UMLS:C0023418 - FACTA Search

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)

Cordyceps militaris is a traditional herbal ingredient, which has been used for patients suffering from cancer in Oriental medicine. In the present study, we investigated the biochemical mechanisms of anti-proliferative effects by aqueous extract of C. militaris (AECM) in human leukemia U937 cells. It was found that AECM could inhibit cell growth of U937 cells in a dose-dependent manner, which was associated with morphological change and apoptotic cell death such as formation of apoptotic bodies and DNA fragmentation. We observed the down-regulation of anti-apoptotic Bcl-2 expression and proteolytic activation of caspase-3 in AECM-treated U937 cells. However, AECM did not affect the pro-apoptotic Bax expression and activity of caspase-9. Furthermore, Western blotting and RT-PCR revealed that AECM treatment caused a dose-dependent inhibition of cyclooxygenase-2 and prostaglandin E2 accumulation. Taken together, these results indicated that the anti-proliferative effects of AECM were associated with the induction of apoptotic cell death through regulation of several major growth regulatory gene products such as Bcl-2 family expression and caspase protease activity, and AECM may have therapeutic potential in human leukemia treatment.
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PMID:Growth inhibition of U937 leukemia cells by aqueous extract of Cordyceps militaris through induction of apoptosis. 1587 Sep 44

Induction of cytotoxicity and internucleosomal DNA fragmentation by 4-allyl-2-methoxyphenol (eugenol, EUG), 2-methoxy-4-methylphenol (MMP), 3,3'-dimethoxy-5,5'-di-2-propenyl-1,1'-biphenyl-2,2'-diol (bis-EUG) and 3,3'-di-methoxy-5,5'-dimethyl-1,1'-biphenyl-2,2'-diol (bis-MMP) were investigated in HL-60 leukemia cells. The 50% cytotoxic concentrations (CC50) for EUG, MMP, bis-EUG and bis-MMP were 0.38 mM, 0.38 mM, 0.18 mM and 0.20 mM, respectively. DNA fragmentation was induced most strongly by bis-EUG, followed by EUG, MMP and bis-MMP. The expression of MnSOD and, less strongly, Cu/ZnSOD activity, as assessed by acrylamide gel electrophoresis, was inhibited by EUG, suggesting mitochondrial dysfunction. The expression of the mRNAs for MnSOD and Cu/ZnSOD in HL-60 cells, as assessed by RT-PCR, was significantly inhibited by treatment with 1 mM EUG for 1 hour. Furthermore, inhibition of SOD mRNAs expression by EUG was strongly potentiated by the addition of 5 mM N-acetyl cysteine (NAC) or glutathione (GSH), whereas NAC or GSH alone did not affect the expression of SOD mRNAs. The cytotoxicity of EUG was significantly enhanced by high concentrations of NAC or GSH, which may be attributed to the inhibition of SOD mRNAs expression by the synergistic action of EUG and GSH or NAC. The regulatory effects of eugenol-related compounds on lipopolysaccharide (LPS)-induced cyclooxygenase-2 (COX-2) gene expression in RAW 264.7 cells were investigated by Northern blot analysis. Bis-EUG, MMP and bis-MMP inhibited COX-2 gene expression at concentrations of 300 microM, 500 microM and 500 microM, respectively. In contrast, no inhibitory effect of EUG was found over the wide concentration range of 10-500 microM, possibly as a result of the extensive mitochondrial dysfunction induced by this compound, which possesses potent pro-oxidative activity. Eugenol-related compounds, particularly bis-EUG, may act as nonsteroidal anti-inflammatory drug (NSAID)-like compounds.
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PMID:Induction of cytotoxicity and apoptosis and inhibition of cyclooxygenase-2 gene expression by eugenol-related compounds. 1610 Nov 37

Peroxisome proliferator-activated receptor-gamma (PPAR-gamma) is a transcription factor important in fat metabolism and PPAR-gamma agonists were recently demonstrated to affect proliferation, differentiation, and apoptosis of different cell types. In the present study, two PPAR-gamma agonists, 15-deoxy-delta (12,14)-prostaglandin J2 (15d-PGJ2) and a synthetic PPAR-gamma agonist troglitazone (TGZ), were used to investigate activated PPAR-gamma-induced apoptosis on human monocyte leukemia U937 and Mono Mac 6 cells in vitro. The results showed that both U937 and Mono Mac 6 cells demonstrated constitutive activation of COX-2 expression; treatment by 15d-PGJ2 and TGZ could induce apoptosis remarkably in human monocyte leukemia cells by disruption of mitochondrial membrane potential, activation of caspase-3, and causing cleavage of the caspase substrate poly (ADP-ribose) polymerase (PARP). Further studies revealed that treatment by both 15d-PGJ2 and TGZ remarkably downregulated COX-2 expression in these two kind of monocyte leukemia cells as measured by reverse transcriptase PCR (RT-PCR) and Western blot. Furthermore, the expression of Bcl-2 and Bcl-Xl and Mcl-1 was downregulated while Bax expression was upregulated concurrently after the cells were treated by these two agonists, and no variations were found in other Bcl-2 family members such as Bak, Bid, and Bad. Taken together, our results demonstrate for the first time that downregulation of cyclooxygenase-2 expression, disruption of mitochondrial membrane potential, activation of caspase-3, downregulation of Bcl-2, Bcl-Xl, and Mcl-1, and upregulation of Bax are involved in PPAR-gamma agonists-induced apoptosis in these two human monocyte leukemia cells.
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PMID:Downregulation of cyclooxygenase-2 expression and activation of caspase-3 are involved in peroxisome proliferator-activated receptor-gamma agonists induced apoptosis in human monocyte leukemia cells in vitro. 1708 25

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) induces apoptosis in many transformed cells; however, not all human tumors respond to TRAIL, potentially limiting its therapeutic utility. Although there is substantial evidence that cytotoxic drugs can augment sensitivity to TRAIL, it has become important to know what kinds of nontoxic drugs can be used together with TRAIL. We thus screened several natural compounds that can overcome resistance to TRAIL and found that a cycloanthranilylproline derivative, Fuligocandin B (FCB), an extract of myxomycete Fuligo candida, exhibited significant synergism with TRAIL. Treatment of the TRAIL-resistant cell line KOB with FCB and TRAIL resulted in apparent apoptosis, which was not induced by either agent alone. FCB increased the production of 15-deoxy-Delta(12,14) prostaglandin J(2) (15d-PGJ(2)), an endogenous PPAR gamma ligand, through activation of cyclooxygenase-2 (COX-2). This unique mechanism highlighted the fact that 15d-PGJ(2) directly enhanced sensitivity to TRAIL by inhibiting multiple antiapoptotic factors. More importantly, similar effects were observed in other leukemia cell lines irrespective of their origin. The enhancement was observed regardless of PPAR gamma expression and was not blocked even by peroxisome proliferator-activated receptor-gamma (PPAR gamma) siRNA. These results indicate that 15d-PGJ(2) sensitizes TRAIL-resistant cells to TRAIL in a PPAR gamma-independent manner and that the use of 15d-PGJ(2) or its inducers, such as FCB, is a new strategy for cancer therapy.
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PMID:A novel natural compound, a cycloanthranilylproline derivative (Fuligocandin B), sensitizes leukemia cells to apoptosis induced by tumor necrosis factor related apoptosis-inducing ligand (TRAIL) through 15-deoxy-Delta 12, 14 prostaglandin J2 production. 1755 Oct 94

Epidemiological studies indicate that exposure to environmental pollutants such as pesticides and dioxins leads to the pathogenesis of lymphoma and leukemia. Here, we show that activation of the aryl hydrocarbon receptor (AhR) by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) resulted in loss of the programmed cell death (apoptosis) response in three different lymphoma cell lines, which plays a key role in the development of cancer, especially lymphoma and leukemia. The AhR-mediated inhibition of apoptosis in vitro was associated with a clear increase of cyclooxygenase-2 (COX-2) and deregulation of genes of the B-cell lymphoma-2 (Bcl-2) family involved in apoptosis including Bcl-xl and Mcl-1 in several lymphoma cell lines. Treatment with the COX-2 inhibitor NS-398 and the AhR antagonist 3'-methoxy-4'-nitroflavone abolished the TCDD-induced resistance of apoptosis in vitro. Furthermore, using micropositron emission tomography imaging, in vivo findings demonstrated that exposure to TCDD promotes the development of lymphoma in superficial lymph nodes of C57BL/10J mice, which was associated with a marked increase of COX-2 expression in the affected lymph nodes. The results indicate that AhR activation and COX-2 overexpression likely represent a mechanism of resistance to apoptosis in lymphoma cell lines that might be relevant for the development of lymphoma in vivo.
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PMID:Pathogenesis of aryl hydrocarbon receptor-mediated development of lymphoma is associated with increased cyclooxygenase-2 expression. 1782 87

Recent studies confirmed that the new cell survival signal pathway of Insulin-PI3K-Akt exerted cyto-protective actions involving anti-apoptosis. This study was undertaken to investigate the potential neuroprotective effects of insulin in the pathogenesis of spinal cord injury (SCI) and evaluate its therapeutic effects in adult rats. SCI was produced by extradural compression using modified Allen's stall with damage energy of 40 g-cm force. One group of rats was subjected to SCI in combination with the administration of recombinant human insulin dissolved in 50% glucose solution at the dose of 1 IU/kg day, for 7 days. At the same time, another group of rats was subjected to SCI in combination with the administration of an equal volume of sterile saline solution. Functional recovery was evaluated using open-field walking, inclined plane tests, and motor evoked potentials (MEPs) during the first 14 days post-trauma. Levels of protein for B-cell lymphoma/leukemia-2 gene (Bcl-2), Caspase-3, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) were quantified in the injured spinal cord by Western blot analysis. Neuronal apoptosis was detected by TUNEL, and spinal cord blood flow (SCBF) was measured by laser-Doppler flowmetry (LDF). Ultimately, the data established the effectiveness of insulin treatment in improving neurologic recovery, increasing the expression of anti-apoptotic bcl-2 proteins, inhibiting caspase-3 expression decreasing neuronal apoptosis, reducing the expression of proinflammatory cytokines iNOS and COX-2, and ameliorating microcirculation of injured spinal cord after moderate contusive SCI in rats. In sum, this study reported the beneficial effects of insulin in the treatment of SCI, with the suggestion that insulin should be considered as a potential therapeutic agent.
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PMID:Anti-apoptotic effect of insulin in the control of cell death and neurologic deficit after acute spinal cord injury in rats. 1789 11

The aim of the present study was to assess genes expressed in maternal uterine tissue and pre-implantation embryos which are presumably involved in maternal recognition and establishment of canine pregnancy. For this purpose, 10 pregnant bitches were ovariohysterectomized between days 10 and 12 after mating. Four non-pregnant bitches served as controls. Early pregnancy was verified by flushing the uterine horns with PBS solution. The collected embryos (n = 60) were stored deep-frozen (-80 degrees C). Uterine tissue was excised, snaps frozen in liquid nitrogen and homogenized using TRI Reagent. All embryos from one litter were thawed together and also homogenized in TRI Reagent. RT-PCR was performed to prove mRNA expression of progesterone receptor, key enzymes of the prostaglandin synthesis pathway, selected growth factors, cytokines, immune cell receptors, major histocompatibility complex (MHC) and matrix-metalloproteinases (MMP). Only pregnant uteri revealed the presence of mRNA for interferon (IFN)-gamma, IL-4 and CD-8, which resembles the milieu in humans and other mammalians. Similarly, in day 10 embryos, mRNA for transforming growth factor-beta, insulin-like growth factor-1,-2, hepatocyte growth factor, leukaemia inhibitor factor, tumour necrosis factor-alpha, interleukin-1beta,-6,-8, cyclooxygenase-2, CD4(+) cells, and MMP-2 and -9 were detected, but not MHC-I or -II. We therefore suppose that the canine embryo, like its human counterpart, actively initiates measures to prevent attacks from the maternal immune system to prepare its own adhesion, nidation, growth and further development.
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PMID:Expression of genes in the canine pre-implantation uterus and embryo: implications for an active role of the embryo before and during invasion. 1839 90

Differentiation induction as a therapeutic strategy has, so far, the greatest impact in hematopoietic malignancies, most notably leukemia. Diosgenin is a very interesting natural product because, depending on the specific dose used, its biological effect is very different in HEL (human erythroleukemia) cells. For example, at 10 microM, diosgenin induced megakaryocytic differentiation, in contrast to 40 microM diosgenin, which induced apoptosis in HEL cells previously demonstrated using sedimentation field-flow fractionation (SdFFF). The goal of this work focused on the correlation between cyclooxygenase-2 (COX-2) and thromboxane synthase (TxS) and megakaryocytic differentiation induced by diosgenin in HEL cells. Furthermore, the technique of SdFFF, having been validated in our models, was used in this new study as an analytical tool that provided us with more or less enriched differentiated cell fractions that could then be used for further analyses of enzyme protein expression and activity for the first time. In our study, we showed the implication of COX-2 and TxS in diosgenin-induced megakaryocytic differentiation in HEL cells. Furthermore, we showed that the analytical technique of SdFFF may be used as a tool to confirm our results as a function of the degree of cell differentiation.
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PMID:Increased cyclooxygenase-2 and thromboxane synthase expression is implicated in diosgenin-induced megakaryocytic differentiation in human erythroleukemia cells. 1854 4

In order to identify the active anti-inflammatory ingredient(s) in Cirsium chanroenicum (Compositae), its methanol extract and several solvent fractions were prepared; the methanol extract and the ethylacetate fraction inhibited cyclooxygenase-2 (COX-2)-mediated prostaglandin E2 (PGE2) and 5-lipoxygenase (5-LOX)-mediated leukotriene (LT) production in lipopolysaccharide-treated RAW 264.7 cells and A23187-treated rat basophilic leukemia (RBL-1) cells, respectively. Further bioactivity-guided fractionation of the ethylacetate fraction using column chromatography led to the isolation of pectolinarigenin (5,7-dihydroxy-4',6-dimethoxyflavone), along with pectolinarin [pectolinarigenin 7-rhamnosyl-(1-->6)-glucoside]. Pectolinarigenin strongly inhibited COX-2-mediated PGE2 and 5-LOX-mediated LT production at >1 microM, indicating that it is a dual inhibitor of COX-2/5-LOX. However, pectolinarigenin did not affect COX-2 expression or nuclear transcription factor (NF-kappaB) activation. In addition, in vivo studies demonstrated that oral administration of these two compounds at 20-100 mg/kg resulted in similar inhibitory activities against several animal models of inflammation/allergy: arachidonic acid-induced mouse ear edema, carrageenan-induced mouse paw edema and passive cutaneous anaphylaxis. All of these results suggest that pectolinarigenin and pectolinarin possess anti-inflammatory activity and that they may inhibit eicosanoid formation in inflammatory lesions. These activities certainly contribute to the anti-inflammatory mechanism of C. chanroenicum.
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PMID:Anti-inflammatory activity of pectolinarigenin and pectolinarin isolated from Cirsium chanroenicum. 1898 74

The objective of this study was to investigate the effect of cyclooxygenase-2 (COX-2) in the angiogenesis of bone marrow in leukemia patients. 51 patients with newly diagnosed acute leukemia were taken as study objects, 18 healthy volunteers were enrolled in the control group. Bone marrow microvessel density (MVD) in bone marrow biopsy tissue section was determined with immunohistochemistry method, the vascular endothelial growth factor level in serum was detected with ELISA method and the expression of cyclooxygenase-2 in bone marrow cells was assayed by flow cytometry. The results showed that the MVD, VEGF level, positive rate of COX-2 expression in leukemia group all obviously increased as compared with the control group (p < 0.05). The correlative coefficients of MVD, VEGF level and COX-2 expression rate were 0.614, 0.423 and 0.577 respectively (p < 0.05). In conclusion, as well as solid tumors, leukemia may be also a angiogenesis-dependent malignant tumor. Coordination of COX-2 with VEGF may promote angiogenesis in bone marrow.
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PMID:[Expression of cyclooxygenase-2 in bone marrow cells of leukemia patients and its association with angiogenesis]. 1923 44

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