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

Friend murine erythroleukaemia (F-MEL) cells are a permanent line of primitive erythroid precursors originally derived from the spleens of mice infected with the Friend strain of murine leukaemia virus. F-MEL cells differentiate in vitro in response to various chemical inducers. Concomitantly with induction, a biphasic regulation of c-myc oncogene transcripts is observed. Within one hour of the addition of dimethyl sulphoxide (DMSO) or hypoxanthine (Hyp), the levels of c-myc transcripts fall dramatically and remain virtually undetectable for the next few hours. Between 8 and 24 hours after induction, c-myc transcripts return to pre-induction levels and then decline again between 3 and 5 days as most of the cells undergo terminal differentiation. To explore the potential relationship between c-myc expression and F-MEL terminal differentiation, we have investigated here whether reversing the early fluctuations in c-myc transcript levels affects the ability of F-MEL cells to differentiate. We therefore constructed an amplifiable plasmid vector containing a full-length mouse c-myc complementary DNA and introduced it stably into recipient F-MEL cells. The exogenous c-myc sequences are transcribed in F-MEL cells and the transcript levels do not change significantly in response to inducing agents. The net result is continued c-myc expression following DMSO or Hyp induction and a complete or partial inhibition of F-MEL differentiation.
 ...
PMID:Deregulated expression of c-myc by murine erythroleukaemia cells prevents differentiation. 352 63

Fifteen sulfur-containing compounds were examined for their ability to both protect normal hematopoietic stem cells (NCFU) from the cytotoxic effect of nitrogen mustard (HN2), and potentiate the cytotoxicity of HN2 to AKR leukemia cells (LCFU). All except four agents demonstrated some protection of NCFU with WR-2721 being most active. Five of the agents were also protective for LCFU with cysteine and glutathione being most active. However, a number of agents potentiated the cytotoxicity of HN2 to LCFU, the most active being disulfiram and AET followed by cysteamine, DMSO, WR-638, and WR-3689. The dose-response relationship for the potentiation was defined for DMSO. A second leukemia model, L1210, was also studied for potentiation of HN2 cytotoxicity by four of the most active agents--WR-2721, AET, DMSO, and disulfiram. The first two agents showed no effect (either protection or potentiation) when given either 15 min or 6 hr before HN2 administration. The last two agents, however, potentiated the cytotoxicity to a level similar to that found with the AKR leukemia.
 ...
PMID:Potentiation of nitrogen mustard cytotoxicity to leukemia cells by sulfur-containing compounds administered in vivo. 374 35

Serum-free cultures of HL60 promyelocytic leukemia cells and cultured fresh leukemia and normal marrow cells were used to investigate relationships between proliferation, transferrin receptor (TfR) display and intracellular ferritin (Fer). HL60 cells in serum- und Tf-free medium displayed 3 times less TfR than cells in serum or Tf containing medium. But Fer in Tf-independent cells was 50 times higher than Fer in serum- or Tf-supplemented cells. HL60 cells induced to differentiate by DMSO or vitamin D3 decreased TfR but increased Fer. Expression of TfR with fresh leukemia and normal marrow cells was less clear than in HL60 cells; DMSO or vitamin D3 induced differentiation was associated with a 10-fold Fer increase in leukemia cells and greater than 100-fold increase in marrow cells. TfR-expression and ferritin synthesis may be important events in cell differentiation and growth.
 ...
PMID:[Interrelation between transferrin receptor expression and intracellular ferritin concentration in leukemia cells and normal marrow cells]. 378 30

Reduction of nitro blue tetrazolium (NBT) to insoluble blue formazan granules occurs during the stimulus-induced respiratory burst of mature granulocytes and is routinely used as an indicator of the extent of granulocytic differentiation of HL-60 acute promyelocytic leukemia cells. In the present study, the differentiation of HL-60 leukemia cells induced by dimethylsulfoxide (DMSO) or retinoic acid was monitored by flow cytometric (FCM) measurement of forward and 90 degree light scatter of NBT treated cells. Two-parameter correlated analysis permitted a distinction between cells with increased forward and decreased 90 degree light scatter (NBT-), and cells with decreased forward and increased 90 degree light scatter (NBT+). Fixation of NBT treated cells with 1% paraformaldehyde facilitated flow cytometric analysis, and allowed differences in NBT reduction to be quantitated. DMSO-induced cells expressed an all-or-none reduction of NBT to formazan, compared with retinoic acid treated cells that exhibited a graded response. Three parameter flow cytometric analysis of HL-60 leukemia cells stained with propidium iodide in combination with NBT allowed the determination of the cell cycle distribution of NBT-treated cells.
 ...
PMID:Differentiation of HL-60 promyelocytic leukemia cells monitored by flow cytometric measurement of nitro blue tetrazolium (NBT) reduction. 385 96

Dimethyl sulfoxide (DMSO) treatment of the Friend erythroleukemia cell line GM 979 markedly increased its susceptibility to natural cytotoxicity by splenocytes from normal inbred DBA/2 mice. Cytotoxicity occurred with normal adherent spleen cells as well as dextran-elicited peritoneal exudate (PE) cells but not with resident PE cells. Susceptibility of the leukemia cells to natural cytotoxicity increased to maximum levels upon treatment with 210 mM DMSO for 2-3 days. The natural cytotoxicity assayed by the 51Cr release procedure was first detectable after 9 hours of incubation and reached maximum levels by 24-30 hours. Although both DMSO and n-butyric acid induced rapid erythroid cell differentiation of the GM 979 cells, and both resulted in increased hemoglobin synthesis, only DMSO treatment enhanced the susceptibility of the cells to natural cytotoxicity by normal splenocytes. Cell-free supernatants from adherent spleen cells cocultured with DMSO-treated GM 979 cells for 6-15 hours were markedly cytotoxic for cultures of other chromium-labeled DMSO-treated leukemia cells. Supernatants from cultured adherent spleen cells alone, or lysates of DMSO-treated leukemia cells, did not possess cytotoxic activity. Resident peritoneal macrophages also had no cytotoxic activity against DMSO-treated cells, and culture supernatants from resident PE cells, even after incubation with DMSO-treated target cells, failed to show significant levels of cytotoxicity. These results indicate that normal splenic adherent cells as well as elicited PE cells have the ability to lyse DMSO-treated leukemia cells.
 ...
PMID:Macrophage-mediated natural cytotoxicity of dimethyl sulfoxide-treated Friend erythroleukemia cells. 385 84

In vitro terminal differentiation in a female myeloid leukaemia cell line (HL-60) was induced by either of the two inducing agents, dimethylsulphoxide (DMSO) and dimethylformamide (DMF). A higher frequency of more mature myeloid cells was noted with increasing concentrations of the inducing agents up to the optimal dose limits for cell viability, and with longer post-induction incubation periods. The highest percentage of polymorphs was obtained at 8 days post-induction with 1.25% DMSO and after 6 and 8 days exposure to 90 mM DMF. A proportion of polymorphs showed non-sex specific drumstick-like nuclear appendages, which were morphologically similar to the sex-specific drumsticks found in polymorphs from normal females in vivo. The correlation between the nuclear lobe counts and the frequencies of drumstick-like appendages in polymorphs was also similar to that reported for drumsticks in blood cells in vivo. The various stages of terminal differentiation and nuclear appendage formation in polymorphs under induced differentiation were similar to those occurring in vivo. Chromosomal analyses of this cell line indicated that individual cells had lost one X chromosome, and no portion of the missing X was detected in any of the rearranged chromosomes. Since no truly sex-specific drumsticks appeared to be present in the polymorphs of this cell line containing only one X chromosome, the study supports the accepted notion that there is a correlation between drumstick frequency and the presence of one versus two X chromosomes.
 ...
PMID:Induction of terminal differentiation and nuclear appendage(s) formation in a human myeloid leukaemia cell line (HL-60). 386 19

In this study we have demonstrated that the human promyelocytic leukaemia cell line (HL-60 cells) completely lack the biological functions of chemotaxis and degranulation. In addition, they were also unable to bind the anti-neutrophil monoclonal antibody NCD 1 which has been shown to inhibit these functions in the peripheral blood neutrophil. When HL-60 cells were induced to differentiate by culturing for 6 days at 37 degrees C in the presence of either 1.25% dimethylsulphoxide (DMSO) or 0.5% dimethylformamide (DMF), up to 35% bound NCD 1. Differentiated HL-60 cells are capable of chemotaxis, degranulation and these newly acquired functions were inhibited by NCD 1 in a manner similar to that seen for the peripheral blood neutrophil. The results correlate the appearance of an antigen on the cell surface of DMSO- or DMF-induced HL-60 cells with the acquisition of two specific cellular functions.
 ...
PMID:A cell surface differentiation antigen involved in human neutrophil chemotaxis and degranulation. 630 61

With an increasing number of bone marrow transplantations (BMT) being contemplated in leukemia and cancer patients, it is prudent for blood banks to develop a suitable program within their resources for harvesting, purifying and freezing bone marrow stem cells. In order to do this, initially a prototype has been developed involving buffy coat model (BC) using normal donor blood. Centrifugation, sedimentation and machine apheresis methods were separately evaluated leading to a combined and sequential handling procedure. Blood was passed through a cell separator resulting collection of BC with 90% reduction of the volume showing 80% recovery of total leucocytes and 87% yield of mononuclear cells. Following centrifugation the cells with DMSO were frozen in a controlled freezing system and stored in liquid nitrogen. After thawing 94% cells were recovered with 93% viability. The initial experience gained in the model system could be incorporated in autologous BMT program in patients but requires modifications for improved results; the latter will be described separately.
 ...
PMID:Comparison of apheresis and other methods for separation and purification of hemopoietic stem cells: initial experience with a blood buffy coat model for the use of autologous bone marrow transplantation. 637 75

Rhodamine 123, a fluorescent dye which binds as a result of the transmembrane potential, was used to stain the mitochondria of HL-60 cells, a cell line established from human promelocytic leukemia cells. The DMSO-induced differentiation of promyelocytic cells into mature granulocytes caused a fourfold decrease in fluorescence intensity that paralleled the disappearance of S-phase and G2M cells. This suggests that upon myeloid differentiation whereby the cells enter an irreversible quiescent state, the mitochondrial mass of the cells has decreased. This suggestion is corroborated by electron microscopy, which shows a decrease in the number of mitochondria, and by decreases in total mitochondrial protein and cytochrome oxidase activity. The respiratory rate of isolated mitochondria did not change, suggesting that the transmembrane potential remained the same. Undifferentiated cells in exponential phase of growth exhibit an intracellular heterogeneity of fluorescence intensity. This heterogeneity appears to have a cell age basis, as late S/G2M cells, obtained by centrifugal elutriation, yielded twice the fluorescence intensity of early G1 cells.
 ...
PMID:Differentiation of promyelocytic (HL-60) cells into mature granulocytes: mitochondrial-specific rhodamine 123 fluorescence. 657 92

The characteristics of hematin uptake were examined in three malignant cell lines [L1210 leukemia, 745 murine erythroleukemia (MEL) and Walker carcinoma (W256)], a cell line derived from normal rat liver (BRL-3A) and a normal embryonic cell, chick embryo fibroblasts (CEF). Uptake in the normal liver cell line was slight and occurred at a slow rate in contrast to the rapid uptake, which was more rapid and of greater magnitude in the three tumor cell lines, Saturation of the heme uptake mechanism was observed in MEL cells at an extra-cellular hematin concentration of 160 micro M and in L1210 cells at 300 micro M. At saturation L1210 cells achieved a cellular heme concentration nine times as high as MEL cells. Hematin uptake in MEL cells was markedly augmented by pretreatment with DMSO, procaine, detergent or proteolytic enzymes or by increases in the pH of the medium from 8 to 9.5. In contrast to MEL cells where SA inhibits growth by lowering cellular heme, the inhibition of growth of L1210 cells by SA appears to operate by a mechanism independent of heme. In gradual increase in hematin uptake capacity in MEL cells over a period of days. Afer exposure of MEL cells to a high concentration of hematin in the medium, the egress of heme was followed under various conditions. Of the various agents studied, only cyanide produced a loss of heme from MEL cells.
 ...
PMID:Characteristics of hematin uptake in malignant, embryonic and normal cells. 657 44


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>