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)

Results concerning a possible link between susceptibility to natural-cell-mediated immune cytolysis and the multi-drug resistance (MDR) phenotype are conflicting. We evaluated in human acute lymphocytic leukemia the relationship between acquired drug resistance and susceptibility to cytolysis mediated by endogenous, interferon-activated, and interleukin-2-activated natural cytotoxic cells. Eight human leukemia drug-resistant/sensitive cell line pairs were evaluated; drug-resistant sub-lines included those selected for primary resistance to adriamycin, etoposide, teniposide, vincristine, and vinblastine. A majority of P-glycoprotein-positive MDR sub-lines displayed slight but statistically significant resistance to endogenous and/or interferon-activated natural-killer(NK)-cell-mediated lysis, as compared with the drug-sensitive parental type. P-glycoprotein-negative sub-lines displayed variable NK susceptibility; within this group, the variants selected for primary etoposide resistance were more susceptible to NK cytolysis than parental cells. Results of cold-target-inhibition experiments suggest that altered NK susceptibility does not arise solely from modulation of NK target recognition and adherence structures. IL2-activated killer (LAK) cells lysed both drug-sensitive and drug-resistant lines. Two MDR lines selected for primary etoposide resistance displayed enhanced LAK susceptibility. In contrast, the 2 variants selected for resistance to adriamycin exhibited partial resistance to LAK-mediated killing, which could be overcome at high effector-to-target ratios. Our results support the development of interleukin-2/LAK immunotherapy for the treatment of leukemias with acquired drug resistance.
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PMID:The relationship between multi-drug resistance and resistance to natural-killer-cell and lymphokine-activated killer-cell lysis in human leukemic cell lines. 137 Apr 37

The expression and function of neural cell adhesion molecule (NCAM, CD56, Leu19) on leukaemic blasts was investigated. The expression of NCAM was frequent (64%) in 14 studied cases of acute myeloid leukaemia (AML) but not in chronic lymphocytic leukaemia (CLL: 1/3 cases positive) or immunocytoma (IC: no positivity). No correlation with the expression of other AM (intercellular adhesion molecule-1 (ICAM-1), leucocyte function antigen-1 (LFA-1). VLA beta chain) or with AML type, according to FAB classification, was observed. Blocking of NCAM with anti-Leu 19 MoAb on AML targets resulted in a significant decrease of their susceptibility to LAK killing and in inhibition of conjugate formation. In the case of B prolymphocytic leukaemia (B-PLL) which did not express ICAM-1 or LFA-1 but was NCAM+, a complete resistance to LAK activity and lack of conjugate formation was observed. Blocking of NCAM on LAK effectors did not decrease their cytotoxic activity. Our results suggest that NCAM, in the presence of other AM, may have a supportive role in adhesion of leukaemic targets to LAK effectors.
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PMID:A supportive role of neural cell adhesion molecule (NCAM) in adhesion between leukaemic blasts and cytotoxic lymphocytes. 137

The killing of human leukemia cells by cloned human LAK cell was investigated with 51Cr release, semisolid agar colony-formation and MTT assay. Human LAK cells were generated and cloned from normal peripheral blood mononuclear cells stimulated with IL-2. Cloned LAK cells showed significant cytotoxicity against human erythroleukemia cell line K 562, promyelocytic leukemia cell line HL 60 and T-lymphoblastic leukemia cell line Jurkat in standard 4-hr 51Cr release assay and the lytic percentage were 67.1%, 58.4% and 53.1% with E/T ratio of 40:1. Moreover, cloned LAK cells could also inhibit the 6-day spontaneous colony-formation of K 562 and HL 6 C cells in semisolid cultures when the LAK cells were preincubated with target cells for 4 hours in liquid medium at 37 degrees C. The degree of colony inhibition was 91% for K 562 and 96% for HL 60, which was quantitatively greater than that determined by 51Cr release at the same E/T ratio of 40:1. In addition, with MTT assay, cytotoxicity of supernatant of cloned LAK cells 3 days in culture against K 562 and HL 60 cells was observed. Our data indicated that cloned human LAK cells could kill both human leukemia cells and their stem cells and the mechanism may involve direct lysis and/or inhibition mediated by LAK cells and indirect inhibition of some soluble factors released from LAK cells.
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PMID:[Mechanism of cloned human lymphokine-activated killer (LAK) cells killing human leukemia cells in vitro]. 139 52

Lymphokine activated killer cells have potent antitumor effect both in vitro and in vivo. They have been reported to suppress bone marrow (BM) progenitor cell activity (PCA) in vitro, thus raising concern about the feasibility of their use after autologous bone marrow transplantation. The present study was carried out to evaluate the effect of LAK cells on BM engraftment in a syngeneic BMT setting in mice. LAK cells supplemented with or without exogenous interleukin-2 therapy did not impair the hematopoietic reconstitution or survival of mice undergoing BMT. LAK cells also did not reduce the PCA of the engrafted BM. LAK cell therapy did not cause graft-versus-host disease. Finally, LAK cells supplemented with IL-2 therapy improved the graft-versus-leukemia effect. These findings suggest that LAK cells plus IL-2 therapy after BMT does not impede hematopoiesis and should be evaluated as an adjuvant therapy with the aim of eradication of minimal residual disease after autologous BMT.
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PMID:Lymphokine-activated killer cells in autologous bone marrow transplantation. Evidence against inhibition of engraftment in vivo. 146 68

We have identified and partially purified a novel cytolytic factor isolated from enriched plasma membranes prepared from highly purified lymphokine-activated killer cells (adherent-LAK. A-LAK cells) and a large granular lymphocytic NK cell leukemia, CRNK-16. The enriched plasma membranes were shown to be physically devoid of lytic granules and contained no detectable pore-forming protein (PFP, perforin) activity. The plasma membrane-associated cytolytic factor (designated M-CTX) was solubilized in biologically active form and was highly lytic to a large panel of target cells in 2- to 4-hr 51Cr release assays. Characteristics of the M-CTX include: (1) it is plasma membrane- not granule-associated: (2) it is not hemolytic and functions in the absence of Ca2+: (3) nucleated target cells are lysed in 2 to 4 hr at 37 degrees C but not at 4 degrees C: (4) it induces apoptotic cell death with nuclear DNA fragmentation and massive membrane blebbing: (5) it is isolated from the plasma membranes of cultured A-LAK cells, a lytically active LGL leukemia (CRNK-16), and fresh spleen cells but not from thymocytes or L929 fibroblasts: and (6) the lytic activity of the partially purified toxin is inactivated by trypsin, serum, and heat, but is not blocked by antibodies that inactivate TNF-alpha, LT or IFN-gamma. Taken collectively, these data suggest that M-CTX may represent a heretofore undescribed membrane-associated toxin possibly involved in contact-mediated cell killing.
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PMID:Identification and partial characterization of a novel plasma membrane-associated lytic factor isolated from highly purified adherent lymphokine-activated killer cells. 155 54

The NK and LAK activity of peripheral blood lymphocytes of leukemic patients as well as the susceptibility of their acute myeloid (AML) and lymphoblastic (ALL) leukemia cells to autologous and allogeneic LAKs were examined. In addition, neoplastic cells at diagnosis and at relapse were compared in the same patients for several features, including in vitro susceptibility to LAKs and to the drugs used in the induction phase, expression of MDR phenotype and of adhesion molecules, and differentiation markers. The NK activity of patients' LAK cells on K562 was significantly lower than that of a group of healthy donors whereas no differences were found in LAK activity as evaluated on Daudi cells. Three of 5 AML and 3 of 4 ALL were significantly more susceptible to autologous and allogeneic LAK lysis when blasts obtained at relapse were compared with leukemic cells of the same patients at diagnosis. This different lysability was not associated with in vitro modified sensitivity to drugs used in induction treatment. Moreover, no elevation in the expression of the multidrug-resistance (MDR)-related P170 glycoprotein was noted in relapsing leukemic cells. Even the expression of adhesion molecules and differentiation markers did not correlate with lysability of leukemic cells. These data demonstrate that relapsing leukemic blasts can be significantly lysed by LAK cells and suggest a rationale for adoptive immunotherapy with IL-2 and LAK cells in the treatment of acute leukemic patients.
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PMID:Increased susceptibility to lymphokine activated killer (LAK) lysis of relapsing vs. newly diagnosed acute leukemic cells without changes in drug resistance or in the expression of adhesion molecules. 160 87

In an attempt to prolong disease-free survival in children with acute leukemia, we tested the feasibility of interleukin-2 (IL-2) administration after an autologous bone marrow transplantation (ABMT). We report the clinical and biological data obtained in three children with acute myelocytic leukemia (AML) in second complete remission (CR) and in seven children with acute lymphocytic leukemia (ALL) in second or subsequent CR, who received IL-2 at a median interval of 78 days (range 38-125) from ABMT. Patients were treated with 1-2 cycles of IL-2 given by continuous infusion over a 5-day period using a daily escalating protocol, from 100 micrograms/m2 per day to the maximum tolerated dose, followed after 3 weeks by low-dose IL-2 for 5 days monthly over a 6-h infusion on an out-patient basis. Side effects greater than grade 2 (WHO system), consisting of thrombocytopenia, fever, cutaneous rash, nausea and vomiting, diarrhoea were common during the high-dose IL-2 cycles, but resolved 24-48 h after stopping IL-2. Only one patient developed liver toxicity (grade 3, WHO) on day +3 of the first cycle which prompted us to stop the administration of IL-2. An increase in lymphocytes and eosinophils was also observed. IL-2 treatment was followed by a normalization of NK function and by the generation of a high proportion of endogenous LAK cells. All seven ALL patients relapsed at a median of 5 months (range 1-23). Two AML patients relapsed at 1 and 11 months, while the other is still in continuous CR at 23 months after IL-2 treatment. Our IL-2 schedule for treatment of leukemia in children after ABMT is thus feasible but its efficacy requires further investigation.
Leukemia 1992 Aug
PMID:Autologous bone marrow transplantation followed by interleukin-2 in children with advanced leukemia: a pilot study. 164 Jul 29

Progress in genetics now enables the synthesis of molecules acting on the regulation of the immune system which are called cytokines. Currently there are several cytokines, Interferon (IFN), Interleukin 2 (IL2), tumour necrosis factor (TNF) as well as haematopoietic growth factors and these are the object of study in clinical trials. Interferon has already been used in the therapy of hairy cell leukaemia, Kaposi sarcoma associated with AIDS(SIDA) and metastasis of malignant melanoma. Interleukin 2 allows for an increase in the cytotoxic activity of NK cells in producing LAK cells, the lymphocyte infiltrating the tumour (TIL). Therapeutic combinations combining IL2 associated with LAK or of TIL have been evaluated in some private studies. These treatments have shown some interesting response levels on those tumours which are usually resistant, such as malignant melanoma or carcinoma of the kidney. TNF is active in vitro on human tumours; its potential toxicity is important; it is the object of a phase 1 clinical trial. Haematopoietic growth factors, G-CSF and GM-CSF, stimulate the production of leucocytes which will be valuable to correct toxic affects on the marrow during chemotherapy. This will enable chemotherapy to be given at a high dose.
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PMID:[Immunotherapy of cancer using cytokinins. Use and perspectives in lung oncology]. 169 91

The expression of adhesion molecules on blasts from 14 patients with acute myeloid leukemia (AML) was investigated by immunofluorescence and flow cytofluorometry. All tested blast populations expressed CD18/CD11a complex [leukocyte function antigen-1 (LFA-1)] and CD29 (very-late antigen (VLA)) and the majority were positive for CD54 [intercellular adhesion molecule-1 (ICAM-1), 78.6%] and CD56 [neural cell adhesion molecule (NCAM), 64.3%]. The expression of two other alpha chains of CD18/CD11b and CD11c varied considerably (64.3% and 42.8% of positive cases, respectively). Only one case (AML-M4) showed a weak expression of the activated platelet antigen CD41b. None of the tested blasts expressed the vitronectin receptor (CD61/CD51). No significant correlation between the expression of adhesion molecules and the FAB type of leukemia could be found. All tested blast populations were completely resistant to NK-mediated cytotoxicity and relatively resistant to LAK-mediated cytotoxicity in the standard 51Cr release assay. While no statistically significant correlation of the results in cytotoxicity assays with the expression of adhesion molecules or the expression of HLA-DR antigen could be observed, 2 out of 3 completely resistant cases lacked ICAM-1. These results show that even leukemic blasts which express all of the tested adhesion molecules can still be resistant to LAK-mediated cytotoxicity.
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PMID:Resistance of leukemic blasts to lymphokine activated killer (LAK)-mediated cytotoxicity is not related to their adhesion properties. 171 15

Successful generation of adherent lymphokine-activated killer (A-LAK) cells, highly-enriched in CD3-CD56+ antitumour effector cells, from the peripheral blood of ten patients with acute myelogenous leukaemia (AML) is described. The AML patients were either untreated or in remission. In vitro proliferation of A-LAK cells in patients with AML was generally poor, unless the cells were cocultured with irradiated concanavalin A (ConA)--prestimulated allogeneic PBL or selected lymphoblastoid cell lines (LCL) as feeder cells. Using this method, the median fold proliferation was 290 for A-LAK cells cultured with ConA-activated feeders and 291 for those grown with LCL, both significantly higher (both P less than 0.001) than the median of 2-fold expansion observed in cultures without feeders. A-LAK cultures generated in the presence of feeders consistently showed good enrichment (up to 90%) in CD3-CD56+ NK cells. Although NK activity was not significantly increased on a per cell basis in A-LAK cells grown with feeder cells, total lytic activities against both NK-sensitive target, K562, and NK-resistant target, Daudi, were significantly greater (P less than 0.02 for ConA-PBL feeders and P less than 0.005 for LCL feeders) as compared to those in paired cultures without feeders. In the presence of irradiated allogeneic feeder cells, 7/10 AML patients generated A-LAK cultures characterised by good proliferation and increased purity as well as cytotoxic activity.
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PMID:Generation of adherent lymphokine activated killer (A-LAK) cells from patients with acute myelogenous leukaemia. 173 21


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