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)

Melanoma-derived lipoprotein lipase inhibitor (MLPLI) is a factor purified from the conditioned medium of a human melanoma cell line, SEKI, which induced severe cachexia in tumor-bearing nude mice. Amino acid sequencing revealed that the amino-terminal portion was identical to that of leukemia-inhibitory factor (LIF). To determine whether MLPLI is actually LIF, the expression of LIF mRNA was examined in the SEKI melanoma cell line. Northern blot analyses revealed that the cell line displayed an intense hybridizable band with a molecular size of 3.8 kilobases, suggesting that MLPLI is identical to LIF. The relationship between the development of the cancer cachexia syndrome and the expression of LIF mRNA was examined in four melanoma xenografts, SEKI, G361, A375 and MEWO, in nude mice. SEKI- and G361-bearing nude mice developed cancer cachexia syndrome, and their body weights decreased by the 25th day after the transplantation to 73.6% and 73.8% of the control, respectively. A375- and MEWO-bearing nude mice, however, did not develop the syndrome. Northern blot analyses revealed that G361 as well as SEKI expressed a large amount of LIF mRNA, but A375 and MEWO did not, suggesting a close relationship between the expression of LIF mRNA and the development of the syndrome. These data support the concept that MLPLI, or LIF, plays an important role in the development of the cancer cachexia syndrome observed in melanoma-bearing nude mice.
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PMID:Cancer cachexia syndrome developed in nude mice bearing melanoma cells producing leukemia-inhibitory factor. 174 40

Studies were conducted on lipemic serum obtained from a 26 month old male to determine possible mechanisms for the association of a Type V hyperlipidemic phenotype with advanced lymphoblastic leukemia (ALL). Antibodies to apolipoproteins and endogenous heparin were not detected as previously reported. Fatty acid analysis of the triglyceride esters revealed a high proportion of stearic-acid (18:0) which was associated with a slower in vitro degradation of very low density lipoproteins (VLDL) by human milk lipoprotein lipase (LPL). This suggests that a cause of the hyperlipidemia could be abnormal composition of triglycerides which render the VLDL a poor substrate for lipoprotein lipase. Hyperlipidemia in leukemia may be more prevalent than previously realized since nine other cases of newly diagnosed ALL have been studied who had moderate hypertriglyceridemia associated with elevated ApoB and low ApoA-I levels, but normal triglyceride composition. These findings suggest that the abnormal triglyceride composition is a late feature of the hyperlipidemia in leukemia, as observed in the case studied.
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PMID:Hyperlipidemia in acute lymphoblastic leukemia. 658 75

Endotoxin (lipopolysaccharide [LPS]) stimulates the production of cytokines, which mediate many of the metabolic effects associated with infection. In LPS-sensitive C57B1/6 mice, LPS doses as low as 0.01 micrograms per mouse decreased adipose tissue lipoprotein lipase (LPL) activity by greater than 50%. In LPS-resistant C3H/HeJ mice, which do not produce cytokines in response to LPS, doses of LPS as high as 10 micrograms per mouse did not affect LPL activity in adipose tissue. In muscle of C57Bl/6 mice, LPL activity was decreased by 27% after 10 micrograms of LPS, whereas in C3H/HeJ mice there was no effect. These results indicate that the LPS-induced decrease in both adipose and muscle LPL activity is mediated by cytokines. Tumor necrosis factor (TNF), interleukin (IL)-1, leukemia-inhibiting factor (LIF), interferon alfa, and interferon gamma all decreased adipose tissue LPL activity in intact mice. In skeletal and cardiac muscle, only IL-1 and interferon gamma decreased LPL activity, whereas TNF, LIF, and interferon alfa had no effect. Inhibition of TNF activity blocked the increase in serum triglycerides that is characteristically observed after LPS but did not affect the ability of LPS to decrease adipose tissue LPL activity. Inhibition of IL-1 activity with IL-1 receptor antagonist partially inhibited the increase in serum triglycerides; however, the ability of LPS to decrease LPL activity in either adipose or muscle tissue was not affected. These data indicate that although TNF and IL-1 play a role in mediating the increase in serum triglyceride levels, these cytokines do not play a crucial role in the inhibition of either adipose or muscle LPL activity.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effect of endotoxin and cytokines on lipoprotein lipase activity in mice. 794 14

Alterations in lipid metabolism characterized in major part by a decrease in lipoprotein lipase (LPL) activity in adipose tissue are a central feature of cachexia from chronic infection or malignancy. These metabolic derangements may be mediated in large part through endogenous host proteins produced in response to various pathological stimuli. Differentiation factor/leukaemia inhibitory factor (D-factor) is a cytokine whose functions overlap those of tumour necrosis factor-alpha (TNF), IL-6 and IL-1. Recombinant murine D-factor produced a dose- and time-dependent inhibition of heparin-releasable LPL activity in differentiated 3T3-L1 adipocytes. Although 2-10 fold less potent than recombinant murine TNF, D-factor inhibited LPL activity at concentrations of 1-10 ng/ml. When added together, D-factor and TNF produced a synergistic inhibition of LPL activity. Interleukin 6 (IL-6) was 100-fold less potent than D-factor; 0.1 ng/ml of D-factor or 10 ng/ml of IL-6 caused a 50% inhibition of LPL activity. D-factor and TNF increased IL-6 production in 3T3-L1 cells. Ten ng/ml of D-factor or 1.0 ng/ml of TNF stimulated the release of < 1 ng/ml of IL-6 and inhibited LPL activity to 11 +/- 3% and 3 +/- 2% of control, respectively, whereas 50 ng/ml of recombinant IL-6 was required to decrease LPL activity to 24 +/- 19% of control. TNF produced a marked decrease in LPL mRNA, whereas D-factor had minimal or no effect at doses which inhibited LPL activity almost completely. Western blot analysis of cell extracts showed that TNF caused a greater decrease in LPL protein production than D-factor.2+ with TNF, may contribute to the manifestations of cachexia.
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PMID:Characterization of differentiation factor/leukaemia inhibitory factor effect on lipoprotein lipase activity and mRNA in 3T3-L1 adipocytes. 794 51

Cachexia is a common problem in the clinical management of cancer patients, particularly those with solid tumors. Cachexia is most obviously manifested as weight loss with massive depletion of both adipose tissue and muscle mass, and death is probably due to loss of lean body tissue. Not only is the survival time shorter in patients with cachexia, but the frequency of response to chemotherapy is also significantly reduced. Although anorexia frequently accompanies cachexia, attempts to halt or reverse cachexia by nutritional repletion have not been successful. This suggests that cachexia is due to metabolic abnormalities produced by the tumor in addition to the underlying anorexia. In some patients weight loss is associated with an increased relative energy expenditure possibly through an elevated adrenergic state. Several factors have been postulated as mediators of cancer cachexia and can be divided into two groups. (i) Materials with hormone-like characteristics which result in direct catabolism of host tissues. (ii) Cytokines which cause alterations in host metabolism indirectly. Included in group (i) are the conventional catabolic hormones and a lipid mobilizing factor (LMF) produced by tumors, which causes direct breakdown of adipose tissue. Included in group (ii) are tumor necrosis factor-alpha, interleukin-6, interferon-gamma and leukaemia inhibitory factor. The materials appear to influence adipose tissue indirectly through an inhibition of lipoprotein lipase. Reversal of cachexia has been achieved by two groups of agents. (i) Those stimulating food intake, e.g. megestrol acetate. (ii) Those directly inhibiting the LMF, e.g. eicosapentaenoic acid. While agents in group (i) can cause tumor growth stimulation, those in group (ii) act as tumor growth inhibitors. This latter results suggests that the products of catabolism of host tissues may be important for tumor growth and provides a new avenue for chemotherapeutic intervention.
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PMID:Cancer cachexia. 849 Jan 91

Precursors from the neuroepithelium of the developing cortex and the adult subventricular zone can be cloned in vitro after stimulation with fibroblast growth factor 2 (FGF-2), and they have the potential to give rise to both neurons and glia. The generation of neurons from these clones can be stimulated by either a factor derived from an astrocyte precursor line, Ast-1, or FGF-1. We have shown that neuronal differentiation stimulated by FGF-1 can be inhibited by diacylglycerol lipase inhibitor and mimicked by arachidonic acid, suggesting that the neuronal differentiation is signalled through the phospholipase C gamma pathway. The sequential expression of FGF-2, followed by FGF within the developing forebrain neuroepithelium, fits with the different functions that the two FGFs play in precursor regulation. We have shown that the precursor response to FGF-1 is regulated by a heparan sulphate proteoglycan expressed within the developing neuroepithelium. Precursors restricted to the astrocyte cell lineage can be stimulated by epidermal growth factor or FGF-2F however, the differentiation into glial fibrillary acidic protein-positive astrocytes appears to require a cytokine acting through the leukaemia inhibitory factor-beta receptor.
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PMID:Factors regulating the differentiation of neural precursors in the forebrain. 872 88

The regulation of macrophage lipoprotein lipase (LPL) by cytokines is of potentially crucial importance in the pathogenesis of atherosclerosis and in the responses to endotoxin challenge. However, the precise mechanisms by which different cytokines modulate the expression of macrophage LPL activity are poorly understood. The action of six cytokines and bacterial lipopolysaccharide (LPS) on LPL function using the murine J774.2 cell line as a model system has, therefore, been studied. Although exposure to LPS, interleukin 11 (IL-11), tumour necrosis factor alpha (TNF-alpha), interferon gamma (IFN-gamma) and IL-1, over the physiological range of concentrations, resulted in a decrease in the heparin-releasable LPL activity, LPL-mRNA levels and LPL-protein content of the cells, stimulation with IL-6 and leukaemia inhibitory factor (LIF) had no effect. The maximum suppression of LPL activity and mRNA levels in the cells by IFN-gamma (60%) was lower than that produced by LPS, IL-11, TNF-alpha and IL-1 (78-97%). Each cytokine displayed a characteristic dose-dependent pattern for the suppression of LPL activity and mRNA levels with IL-11/TNF-alpha being more potent than IFN-gamma/IL-1. More than 80% of the decrease in the LPL activity, at all doses of IL-11, TNF-alpha, IFN-gamma and IL-1, was due to a corresponding reduction in the mRNA levels. The time course of responses to LPS, IL-11, TNF-alpha, IFN-gamma and IL-1 were similar, with the time required to achieve half maximal suppression of LPL activity being between 7 and 9.5 h in each case. These results indicate that LPL in J774.2 macrophages is regulated differentially by various cytokines and that the major control responsible for the reduction of LPL activity by IL-11, TNF-alpha, IFN-gamma and IL-1 is exerted at the level of mRNA metabolism (decreased transcription or RNA stability). The responses identified also displayed several differences to those described previously for adipocytes (e.g. 3T3-L1 cell line), thereby suggesting the existence of potential cell-specific mechanisms for the regulation of LPL by cytokines.
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PMID:Differential regulation of lipoprotein lipase in the macrophage J774.2 cell line by cytokines. 889 33

A 13-year-old girl with acute lymphoblastic leukemia (ALL) developed extremely high plasma triglyceride (TG) concentrations of 103 mmol/l (reference value <1.8 mmol/l) during combination treatment with corticosteroids and asparaginase. Corticosteroids are known to induce the production of TG-rich particles. On the other hand, corticosteroids increase the activity of lipoprotein lipase (LPL), a key enzyme in the removal of TG from plasma. Generally, the increased LPL activity prevents an extreme rise in TG levels upon therapy with corticosteroids. In our patient, we found that the corticosteroid-induced LPL activity dramatically declined after therapy with L-asparaginase. This suggests that the extensive hypertriglyceridemia in our patient was due to an L-asparaginase-induced decrease in LPL activity. This hypothesis was further supported by the finding that hypertriglyceridemia was less severe when corticosteroids and asparaginase were given separately.
Leukemia 1997 Aug
PMID:Transient hyperlipidemia during treatment of ALL with L-asparaginase is related to decreased lipoprotein lipase activity. 926 96

The regulation of macrophage lipoprotein lipase (LPL) by cytokines is of potentially crucial importance in the pathogenesis of atherosclerosis. The effect of combinations of interleukin 1 (IL-1), 6 (IL-6), and 11 (IL-11), interferon gamma (INF-gamma), leukaemia inhibitory factor (LIF) and tumour necrosis factor alpha (TNF-alpha) on the expression of LPL in macrophages was studied using the murine J774.2 cell line. The suppression of heparin-releasable LPL activity produced by combinations of IL-1 and IL-11, IL-1 and TNF-alpha, IL-11 and TNF-alpha, and, IL-11 and INF-gamma was substantially lower than that expected from the additive action of the corresponding two cytokines. By contrast, co-exposure of cells to LIF and IFN-gamma, IL-6 and LIF, and INF-gamma and TNF-alpha resulted in a more than additive, synergistic, suppression of LPL activity with the maximum reduction and maximum degree of synergism produced by combinations of IFN-gamma and TNF-alpha. The synergism between IFN-gamma and TNF-alpha was observed over a range of complementary dose combinations and also occurred when the cells were exposed first to INF-gamma (priming), washed, and then stimulated subsequently with TNF-alpha. The reduction in LPL activity by combinations of IFN-gamma and TNF-alpha and the priming action of IFN-gamma were accompanied by a comparable decrease in LPL mRNA concentrations, thereby indicating that the major control responsible for the changes in LPL activity was being exerted at the level of mRNA metabolism (decreased transcription or RNA stability). These results suggest that the modulation of macrophage LPL function in atherosclerosis by cytokine combinations may be more important than the presence or absence of any given cytokine.
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PMID:Synergism between interferon gamma and tumour necrosis factor alpha in the regulation of lipoprotein lipase in the macrophage J774.2 cell line. 950 44

Overexpression of SSAT (polyamine catabolic enzyme) in female mice results in impaired ovarian folliculogenesis and uterine hypoplasia. To identify the molecular basis for this, the gene expression profiles in uterus and ovary and for comparison, liver and kidney, from non-transgenic (NT) and SSAT transgenic (ST) mice were compared. The mRNA abundance for lipoprotein lipase and glyceraldehyde-3-phosphate dehydrogenase was elevated in all four ST (>NT) tissues. The translation initiation factor-3 subunit 5 mRNA, and transcripts related to endogenous murine leukemia provirus (MLV-related) and murine retrovirus-related sequences (MuRRS) were decreased in ST tissues. A novel calmodulin-related mRNA was strongly induced in ST liver and kidney. SSAT overexpression was associated with increased levels of IGF-binding protein-2 (IGFBP-2) in the uterus and ovary, and a reduction in IGFBP-3 mRNA levels in the uterus. Exogenous spermidine and spermine elevated endogenous IGFBP-2 and SSAT mRNA abundance, whereas, putrescine stimulated IGFBP-2 mRNA abundance and transfected IGFBP-2 gene promoter activity in human (Hec-1-A) uterine cells. Sp1 and BTEB1 mRNAs that encode transcription factors for the IGFBP-2 gene also were induced in some ST tissues. The data suggest that SSAT and polyamines are important for the control of molecular pathways underlying reproductive tract tissue growth, phenotype, and function.
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PMID:Altered levels of growth-related and novel gene transcripts in reproductive and other tissues of female mice overexpressing spermidine/spermine N1-acetyltransferase (SSAT). 1170 47


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