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Giannoula Lakka Klement,
Tai-Tung Yip, Flavia Cassiola,
Lena Kikuchi,
David Cervi,
Vladimir Podust,
Joseph E Italiano,
Erin Wheatley,
Abdo Abou-Slaybi,
Elise Bender,
Nava Almog,
Mark W Kieran,
Judah Folkman
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ABSTRACT: Clinical trials with antiangiogenic agents have not been able to validate plasma or serum levels of angiogenesis regulators as reliable markers of cancer presence or therapeutic response. We recently reported that platelets contain numerous proteins that regulate angiogenesis. We now show that accumulation of angiogenesis regulators in platelets of animals bearing malignant tumors exceeds significantly their concentration in plasma or serum, as well as their levels in platelets from non-tumor-bearing animals. This process is selective, as platelets do not take up a proportional amount of other plasma proteins (eg, albumin), even though these may be present at higher concentrations. We also find that VEGF-enriched Matrigel pellets implanted subcutaneously into mice or the minute quantities of VEGF secreted by microscopic subcutaneous tumors (0.5-1 mm(3)) result in an elevation of VEGF levels in platelets, without any changes in its plasma levels. The profile of other angiogenesis regulatory proteins (eg, platelet-derived growth factor, basic fibroblast growth factor) sequestered by platelets also reflects the presence of tumors in vivo before they can be macroscopically evident. The ability of platelets to selectively take up angiogenesis regulators in cancer-bearing hosts may have implications for the diagnosis and management of many angiogenesis-related diseases and provide a guide for antiangiogenic therapies.
Blood 12/2008; 113(12):2835-42. · 9.90 Impact Factor
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Ofra Benny,
Ofer Fainaru,
Avner Adini, Flavia Cassiola,
Lauren Bazinet,
Irit Adini,
Elke Pravda,
Yaakov Nahmias,
Samir Koirala,
Gabriel Corfas,
Robert J D'Amato,
Judah Folkman
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ABSTRACT: Targeting angiogenesis, the formation of blood vessels, is an important modality for cancer therapy. TNP-470, a fumagillin analog, is among the most potent and broad-spectrum angiogenesis inhibitors. However, a major clinical limitation is its poor oral availability and short half-life, necessitating frequent, continuous parenteral administration. We have addressed these issues and report an oral formulation of TNP-470, named Lodamin. TNP-470 was conjugated to monomethoxy-polyethylene glycol-polylactic acid to form nanopolymeric micelles. This conjugate can be absorbed by the intestine and selectively accumulates in tumors. Lodamin significantly inhibits tumor growth, without causing neurological impairment in tumor-bearing mice. Using the oral route of administration, it first reaches the liver, making it especially efficient in preventing the development of liver metastasis in mice. We show that Lodamin is an oral nontoxic antiangiogenic drug that can be chronically administered for cancer therapy or metastasis prevention.
Nature Biotechnology 08/2008; 26(7):799-807. · 29.50 Impact Factor
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ABSTRACT: Angiopoietins were thought to be endothelial cell-specific via the tie2 receptor. We showed that angiopoietin-1 (ang1) also interacts with integrins on cardiac myocytes (CMs) to increase survival. Because ang1 monomers bind and activate integrins (not tie2), we determined their function in vivo. We examined monomer and multimer expressions during physiological and pathological cardiac remodeling and overexpressed ang1 monomers in phenylephrine-induced cardiac hypertrophy. Cardiac ang1 levels (mRNA, protein) increased during postnatal development and decreased with phenylephrine-induced cardiac hypertrophy, whereas tie2 phosphorylations were unchanged. We found that most or all of the changes during cardiac remodeling were in monomers, offering an explanation for unchanged tie2 activity. Heart tissue contains abundant ang1 monomers and few multimers (Western blotting). We generated plasmids that produce ang1 monomers (ang1-256), injected them into mice, and confirmed cardiac expression (immunohistochemistry, RT-PCR). Ang1 monomers localize to CMs, smooth muscle cells, and endothelial cells. In phenylephrine-induced cardiac hypertrophy, ang1-256 reduced left ventricle (LV)/tibia ratios, fetal gene expressions (atrial and brain natriuretic peptides, skeletal actin, beta-myosin heavy chain), and fibrosis (collagen III), and increased LV prosurvival signaling (akt, MAPK(p42/44)), and AMPK(T172). However, tie2 phosphorylations were unchanged. Ang1-256 increased integrin-linked kinase, a key regulator of integrin signaling and cardiac health. Collectively, these results suggest a role for ang1 monomers in cardiac remodeling.
The FASEB Journal 06/2008; 22(8):3010-23. · 5.71 Impact Factor
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Tammy F Chu,
Maria A Rupnick,
Risto Kerkela,
Susan M Dallabrida,
David Zurakowski,
Lisa Nguyen,
Kathleen Woulfe,
Elke Pravda, Flavia Cassiola,
Jayesh Desai,
Suzanne George,
Jeffrey A Morgan,
David M Harris,
Nesreen S Ismail,
Jey-Hsin Chen,
Frederick J Schoen,
Annick D Van den Abbeele,
George D Demetri,
Thomas Force,
Ming Hui Chen
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ABSTRACT: Sunitinib, a multitargeted tyrosine-kinase inhibitor, which is approved by both US and European Commission regulatory agencies for clinical use, extends survival of patients with metastatic renal-cell carcinoma and gastrointestinal stromal tumours, but concerns have arisen about its cardiac safety. We therefore assessed the cardiovascular risk associated with sunitinib in patients with metastatic gastrointestinal stromal tumours.
We retrospectively reviewed all cardiovascular events in 75 patients with imatinib-resistant, metastatic, gastrointestinal stromal tumours who had been enrolled in a phase I/II trial investigating the efficacy of sunitinib. The composite cardiovascular endpoint was cardiac death, myocardial infarction, and congestive heart failure. We also examined sunitinib's effects on left ventricular ejection fraction (LVEF) and blood pressure. We investigated potential mechanisms of sunitinib-associated cardiac effects by studies in isolated rat cardiomyocytes and in mice.
Eight of 75 (11%) patients given repeating cycles of sunitinib in the phase I/II trial had a cardiovascular event, with congestive heart failure recorded in six of 75 (8%). Ten of 36 (28%) patients treated at the approved sunitinib dose had absolute LVEF reductions in ejection fraction (EF) of at least 10%, and seven of 36 (19%) had LVEF reductions of 15 EF% or more. Sunitinib induced increases in mean systolic and diastolic blood pressure, and 35 of 75 (47%) individuals developed hypertension (>150/100 mm Hg). Congestive heart failure and left ventricular dysfunction generally responded to sunitinib being withheld and institution of medical management. Sunitinib caused mitochondrial injury and cardiomyocyte apoptosis in mice and in cultured rat cardiomyocytes.
Left ventricular dysfunction might be due, in part, to direct cardiomyocyte toxicity, exacerbated by hypertension. Patients treated with sunitinib should be closely monitored for hypertension and LVEF reduction, especially those with a history of coronary artery disease or cardiac risk factors.
The Lancet 12/2007; 370(9604):2011-9. · 38.28 Impact Factor
