Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P15088 (mast cell)
 14,925 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Phenylalanine methylester (PME), a lysosomotropic compound can be used to deplete monocytes and myeloid cells from peripheral blood and bone marrow (BM). The potential of PME for purging leukemic cells from BM was investigated using U937 and HL-60 cell lines as models. Optimal purging conditions for U937 cells were determined using an MTT assay (3-4, 5-dimethylthiazol-2, 5-diphenyl tetrazolium biomide; Sigma). Elimination of U937 cells was time-, temperature-, and dose-dependent. PME activity was optimal at 37 degrees C for 45 minutes. Depletion of U937 was > 2.8 logs for 50 mmol/L PME. Compared with another purging agent, 100 micrograms/mL 4-hydroperoxycyclophosphamide had activity comparable to 40 mmol/L PME. HL-60 cells were even more sensitive to PME than U937 cells. To support observations made with the MTT assay, clonogenic assays were performed. PME, 50 mmol/L at 37 degrees C resulted in total depletion (> 5 logs) of U937 colonies. Progressive depletion of normal progenitor cells occurred when BM was incubated with PME at concentrations from 5 to 100 mmol/L. At 37 degrees C, 50 mmol/L PME reduced colony-forming units-granulocyte-macrophage and burst-forming units-erythroid (BFU-E) recovery by 98%. Recombinant human mast cell factor augmented BFU-E after PME treatment but had no effect on HL-60 or U937. These studies suggest that PME deserves further study as an agent for ex vivo marrow purging.
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PMID:Potential of phenylalanine methylester as a bone marrow purging agent. 138 2

A new tetrazolium salt XTT, sodium 3'-[1-[(phenylamino)-carbonyl]-3,4-tetrazolium]-bis(4-methoxy-6- nitro)benzene-sulfonic acid hydrate, was evaluated for use in a colorimetric assay for cell viability and proliferation by normal activated T cells and several cytokine dependent cell lines. Cleavage of XTT by dehydrogenase enzymes of metabolically active cells yields a highly colored formazan product which is water soluble. This feature obviates the need for formazan crystal solubilization prior to absorbance measurements, as required when using other tetrazolium salts such as MTT. Bioreduction of XTT by all the murine cells examined was not particularly efficient, but could be potentiated by addition of electron coupling agents such as phenazine methosulfate (PMS) or menadione (MEN). Optimal concentrations of PMS or MEN were determined for the metabolism of XTT by the T cell lines HT-2 and 11.6, NFS-60 a myeloid leukemia, MC/9 a mast cell line and mitogen activated splenic T cells. When used in combination with PMS, each of these cells generated higher formazan absorbance values with XTT than were observed with MTT. Thus the use of XTT in colorimetric proliferation assays offer significant advantages over MTT, resulting from reduced assay time and sample handling, while offering equivalent sensitivity.
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PMID:An improved colorimetric assay for cell proliferation and viability utilizing the tetrazolium salt XTT. 191 29

We have examined the effects of mercuric chloride (HgCl2) on growth and IL-4, IL-8, TNF-alpha and MHC class II gene expression in the HMC-1 human leukemic mast cell line. Proliferation, measured by [3H]thymidine incorporation or production of a formazan product (MTT assay), was substantially inhibited by HgCl2 at concentrations of 10(-6) M and above. Inspection of the DNA by agarose gel electrophoresis from HgCl2-treated cells revealed that it was intact, indicating inhibition of DNA synthesis, but not denaturation. HgCl2 inhibited expression of mRNA for IL-8, TNF-alpha and MHC class II at 4 x 10(-6) M and inhibited expression of IL-4 mRNA at 8 x 10(-6) M and above. At a concentration of 10(-5)M, HgCl2 almost completely blocked mRNA expression for IL-4, IL-8, TNF-alpha and MHC class II, but produced negligible inhibition of expression of mRNA encoding the housekeeping gene beta-actin, thus demonstrating selective toxicity for the cytokine and MHC class II genes studied. Pre-exposure of the cells to human recombinant IL-4 prior to treatment with HgCl2 had no effect on expression levels of any of the genes examined. The effects seen in this study are consistent with previous reports showing immunotoxic effects of HgCl2 on other cell types, therefore, the HMC-1 mast cell line may prove useful in further studies of mast cell cytokine gene expression and the mechanisms involved in cytokine gene toxicity.
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PMID:The effects of mercuric chloride on growth, cytokine and MHC class II gene expression in a human leukemic mast cell line. 856 Apr 97

Histamine, an important mast cell mediator in allergic disorders, may affect extracellular matrix production and cell growth in vernal keratoconjunctivitis (VKC). In the present study, the histamine reactivity of conjunctival fibroblasts derived from VKC patients was investigated in vitro. Conjunctival fibroblast cultures were derived from biopses of 8 tarsal VKC patients and 5 normal subjects. These cells were maintained in vitro and stimulated with different concentrations of histamine with and without H1 (clorpheniramine) and H2 (cimetidine) receptor antagonists. Comparisons were made to fibroblasts grown in the same media without histamine and to fibroblasts stimulated with just antihistamine. The effects of histamine were evaluated by: (1) the MTT test to assess cell proliferation; (2) an in vitro wound model for cell migration and (3) the measurement of procollagen I (PIP) and procollagen III (PIIIP) in supernatants for collagen production. Results showed: (1) While VKC-derived fibroblasts proliferated at a faster rate than normal cells in unstimulated media, after histamine stimulation, VKC and normal cells grew at a similar rate. Both H1 and H2 antagonists significantly inhibited (P<0.05) histamine-induced cell proliferation. (2) Histamine enhanced cell migration after wounding; this effect was inhibited only by H2 antagonism. (3) When stimulated with histamine, VKC fibroblasts produced significantly more PIP than those in control media. Furthermore, VKC-derived fibroblasts were more sensitive to histamine challenge, producing significantly more PIP than normal fibroblasts. H1 and H2 antagonists did not modify histamine-stimulated PIP production. The enhanced proliferative and productive capacity of VKC fibroblasts may be the result of a selective overgrowth of one or more fibroblast subpopulations in a chronically inflamed tissue. Histamine increased proliferation, migration and collagen production in both normal and VKC fibroblasts. Since H2 antagonism modulated both cell growth and migration, but not histamine-induced collagen production, the latter may be mediated by a different receptor. These results showed that histamine is at least partially responsible for fibroblast stimulation.
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PMID:Histamine effects on conjunctival fibroblasts from patients with vernal conjunctivitis. 1037 37

The synthesis and biological evaluation of a homologous series of conjugates (9-13) of 2,5-diaziridinylbenzoquinone (DZQ) and 9-carbonylacridine, a DNA intercalating moiety, via a polymethylene unit (n=2-6) are described. In addition, the non-acridine compound 14, analogous to compound 12, and the 5-methyl-DZQ derivatized conjugate 15, an analog of compound 10, were also prepared. Through a Comet assay, compounds 9-13 were shown to produce DNA interstrand cross-links at submicromolar concentrations, consistent with K562 leukemia cells accumulating in the G2/M stage in the cell cycle. The cytotoxicity of compounds 9-15 was examined using a MTT assay on several human cancer cell lines, including chronic myeloid leukemia K562, the non-small cell lung cancers H596 and H460, and colon carcinoma cells BE and HT29. H460 and HT29 are rich in DT-diaphorase (DTD), and H596 and BE cells have negligible amounts of functional DTD. Under continuous exposure of drugs, except to the non-aziridine compound 19b, the IC50 values of all other compounds were determined to be in the range of 0.3-11.3 nM. Compound 10, which has a propyl linker group, was subjected to in vivo studies. When BDF1 mice with established mouse mammary carcinoma were treated with compound 10 (2 mg/kg at day 1 and 5 mg/kg at day 7), a significant delay (9-10 days) in cancer growth was recorded when compared to untreated controls. Furthermore, administration of compound 10 to nu/nu BDF1 mice bearing human lung cancer H460 xenograft (1.5 mg/kg for 10 for five consecutive days from day 13 and 17) also showed a significant reduction in tumor growth compared to untreated controls. The half-life of compound 10 in the presence of five different peptidases (porcine esterase, carboxypeptidase A, B and Y, and pepsin) was determined to be between 30 and 60 h.
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PMID:Synthesis and biological evaluation of novel diaziridinylquinone-acridine conjugates. 1450 82

Carpopeltis affinis Okamura (CA, Halymeniaceae) has long been used as therapeutics for various allergic diseases in Korea. The precise effects of CA in experimental models, however, have remained unknown. We studied the effects of a methanol extract of CA on atopic allergic reaction. Histamine content was measured by the o-phthalaldehyde spectrofluorometric procedure. Cytokines were measured by a modified enzyme-linked immunosorbent assay. Cytotoxicity was determined by the 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay. CA significantly inhibited the histamine release and beta-hexosaminidase release from rat peritoneal mast cells. CA also inhibited interleukin-8 and tumor necrosis factor-alpha secretion from the phorbol 12-myristate 13-acetate and A23187-induced HMC-1 cells (human mast cell line). 48 h exposure to CA (1.0, 10, and 100 microg/ml) had little effect on HMC-1 cell viability. Our results suggest that CA has an inhibitory effect on mast cell-dependent allergic reaction and thus may be useful in the treatment of atopic dermatitis.
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PMID:Regulatory effect of atopic allergic reaction by Carpopeltis affinis. 1589 95

(51)Cr release assay (CRA) is still the standard method to study mast cell (MC)-mediated cytotoxicity in vitro. Non-radioactive methods e.g. MTT, Hoechst 22147 staining, have also been used. Though CRA has the benefit of being reproducible, it has several drawbacks e.g. spontaneous release and radioactivity. The basic strategy of this new flow cytometric assay involves labeling target cells with DIOC18, in addition to staining with propidium iodide to identify dead cells. 8-week-old human MCs were used as effectors. Human LAK-sensitive K-562; and LAK-resistant myeloid leukemia cell lines (DAMI, HL-60 and Meg-01) as well as 6 LAK-resistant myeloid leukemia patient samples were utilized. MCs/targets were co-incubated in certain ratios for short/long-term. Although there was some insignificant killing at 2 h/18 h, probably due to small sample size, significant killing in Meg-01 and HL-60 cells (27% and 39%; respectively) was observed at 48 h. This method clearly showed human MC-mediated cytotoxicity against human tumor cells. It was reproducible, reliable and cheaper without any radiation and spontaneous release. This is the first study to elucidate MC-mediated cytotoxicity by a flow cytometric assay.
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PMID:Evaluation of human mast cell-mediated cytotoxicity by DIOC18 target cell labeling in flow cytometry. 1718 5

Recent reports and our previous study suggest that mast cells play a crucial role in the pathological processes that follow cerebral ischemia. In this study, the effect of mast cells on neuron injury after cerebral ischemia was determined by adding in vitro ischemia-induced supernatant from mast cells to neurons and PC12 cells under the same conditions (oxygen-glucose deprivation, OGD). The degree of cell injury was evaluated by the 3-[4,5-dimethylthiazol-2-yl]-2,5-dipheny-ltetrazolium bromide (MTT) assay. Mast cell-derived supernatant protected against OGD-induced injury of PC12 cells and neurons, and this protection was reversed by a histamine H1 antagonist and by anti-histamine serum, but not by an H2 antagonist. However, histamine and nerve growth factor (NGF) added separately or together did not have protective effects against OGD-induced injury. These results indicate that mast cell-derived protection during in vitro ischemia is histamine-dependent, and involves cooperation with other mediators, but not NGF.
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PMID:Mast cell-derived mediators protect against oxygen-glucose deprivation-induced injury in PC12 cells and neurons. 1766 24

To explore effects of Forsythia koreana methanol extract (FKME) on mast cell-mediated allergic and inflammatory properties, the effect of FKME was evaluated on compound 48/80-induced systemic anaphylaxis, ear swelling, and anti-dinitrophenyl (DNP) immunoglobulin E (IgE)-induced passive cutaneous anaphylaxis (PCA). In addition, the effect of FKME was investigated on the histamine release from rat peritoneal mast cells (RPMCs) stimulated by compound 48/80, which promotes histamine release. The human mast cell line HMC-1 was stimulated by phorbol 12-myristate 13-acetate plus calcium ionophore A23187. Activated HMC-1 can produce several proinflammatory and chemotactic cytokines such as tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-6, and IL-8. Cytokine levels in the culture supernatant were measured by an enzyme-linked immunosorbent assay. Cytotoxicity by FKME was determined by a 3-(4,5-dimethylthiazol-2-yl)-diphenyl-tetrazolium bromide (MTT) assay. FKME inhibited compound 48/80-induced systemic anaphylactic shock and ear swelling in mice. When 1 g/kg FKME was pretreated or posttreated with mice, compound 48/80-induced mice morality was 50 and 66.7%, respectively. One gram per kilogram of FKME pretreatment inhibited ear-swelling responses derived from compound 48/80 by 29.75%. A PCA reaction was inhibited by 17.9%. In an in vitro model, FKME (1 mg/ml) inhibited histamine release from the RPMCs by 13.8% and TNF-alpha, IL-6, and IL-8 production from HMC-1 cells by 71.16% (P < 0.001), 86.72% (P < 0.001), and 44.6%, respectively. However, FKME had no cytotoxic effects on cell viability. In conclusion, FKME inhibited not only systemic anaphylaxis and ear swelling induced by compound 48/80 but also inhibited a PCA reaction induced by anti-DNP IgE in vivo. Treatment with FKME showed significant inhibitory effects on histamine, TNF-alpha, IL-6, and IL-8 release from mast cells.
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PMID:Observations of Forsythia koreana methanol extract on mast cell-mediated allergic reactions in experimental models. 1772 24

Mast cell tumor (MCT) is one of the most prevalent neoplasms that affect the skin and soft tissue of dogs. Because mast cell tumors present a great variety of clinical appearance and behavior, their treatment becomes a challenge. While retinoids are well recognized as promising antitumor agents, there have been only a few reports about retinoids' effect on canine cancers. The aim of this study was to investigate the chemosensitivity of MCT grades II and III to all-trans retinoic acid (ATRA). Immediately after surgical resection, MCT were prepared for primary culture. Samples of MCTs were also fixed in formalin for histopathology and grading according to the classification of Patnaik et al. (Veterinary Pathology 21(5):469-474, 1984). The best results were obtained when neoplastic mast cells were co-cultivated with fibroblasts. Cultured mast cells were, then, treated with concentrations of 10(-4) to 10(-7) M of ATRA, in order to evaluate their chemosensitivity to this retinoid. MTT assay was performed to estimate cell growth and death. The highest level of mast cell chemosensivity was obtained at the dose of 10(-4) M (p < 0,002). MCT of grades II or III were equally susceptible to the treatment with ATRA. Cell death was observed on the first 24 h until 48 h. According to these results, ATRA may be a potential chemotherapeutic agent for the treatment of canine MCT.
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PMID:In vitro chemosensitivity of canine mast cell tumors grades II and III to all-trans-retinoic acid (ATRA). 1914 41


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