils, whereas expression of microsomal glutathione S-transferase 2 occurred occasionally. Expectedly, LTC(4) synthase activity or expression of the protein could not be demonstrated in CD16(+) neutrophil suspensions from any of the healthy individuals. Instead, these cells, as well as CML CD16(+) neutrophils, transformed LTA(4) to LTB(4). The results indicate that aberrant expression of LTC(4) synthase is a regular feature of morphologically mature CML CD16(+) neutrophils. This abnormality, possibly associated with malignant transformation, can lead to increased LTC(4) synthesis in vivo. Such overproduction may be of pathophysiological relevance because LTC(4 )has been demonstrated to stimulate proliferation of human bone marrow-derived myeloid progenitor cells. (Blood. 2000;95:1456-1464)
 ...
PMID:Aberrant expression of active leukotriene C(4) synthase in CD16(+) neutrophils from patients with chronic myeloid leukemia. 1066 25

The management of chronic myelogenous leukemia (CML) has become complex due to the availability of improved diagnostic procedures and life-prolonging or even curative treatment strategies that are more successful the earlier they are applied in the course of the disease. This is true for allogeneic bone-marrow transplantation, treatment with interferon alpha (IFN) and Philadelphia-negative stem-cell collections for autografting. Outcome differs according to risk profiles of patients at diagnosis. In addition, molecular techniques for the detection of the BCR-ABL fusion gene or its products, such as the reverse-transcriptase polymerase chain reaction (PCR), Southern blot analysis, or fluorescence in situ hybridization, facilitate accurate diagnosis and the monitoring of residual disease. They allow the individualization of treatment such as early infusion of donor lymphocytes if molecular relapse is detected after allografting, or discontinuation of IFN in the presence of very low BCR-ABL transcript levels). The availability of real-time PCR devices further improves and accelerates the diagnosis and monitoring of residual disease. This article addresses recent developments in drug therapy and allografting, including treatment intensification with low-dose ara C or intensive chemotherapy followed by autografting, introduction of new drugs (such as homoharringtonine or tyrosine kinase inhibitor STI571), progress with unrelated donor transplantations, use of peripheral blood stem cells for allografting, and transplantation without myeloablative conditioning. Tradeoffs between the treatment options will be discussed in the context of the evidence-based guidelines for treating CML, as recently published by the American Society of Hematology. Finally, the new competence network on acute and chronic leukemias will be introduced.
 ...
PMID:Current trends in the management of chronic myelogenous leukemia. 1096 82


<< Previous 1 2 3 4 5 6 Next >>