Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tyrosine kinase has an important role with regard to self-renewal and as a comitogen in the movement of stem cells out of the haemopoietic stem cell pool into the progeny pool. The present investigation has an objective to evaluate the protein tyrosine kinase (PTK) activity of bone marrow derived pluripotent cells before and after application of biological response modifiers (BRMs) in normal and leukaemic mice. The PTK activity of the cytosolic fraction of bone marrow cells has been determined by the assay kit based on per-oxidase labeled substrate analog and biotin-streptavidin expression. A consequent cell population kinetic study has also been conducted. Results showed a higher activity in the cells of leukaemic mice, which under the influence of interleukin-2 (IL-2) and the non-specific BRM sheep erythrocytes (SRBC) undergo further activation. Interferon-gamma (IFN-gamma) when administered alone showed a suppressive effect and the combination of the three manifested a resultant suppression. Corresponding migration (cell population kinetics) of the bone marrow cells (BMC) also correlated well with the PTK activity of the cells concerned. The observations indicated that the pluripotent BMCs are under regulated control of the PTK activity, which can be manipulated by selective BRMs. The data also suggested the therapeutic benefit of IFN-gamma along with chemotherapeutics against leukaemia and that of IL-2 and SRBC during bone marrow failure.
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PMID:Role of biomodulators and involvement of protein tyrosine kinase on stem cell migration in normal and leukaemic mice. 1270 33

The aim of this study was to validate the application of a commercially available multiplex reverse transcription polymerase chain reaction (RT-PCR) assay [Hemavision-7 System] for the seven most common leukemia translocations for routine molecular diagnostic hematopathology practice. A total of 98 samples, comprising four groups, were evaluated: Group 1, 16 diagnostic samples molecularly positive by our existing laboratory-developed assays for PML-RARalpha/t (15;17) or BCR-ABL/t (9;22); Group 2, 51 diagnostic samples negative by our laboratory-developed assays for PML-RARalpha/t (15;17) or BCR-ABL/t (9;22); Group 3, 21 prospectively analyzed diagnostic cases, without prior molecular studies; and Group 4, 10 minimal residual disease (MRD) samples. Analysis of the two previously studied cohorts (Groups 1 and 2) confirmed the diagnostic sensitivity and specificity of the multiplex assay with regard to these two translocations. Additionally, however, in the "negative" Group (Group 2) the assay revealed three unanticipated translocations (CBFbeta-MYH11, BCR-ABL, and MLL-AF4), two of which were confirmed on cytogenetics. Analysis of the prospective cohort demonstrated that the assay was cost-effective and amenable to standard laboratory practice, with an identically sensitive MRD detection rate to that of our laboratory-developed tests. Virtually all of the results obtained were consistent with the phenotype and karyotype by conventional methods. This study illustrates the utility of a kit-based multiplex RT-PCR assay for the molecular diagnosis and monitoring of leukemias and reinforces the complementary roles of molecular testing and cytogenetics in diagnostic hematopathology.
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PMID:Multiplex RT-PCR for the detection of leukemia-associated translocations: validation and application to routine molecular diagnostic practice. 1457 82

To investigate the effect of cyclin G1 antisense oligodeoxynucleotide (ASON) with liposomal transfection on mediating proliferation of HL-60 cell, the cyclin G1 ASON with liposomal transfection was used in vitro in co-culture with HL-60 cell, the protein and mRNA expression levels of cyclin G1 were measured by immunocytochemistry assay and RT-PCR. The cell apoptosis was detected by electron microscopy, in situ cell apoptosis detection kit (POD), DNA gel electrophoresis and flow cytometry (FCM). The results showed that in the cyclin G1 ASON group the protein and mRNA expression of cyclin G1 were significantly inhibited as compared with sense oligodeoxynucleotide (SON) group and blank group. When the ASON concentration increased, the proliferation ratio of HL-60 cell and CFU of HL-60 were also significantly inhibited. There was apoptosis of HL-60 cell. In conclusion, cyclin G1 ASON can specifically inhibit its protein and mRNA expression levels as well as the HL-60 cell proliferations and can accelerate the apoptosis of leukemia cells with concentration-dependent effect of ASON.
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PMID:[Proliferation regulation effect of cyclin G1 antisense oligodeoxy-nucleotides with liposomal transfection on HL-60 cell]. 1498 68

6-Mercaptopurine (6-MP) and its prodrug azathioprine (AZA) are well known for their lymphocytotoxic and bone marrow suppressive effects in the management of patients with leukemia. Although their immunosuppressive properties are mediated by the active AZA antimetabolite 6-thioguanine (6-TG), its mechanism of action is largely unknown. In IBD, a significant inverse correlation has been shown between erythrocyte 6-TG metabolite levels and disease activity, further supporting the proposed immunosuppressive role for 6-TG. Since leukocytes possess quantitatively different purine metabolic pathways compared to erythrocytes, this study aims to measure lymphocyte DNA 6-TG metabolites and correlate levels with the INF-gamma and IL-10 cytokine profile in patients with Crohn's disease (CD). Forty-six adult patients with CD, either naive (17) or on long-term (>4-month) AZA therapy (29), had erythrocyte and lymphocyte DNA 6-TG levels measured by reverse-phase HPLC under UV detection (6-TG, 340 nm). Lymphocyte DNA 6-TG was expressed as picomoles per milligram of DNA. Lymphocyte DNA 6-TG metabolite levels were correlated with INF-gamma and IL-10 cytokine profiles using the OptEIA kit (Pharmigen). Lymphocyte DNA 6-TG metabolite levels correlate with erythrocyte 6-TG levels (P < 0.03) but not total patient leukocyte levels. Erythrocyte 6-TG metabolite levels correlated (P < 0.01) inversely with INF-gamma but not IL-10 cytokine levels. This study suggests a preferential dampening of the TH1 response on exposure to 6-TG and a possible immunosuppressive mechanism of action for AZA. Future studies are needed to determine if cytokine profiles can be used to predict recalcitrant CD to AZA therapy.
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PMID:Peripheral blood mononuclear cell DNA 6-thioguanine metabolite levels correlate with decreased interferon-gamma production in patients with Crohn's disease on AZA therapy. 1499 47

The Kasumi-1 cell line is an intensively investigated model system of Acute Myeloid Leukemia with t(8;21) translocation, that represents 1 of the 2 main subtypes of Core Binding Factor Leukemia (CBFL). Since establishment in 1991 the Kasumi-1 cell line has provided the tool to study the peculiar molecular, morphologic, immunophenotypic findings of AML with t(8;21) and the functional consequences of the AML1-ETO fusion oncogene on myeloid differentiation. Leukemogenesis involves multiple genetic changes and, as suggested by murine experiments and other findings in humans, AML1-ETO expression may not be sufficient for full blown leukemia. In agreement with the "two hits" model of leukemogenesis, based on the cooperation between 1 class of mutations that impair hematopoietic differentiation and a second class of mutations that confer a proliferative and/or survival advantage to hematopoietic progenitors an activating mutation in the tyrosine kinase domain of the c-kit gene was identified in the AML1/ETO expressing Kasumi-1 cell line. The dosage of the Asn822Lys mutated allele was shown to be about 5-fold compared to the normal allele and c-kit amplification was found to map to minute 4cen-q11 marker chromosomes, likely derived from the extra chromosome 4 recorded in the newly established cell line. The combination of t(8;21) and trisomy 4 leading to enhanced dosage of a mutated kit allele is a feature of a few CBFL patients reproduced by the Kasumi-1 cell model. The Kasumi-1 cell line, paralleling the commitment stage of CBF leukemia also provides a valuable resource to investigate the effect of tyrosine kinase kit mutant on the main KIT-regulated signal transduction pathways, i.e. MAPK, PI3K/AKT and STAT3 and the diverse inhibitory effect exerted by STI 571 on these KIT mutant activated pathways. PI3K-dependent activation of AKT and STAT activation was observed in Kasumi-1 cells. Contrary to the expectations for an amplified tyrosine kinase kit mutant, we found that STI 571 inhibited KIT Asn822Lys tyrosine phosphorylation and downstream JNK and STAT3 effectors in Kasumi-1 cells, but had no effect on constitutive activation of AKT, suggesting that signaling by tyrosine kinases other than KIT may be responsible for its activation in Kasumi-1 cells. Independent findings on the same model system provide complementary insights into designing strategies for treatment of CBF leukemia associated with mutations in the KIT catalytic domain.
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PMID:The Kasumi-1 cell line: a t(8;21)-kit mutant model for acute myeloid leukemia. 1562 9

Chronic lymphocytic leukemia (CLL) is the most common adult leukemia. Prognosis is related to clinical staging and cytogenetic findings. Conventional cytogenetic analysis of CLL reveals abnormalities in approximately one third of patients. Fluorescence in situ hybridization (FISH) is analytically more sensitive than conventional cytogenetics for specific chromosomal abnormalities. To evaluate the usefulness of FISH in CLL, a study of 100 CLL patients comparing conventional cytogenetics and a commercially available multiprobe FISH kit was undertaken. One hundred consecutive CLL patients (67 males, 33 females) were studied. The male-female patient ratio was approximately 2.0 to 1. Twenty-eight percent (28/98) of patients had abnormal karyotypes by conventional cytogenetics (one patient had no specimen for conventional cytogenetics and one had an unanalyzable karyotype), and of those 19/100 (19%) had more than one chromosomal abnormality. Sixty-four percent (64/100) of the patients were positive for at least one abnormality by the FISH probes used. The following abnormalities were noted with FISH: 11q22 ATM, 23/100 (23%); trisomy 12, 11/100 (11%); 13q14.3, 40/100 (40%); 13q34.3, 4/100 (4%); 17p13.1, 12/100 (12%). Conventional karyotypes revealed 2 patients with abnormalities of chromosome 6 (which FISH did not address); 11 with abnormalities of 11 or 11q; 6 with trisomy 12; and 4 with abnormalities of 17. Aberrations of 11q and 17p are reported to have a poor prognosis in CLL. FISH can identify abnormalities missed with conventional cytogenetics and is helpful in diagnosis, prognosis, and evaluation of therapy for CLL. Additional chromosomal changes are identified with conventional cytogenetics that are not addressed by the multiprobe FISH kit.
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PMID:The value of fluorescence in situ hybridization in the diagnosis and prognosis of chronic lymphocytic leukemia. 1577 12

KRN321, darbepoetin alfa, is a hyperglycosylated analog of recombinant human erythropoietin (rHuEPO, epoetin alfa). We carried out the validation study by using a commercially available ELISA assay kit to establish the ELISA quantitation method for KRN321 in rat serum for the implementation of the pharmacokinetic studies with a lower limit of quantitation at 100 pg/mL and quantitation range from 100 to 4,000 pg/mL. We also established the in vitro bioassay method as an index of biological activity using UT-7/Epo, derived from a human leukemia cell line with a lower limit of quantitation, at 10 ng/mL. Furthermore, good correlation was observed between the two methods; it indicated that KRN321 concentration determined by the ELISA maintained biological activity.
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PMID:Determination of KRN321 in rat serum by ELISA and correlation between ELISA and in vitro bioassay. 1682 28

In order to investigate the inhibition role of anti-Fas hammerhead ribozyme on Fas expression and Fas-mediated apoptosis in CTLL-2 cells (mouse CTL cell line), and to explore a new way for enhancing the ability of T cells against Leukemia in donor lymphocytes infusion, CTLL-2 cells were transfected with pEGFP-RZ596 and pEGFPC1 (mock-transfected) via electroporation. Fas expression on CTLL-2 cells was detected by RT-PCR and Western blot. The killing effect of CTL against WEHI-3 (mouse acute myelomonocytic leukemia cell line) highly expressing FasL in vitro was detected by MTT assay. The caspase-3 proteolytic activity and the apoptosis rate of CTLL-2 cells were detected by means of BD AproAlert Caspase-3 Colorimetric kit and FITC labeled Annexin-V apoptosis detecting kit respectively. The results showed that the anti-Fas ribozyme could be successfully introduced into mouse CTLL-2 cells; Fas expression on the surface of cells transfected with the ribozyme was obviously decreased, in comparison with control and mock-transfected cells; after cocultured with WEHI-3 cells, the viability of CTLL-2 cells transfeced with the ribozyme was significantly increased, as compared with other two groups; caspase-3 activity and apoptosis rate of the ribozyme-transfeced cells were significantly decreased, the killing effect of CTLL-2 transfected with the ribozyme was stronger than that of other groups. It is concluded that anti-Fas ribozyme can remarkably decrease Fas expression on CTLL-2 cells, so as to avoid Fas-mediated apoptosis by Fas ligand on WEHI-3 cells, and to enhance their killing activity against WEHI-3 cells, as a result, the immune escape of acute myelomonocytic leukemia was depressed.
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PMID:[Depressing the immune escape of acute myelomonocytic leukemia via an anti-Fas ribozyme]. 1709 77

We quantitatively assessed the expression of cytokine receptors (interleukin-2 receptor (IL-2R), IL-3R, IL-4R, IL-5R, IL-6R, IL-7R, granulocyte-macrophage colony-stimulating factor R (GM-CSFR), G-CSFR, c-fms, c-mpl, c-kit and FLT3) in cells from 211 adults with acute lymphoblastic leukemia (ALL) by flow cytometry and determined their prevalence and clinical significance. Although all cytokine receptors were expressed to various degrees, the levels of IL-3R alpha-chain (IL-3Ralpha), IL-2Ralpha, IL-2Rbeta, IL-7Ralpha, common-Rgamma(gammac), c-mpl, c-kit and FLT3 exhibited a wide spectrum > or =2000 sites/cell. Among them, IL-3Ralpha, IL-2Ralpha and FLT3 were highly expressed in B-lineage ALL, whereas IL-7Ralpha, gammac and c-kit predominated in T-lineage ALL. Higher levels of IL-3Ralpha, IL-2Ralpha, c-kit and FLT3 correlated with the expression of CD13/33. Increased IL-2Ralpha levels related to the presence of Philadelphia chromosome (Ph), leukocytosis and shorter event-free survival (EFS). C-kit preferred in male. Elevated FLT3 levels correlated with age > or =60 years. Multivariate analysis in B-lineage ALL revealed only IL-2Ralpha (P=0.028) and Ph (P=0.020) as independent factors for EFS. These findings suggest that several cytokine receptors associated with certain cellular and clinical features, but IL-2Ralpha solely had a prognostic value and should be considered as a major prognostic factor for adult ALL that is comparable with Ph.
Leukemia 2007 Feb
PMID:Clinical and prognostic significance of cytokine receptor expression in adult acute lymphoblastic leukemia: interleukin-2 receptor alpha-chain predicts a poor prognosis. 1720 58

Apoptosis, or active cell death, is a specific mode of cell death, which is characterized by morphological changes such as chromatin condensation, fragmentation of the nucleus, cytoplasmic retraction and appearance of apoptotic bodies' containing apparently intact organelles. Apoptosis occurs in physiological conditions as a regulatory mechanism of tissue growth, where cell proliferation is balanced. The aim of this research was to study the ability of Fas to initiate apoptosis in vitro before and after treatment with Cytarabin on tissue culture and to correlate the response. The human leukemia and normal cells were treated with cytarabin in tissue culture, and apoptotic treated cells were estimated by flow cytometry and phosphatidylserines kit. The results were analyzed by statistical tests (post hoc). From these data, it was found that Fas antigen was expressed in all cases, but the expression level varied widely. Apoptosis and also Fas antigen expression in short term cell culture were higher in media containing drug than in media without drug; but there had been no reasonable correlation between percentage of Fas antigen and apoptosis responses before culture.Expression of Fas antigen was low in most of the leukemic cells and the preliminary results showed that increase in Fas antigen expression (above 20%) after treatment, was a favorable prognostic outcome. It is associated with increase relapse, free and total survival. In addition, using this antigen as a chemotherapic and immunotherapic target, would initiate a new strategy for treatment of leukemia (chemotherapy and immunotherapy).
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PMID:In vitro Evaluation of Cytarabin Induced Apoptosis in Leukemic Blasts. 1730 42


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