Atorvastatin neutralizes the up-regulation of thrombospondin-1 induced by thrombin in human umbilical vein endothelial cells

Phase II trial of irinotecan and metronomic temozolomide in patients with recurrent glioblastoma

This phase II study was conducted to determine the efficacy and safety of metronomic temozolomide (TMZ) in combination with irinotecan in glioblastoma (GB) at first relapse. Patients with GB at first relapse received TMZ 50 mg/m/2day divided into three doses, except for a single 100 mg/m2 dose, administered between 3 and 6 h before every irinotecan infusion. Irinotecan was given intravenously at the previously established dose of 100 mg/m2 on days 8 and 22 of 28-day cycles. Treatment was given for a maximum of nine cycles or until progression or unacceptable toxicity occurred. Vascular endothelial growth factor and its soluble receptor 1, thrombospondin-1, microparticles, and microparticle-dependent procoagulant activity were measured in blood before treatment. The primary objective was 6-month progression-free survival (PFS). Twenty-seven evaluable patients were enrolled. Six-month PFS was 20.8%. Median PFS was 11.6 weeks (95% confidence interval: 7.5-15.7). Stable disease was the best response for nine (37.5%) patients, with a median duration of 11.2 weeks (4.2-35.85 weeks). No differences in PFS or response were observed among patients who relapsed during or after completion of adjuvant TMZ. Grade 3/4 adverse events included lymphopenia (15%), fatigue, diarrhea and febrile neutropenia (3.7% each), lymphopenia, neutropenia, and nausea/vomiting (11.1% each). One patient died from pneumonia and one patient died from pulmonary thromboembolism. Pretreatment levels of angiogenesis biomarkers, microparticles, and microparticle-related procoagulant activity were elevated in patients compared with healthy volunteers. This regimen is feasible, but failed to improve the results obtained with other second-line therapies in recurrent GB.

VEGF and TSP1 levels correlate with prognosis in advanced non-small cell lung cancer

PURPOSE

There is a need for biomarkers that may help in selecting the most effective anticancer treatments for each patient. We have investigated the prognostic value of a set of angiogenesis, inflammation and coagulation markers in patients treated for advanced non-small cell lung cancer.

PATIENTS AND METHODS

Peripheral blood samples were obtained from 60 patients before first line platinum-based chemotherapy ± bevacizumab, and after the third cycle of treatment. Blood samples from 60 healthy volunteers were also obtained as controls. Angiogenesis, inflammation and coagulation markers vascular endothelial growth factor (VEGF), their soluble receptors 1 (VEGFR1) and 2 (VEGFR2), thrombospondin-1 (TSP-1), interleukin-6 (IL6), sialic acid (SA) and tissue factor (TF) were quantified by ELISA.

RESULTS

Except for TSP-1, pre- and post-treatment levels of all markers were higher in patients than in controls (p < 0.05). There was a positive and significant correlation between VEGF and VEGFR2 before treatment. VEGF also correlated with inflammatory markers IL-6 and SA. Moreover, there was a positive and significant correlation between levels of VEGFR1 and TF. Decreased levels of TSP-1 and increased levels of VEGF were associated with shorter survival. Bevacizumab significantly modified angiogenesis parameters and caused a decrease of VEGF and an increase of TSP-1.

CONCLUSION

Angiogenesis, inflammation and coagulation markers were increased in NSCLC patients. Increased levels of VEGF and low levels of TSP-1 correlated with a poor prognosis.

Atorvastatin neutralises the thrombin-induced tissue factor expresion in endothelial cells via geranylgeranyl pyrophosphate

Statins may have beneficial effects in atherogenesis given their antithrombotic properties involving non-lipid mechanisms that modify endothelial function of tissue factor induction by thrombin. In this study, we investigate the effect of atorvastatin on tissue factor (TF) activity in thrombin-stimulated endothelial cells and its regulation through mevalonate or its derivatives. First subculture of human umbilical endothelial cells was used for this study. Cells were treated with thrombin and atorvastatin for different time intervals and dosage. Tissue factor activity was measured as Factor Xa generation induced by Tissue Factor-Factor VIIa complex on confluent cells. Our results show that atorvastatin prevents the thrombin-induced up-regulation of tissue factor activity in a concentration-dependent manner. Mevalonate and geranylgeranyl pyrophosphate reversed this inhibitory effect of atorvastatin on tissue factor activity, while the presence of farnesyl pyrophosphate did not prevent the atorvastatin effect on thrombin-induced tissue factor activity. Rho-kinase inhibitor did not affect the thrombin stimulation of tissue factor activity. High amount of hydrophobic isoprenoid groups decreases the thrombin-induced TF activity and may promote endothelial cell anti-thrombotic action. Rho kinase pathways do not have a major role in the thrombin-mediated TF activity. The inhibitory effect of atorvastatin on thrombin-induced TF activity was partially reversed by MVA and GGPP but not FPP.

Circulating markers of angiogenesis, inflammation, and coagulation in patients with glioblastoma

Inflammation, angiogenesis, and coagulation are linked to the development of cancer. In glioblastoma, microvascular proliferation is a hallmark, and lymphocytic infiltration is a common finding. Thromboses are frequent in patients with glioblastoma. The objective of this study was to assess presurgical levels of circulating markers of inflammation, angiogenesis, and coagulation in a prospective series of patients with glioblastoma, and to explore their correlations and possible associations with clinical findings. Angiogenesis markers included were vascular endothelial growth factor (VEGF), soluble vascular endothelial growth factor-receptor 1 (sVEGFR-1), and thrombospondin-1 (TSP-1). Inflammatory markers included were C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor alpha (TNFα), and sialic acid (SA). Coagulation markers included were fibrinogen (Fg), endogen thrombin generation (ETG), prothrombin fragments 1 + 2 (F1 + 2), and tissue factor (TF). Forty-seven patients and 60 healthy subjects were included in the study. Signs of tumor necrosis in presurgical MRI were associated with shorter survival (P < 0.01). All inflammation markers, F1 + 2, ETG, VEGF and sVEGFR-1, were significantly elevated in glioblastoma patients. Correlations were found between ETG and Fg (r = 0.44, P < 0.01). Sialic acid correlated with Fg (r = 0.63, P < 0,001); CPR correlated with SA (r = 0.60, P < 0.001), Fg (r = 0.76, P < 0.001), TNFα (r = 0.56, P < 0.001), and IL-6 (r = 0.65, P < 0.001); and IL-6 also correlated positively with TNFα (r = 0.40, P < 0.02) and Fg (r = 0.45, P < 0.01). Vascular endothelial growth factor inversely correlated with sVEGFR-1 (r = -0.35, P < 0.02). No associations were found between marker levels and survival or progression-free survival.

Thrombospondin-1 as a Paradigm for the Development of Antiangiogenic Agents Endowed with Multiple Mechanisms of Action

Uncontrolled neovascularization occurs in several angiogenesis-dependent diseases, including cancer. Neovascularization is tightly controlled by the balance between angiogenic growth factors and antiangiogenic agents. The various natural angiogenesis inhibitors identified so far affect neovascularization by different mechanisms of action. Thrombospondin-1 (TSP-1) is a matricellular modular glycoprotein that acts as a powerful endogenous inhibitor of angiogenesis. It acts both indirectly, by sequestering angiogenic growth factors and effectors in the extracellular environment, and directly, by inducing an antiangiogenic program in endothelial cells following engagement of specific receptors including CD36, CD47, integrins and proteoglycans (all involved in angiogenesis ). In view of its central, multifaceted role in angiogenesis, TSP-1 has served as a source of antiangiogenic tools, including TSP-1 fragments, synthetic peptides and peptidomimetics, gene therapy strategies, and agents that up-regulate TSP-1 expression. This review discusses TSP-1-based inhibitors of angiogenesis, their mechanisms of action and therapeutic potential, drawing our experience with angiogenic growth factor-interacting TSP-1 peptides, and the possibility of exploiting them to design novel antiangiogenic agents.

Update on statin-mediated anti-inflammatory activities in atherosclerosis

Anti-inflammatory activities of statins in atherosclerosis have been well documented by both basic research and clinical studies. Statins have been introduced in the 1980s as 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors to block cholesterol synthesis and lower cholesterol serum levels. In the last three decades, statins have been shown to possess several anti-inflammatory and antioxidant activities resulting in the beneficial reduction of atherosclerotic processes and cardiovascular risk in both humans and animal models. Inflammatory intracellular pathways involving kinase phosphorylation and protein prenylation are modulated by statins. The same intracellular mechanisms might also cause statin-induced myotoxicity. In the present review, we will update evidence on statin-mediated regulation of inflammatory pathways in atherogenesis.

Distinct functions of activated protein C differentially attenuate acute kidney injury

Administration of activated protein C (APC) protects from renal dysfunction, but the underlying mechanism is unknown. APC exerts both antithrombotic and cytoprotective properties, the latter via modulation of protease-activated receptor-1 (PAR-1) signaling. We generated APC variants to study the relative importance of the two functions of APC in a model of LPS-induced renal microvascular dysfunction. Compared with wild-type APC, the K193E variant exhibited impaired anticoagulant activity but retained the ability to mediate PAR-1-dependent signaling. In contrast, the L8W variant retained anticoagulant activity but lost its ability to modulate PAR-1. By administering wild-type APC or these mutants in a rat model of LPS-induced injury, we found that the PAR-1 agonism, but not the anticoagulant function of APC, reversed LPS-induced systemic hypotension. In contrast, both functions of APC played a role in reversing LPS-induced decreases in renal blood flow and volume, although the effects on PAR-1-dependent signaling were more potent. Regarding potential mechanisms for these findings, APC-mediated PAR-1 agonism suppressed LPS-induced increases in the vasoactive peptide adrenomedullin and infiltration of iNOS-positive leukocytes into renal tissue. However, the anticoagulant function of APC was responsible for suppressing LPS-induced stimulation of the proinflammatory mediators ACE-1, IL-6, and IL-18, perhaps accounting for its ability to modulate renal hemodynamics. Both variants reduced active caspase-3 and abrogated LPS-induced renal dysfunction and pathology. We conclude that although PAR-1 agonism is solely responsible for APC-mediated improvement in systemic hemodynamics, both functions of APC play distinct roles in attenuating the response to injury in the kidney.