Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026764 (multiple myeloma)
 36,148 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Rat liver microsomal 3-hydroxy-3-methylglutaryl-CoA reductase [HMG-CoA reductase; mevalonate:NADP+ oxidoreductase (CoA-acylating), EC 1.1.1.34], the key regulatory enzyme in cholesterol biosynthesis, has been purified to apparent homogeneity. Purified HMG-CoA reductase yields a single diffuse band when NaDodSO4/polyacrylamide gels are stained with Coomassie blue and yields two adjacent bands when gels are stained with silver. Purified reductase was used to elicit the production of monoclonal antibodies. Spleen cells from BALB/c mice immunized with purified HMG-CoA reductase were fused with Sp-2/0 myeloma cells. Clones producing monoclonal antibodies to HMG-CoA reductase were identified by using a solid-phase radioimmunoassay and were subcloned in soft agar. The three relatively stable hybridoma lines isolated secrete different Igs as judged by their antibody subclasses and differing abilities to inhibit HMG-CoA reductase in solution. Efficient precipitation of solubilized HMG-CoA reductase was achieved with the two IgG antibodies but not with the IgM. A mixture of all three monoclonal antibodies immunoprecipitates more than 90% of the HMG-CoA reductase activity in solubilized rat liver extracts. These monoclonal antibodies should be useful probes for investigation of the regulation of HMG-CoA reductase and cholesterol synthesis.
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PMID:Production and characterization of monoclonal antibodies to rat liver microsomal 3-hydroxy-3-methylglutaryl-coenzyme A reductase. 695 16

Lovastatin is an irreversible inhibitor of HMG-CoA reductase and blocks the production of mevalonate, a critical compound in the production of cholesterol and isoprenoids. Isoprenylation of target proteins, like the GTP-binding protein Ras, is essential for their membrane localization and subsequent participation in intracellular signaling cascades. Lovastatin effectively decreased the viability of plasma cells from cell lines (n = 10) and myeloma patients' samples (n = 8) in a dose- and time-dependent way. Importantly, co-incubation of lovastatin with dexamethasone had a synergistic effect in inducing plasma cell cytotoxity. This effect was not the consequence of a change in the protein expression levels of Bcl-2 or Bax induced by lovastatin. The decrease in plasma cell viability was the result of induction of apoptosis and inhibition of proliferation. Mevalonate effectively reversed the cytotoxic and cytostatic effects of lovastatin in plasma cells. The cytotoxic activity of lovastatin was higher in Pgp expressing cell lines, but did not correlate with the multidrug resistance (MDR)-related proteins LRP, Bcl-2 and Bax. Lovastatin treatment resulted in a shift of Ras localization from the membrane to the cytosol that was reversed by mevalonate. The data presented in this paper warrant study of lovastatin alone or in combination with therapeutic drugs, in the treatment of myeloma patients.
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PMID:The cholesterol lowering drug lovastatin induces cell death in myeloma plasma cells. 1209 62

HMG-CoA reductase is the rate-limiting enzyme of the mevalonate pathway leading to the formation of cholesterol and isoprenoids such as farnesylpyrophosphate (FPP) and geranylgeranylpyrophosphate (GGPP). The inhibition of HMG-CoA reductase by lovastatin induced apoptosis in plasma cell lines and tumor cells from patients with multiple myeloma. Here we show that cotreatment with mevalonate or geranylgeranyl moieties, but not farnesyl groups, rescued myeloma cells from lovastatin-induced apoptosis. In addition, the inhibition of geranylgeranylation by specific inhibition of geranylgeranyl transferase I (GGTase I) induced the apoptosis of myeloma cells. Apoptosis triggered by the inhibition of geranylgeranylation was associated with reduction of Mcl-1 protein expression, collapse of the mitochondrial transmembrane potential, expression of the mitochondrial membrane protein 7A6, cytochrome c release from mitochondria into the cytosol, and stimulation of caspase-3 activity. These results imply that protein geranylgeranylation is critical for regulating myeloma tumor cell survival, possibly through regulating Mcl-1 expression. Our results show that pharmacologic agents such as lovastatin or GGTase inhibitors may be useful in the treatment of multiple myeloma.
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PMID:Inhibition of protein geranylgeranylation induces apoptosis in myeloma plasma cells by reducing Mcl-1 protein levels. 1285 56

This study assessed the changes in the isoprenoid pathway and its metabolites digoxin, dolichol and ubiquinone in multiple myeloma. The following parameters were assessed: isoprenoid pathway metabolites, tyrosine and tryptophan catabolites, glycoconjugate metabolism, RBC membrane composition and free radical metabolism. There was elevation in plasma HMG CoA reductase activity, serum digoxin and dolichol and a reduction in RBC membrane Na+ - K+ ATPase activity, and serum ubiquinone levels. Serum tryptophan, serotonin, nicotine, strychnine and quinolinic acid were elevated while tyrosine, dopamine, noradrenaline and morphine were decreased. The total serum glycosaminoglycans and glycosaminoglycan fractions, the activity of GAG degrading enzymes and glycohydrolases, carbohydrate residues of glycoproteins and serum glycolipids were elevated. The RBC membrane glycosaminoglycans, hexose and fucose residues of glycoproteins, cholesterol and phospholipids were reduced. The activity of all free radical scavenging enzymes, concentration of glutathione, iron binding capacity and ceruloplasmin decreased significantly while the concentration of lipid peroxidation products and NO increased. Hyperdigoxinemia related altered intracellular Ca++ mediated oncogene activation, dolichol induced altered glycoconjugate metabolism and ubiquinone deficiency related mitochondrial dysfunction can contribute to the pathogenesis of multiple myeloma. The biochemical findings reported could be the cause or the consequence of multiple myeloma.
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PMID:Isoprenoid pathway related cascade in multiple myeloma. 1285 16

This study assessed the changes in the isoprenoid pathway and its metabolites digoxin, dolichol, and ubiquinone in multiple myeloma. The isoprenoid pathway and digoxin status were also studied for comparison in individuals of differing hemispheric dominance to find out the rote of cerebral dominance in the genesis of multiple myeloma and neoplasms. The following parameters were assessed: isoprenoid pathway metabolites, tyrosine and tryptophan catabolites, glycoconjugate metabolism, RBC membrane composition, and free radical metabolism--in multiple myeloma, as well as in individuals of differing hemispheric dominance. There was elevation in plasma HMG CoA reductase activity, serum digoxin, and dolichol, and a reduction in RBC membrane Na(+)-K+ ATPase activity, serum ubiquinone, and magnesium levels. Serum tryptophan, serotonin, nicotine, strychnine, and quinolinic acid were elevated, while tyrosine, dopamine, noradrenaline, and morphine were decreased. The total serum glycosaminoglycans and glycosaminoglycan fractions, the activity of GAG degrading enzymes and glycohydrolases, carbohydrate residues of glycoproteins, and serum glycolipids were elevated. The RBC membrane glycosaminoglycans, hexose, and fucose residues of glycoproteins, cholesterol, and phospholipids were reduced. The activity of all free-radical scavenging enzymes, concentration of glutathione, iron binding capacity, and ceruloplasmin decreased significantly, while the concentration of lipid peroxidation products and nitric oxide increased. Hyperdigoxinemia-related altered intracellular Ca++/Mg++ ratios mediated oncogene activation, dolichol-induced altered glycoconjugate metabolism, and ubiquinone deficiency-related mitochondrial dysfunction can contribute to the pathogenesis of multiple myeloma. The biochemical patterns obtained in multiple myeloma are similar to those obtained in left-handed/right hemispheric chemically dominant individuals by the dichotic listening test. But all the patients with multiple myeloma were right-handed/left hemispheric dominant by the dichotic listening test. Hemispheric chemical dominance has no correlation with handedness or the dichotic listening test. Multiple myeloma occurs in right hemispheric chemically dominant individuals and is a reflection of altered brain function.
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PMID:Hypothalamic digoxin, hemispheric chemical dominance, and oncogenesis: evidence from multiple myeloma. 1460 44

In order to investigate the anti-tumor activity of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors and the mechanism underlying the cell proliferation and apoptosis modulated in myeloma cells, the effects of mevastatin, an HMG-CoA reductase inhibitor, on cell growth, cell cycle progression and apoptosis in U266 human multiple myeloma (MM) cell line in vitro were explored by MTT colorimetric assay, morphologic observation, flow cytometry, DNA gel electrophoresis, and RT-PCR. The results demonstrated that mevastatin inhibited the growth of U266 cells in time- and dose-dependent manners. Cell cycle analysis showed that U266 cells underwent G(0)/G(1) arrest under exposure to mevastatin, but it did not affect p27 expression at both mRNA and protein level. Morphologic observations revealed cytoplasm shrinkage, nuclear condensation and fragmentation in mevastatin-treated cells, and fraction of annexin V(+)PI(-) cells increased significantly in the presence of the agent as determined by flow cytometric assay. In addition, mevastatin caused the collapse of mitochondrial transmembrane potential (Deltapsim), induced DNA fragmentation, and down-regulated the mRNA expression of bcl-2. The growth-inhibitory, cell cycle arresting, and proapoptotic effects of mevastatin in U266 cells could be effectively reversed by the addition of mevalonate (MVA), the immediate endproduct of the reaction catalyzed by HMG-CoA reductase. It is concluded that mevastatin suppresses proliferation by inducing G(0)/G(1) phase arrest and triggering apoptosis via down-regulation of bcl-2 and reduction of Deltapsim, which may be attributed to the inhibition of MVA pathway by mevastatin. Statins including mevastatin may find their future application in the treatment of MM.
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PMID:[In vitro effects of mevastatin on the proliferation and apoptosis in human multiple myeloma cell line U266]. 1522 63

Apomine, a novel 1,1 bisphosphonate ester, increases the rate of degradation of HMG-CoA reductase, inhibiting the mevalonate pathway and thereby blocking cholesterol biosynthesis. We have investigated whether Apomine can induce myeloma cell apoptosis in vitro and modulate myeloma disease in vivo. Apomine induced a dose-dependent increase in apoptosis in NCI H929, RPMI 8226 and JJN-3 human myeloma cells. Apomine, unlike the bisphosphonate, alendronate, had no measurable effect on osteoclastic bone resorption in vitro. To investigate the effect of Apomine in vivo, 5T2MM murine myeloma cells were injected into C57BL/KaLwRij mice. After 8 weeks all animals had a serum paraprotein and were treated with Apomine (200 mg/kg), or vehicle, for 4 weeks. Animals injected with 5T2MM cells and treated with vehicle developed osteolytic bone lesions, reduced cancellous bone area, decreased bone mineral density (BMD) and increased osteoclast number. Apomine caused a decrease in serum paraprotein and a decrease in tumor burden. Apomine inhibited the development of osteolytic lesions and prevented the tumor-induced decreases in BMD. Apomine had no effect on osteoclast number in contrast to what had been seen previously with the bisphosphonate, zoledronic acid, suggesting that these are direct effects of Apomine on myeloma cells. This demonstrates that Apomine is able to promote myeloma cell apoptosis in vitro and inhibit the development of multiple myeloma and lytic bone disease in vivo. The use of bisphosphonate esters such as Apomine represents a novel therapeutic approach in the treatment of myeloma and, indirectly, the associated bone disease.
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PMID:Apomine, an inhibitor of HMG-CoA-reductase, promotes apoptosis of myeloma cells in vitro and is associated with a modulation of myeloma in vivo. 1723 May 22

Interactions between UCN-01 and HMG-CoA reductase inhibitors (ie, statins) have been examined in human leukemia and myeloma cells. Exposure of U937 and U266 cells to minimally toxic concentrations of UCN-01 and various statins (eg, lovastatin, simvastatin, or fluvastatin) dramatically increased mitochondrial dysfunction, caspase activation, and apoptosis. Comparable effects were observed in other leukemia and myeloma cell lines as well as in primary acute myeloid leukemia (AML) blasts but not in normal hematopoietic cells. Potentiation of UCN-01 lethality by lovastatin was associated with disruption of Ras prenylation and activation. These events were significantly attenuated by farnesyl pyrophosphate (FPP) but not by geranylgeranyl pyrophosphate (GGPP), implicating perturbations in farnesylation rather than geranylgeranylation in synergistic interactions. Coexposure to statins and UCN-01 resulted in inactivation of ERK1/2 and Akt, accompanied by JNK activation. U266 cells ectopically expressing JNK1-APF, a dominant negative JNK1 mutant, displayed significantly reduced susceptibility to lovastatin/UCN-01-mediated lethality. Moreover, transfection of U266 cells with constitutively activated H-Ras (Q61L) attenuated ERK1/2 inactivation and dramatically diminished the lethality of this regimen. Collectively, these findings indicate that HMG-CoA reductase inhibitors act through a Ras farnesylation-associated mechanism to induce signaling perturbations, particularly prevention of Ras and ERK1/2 activation, in UCN-01-treated cells, resulting in the synergistic induction of cell death.
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PMID:Statins synergistically potentiate 7-hydroxystaurosporine (UCN-01) lethality in human leukemia and myeloma cells by disrupting Ras farnesylation and activation. 1726 3

Apomine, a 1,1-bisphosphonate-ester with antitumor activity, has previously been reported to strongly down-regulate 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMG-CoA reductase), the rate-limiting enzyme in the mevalonate pathway responsible for the prenylation of proteins. Here, we show that although apomine down-regulated HMG-CoA reductase protein levels in myeloma cells, it did not inhibit protein prenylation, and apomine-induced apoptosis could not be prevented by mevalonate, indicating that apomine cytotoxicity is independent from its effects on HMG-CoA reductase. Instead, apomine cytotoxicity was prevented by the addition of phosphatidylcholine, which is similar to the previously reported ability of phosphatidylcholine to overcome the cytotoxicity of farnesol, whereas phosphatidylcholine had no effect on down-regulation of HMG-CoA reductase by apomine. These findings raised the possibility that apomine, independent from its own cytotoxic effects, could enhance the antitumor effects of the competitive HMG-CoA reductase inhibitor lovastatin via down-regulating HMG-CoA reductase. Indeed, treatment with apomine in combination with lovastatin resulted in synergistic decreases in viable cell number and induction of apoptosis. At the concentrations used, apomine down-regulated HMG-CoA reductase protein levels without being cytotoxic. Accumulation of unprenylated Rap1A by lovastatin was enhanced in the presence of apomine. Furthermore, synergy was completely prevented by mevalonate, and apomine did not synergize with desoxolovastatin, which does not inhibit HMG-CoA reductase. We conclude that the synergistic drug interaction results from an enhancement by apomine of the effects of lovastatin, mediated by down-regulation of HMG-CoA reductase by apomine. Thus, these findings demonstrate a novel strategy for enhancing the antitumor effects of lovastatin.
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PMID:Apomine enhances the antitumor effects of lovastatin on myeloma cells by down-regulating 3-hydroxy-3-methylglutaryl-coenzyme A reductase. 1741 84

Adhesion is a hallmark of haematological and solid cancer cells. All five classes of cell adhesion molecules (CAM) - integrins, cadherins, immunoglobulin-like CAMs, selectins and CD44s - are characteristically dysregulated in human cancer. Adhesion enables and promotes cancer-defining biological processes like growth, survival, migration, extravasation, homing, and metastasis. Furthermore, cell adhesion mediates drug resistance (CAM-DR) in multiple myeloma, malignant lymphoma, acute and chronic leukaemias, as well as in pancreatic cancer, neuroblastoma, small cell and non-small cell lung cancer, mesothelioma, colorectal carcinoma, and breast cancer. Cell adhesion protects from death by radiation, genotoxic chemotherapy, or targeted pathway inhibitors. Adhesion molecules are overexpressed on drug resistant cells (e.g. multiple myeloma or prostate cancer). Very recently, several cell adhesion mediated survival pathways have been elucidated, with key mediators being LFA-1, VLA-4, FAK, ILK, Src, PI3K, Akt, Ras, MEK, Erk, HMG-CoA reductase, Rho, Rho kinase, PKC, and NFkB. Because the surface and the intracellular targets are now known and because specific compounds are becoming increasingly available, first clinical trials regarding ANTI-ADHESION therapies are ongoing. However, in comparison to the comprehensive preclinical and clinical knowledge about CAMs, the number of drugs developed thusfar is quite low. ANTI-ADHESION strategies include targeting of surface antigens, inhibition of cell adhesion associated pathways, inhibition of CAM-DR, and targeted drug delivery. As ANTI-ADHESION is based on general characteristics of cancer cells independent of specific disease entities or treatment modalities, it may become a successful, low-toxic and broadly applicable concept in cancer treatment.
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PMID:ANTI-ADHESION evolves to a promising therapeutic concept in oncology. 1839 55


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