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)

Salicylates and nonsteroidal anti-inflammatory drugs (NSAIDs) induce apoptosis in a variety of cancer cells, including those of colon, prostate, breast, and leukemia. We examined the effects of sodium salicylate (NaSal) on reactive oxygen species (ROS) production and the association of these effects with apoptotic tumor cell death. We demonstrate that NaSal mediates ROS production followed by a decrease in mitochondrial membrane potential (deltapsi(m)), release of cytochrome c, and activation of caspase-9 and caspase-3. However, expression of Bcl-2 or Bcl-x(L) prevents ROS production and subsequent loss of deltapsi(m), thereby inhibiting apoptotic cell death. The presence of ROS scavengers and an inhibitor of NADPH oxidase or expression of a dominant negative form of Rac1 blocks ROS production, deltapsi(m) collapse, and the subsequent activation of caspases. These observations indicate that NaSal mediates ROS production critical in the triggering of apoptotic tumor cell death through a Rac1-NADPH oxidase-dependent pathway. Our data collectively imply that NaSal-induced ROS are key mediators of deltapsi(m) collapse, which leads to the release of cytochrome c followed by caspase activation, culminating in tumor apoptosis.
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PMID:Molecular ordering of ROS production, mitochondrial changes, and caspase activation during sodium salicylate-induced apoptosis. 1256 69

Recent reports indicate a broad spectrum of antileukemic activity for arsenic trioxide (As(2)O(3)) due to its ability to induce apoptosis via intracellular production of reactive oxygen species (ROS). Despite its potent apoptotic mechanism, As(2)O(3) is not equally effective in all leukemic cells, which has prompted a search for agents enhancing As(2)O(3) efficacy. Recently, evidence has been gathered that the polyunsaturated fatty acid docosahexaenoic acid (DHA) may sensitize tumor cells to ROS-inducing anticancer agents. The aim of our investigation was to evaluate whether DHA enhances As(2)O(3)-mediated apoptosis in As(2)O(3)-resistant HL-60 cells. While 1 microM As(2)O(3) or 25 microM DHA reduced cell viability to 85.8% +/- 2.9% and 69.2% +/- 3.6%, combined treatment with As(2)O(3) and DHA reduced viability to 13.0% +/- 9.9% with a concomitant increase of apoptosis. Apoptotic cell death was preceded by collapse of the mitochondrial membrane potential, increased expression of proapoptotic B-cell lymphoma protein-2-associated X protein (Bax), and caspase-3 activation. Importantly, the combined effect of As(2)O(3) and DHA was associated with increased production of intracellular ROS and toxic lipid peroxidation products and was abolished by the antioxidant vitamin E or when oleic acid (a nonperoxidizable fatty acid) was used in place of DHA. Intracellular ROS and toxic lipid peroxidation products most likely constitute the key mediators contributing to the combined effect of As(2)O(3) and DHA. Our data provide the first evidence that DHA may help to extend the therapeutic spectrum of As(2)O(3) and suggest that the combination of As(2)O(3) and DHA could be more broadly applied in leukemia therapy.
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PMID:Docosahexaenoic acid enhances arsenic trioxide-mediated apoptosis in arsenic trioxide-resistant HL-60 cells. 1260 32

The synergistic effect of ultrasound and drugs on cells is known as sonodynamic therapy. The use of sonodynamic therapy for the potential clinical treatment of certain tumors is promising, however, the mechanism of sonodynamic therapy could be due to either sonomechanical and/or sonochemical effects on the cells. The aim of the current study is to determine the importance of the sonochemical mechanism for sonodynamic therapy. Sonochemical effects arise from the formation of radical species following collapse of cavitation bubbles. The synergistic effect of ultrasound (47 kHz) and analogues of a gallium-porphyrin derivative (ATX-70) on cytolysis of Human leukemia cells (HL-525 and HL-60) suspended in a cell culture medium were studied. Organic surfactants preferentially accumulate and subsequently decompose at the gas/solution interface of cavitation bubbles, producing secondary radicals that can diffuse to the bulk solution. The gallium porphyrin analogues used in the current study possess two n-alkyl side chains (ATX-C(x), where x = number of carbon atoms, ranging from x = 2 to x = 12). By varying the n-alkyl chain length, thereby modifying the surfactant properties of the ATX-C(x) derivatives, cell killing in relation to the accumulation of ATX-C(x) derivatives at the gas/solution interface of cavitation bubbles was determined. Following sonolysis in the presence of ATX-C(x), a strong correlation for the yield of carbon-centered radicals and cell killing was observed. These results support the hypothesis that a sonochemical mechanism is responsible for the synergistic effect of ultrasound and ATX-C(x) on HL-525 and HL-60 cells.
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PMID:Correlation between sonochemistry of surfactant solutions and human leukemia cell killing by ultrasound and porphyrins. 1263 48

Sodium azide is a white crystalline solid used in the manufacture of the explosive lead azide. It is the principal chemical used to generate nitrogen gas in automobile safety airbags and airplane escape chutes and is a broad-spectrum biocide used in both research and agriculture. Toxicology and carcinogenicity studies were conducted by administering sodium azide (greater than 99% pure) in distilled water by gavage to groups of male and female F344/N rats once daily, 5 days per week for 14 days, 13 weeks, or 2 years. Genetic toxicology studies were conducted in Salmonella typhimurium and Chinese hamster ovary cells. 14-Day Studies: Rats received 0, 5, 10, 20, 40, or 80 mg/kg sodium azide. All male and female rats receiving 40 or 80 mg/kg and two of five female rats receiving 20 mg/kg died during the first week of the studies. Clinical findings of toxicity included lethargy and inactivity. No grossly observable lesions were present in any of the dose groups. 13-Week Studies: Rats received 0, 1.25, 2.5, 5, 10, or 20 mg/kg sodium azide. Seven of 9 males and all 10 females receiving 20 mg/kg died before the end of the studies. Final mean body weights of treated rats were within 10% of those of the controls. Compound-related clinical findings of toxicity in the 20 mg/kg dose groups included lethargy and labored breathing. Histopathologic lesions induced by sodium azide were limited to the brain (necrosis of the cerebrum and thalamus) and lung (congestion, hemorrhage, and edema), and were observed in rats receiving 20 mg/kg that died during the studies. Body Weights, Feed Consumption, and Survival in the 2-Year Studies: Because compound-related deaths were observed in the groups receiving 20 mg/kg in the 13-week studies, lower dose levels were used in the 2-year studies. Two-year studies were conducted by administering 0, 5, or 10 mg/kg sodium azide to groups of 60 male and 60 female rats. Dose-related depression in mean body weight was observed throughout the study period. Mean feed consumption values in low- and high-dose groups were lower than control values. Survival of high-dose rats of each sex was significantly (P<0.05) lower than controls (males-control, 24/60; low-dose, 27/60; high-dose, 9/60; females-37/60; 43/60; 21/59). The reduced survival was attributed to brain necrosis and cardiovascular collapse induced by sodium azide. Neoplastic and Nonneoplastic Effects in the 2-Year Studies: There were no compound-related increases in incidences of neoplasms in rats. Significantly decreased incidences were observed for certain neoplasms, including mononuclear cell leukemia in male rats (control, 33/60; low-dose, 28/60; high-dose, 14/60), adrenal gland pheochromocytoma in male rats (26/55; 16/56; 6/54), mammary gland fibroadenoma in female rats (20/60; 11/60; 8/59), and pituitary gland neoplasms in female rats (37/60; 28/60; 17/59). These decreases reflected to some extent, but could not be attributed solely to, the reduced survival of the high-dose groups. Compound-related nonneoplastic brain lesions (necrosis of the cerebrum and thalamus) were observed at significantly (P<0.001) increased incidences in high-dose male and female rats. The increased incidence of lung congestion observed in this dose group was considered due to cardiovascular collapse secondary to brain necrosis. Genetic Toxicology: Sodium azide was mutagenic in Salmonella typhimurium strains TA100 and TA1535, with or without exogenous metabolic activation (S9); it was not mutagenic in strain TA1537 or TA98. In cytogenetic tests with Chinese hamster ovary cells, sodium azide induced sister chromatid exchanges, but not chromosomal aberrations, in the presence and the absence of S9. Conclusions: Under the conditions of these 2-year gavage studies, there was no evidence of carcinogenic activity of sodium azide in male or female F344/N rats administered 5 or 10 mg/kg. Sodium azide induced necrosis in the cerebrum and the thalamus of the brain in both male and female rats. Synonyms: Azide, Azium, Smite
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PMID:NTP Toxicology and Carcinogeneis Studies of Sodium Azide (CAS: 26628-22-8) in F344 Rats (Gavage Studies). 1263 70

The Bcl-2 family proteins are major regulators of cell survival and death in human leukaemia. BH3-containing peptides induce apoptosis by binding to the hydrophobic pocket of the anti-apoptotic proteins, such as Bcl-2 or Bcl-XL. A small cell-permeable compound, BH3I-2' (3-iodo-5-chloro-N-[2-chloro-5-((4-chlorophenyl)sulphonyl)phenyl]-2-hydroxybenzamide), has been recently reported to have a function similar to Bak BH3 peptide. BH3I-2' induces apoptosis by disrupting interactions mediated by the BH3 domain, between pro-apoptotic and anti-apoptotic members of the Bcl-2 family. This study found that BH3I-2' induced cytochrome c release from the mitochondrial outer membrane in a Bax-dependent manner and that this correlated with the sensitivity of leukaemic cells to apoptosis. Moreover, it also induced rapid damage to the inner mitochondrial membrane, represented by a rapid collapse of mitochondrial membrane potential (DeltaPsim), prior to the cytochrome c release. This occurred both in whole cells and isolated mitochondria, and was not associated with the sensitivity of cells to BH3I-2'-induced apoptosis. Exogenous Bcl-2 or Bcl-XL neutralized BH3I-2'in vitro and diminished its effect on the inner mitochondrial membrane. Our results indicate that BH3I-2' not only induces cytochrome c release from the outer mitochondrial membrane but also damages the inner mitochondrial membrane, probably by interacting with Bcl-2 family proteins.
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PMID:BH3-domain mimetic compound BH3I-2' induces rapid damage to the inner mitochondrial membrane prior to the cytochrome c release from mitochondria. 1269 57

We have established that CpG oligodeoxynucleotide 5mers, of sequence type CGNNN (N = A, G, C or T), rapidly induce apoptosis/cell cycle arrest in human leukaemia lines. The 5'-CpG is obligatory for these effects. Induction of apoptosis in MOLT-4 cells did not require new protein synthesis and was insensitive to the caspase 3 inhibitor, Ac-DEVD-CHO, although the latter abrogated DNA laddering, phosphatidylserine externalization and collapse of the mitochondrial transmembrane potential. A subline of MOLT-4 cells, MOLT-4CpGR, was selected for acquired resistance to CpG 5mers. Differences in gene expression between MOLT-4 and MOLT-4CpGR cells were identified following three independent reciprocal cDNA subtractions, consensus selection and virtual cloning through targeted display. Several known genes were implicated in the action of or resistance to CpG oligodeoxynucleotide 5mers. Their protein products listed below immediately suggest cell signalling pathways/processes worthy of further investigation in elucidating the mechanism of CpG 5mer activity: caspase 2, the transcription factors Atf4, Hic, HoxB3 and Rqcd1, the splicing factors Rbmx, Sfrs5 and Sfrs7, the DNA replication factors Mcm5 and Brd4, phosphoinositide-3-kinase, annexin A1, mucosa-associated lymphoid tissue lymphoma translocation 1 and three enzymes involved in protein ubiquitylation, Siah1, Gsa7 and Nin283.
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PMID:CpG oligodeoxynucleotide 5mer-induced apoptosis in MOLT-4 leukaemia cells does not require caspase 3 or new protein synthesis. 1271 74

Arsenic trioxide (As(2)O(3)), an effective drug for the treatment of acute promyelocytic leukemia (APL), can induce apoptosis and partial differentiation in APL cells in vitro and in vivo. However, As(2)O(3) also induces apoptosis in cancer cells other than APL with complex mechanisms, which seem to be cell type dependent. In this study, we report that APL cells (NB4 cell line) are arrested at early mitotic phase before the collapse of mitochondrial transmembrane potential (Deltavarphi(m)) and apoptosis after treatment with pharmacological concentrations (1.0-2.0 micro M) of As(2)O(3). We have also made the following new discoveries: (1) 0.5 micro M As(2)O(3) that fails to induce apoptosis has no effects on cell cycle distribution. (2) With inhibition of As(2)O(3)-induced Deltavarphi(m) collapse and apoptosis, dithiothreitol also effectively inhibits As(2)O(3)-induced mitotic arrest, suggesting that both As(2)O(3)-induced apoptosis and mitotic arrest involve proteins with thiol groups. (3) 1.5 mM caffeine that relieves cells from G(2)/M arrest also inhibits As(2)O(3)-induced Deltavarphi(m) collapse and apoptosis, (4) 1.0 micro M As(2)O(3) increases the expression of both cyclin B(1) and hCDC20 whereas it inhibits Tyr15 phosphorylation of p34(cdc2). In conclusion, our results strongly support that there is a tight link between As(2)O(3)-induced apoptosis and mitotic arrest, the latter being one of common mechanisms for As(2)O(3)-induced apoptosis in cancer cells.
Leukemia 2003 Jul
PMID:Arsenic trioxide-induced mitotic arrest and apoptosis in acute promyelocytic leukemia cells. 1283 21

Splenic artery aneurysm presented with rupture is an unusual and potentially deadly reason of intraperitoneal hemorrhage. There are a lot of pathogenetic hypothesis; timing according to disease severity and surgical choices aren't definitely codified authors present one patient with hemoperitoneum for ruptured splenic artery aneurysm affected by chronic lymphatic leukaemia too and review international literature; they underline pathogenesis, symptoms, preoperative investigations and therapy. Degeneration of the media, atherosclerotic changes and high blood flow due to pregnancy and portal hypertension could be the main pathogenetic factors. Ultrasonography is the first investigation we have to practice if we suspect hemoperitoneum. We can practice computed tomography and angiography too if cardiovascular condition are good. Rupture showing acute abdominal pain and cardiovascular collapse suggest strongly urgent operation. The choice of operation is determined by location of the aneurysm. When located in the distal third of the splenic artery, the aneurysm is resected with spleen; alternatively, when it is located in prossimal third we can perform conservative operation.
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PMID:[Intraperitoneal hemorrhage from rupture of an aneurysm of splenic artery: case report and literature review]. 1287 Feb 88

The stromal structure of the bone marrow was studied in 96 cases of leukaemia and related disorders. The reticulin stroma forms an integral component of any given marrow proliferation and may often be increased in amount, sometimes normal, and occasionally decreased. The pattern is often indeterminate but certain distinguishable patterns may be found, including a sinusoidal pattern in myelofibrotic chronic myeloses, a pattern characterized by an abundance of hyperplastic capillaries and arterioles often seen in lymphoid leukaemias, and one with irregular focal reticulin proliferation in many acute undifferentiated leukaemias.Adventitious collagen fibres are demonstrable in about half of all myeloses, acute and chronic, leukaemic and aleukaemic, and may be diffuse or focal. They apparently develop from thickening and collapse and condensation of the basic reticulin network, not from any primary fibroblastic proliferation. The development of fibrosis does not denote an aetiological relationship between the conditions in which it occurs, since it appears to be a non-specific sequel to marrow exhaustion and marrow necrosis. There is no justification for the diagnosis of acute or ;malignant' myelofibrosis as a disease entity in cases of acute leukaemia with marrow fibrosis.Osteolytic change due to resorption of bony trabeculae is a common event in all the conditions studied and may be accompanied by remoulding of the eroded trabeculae. Fibre bone formation is found in about 15% of cases, including acute lymphoblastic leukaemias and acute undifferentiated leukaemias, but is extensive and well-developed only in cases of primary myelofibrosis.
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PMID:STROMAL CHANGES IN LEUKAEMIC AND RELATED BONE MARROW PROLIFERATIONS. 1420 89

Chalcones are being considered as anticancer agents as they are natural compounds that are particularly cytotoxic towards K562 leukemia or melanoma cells. In this study, we have investigated phloretin, isoliquiritigenin, and 10 other hydroxylated chalcones for their cytotoxic mechanisms towards isolated rat hepatocytes. All hydroxychalcones partly depleted hepatocyte GSH and oxidized GSH to GSSG. These chalcones also caused a collapse of mitochondrial membrane potential and increased oxygen uptake. Furthermore, glycolytic or citric acid cycle substrates prevented cytotoxicity and mitochondrial membrane potential collapse. The highest pKa chalcones were the most effective at collapsing the mitochondrial membrane potential which suggests that the cytotoxic activity of hydroxychalcones are likely because of their ability to uncouple mitochondria.
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PMID:Molecular cytotoxic mechanisms of anticancer hydroxychalcones. 1522 57


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