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)

Urokinase-related proteins in human urine occur mainly as a 1:1 complex of urokinase with an inhibitor (Stump, D. C., Thienpont, M., and Collen, D. (1986) J. Biol. Chem. 261, 1267-1273). BALB/c mice were immunized with this urokinase-urokinase inhibitor complex and spleen cells fused with mouse myeloma cells, resulting in hybridomas producing monoclonal antibodies. Three antibodies reacting with the complex but not with urokinase were utilized to develop a sensitive (0.5 ng/ml) enzyme-linked immunosorbent assay for the urokinase inhibitor, which was used for monitoring its purification by chromatography on zinc chelate-Sepharose, concanavalin A-Sepharose, SP-Sephadex C-50, and Sephadex G-100. A homogenous glycoprotein of apparent Mr 50,000 was obtained with a yield of 40 micrograms/liter urine and a purification factor of 320. One mg of the purified protein inhibited 35,000 IU of urokinase within 30 min at 37 degrees C. This protein was immunologically related to both the purified urokinase-urokinase inhibitor complex and to the inhibitor portion dissociated from it by nucleophilic dissociation. It was immunologically distinct from all known protease inhibitors, including the endothelial cell-derived fast-acting inhibitor of tissue-type plasminogen activator, the placental inhibitor of urokinase and protease nexin. In electrophoresis the protein migrated with beta-mobility. Inhibition of urokinase occurred with a second order rate constant (k) of 8 X 10(3) M-1 s-1 in the absence and of 9 X 10(4) M-1 s-1 in the presence of 50 IU of heparin/ml. The urokinase inhibitor was inactive towards single-chain urokinase-type plasminogen activator and plasmin, but it inhibited two-chain tissue-type plasminogen activator with a k below 10(3) M-1 s-1 and thrombin with a k of 4 X 10(4) M-1 s-1 in the absence and 2 X 10(5) M-1 s-1 in the presence of heparin. The concentration of this urokinase inhibitor in plasma from normal subjects determined by immunoassay was 2 +/- 0.7 micrograms/ml (mean +/- S.D., n = 25). The protein purified from plasma by immunoabsorption had the same Mr, amino acid composition, and immunoreactivity as the urinary protein. Furthermore, when urokinase was added to plasma, time-dependent urokinase-urokinase inhibitor complex formation was observed at a rate similar to that observed for the inhibition of urokinase by the purified inhibitor from urine. This urokinase inhibitor, purified from human urine, most probably represents a new plasma protease inhibitor.
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PMID:Purification and characterization of a novel inhibitor of urokinase from human urine. Quantitation and preliminary characterization in plasma. 309 4

Four monoclonal antibodies for a calcium-dependent protease inhibitor protein were produced by fusing Sp2/0 myeloma cells with spleen cells from a Balb/C mouse immunized with purified bovine heart inhibitor. Each of the monoclonal antibodies was highly specific for the inhibitory protein as revealed by electro-blot analysis. The antibodies recognized different antigenic sites on CNBr peptides prepared from the purified inhibitor protein. Immunofluorescent microscopy of sections from bovine heart ventricles treated with each of the antibodies demonstrated the same fluorescent pattern. Fluorescence was observed at or near the sarcolemma of the myocytes, and along the Z-discs of relaxed myofibrils within the myocytes. Contracted myofibrils did not appear to bind antibody. Immunostaining of glycerinated relaxed cardiac myofibrils revealed staining at the Z-discs. One of the antibodies could also stain the Z-disc region of bovine skeletal muscle myofibrils.
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PMID:Subcellular localization of bovine heart calcium-dependent protease inhibitor. 390 Apr 27

Culture supernatants of lipopolysaccharide-stimulated P388D1 macrophage-like tumor cells showed a growth inhibitory effect on plasmacytoma MOPC-315, MPC-11 and myeloma FO cells, but had no effect on J558 plasmacytoma cells. Based on the results of trypan blue staining and a 51Cr release assay, the supernatant had both cytotoxic and cytostatic activity for MOPC-315 plasmacytoma cells. The inhibitory activity was trypsin-sensitive, heat-stable at 100 degrees C for 20 min., but sensitive to 2-mercaptoethanol and cystein HCl. At least 6 hrs of exposure period were required for the P388D1 culture supernatant to show an inhibitory effect on plasmacytoma cells. Since the inhibitory activity could not be blocked by protease inhibitor or neutralized by antibodies to mouse IL-1 beta, IL-6 and TNF-alpha, the inhibitory factor(s) was distinct from the defined cytotoxic factors. After partial purification with DEAE-Sephacel and Sephacryl S-300 chromatography, four major active peaks with the molecular mass of 874-KDa (near the void volume), 112-KDa, 45-KDa and 18-KDa were obtained.
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PMID:Inhibitory effect of lipopolysaccharide-stimulated P388D1 macrophage-like cells on plasmacytoma cells. 835 65

Recent clinical results from Edmonton have demonstrated the feasibility of achieving normoglycemia in type I diabetic patients by islet transplantation. One of the key issues in obtaining this success was transplanting sufficient numbers of islets by sequential transplants. Although the development of semipurified endotoxin-free Clostridium histolyticum-derived collagenase (Liberase) has improved islet yields from the human pancreas, batch-to-batch variation and loss of activity with time still hampers progress in obtaining consistent islet preparations. In order to define key components of crude collagenase, a panel of monoclonal antibodies (McAbs) was raised against crude collagenase. Monoclonal antibodies were generated by fusions between splenocytes of BALB/c mice immunized with Boheringer P collagenase and the myeloma cell line NS-0. These monoclonal antibodies were used as probes to study molecular differences between effective and ineffective collagenase batches using Western blotting. Two monoclonal antibodies (LDS71 and LDS81) were raised and characterized as recognizing separate epitopes on a 125-kDa component. Western blotting indicated that the 125-kDa band was rapidly broken down by storage or by dialysis in the presence of dithiothreitol. However, this breakdown could be prevented by the addition of leupeptin (a protease inhibitor) to the dialysis buffer. On testing fractions at 5-min intervals from the "Ricordi" digestion circuit during porcine and human pancreas digestion, the 125-kDa component was rapidly broken down in relatively ineffective collagenase batches but in effective batches was present throughout the digestion process. The correlation between the presence of the 125-kDa band and effectiveness of pancreas digestion suggests that this may be a key component in the formulation of C. histolyticum collagenase.
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PMID:Characterization of an important enzymatic component in collagenase that is essential for the effective digestion of the human and porcine pancreas. 1181 13

The biosynthesis of immunoglobulin leads to constitutive endoplasmic reticulum (ER) stress in myeloma cells, which activates the unfolded protein response (UPR). The UPR promotes protein folding by chaperones and increases proteasomal degradation of misfolded protein. Excessive ER stress induces apoptosis and represents a molecular basis for the bortezomib sensitivity of myeloma. Most solid malignancies such as sarcoma, by contrast, are poorly bortezomib sensitive and display low levels of ER stress. We hypothesized that pharmacologic induction of ER stress might sensitize malignancies to bortezomib treatment. We show that the HIV protease inhibitor ritonavir induces ER stress in bortezomib-resistant sarcoma cells. Ritonavir triggered the UPR, decreased the degradation of newly synthesized protein, but did not directly inhibit proteasomal active sites in the therapeutic dose range in contrast to bortezomib. Whereas neither bortezomib nor ritonavir monotherapy translated into significant apoptosis at therapeutic drug levels, the combination strongly increased the level of ER stress and activated PERK, IRE1, and ATF6, synergistically induced CHOP, JNK, caspase-4, and caspase-9, and resulted in >90% apoptosis. In summary, ritonavir increases the level of ER stress induced by bortezomib, which sensitizes bortezomib-resistant cells to bortezomib-induced apoptosis. Ritonavir may therefore be tested clinically to improve the sensitivity of solid malignancies toward bortezomib treatment.
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PMID:Ritonavir induces endoplasmic reticulum stress and sensitizes sarcoma cells toward bortezomib-induced apoptosis. 1864 4

The incidence of cancer is greater in transplant recipients compared with the general population. Posttransplantation lymphoproliferative disorder (PTLD) is the second most common cancer in these patients. Non-Hodgkin lymphoma is most commonly observed, and multiple myeloma (PTLD-MM) accounts for less than 4% of PTLDs. Most reported PTLD-MM is of recipient origin, and to date, few cases of donor-origin PTLD-MM have been reported. Bortezomib is a protease inhibitor that has been used successfully to treat multiple myeloma. Herein, we describe the case of a patient in whom multiple myeloma developed shortly after paid living-unrelated renal transplantation performed abroad (in Egypt). The patient had no apparent risk factors for PTLD-MM. Thus, it was supposed that PTLD-MM was of donor origin, considering its early development, lack of recipient risk factors, and no available donor medical status. To our knowledge, this report is the first to describe the use of bortezomib in this setting. Although bortezomib plus dexamethasone therapy resulted in hematologic remission, the patient remained dialysis-dependent.
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PMID:Cost of paid transplantation abroad: possible donor-origin early multiple myeloma in a renal transplant recipient treated using bortezomib. 2083 95

The incidence of acute promyelocytic leukemia (APL) in patients with HIV is exceedingly rare, making the establishment of therapeutic approaches challenging and often individualized. We report the case of a 43-year-old female who presented with fatigue and malaise, and was concurrently diagnosed with APL and HIV. Induction and consolidation with all-trans-retinoic acid (ATRA), idarubicin, and mitoxantrone were initiated in conjunction with highly active anti-retroviral therapy (HAART) consisting of tenofovir/emtricitabine, fosamprenavir, and raltegravir. A complete morphologic, cytogenetic, and molecular response was achieved post-induction. Therapeutic strategies should consider overlapping effects of current agents in targeting both pathologies. ATRA has been found to induce apoptosis in HIV-infected leukemic cells, and protease inhibitor therapy has furthermore been reported to be synergistic with ATRA in inducing differentiation of APL cell lines. Pending further investigation, regimens with protease inhibitor backbones may represent a viable first-line strategy for patients elected to receive HAART in addition to ATRA and standard chemotherapy.
Clin Lymphoma Myeloma Leuk 2010 Oct
PMID:Acute promyelocytic leukemia in HIV-infected adults: a case report and review of therapeutic considerations. 2185 51

Multiple myeloma is one of numerous malignancies characterized by increased glucose consumption, a phenomenon with significant prognostic implications in this disease. Few studies have focused on elucidating the molecular underpinnings of glucose transporter (GLUT) activation in cancer, knowledge that could facilitate identification of promising therapeutic targets. To address this issue, we performed gene expression profiling studies involving myeloma cell lines and primary cells as well as normal lymphocytes to uncover deregulated GLUT family members in myeloma. Our data demonstrate that myeloma cells exhibit reliance on constitutively cell surface-localized GLUT4 for basal glucose consumption, maintenance of Mcl-1 expression, growth, and survival. We also establish that the activities of the enigmatic transporters GLUT8 and GLUT11 are required for proliferation and viability in myeloma, albeit because of functionalities probably distinct from whole-cell glucose supply. As proof of principle regarding the therapeutic potential of GLUT-targeted compounds, we include evidence of the antimyeloma effects elicited against both cell lines and primary cells by the FDA-approved HIV protease inhibitor ritonavir, which exerts a selective off-target inhibitory effect on GLUT4. Our work reveals critical roles for novel GLUT family members and highlights a therapeutic strategy entailing selective GLUT inhibition to specifically target aberrant glucose metabolism in cancer.
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PMID:Multiple myeloma exhibits novel dependence on GLUT4, GLUT8, and GLUT11: implications for glucose transporter-directed therapy. 2245 79

Exploiting protein homeostasis is a new therapeutic approach in cancer. Nelfinavir (NFV) is an HIV protease inhibitor that induces endoplasmic reticulum (ER) stress in cancer cells. Under conditions of ER stress, misfolded proteins are transported from the ER back to the cytosol for subsequent degradation by the ubiquitin-proteasome system. Bortezomib (BZ) is a proteasome inhibitor and interferes with degradation of misfolded proteins. Here, we show that NFV and BZ enhance proteotoxicity in non-small cell lung cancer (NSCLC) and multiple myeloma (MM) cells. The combination synergistically inhibited cell proliferation and induced cell death. Activating transcription factor (ATF)3 and CCAAT-enhancer binding protein homologous protein (CHOP), markers of ER stress, were rapidly increased, and their siRNA-mediated knockdown inhibited cell death. Knockdown of double-stranded RNA activated protein kinase-like ER kinase, a signal transducer in ER stress, significantly decreased apoptosis. Pretreatment with the protein synthesis inhibitor, cycloheximide, decreased levels of ubiquitinated proteins, ATF3, CHOP, and the overall total cell death, suggesting that inhibition of protein synthesis increases cell survival by relieving proteotoxic stress. The NFV/BZ combination inhibited the growth of NSCLC xenografts, which correlated with the induction of markers of ER stress and apoptosis. Collectively, these data show that NFV and BZ enhance proteotoxicity in NSCLC and MM cells, and suggest that this combination could tip the precarious balance of protein homeostasis in cancer cells for therapeutic gain.
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PMID:Synergistic effects of nelfinavir and bortezomib on proteotoxic death of NSCLC and multiple myeloma cells. 2282 71

Curcumin is an inexpensive, natural plant ingredient with protease inhibitor effects. The present study aimed to analyze the inhibitory effects of curcumin on the multiple myeloma (MM) RPMI 8226 cell line, and examine the underlying mechanism that promotes the apoptosis of RPMI 8226 cells. A growth curve was constructed in order to observe the relative growth velocity, and MTT was used to analyze the effect of different concentrations of curcumin on inhibiting the proliferation of the RPMI 8226 cells. The mRNA expression of the p53, Bax and MDM2 genes was detected using quantitative polymerase chain reaction. The expression of p53 protein in the MM RPMI 8226 cells following treatment with curcumin was detected by western blotting and ELISA. Curcumin inhibited the proliferation of the MM RPMI 8226 cells in a dose- and time-dependent manner. In the MM RPMI 8226 cells treated with curcumin, the expression of the p53 and Bax genes was upregulated, while the expression of the MDM2 gene was downregulated. p53 protein expression was higher in the curcumin experimental group compared with the control group. Subsequent to treatment with curcumin, the growth of the MM RPMI 8226 cell line was inhibited in a concentration- and time-dependent manner. In the MM RPMI 8226 cells treated with curcumin, p53 protein levels were upregulated, which suggested that curcumin may promote the apoptosis of MM cells by upregulating p53 protein expression.
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PMID:A preliminary study of the effect of curcumin on the expression of p53 protein in a human multiple myeloma cell line. 2578 29


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