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1.
Laryngoscope ; 133(7): 1638-1644, 2023 07.
Article in English | MEDLINE | ID: mdl-37021734

ABSTRACT

OBJECTIVE: To reevaluate the frequency of perioperative blood transfusion, transfusion triggers, and survival impact in patients with incident, surgically treated head and neck cancer (HNC) in restrictive transfusion regimens. METHODS: Retrospective analysis of surgically treated patients with incident HNC with and without perioperative blood transfusion between 2008 and 2019 at the Department of Otorhinolaryngology, Head and Neck Surgery, Medical University of Innsbruck, according to the department's clinical Head and Neck Tumor Registry. RESULTS: Of the 590 patients included, perioperative transfusions were administered in 6.3% (n = 37, transfusion group). Following multivariable logistic regression, likelihood of blood transfusions was increased in patients with poorer general health conditions (ASA score III/IV; OR 3.7; 95% CI 1.9-8.6; p = 0.002), hemoglobin <12.5 g/dL (OR 2.7; 95% CI 1.1-6.4; p = 0.03), longer duration of surgery (OR 1.006 per minute of surgery time; 95% CI 1.003-1.008; p < 0.001), and negative p16 status (OR 5.3; 95% CI = 1.1-25; p = 0.03). Based on 14 matching variables related to survival and perioperative blood transfusion, a control group of 37 matching patients without perioperative transfusion was identified. Using univariate analysis, overall survival in transfusion and control groups did not differ significantly (p = 0.25). After adjusting for four parameters with limited matching accuracy (Chi square p < 0.2) in Cox regression analysis, a transfusion related hazard ratio close to 1 (HR 0.92; 95% CI 0.34-2.51; p = 0.87) was observed. CONCLUSION: Considering current restrictive transfusion regimens and general transfusion risks, the administration of blood products in HNC patients during the perioperative period is not associated with additional oncologic hazard. LEVEL OF EVIDENCE: 3 Laryngoscope, 133:1638-1644, 2023.


Subject(s)
Blood Transfusion , Head and Neck Neoplasms , Humans , Retrospective Studies , Head and Neck Neoplasms/surgery , Logistic Models , Proportional Hazards Models
2.
Transpl Int ; 36: 11062, 2023.
Article in English | MEDLINE | ID: mdl-36936441

ABSTRACT

A positive crossmatch (XM+) is considered a contraindication to solid abdominal organ transplantation except liver transplantation (LT). Conflicting reports exist regarding the effects of XM+ on post-transplant outcomes. The goal of this retrospective single-center analysis is to evaluate the influence of XM+ on relevant outcome parameters such as survival, graft rejection, biliary and arterial complications. Forty-nine adult patients undergoing LT with a XM+ between 2002 and 2017 were included. XM+ LT recipients were matched 1:2 with crossmatch negative (XM-) LT recipients based on the balance of risk (BAR) score. Patient and graft survival were compared using Kaplan-Meier survival analysis and the log-rank test. Comparative analysis of clinical outcomes in XM+ and XM- groups were conducted. Patient and graft survival were similar in XM+ and XM- patients. Rejection episodes did not differ either. Recipients with a strong XM+ were more likely to develop a PCR+ CMV infection. A XM+ was not associated with a higher incidence of biliary or arterial complications. Donor age, cold ischemia time, PCR+ CMV infection and a rejection episode were associated with the occurrence of ischemic type biliary lesions. A XM+ has no effects on patient and graft survival or other relevant outcome parameters following LT.


Subject(s)
Cytomegalovirus Infections , Kidney Transplantation , Liver Transplantation , Adult , Humans , Retrospective Studies , Histocompatibility Testing , Graft Survival , Graft Rejection/epidemiology
4.
Wien Klin Wochenschr ; 133(23-24): 1272-1280, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34698961

ABSTRACT

BACKGROUND: Seroepidemiological studies provide important insight into the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV­2) in our society. We aimed to determine seropositivity of SARS-CoV­2 antibodies and its cross-sectional correlates in a large cohort of blood donors. METHODS: In this observational cohort study, we tested healthy blood donors residing in Tyrol, Austria, for SARS-CoV­2 antibodies using the Abbott SARS-CoV­2 IgG chemiluminescent microparticle immunoassay. We estimated 95% confidence intervals (95% CI) of seroprevalences using bootstrapping and tested for differences by participant characteristics using logistic regression. FINDINGS: Between 8 June and 4 September 2020, we screened 5345 healthy individuals at local blood donor sessions (mean age 42.7 years, SD 13.5 years, 46.7% female). Overall seroprevalence was 3.1% (95% CI 2.7-3.6%, 165 cases), which is 5.1-fold higher (95% CI 4.5-6.0%) than the case number identified by the health authorities in the state-wide testing program (0.6%; 4536 out of 757,634). Seroprevalence was higher in the district Landeck (16.6%, P < 0.001) and in individuals aged < 25 years (4.7%, P = 0.043), but did not differ by gender, blood types, or medication intake. The odds ratio for seropositivity was 2.51 for participants who had travelled to Ischgl (1.49-4.21, P = 0.001), 1.39 who had travelled to other federal states (1.00-1.93, P = 0.052), and 2.41 who had travelled abroad (1.61-3.63, P < 0.001). Compared to participants who had a suspected/confirmed SARS-CoV­2 infection but were seronegative, seropositive participants more frequently reported loss of smell (odds ratio = 2.49, 1.32-4.68, P = 0.005) and taste (odds ratio = 2.76, 1.54-4.92, P = 0.001). CONCLUSION: In summer 2020, SARS-CoV­2 seroprevalence in Tyrolean blood donors was 3.1%. Our study revealed regional variation and associations with young age, travel history and specific symptoms.


Subject(s)
Blood Donors , COVID-19 , Adult , Antibodies, Viral , Austria/epidemiology , Cross-Sectional Studies , Female , Humans , Male , Prevalence , SARS-CoV-2 , Seroepidemiologic Studies
5.
J Intensive Care ; 8: 76, 2020.
Article in English | MEDLINE | ID: mdl-33014378

ABSTRACT

BACKGROUND: Sepsis, a dysregulated host response following infection, is associated with massive immune activation and high mortality rates. There is still a need to define further risk factors and laboratory parameters predicting the clinical course. Iron metabolism is regulated by both, the body's iron status and the immune response. Iron itself is required for erythropoiesis but also for many cellular and metabolic functions. Moreover, iron availability is a critical determinant in infections because it is an essential nutrient for most microbes but also impacts on immune function and intravascular oxidative stress. Herein, we used a prospective study design to investigate the putative impact of serum iron parameters on the outcome of sepsis. METHODS: Serum markers of iron metabolism were measured in a prospective cohort of 61 patients (37 males, 24 females) with sepsis defined by Sepsis-3 criteria in a medical intensive care unit (ICU) and compared between survivors and non-survivors. Regulation of iron parameters in patients stratified by focus of infection and co-medication as well as association of the markers with sepsis severity scores and survival were investigated with linear and logistic regression corrected for sex and age effects. RESULTS: Positive correlations of increased serum iron and ferritin concentrations upon ICU admission with the severity of organ failure (SOFA score) and with mortality were observed. Moreover, high TF-Sat, elevated ferritin and serum iron levels and low transferrin concentrations were associated with reduced survival. A logistic regression model consisting of SOFA and transferrin saturation (SOFA-TF-Sat) had the best predictive power for survival in septic ICU patients. Of note, administration of blood transfusions prior to ICU admission resulted in increased TF-Sat and reduced survival of septic patients. CONCLUSIONS: Our study could show an important impact of serum iron parameters on the outcome of sepsis. Furthermore, we identified transferrin saturation as a stand-alone predictor of sepsis survival and as a parameter of iron metabolism which may in a combined model improve the prediction power of the SOFA score. TRIAL REGISTRATION: The study was carried out in accordance with the recommendations of the Declaration of Helsinki on biomedical research. The study was approved by the institutional ethics review board of the Medical University Innsbruck (study AN2013-0006).

6.
Blood ; 111(6): 3097-107, 2008 Mar 15.
Article in English | MEDLINE | ID: mdl-18180381

ABSTRACT

Dasatinib is a multitargeted drug that blocks several tyrosine kinases. Apart from its well-known antileukemic activity, the drug has attracted attention because of potential immunosuppressive and anti-inflammatory effects. We report that dasatinib at 1 microM completely blocks anti-IgE-induced histamine release in blood basophils in healthy donors, and allergen-induced release of histamine in sensitized individuals. In addition, dasatinib inhibited FcepsilonRI-mediated release of IL-4 and IgE-mediated up-regulation of CD13, CD63, CD164, and CD203c in basophils. The effects of dasatinib were dose-dependent (IC(50): 50-500 nM) and specific for FcepsilonRI activation in that the drug failed to inhibit C5a-induced or Ca-ionophore-induced histamine release. Interestingly, at lower concentrations, dasatinib even promoted FcepsilonRI-dependent histamine release in basophils in allergic subjects. In consecutive studies, dasatinib was found to interact with and block several FcepsilonRI downstream targets in basophils, including Btk. Correspondingly, FcepsilonRI-mediated histamine secretion in basophils was markedly reduced in Btk knockout mice and in a patient with Btk deficiency. However, the remaining "low-level" mediator secretion in Btk-deficient cells was fully blocked down again by 1 muM dasatinib. Together, these data suggest that dasatinib inhibits FcepsilonRI-mediated activation of basophils through multiple signaling molecules including Btk. Dasatinib may be an interesting agent for immunologic disorders involving Btk-dependent responses or/and FcepsilonRI activation of basophils.


Subject(s)
Basophils/drug effects , Basophils/immunology , Histamine Release/drug effects , Histamine Release/immunology , Pyrimidines/pharmacology , Receptors, IgE/immunology , Thiazoles/pharmacology , Adolescent , Adult , Agammaglobulinaemia Tyrosine Kinase , Allergens/immunology , Animals , Basophils/metabolism , Cells, Cultured , Dasatinib , Female , Humans , Interleukin-4/biosynthesis , Interleukin-4/metabolism , Male , Mice , Middle Aged , Protein Binding , Protein-Tyrosine Kinases/deficiency , Protein-Tyrosine Kinases/genetics , Protein-Tyrosine Kinases/metabolism , Up-Regulation
7.
Leuk Lymphoma ; 48(10): 1997-2007, 2007 Oct.
Article in English | MEDLINE | ID: mdl-17917967

ABSTRACT

Vascular endothelial growth factor (VEGF) is produced in neoplastic cells in various myeloid neoplasms and may act as an autocrine growth-regulator. We have examined the expression of five VEGF receptors (VEGR1/Flt-1, VEGFR2/KDR, Flt-4, neuropilin-1 = NRP-1, NRP-2) in leukemic cells obtained from patients with acute myeloid leukemia (n = 28), chronic myeloid leukemia (n = 14), chronic eosinophilic leukemia (n = 3), chronic myelomonocytic leukemia (n = 9), or mast cell leukemia/systemic mastocytosis (n = 3) as well as in respective cell lines. Expression of VEGFR mRNA was analyzed by RT-PCR, and expression of VEGFR protein by immunocytochemistry. In most patients, leukemic cells expressed NRP-1 mRNA and NRP-2 mRNA independent of the type of disease. By contrast, transcripts for Flt-1, KDR, and Flt-4 were expressed variably without a clear correlation to the type of leukemia. Expression of VEGF receptors was also demonstrable at the protein level in all cases tested. In conclusion, neoplastic cells in myeloid leukemias frequently express VEGFR including NRP-1 and NRP-2.


Subject(s)
Gene Expression Regulation, Leukemic , Leukemia, Myeloid/genetics , Leukemia, Myeloid/metabolism , Neovascularization, Pathologic , Neuropilin-1/biosynthesis , Neuropilin-2/biosynthesis , Receptors, Vascular Endothelial Growth Factor/biosynthesis , Adult , Aged , Aged, 80 and over , Cell Line, Tumor , Female , Gene Expression Profiling , Humans , Male , Middle Aged , RNA, Messenger/metabolism
8.
Exp Hematol ; 35(10): 1510-21, 2007 Oct.
Article in English | MEDLINE | ID: mdl-17681669

ABSTRACT

Aggressive mast cell (MC) tumors are hematopoietic neoplasms characterized by uncontrolled growth of MC and resistance to conventional drugs. In most cases, the tyrosine kinase (TK) receptor KIT is involved in malignant cell growth. Therefore, several KIT TK-targeting drugs are currently being tested for their ability to block growth of neoplastic MC. We examined the effects of four TK inhibitors (imatinib, midostaurin, nilotinib, and dasatinib) on C2 canine mastocytoma cells, as well as primary neoplastic canine MC. As assessed by (3)H-thymidine incorporation experiments, all TK inhibitors produced dose-dependent inhibition of proliferation in C2 cells with the following IC(50) values: imatinib: 269 +/- 180 nM, midostaurin: 157 +/- 35 nM, nilotinib: 55 +/- 24 nM, dasatinib: 12 +/- 3 nM. Growth-inhibitory effects of TK inhibitors were also observed in primary neoplastic mast cells, although IC(50) values for each drug varied from patient to patient, with midostaurin being the most potent agent in all samples tested. In consecutive experiments, we were able to show that TK inhibitors cooperate with each other in producing growth inhibition in C2 cells with synergistic effects observed with most drug combinations. In flow cytometry and TUNEL assay experiments, growth-inhibitory effects of TK inhibitors were found to be associated with cell-cycle arrest and apoptosis. Together, these data show that several TK-targeting drugs induce apoptosis and inhibit proliferation in canine mastocytoma cells in vitro, and that synergistic drug interactions can be obtained. Clinical trials are now warranted to explore whether these TK inhibitors also counteract growth of neoplastic cells in vivo in patients with aggressive MC tumors.


Subject(s)
Dog Diseases/drug therapy , Hematologic Neoplasms/drug therapy , Hematologic Neoplasms/veterinary , Mast-Cell Sarcoma/drug therapy , Mast-Cell Sarcoma/veterinary , Protein Kinase Inhibitors/pharmacology , Proto-Oncogene Proteins c-kit/metabolism , Animals , Apoptosis/drug effects , Cell Cycle/drug effects , Cell Line, Tumor , Dog Diseases/metabolism , Dogs , Dose-Response Relationship, Drug , Drug Resistance, Neoplasm/drug effects , Drug Screening Assays, Antitumor , Drug Synergism , Hematologic Neoplasms/metabolism , Hematologic Neoplasms/pathology , Humans , Mast Cells/metabolism , Mast Cells/pathology , Mast-Cell Sarcoma/metabolism , Mast-Cell Sarcoma/pathology , Protein Kinase Inhibitors/agonists , Protein Kinase Inhibitors/therapeutic use
9.
Blood ; 110(2): 661-9, 2007 Jul 15.
Article in English | MEDLINE | ID: mdl-17420286

ABSTRACT

Systemic mastocytosis (SM) is a myeloid neoplasm characterized by increased survival and accumulation of neoplastic mast cells (MCs). In most patients, the D816V-mutated variant of KIT is detectable. We report here that heat shock protein 32 (Hsp32), also known as heme oxygenase-1 (HO-1), is a novel KIT-inducible survival factor in neoplastic MCs. As assessed by reverse transcription-polymerase chain reaction (RT-PCR), immunocytochemistry, and Western blotting, the KIT D816V(+) MC line HMC-1.2 as well as highly enriched primary neoplastic MCs were found to express Hsp32 mRNA and the Hsp32 protein. Moreover, KIT D816V and stem cell factor (SCF)-activated wild-type KIT were found to induce Hsp32 promoter activity, expression of Hsp32 mRNA, and expression of the Hsp32 protein in Ba/F3 cells. Correspondingly, the KIT D816V-targeting drug PKC412 decreased the expression of Hsp32 as well as proliferation/survival in neoplastic MCs. The inhibitory effects of PKC412 on the survival of HMC-1.2 cells were counteracted by the HO-1 inductor hemin or lentiviral-transduced HO-1. Moreover, 2 Hsp32-targeting drugs, pegylated zinc protoporphyrin (PEG-ZnPP) and styrene maleic acid copolymer micelle-encapsulated ZnPP (SMA-ZnPP), were found to inhibit proliferation and to induce apoptosis in neoplastic MCs. Furthermore, both drugs were found to cooperate with PKC412 in producing growth inhibition. Together, these data show that Hsp32 is an important survival factor and interesting new therapeutic target in neoplastic MCs.


Subject(s)
Cell Survival/drug effects , Heme Oxygenase-1/genetics , Mast Cells/pathology , Piperazines/pharmacology , Pyrimidines/pharmacology , Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Benzamides , Cell Line, Tumor , Doxycycline/pharmacology , Gene Expression Regulation, Neoplastic/drug effects , Heme Oxygenase-1/metabolism , Humans , Imatinib Mesylate , RNA, Messenger/genetics , RNA, Small Interfering/genetics , Reverse Transcriptase Polymerase Chain Reaction , Thymidine/metabolism
10.
Vet Immunol Immunopathol ; 115(3-4): 320-33, 2007 Feb 15.
Article in English | MEDLINE | ID: mdl-17196258

ABSTRACT

Vascular endothelial growth factor (VEGF) is a major regulator of angiogenesis and a potential autocrine growth factor for neoplastic cells in various malignancies. In the present study, we have investigated expression of VEGF and VEGF receptors in canine mastocytomas and the canine mastocytoma cell line C2. As assessed by immunostaining of tissue sections and cytospin slides, primary neoplastic mast cells (MC) and C2 cells were found to express the VEGF protein. In Northern blot and RT-PCR experiments, C2 cells expressed VEGF mRNA in a constitutive manner. VEGF mRNA expression in C2 cells was counteracted by LY294002 and rapamycin, suggesting involvement of the PI3-kinase/mTOR pathway. Moreover, C2 cells were found to express VEGF receptor-1 (Flt-1) and VEGF receptor-2 (KDR). However, recombinant VEGF failed to promote (3)H-thymidine uptake in C2 cells, and a neutralizing anti-VEGF antibody (bevacizumab) failed to downregulate spontaneous proliferation in these cells. In addition, rapamycin decreased the expression of VEGF in C2 cells at the mRNA and protein level without suppressing their proliferation. Together, canine mastocytoma cells express VEGF as well as VEGF receptors. However, despite co-expression of VEGF and its receptors, VEGF is not utilized as an autocrine growth regulator by canine mastocytoma cells.


Subject(s)
Dog Diseases/metabolism , Mastocytoma/veterinary , Vascular Endothelial Growth Factor A/biosynthesis , Vascular Endothelial Growth Factor Receptor-1/biosynthesis , Vascular Endothelial Growth Factor Receptor-2/biosynthesis , Animals , Antibodies, Monoclonal/pharmacology , Antibodies, Monoclonal, Humanized , Bevacizumab , Blotting, Northern/veterinary , Cell Line, Tumor , Chromones/pharmacology , Dog Diseases/enzymology , Dog Diseases/pathology , Dogs , Female , Flavonoids/pharmacology , Flow Cytometry/veterinary , Immunohistochemistry/veterinary , Male , Mastocytoma/enzymology , Mastocytoma/metabolism , Mastocytoma/pathology , Morpholines/pharmacology , Phosphatidylinositol 3-Kinases/metabolism , Phosphoinositide-3 Kinase Inhibitors , Protein Kinase Inhibitors/pharmacology , RNA/chemistry , RNA/genetics , Reverse Transcriptase Polymerase Chain Reaction/veterinary , Sirolimus/pharmacology , Vascular Endothelial Growth Factor A/genetics , Vascular Endothelial Growth Factor Receptor-1/genetics , Vascular Endothelial Growth Factor Receptor-2/genetics
11.
Blood ; 108(10): 3538-47, 2006 Nov 15.
Article in English | MEDLINE | ID: mdl-16849647

ABSTRACT

Basophil numbers are typically elevated in chronic myeloid leukemia (CML) and increase during disease progression. Histamine is an essential mediator and marker of basophils and is highly up-regulated in CML. We examined the biochemical basis of histamine synthesis in CML cells. The CML-specific oncoprotein BCR/ABL was found to promote expression of histidine decarboxylase (HDC) and synthesis of histamine in Ba/F3 cells. Moreover, the BCR/ABL tyrosine kinase inhibitors imatinib (STI571) and nilotinib (AMN107) decreased histamine levels and HDC mRNA expression in BCR/ABL-transformed Ba/F3 cells, in the CML-derived basophil cell line KU812, and in primary CML cells. Synthesis of histamine was found to be restricted to the basophil compartment of the CML clone and to depend on signaling through the PI3-kinase pathway. CML cells also expressed histamine receptors (HRs), including HR-1, HR-2, HR-4, and histamine-binding CYP450 isoenzymes which also serve as targets of HR antagonists. The HR-1 antagonists loratadine and terfenadine, which bind to CYP450, were found to counteract proliferation of CML cells, whereas no growth inhibition was observed with the HR-1 antagonist fexofenadine which is not targeted or metabolized by CYP450. Moreover, DPPE, an inhibitor of histamine-binding CYP450 isoenzymes, produced growth inhibition in CML cells. Together, these data show that BCR/ABL promotes histamine production in CML cells and that certain HR-targeting drugs exert antileukemic effects on CML cells.


Subject(s)
Fusion Proteins, bcr-abl/physiology , Gene Expression Regulation, Leukemic , Histamine/biosynthesis , Histidine Decarboxylase/genetics , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/metabolism , Animals , Antineoplastic Agents/pharmacology , Cell Line , Histamine Antagonists/pharmacology , Humans , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/enzymology , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/pathology , Mice , Oncogene Proteins , Phosphatidylinositol 3-Kinases/metabolism , Receptors, Histamine/analysis , Tumor Cells, Cultured
12.
Leuk Lymphoma ; 47(3): 451-60, 2006 Mar.
Article in English | MEDLINE | ID: mdl-16396768

ABSTRACT

Recent data suggest that vascular endothelial growth factor (VEGF) is produced in neoplastic cells in various myeloid neoplasms and plays a key role as an autocrine regulator and mediator of angiogenesis. We examined the expression of VEGF in paraffin-embedded bone marrow sections obtained from normal donors (n = 5) and 46 patients with myelodysplastic syndromes [MDS, French-American-British (FAB)-type refractory anemia (RA), n = 10; refractory anemia with ringed sideroblasts (RARS), n = 10; refractory anemia with excess blasts (RAEB), n = 10; RAEB in transformation (RAEB-T), n = 8; chronic myelomonocytic leukemia (CMML), n = 8] by immunohistochemistry using an anti-VEGF antibody. In normal bone marrow, the anti-VEGF antibody was found to react with myeloid progenitor cells, immature monocytic cells, plasma cells and megakaryocytes, but not with erythroid cells or mature granulocytic cells. Higher levels of VEGF were found in patients with MDS, subtypes RAEB, RAEB-T and CMML, compared to patients with RA or RARS, or the normal bone marrow. These differences were found to result from expression of VEGF in immature myeloid cells in RAEB, RAEB-T and CMML. The microvessel density was also higher in patients with RAEB-T and CMML compared to RA and RARS or the normal bone marrow. Expression of VEGF mRNA was demonstrable in isolated neoplastic cells by reverse transcriptase-polymerase chain reaction in all patients examined. In aggregate, these data show that VEGF is expressed in bone marrow cells in patients with MDS. The amount of expressed VEGF is related to the percentage of immature myeloid cells (blasts and monocytic progenitors) and correlates with the FAB category.


Subject(s)
Bone Marrow/pathology , Myelodysplastic Syndromes/classification , Myelodysplastic Syndromes/pathology , Vascular Endothelial Growth Factors/biosynthesis , Vascular Endothelial Growth Factors/genetics , Adult , Aged , Aged, 80 and over , Anemia, Refractory, with Excess of Blasts/metabolism , Anemia, Refractory, with Excess of Blasts/pathology , Bone Marrow/blood supply , Bone Marrow/metabolism , Female , Humans , Immunohistochemistry , Male , Middle Aged , Myelodysplastic Syndromes/metabolism , Neovascularization, Pathologic/metabolism , Neovascularization, Pathologic/pathology , Predictive Value of Tests , RNA, Messenger/genetics , RNA, Messenger/metabolism , Receptors, Vascular Endothelial Growth Factor/antagonists & inhibitors , Receptors, Vascular Endothelial Growth Factor/genetics , Receptors, Vascular Endothelial Growth Factor/metabolism
13.
Cancer Res ; 65(20): 9436-44, 2005 Oct 15.
Article in English | MEDLINE | ID: mdl-16230407

ABSTRACT

Chronic myeloid leukemia (CML) is a myeloproliferative disease in which BCR/ABL enhances survival of leukemic cells through modulation of proapoptotic and antiapoptotic molecules. Recent data suggest that proapoptotic Bcl-2-interacting mediator (Bim) plays a role as a tumor suppressor in myeloid cells, and that leukemic cells express only low amounts of this cell death activator. We here show that primary CML cells express significantly lower amounts of bim mRNA and Bim protein compared with normal cells. The BCR/ABL inhibitors imatinib and AMN107 were found to promote expression of Bim in CML cells. To provide direct evidence for the role of BCR/ABL in Bim modulation, we employed Ba/F3 cells with doxycycline-inducible expression of BCR/ABL and found that BCR/ABL decreases expression of bim mRNA and Bim protein in these cells. The BCR/ABL-induced decrease in expression of Bim was found to be a posttranscriptional event that depended on signaling through the mitogen-activated protein kinase pathway and was abrogated by the proteasome inhibitor MG132. Interestingly, MG132 up-regulated the expression of bim mRNA and Bim protein and suppressed the growth of Ba/F3 cells containing wild-type BCR/ABL or imatinib-resistant mutants of BCR/ABL. To show functional significance of "Bim reexpression," a Bim-specific small interfering RNA was applied and found to rescue BCR/ABL-transformed leukemic cells from imatinib-induced cell death. In summary, our data identify BCR/ABL as a Bim suppressor in CML cells and suggest that reexpression of Bim by novel tyrosine kinase inhibitors, proteasome inhibition, or by targeting signaling pathways downstream of BCR/ABL may be an attractive therapeutic approach in imatinib-resistant CML.


Subject(s)
Antineoplastic Agents/pharmacology , Apoptosis Regulatory Proteins/biosynthesis , Fusion Proteins, bcr-abl/physiology , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/metabolism , Membrane Proteins/biosynthesis , Piperazines/pharmacology , Proto-Oncogene Proteins/biosynthesis , Pyrimidines/pharmacology , Apoptosis/drug effects , Apoptosis/physiology , Apoptosis Regulatory Proteins/genetics , Bcl-2-Like Protein 11 , Benzamides , Bone Marrow Cells/metabolism , Cell Growth Processes/drug effects , Down-Regulation , Extracellular Signal-Regulated MAP Kinases/metabolism , Humans , Imatinib Mesylate , K562 Cells , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/genetics , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/pathology , Leupeptins/pharmacology , MAP Kinase Signaling System/drug effects , Membrane Proteins/genetics , Proteasome Endopeptidase Complex/metabolism , Proto-Oncogene Proteins/genetics , Proto-Oncogene Proteins c-bcl-2/metabolism , RNA, Messenger/biosynthesis , RNA, Messenger/genetics , RNA, Small Interfering/genetics , Signal Transduction , Transfection
14.
Thromb Haemost ; 90(3): 422-8, 2003 Sep.
Article in English | MEDLINE | ID: mdl-12958610

ABSTRACT

Increased plasma plasminogen activator inhibitor-1 (PAI-1) has been implicated in the development of vascular disease. In type 2 diabetes mellitus high PAI-1 levels are associated with increased plasma concentrations of free fatty acids (FFA) and triacylglycerol indicating an association or a causal relationship. To answer that question, the effect of FFA/triacylglycerol on plasma PAI-1 was examined. Ten healthy male volunteers were studied for 6 h during infusion of triacylglycerol [1.5 ml/min]/heparin [0.2 IU/(kg.min)] (LIP; n=10), saline only (SAL; n=10), and saline/heparin (HEP; n=5). Plasma insulin concentrations were kept constant at approximately 35 pmol/l by intravenous somatostatin-insulin infusions and there was no significant change in plasma glucose levels during any of the study protocols. LIP increased plasma triacylglycerol and FFA approximately 3- (p < 0.001) and approximately 8- (p < 0.000001) fold, respectively, within 90 min. Baseline plasma PAI-1 measured by a bio-immunoassay was similar in HEP (11.4 +/- 2.8 ng/ml), SAL (16.6 +/- 3.6 ng/ml), and LIP studies (15.2 +/- 3.4 ng/ml). Since studies were initiated in the morning, PAI-1 decreased (p < 0.025) over time following its normal diurnal variation to 6.4 +/- 2.0 ng/ml and 4.0 +/- 2.4 ng/ml at 360 min in SAL and HEP, respectively. During LIP, however, PAI-1 increased to approximately 2.6 fold higher levels than during SAL at 360 min (16.4 +/- 4.0 ng/ml, p < 0.01). While tissue plasminogen activator (tPA) and adipsin, an adipocyte derived protease, were unaffected by LIP, changes in soluble vascular cell adhesion molecule-1 (sVCAM-1) were significantly correlated (p = 0.02) with those seen for PAI-1. This suggests that hyperlipidemia independent of insulin and plasma glucose levels stimulates vascular tissue and in turn might induce an increase in plasma PAI-1. PAI-1 then could contribute to the development of atherothrombotic vascular disease.


Subject(s)
Plasminogen Activator Inhibitor 1/blood , Triglycerides/pharmacology , Vascular Cell Adhesion Molecule-1/blood , Adult , Blood Glucose , Complement Factor D , Fatty Acids/blood , Heparin/administration & dosage , Heparin/pharmacology , Humans , Hyperlipidemias/blood , Infusions, Parenteral , Insulin/blood , Kinetics , Male , Prospective Studies , Serine Endopeptidases/blood , Solubility , Tissue Plasminogen Activator/blood , Triglycerides/administration & dosage , Triglycerides/blood
15.
Arterioscler Thromb Vasc Biol ; 22(1): 101-7, 2002 Jan.
Article in English | MEDLINE | ID: mdl-11788468

ABSTRACT

Membrane vesicles (MVs) released from activated cells and blebs from apoptotic cells are increased in patients with vascular disease and in those with atherosclerotic lesions, and their contribution to inflammatory reactions has been suggested. At sites of inflammation, MVs could serve as rapidly available substrates for peroxidation, carry oxidized compounds to activate other cells, and amplify inflammation. Here, we show that MVs released from tert-butyl hydroperoxide-treated endothelial cells (ECs) and apoptotic blebs, but not MVs from Ca(2+) ionophore-treated ECs, stimulate monocyte adhesion to ECs, an important step in atherogenesis. We show that oxidized phospholipids, such as the previously identified 1-palmitoyl-2-(5-oxovaleroyl)-sn-glycero-3-phosphorylcholine (POVPC), are responsible for biological activity in MVs and apoptotic blebs. Natural antibodies from apolipoprotein E-null mice that recognize POVPC also recognize oxidized MVs, and pretreatment of MVs with these antibodies inhibits their ability to activate ECs. Furthermore, the biological activity of oxidized MVs is inhibited by platelet-activating factor receptor antagonists, which have been shown to inhibit the action of POVPC. Taken together, we show that oxidized MVs and apoptotic blebs stimulate ECs to specifically bind monocytes, with oxidized phospholipids (POVPC) being the active principle. In addition to oxidized lipoproteins, oxidized MVs and apoptotic blebs may play an important role in chronic inflammatory diseases, such as atherosclerosis.


Subject(s)
Apoptosis/drug effects , Cell Adhesion/drug effects , Cytoplasmic Vesicles/drug effects , Endothelium, Vascular/drug effects , Monocytes/drug effects , Phospholipid Ethers , Receptors, Cell Surface , Receptors, G-Protein-Coupled , Apoptosis/physiology , Arteriosclerosis/etiology , Arteriosclerosis/metabolism , Cytoplasmic Vesicles/metabolism , Endothelium, Vascular/cytology , Endothelium, Vascular/metabolism , Humans , Monocytes/physiology , Oxidation-Reduction , Platelet Membrane Glycoproteins/antagonists & inhibitors , Umbilical Veins/cytology , tert-Butylhydroperoxide/pharmacology
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