A minor role of asparaginase in predisposing to cerebral venous thromboses in adult acute lymphoblastic leukemia patients.

Cerebral venous thrombosis (CVT) covers up to a third of all venous thromboses (VTs) detected in patients with acute lymphoblastic leukemia (ALL). It usually hampers patients' lives and may also endanger efficient leukemia treatment. Although many factors have been suggested to account for an elevated risk of VTs in patients with ALL, there still is a lack of studies focusing on CVTs and especially in the setting of adult ALL patients. We studied in our retrospective population-based cohort the occurrence, characteristics, as well as risk factors for VTs in 186 consecutively diagnosed Finnish adult ALL patients treated with a national pediatric-inspired treatment protocol ALL2000. In the risk factor analyses for VTs we found a distinction of the characteristics of the patients acquiring CVT from those with other kinds of VTs or without thrombosis. In contrast to previous studies we were also able to compare the effects of asparaginase in relation to CVT occurrence. Notably, more than half of the CVTs were diagnosed prior the administration of asparaginase which accentuates the role of other risk factors on the pathophysiology of CVT compared to truncal or central venous line (CVL) VTs in adult ALL patients.

Individualized systems medicine strategy to tailor treatments for patients with chemorefractory acute myeloid leukemia.

UNLABELLED: We present an individualized systems medicine (ISM) approach to optimize cancer drug therapies one patient at a time. ISM is based on (i) molecular profiling and ex vivo drug sensitivity and resistance testing (DSRT) of patients' cancer cells to 187 oncology drugs, (ii) clinical implementation of therapies predicted to be effective, and (iii) studying consecutive samples from the treated patients to understand the basis of resistance. Here, application of ISM to 28 samples from patients with acute myeloid leukemia (AML) uncovered five major taxonomic drug-response subtypes based on DSRT profiles, some with distinct genomic features (e.g., MLL gene fusions in subgroup IV and FLT3-ITD mutations in subgroup V). Therapy based on DSRT resulted in several clinical responses. After progression under DSRT-guided therapies, AML cells displayed significant clonal evolution and novel genomic changes potentially explaining resistance, whereas ex vivo DSRT data showed resistance to the clinically applied drugs and new vulnerabilities to previously ineffective drugs. SIGNIFICANCE: Here, we demonstrate an ISM strategy to optimize safe and effective personalized cancer therapies for individual patients as well as to understand and predict disease evolution and the next line of therapy. This approach could facilitate systematic drug repositioning of approved targeted drugs as well as help to prioritize and de-risk emerging drugs for clinical testing.

Defective glycosylation of cholesteryl ester transfer protein in plasma from alcohol abusers.

AIMS: Alcohol consumption reduces the carbohydrate content of some glycoproteins, e.g. carbohydrate-deficient transferrin. The aim of this study was to investigate if there is such an alcohol-induced glycosylation defect in plasma cholesteryl ester transfer protein (CETP). A defect in the posttranslational glycosylation of CETP may affect its structure and electrical charge and may therefore affect its function. CETP activity is low in alcohol abusers. METHODS: We studied the effect of alcohol consumption on CETP properties in 10 alcohol abusers and 10 control subjects. CETP was partially purified from lipoprotein-free plasma by FPLC using a Phenyl-Sepharose column. Isoelectric focusing, polyacrylamide gel electrophoresis, and western blotting were performed for partially purified CETP. RESULTS: CETP had a lower molecular weight in the alcohol abusers than in the controls (range 50.6-84.0 kDa in the alcohol abusers vs 51.3-85.0 kDa in the controls). CETP purified from alcohol abusers had a higher isoelectric point, indicating a lower negative charge on the surface of the protein than in the controls' CETP. A similar effect was observed when control CETP was incubated with neuraminidase, an enzyme which is known to remove sialic acid from glycoproteins. CONCLUSIONS: We conclude that CETP from alcohol abusers may have a glycosylation defect due to defective sialylation caused posttranslationally by alcohol itself or its metabolite acetaldehyde. The defective glycosylation of CETP associated with altered binding to lipoproteins may lead to the low CETP activity observed previously in alcoholic subjects.

Lipoprotein-associated phosphatidylethanol increases the plasma concentration of vascular endothelial growth factor.

OBJECTIVE: To study whether qualitative changes in high-density lipoprotein (HDL) phospholipids mediate part of the beneficial effects of alcohol on atherosclerosis, we investigated whether phosphatidylethanol (PEth) in HDL particles affects the secretion of vascular endothelial growth factor (VEGF) from endothelial cells. METHODS AND RESULTS: PEth increased the secretion of VEGF into the culture medium of EA.hy 926 endothelial cells. The mitogen-activated protein kinase (MAPK) phosphorylation increased by 3.3-fold and protein kinase C (PKC) by 2.2-fold by PEth-containing HDL. Moreover, we showed that intravenous injection of PEth incorporated into HDL particles increased plasma concentration of VEGF by 2.4-fold in rats in vivo. Similar effect was observed when the rats were injected with HDL particles isolated from alcohol drinkers. CONCLUSIONS: HDL particles containing PEth affect endothelial cells by MAPK and PKC signaling. This may mediate the effects of ethanol on the arterial wall by increasing VEGF secretion from endothelial vascular cells. That may explain, at least in part, the beneficial effect of moderate alcohol consumption on atherosclerosis.

Effects of ethanol on lipids and atherosclerosis.

Moderate alcohol consumption is associated with an increase in plasma high density lipoprotein (HDL) cholesterol concentration and a decrease in low density lipoprotein (LDL) cholesterol concentration. Changes in the concentration and composition of lipoproteins are estimated to account for more than half of alcohol's protective effect for coronary heart disease. Alcohol intake also affects plasma proteins involved in lipoprotein metabolism: cholesteryl ester transfer protein, phospholipid transfer protein, lecithin:cholesterol acyltransferase, lipoprotein lipase, hepatic lipase, and phospholipases. In addition, alcohol intake may result in acetaldehyde modification of apolipoproteins. Furthermore, "abnormal" lipids, phosphatidylethanol and fatty acid ethyl esters are formed in the presence of ethanol and are associated with lipoproteins in plasma. Ethanol and ethanol-induced modifications of lipids may modulate the effects of lipoproteins on the cells in the arterial wall. The molecular mechanisms involved in these processes are complex, requiring further study to better understand the specific effects of ethanol in the pathogenesis of atherosclerosis. This review discusses the effects of ethanol on lipoproteins and lipoprotein metabolism, as well as the novel effects of lipoproteins on vascular wall cells.

High-density lipoprotein increases the abundance of eNOS protein in human vascular endothelial cells by increasing its half-life.

OBJECTIVES: Given the importance of endothelial nitric oxide synthase (eNOS) in regulating endothelium-dependent vasorelaxation, we investigated the effects of high-density lipoprotein in (HDL) on eNOS protein abundance in cultured human vascular endothelial cells. BACKGROUND: Endothelial dysfunction, characterized by decreased nitric oxide production, is one of the early features in the development of atherosclerosis. We have recently shown in vivo that niacin therapy increases plasma HDL concentration and improves endothelium-dependent vasorelaxation in patients with coronary artery disease. METHODS: Human vascular endothelial cells were cultured in the presence or absence of HDL or apolipoprotein (apo)A-I. The eNOS protein abundance was assessed by immunoblotting, and protein half-life was assessed by pulse-chase techniques. The eNOS messenger ribonucleic acid (mRNA) abundance was measured using real-time quantitative polymerase chain reaction. RESULTS: High density lipoprotein, or apoA-I alone, increased eNOS protein abundance by 3.5 +/- 0.7 and 2.7 +/- 0.5-fold, respectively (p < 0.05 for both). However, neither HDL nor apoA-I increased eNOS mRNA abundance. It was shown that HDL increased eNOS protein half-life up to 3.3 +/- 0.2-fold (p = 0.001). Both HDL and apoA-I activated mitogen-activated protein-kinase and phosphatidylinositol 3-kinase (PI3K) Akt-pathways in human arterial endothelial cells, and inhibition of either of these pathways by specific pharmacologic inhibitors abolished the effect of HDL on eNOS. CONCLUSIONS: We demonstrate that HDL activates both extracellular signal-regulated kinase 1/2 (ERK1/2) and Akt, resulting in enhanced eNOS protein stability and subsequent accumulation of eNOS protein. This posttranslational regulation represents a previously unrecognized mechanism for regulating eNOS.

A novel mechanism for the beneficial vascular effects of high-density lipoprotein cholesterol: enhanced vasorelaxation and increased endothelial nitric oxide synthase expression.

BACKGROUND: Low levels of high-density lipoprotein (HDL) cholesterol increase the risk of coronary artery disease (CAD), and recent clinical studies suggest that interventions in low-HDL patients are beneficial. The purpose of this study was to examine the effect of increased HDL levels on endothelium-dependent vasodilation. METHODS: We studied patients with CAD with a low-density lipoprotein (LDL) level of <100 mg/dL. Patients with an HDL level of < or =36 mg/dL were treated with niacin (n = 11), and patients with an HDL level of >36 mg/dL were followed as controls (n = 10). Baseline and 3-month follow-up studies of flow-mediated dilation (FMD) and blood lipid levels were obtained. RESULTS: HDL levels increased from 30.1 +/- 1.2 to 40.5 +/- 1.2 mg/dL in the niacin-treated patients (P <.001) but remained unchanged in the control patients. At baseline, FMD was impaired in both the treated (6.5% +/- 1%) and the control (7.3% +/- 1%) patients compared with 10 healthy subjects (16% +/- 2%, P <.01). After 3 months, FMD improved in the niacin-treated patients (11.8% +/- 1%, P =.001) but remained unchanged in the control patients (6.2% +/- 1%). Exposure of cultured human vascular endothelial cells to HDL in vitro enhanced expression of endothelial nitric oxide synthase (eNOS), as shown by immunoblotting. CONCLUSIONS: In patients with CAD and well-controlled LDL levels, elevation of HDL with niacin improves endothelial function. HDL increases eNOS protein expression in cultured vascular endothelial cells. Taken together, these observations suggest that HDL-mediated increases in eNOS expression may contribute to the observed enhancement in vasorelaxation and thus support a previously unrecognized mechanism for the beneficial cardiovascular effects of HDL.