2012年7月21日星期六

An IP-10 (CXCL10)-Derived Peptide Inhibits Angiogenesis.

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An IP-10 (CXCL10)-Derived Peptide Inhibits Angiogenesis.

PLoS One. 2012;7(7):e40812

Authors: Yates-Binder CC, Rodgers M, Jaynes J, Wells A, Bodnar RJ, Turner T

Abstract
Angiogenesis plays a critical role in processes such as organ development, wound healing, and tumor growth. It requires well-orchestrated integration of soluble and matrix factors and timely recognition of such signals to regulate this process. Previous work has shown that newly forming vessels express the chemokine receptor CXC receptor 3 (CXCR3) and, activation by its ligand IP-10 (CXCL10), both inhibits development of new vasculature and causes regression of newly formed vessels. To identify and develop new therapeutic agents to limit or reverse pathological angiogenesis, we identified a 21 amino acid fragment of IP-10, spanning the ?-helical domain residues 77-98, that mimic the actions of the whole IP-10 molecule on endothelial cells. Treatment of the endothelial cells with the 22 amino acid fragment referred to as IP-10p significantly inhibited VEGF-induced endothelial motility and tube formation in vitro, properties critical for angiogenesis. Using a Matrigel plug assay in vivo, we demonstrate that IP-10p both prevented vessel formation and induced involution of nascent vessels. CXCR3 neutralizing antibody was able to block the inhibitory effects of the IP-10p, demonstrating specificity of the peptide. Inhibition of endothelial function by IP-10p was similar to that described for IP-10, secondary to CXCR3-mediated increase in cAMP production, activation of PKA inhibiting cell migration, and inhibition of VEGF-mediated m-calpain activation. IP-10p provides a novel therapeutic agent that inhibits endothelial cell function thus, allowing for the modulation of angiogenesis.

PMID: 22815829 [PubMed - in process]

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Bevacizumab (Avastin): An anti-angiogenic drug associated with osteonecrosis of the jaw.

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Bevacizumab (Avastin): An anti-angiogenic drug associated with osteonecrosis of the jaw.

Gen Dent. 2011 Nov-Dec;59(6):410-3

Authors: Wynn RL

PMID: 22313910 [PubMed - indexed for MEDLINE]

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Rationale for anti-angiogenic therapy in pheochromocytoma and paraganglioma.

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Rationale for anti-angiogenic therapy in pheochromocytoma and paraganglioma.

Endocr Pathol. 2012 Mar;23(1):34-42

Authors: Favier J, Igaz P, Burnichon N, Amar L, Lib� R, Badoual C, Tissier F, Bertherat J, Plouin PF, Jeunemaitre X, Gimenez-Roqueplo AP

Abstract
Pheochromocytomas and paragangliomas are highly vascularized tumors which are candidates for anti-angiogenic therapies. Several studies have reported the association of vascular endothelial growth factor (VEGF) overexpression with malignancy, but none took into account the genetic status of the patients or tumors, which may have a major influence on such observations. Transcriptome studies indeed revealed that pheochromocytomas and paragangliomas can be classified into two major clusters depending on their gene expression profile: Cluster 1 comprises samples associated with a hypoxic signature such as SDHx- and VHL-related tumors and cluster 2 includes RET, NF1, and TMEM127-mutated tumors, as well as most of sporadic tumors. The aim of this study was to provide a comprehensive rationale for the targeting of angiogenesis in patients with malignant forms of the disease. We used in situ hybridization, immunohistochemistry, and microarray gene expression profiling to evaluate angiogenesis and the expression of several angiogenic factors in a large cohort of pheochromocytomas and paragangliomas. We also studied the activation of mTOR by assessing the phosphorylation of its targets, P70 S6 kinase and 4E-BP1. These results were correlated with both malignancy and transcription signature. Our results reveal that cluster 1 tumors display a marked increase in both vascularization and in the expression of major angiogenic molecules, including VEGF, its receptors, HIF2?, Angiopoietin-2, and the endothelin receptors ETA and ETB. These overexpressions were observed in both benign and malignant samples of cluster 1 and thus appeared to be mainly dependent on the pseudo-hypoxic status of these tumors. The mTOR pathway was potentially activated in half of the tumors studied, with a slight increase in cluster 2 pheochromocytomas. Our results suggest that there is a strong rationale for anti-VEGF-based therapeutic strategies in malignant pheochromocytomas and paragangliomas, in particular in those associated with mutations in the SDHB gene.

PMID: 22183643 [PubMed - indexed for MEDLINE]

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2012年7月20日星期五

Management of hepatocellular carcinoma: beyond sorafenib.

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Management of hepatocellular carcinoma: beyond sorafenib.

Curr Oncol Rep. 2012 Jun;14(3):257-66

Authors: Chan SL, Mok T, Ma BB

Abstract
The positive results of sorafenib have unveiled a new direction of research in the management of hepatocellular carcinoma (HCC). Since then intensive efforts have been focused on development of novel management strategy to further improve the outcome for patients with HCC. Emerging data have suggested that tumor progression of HCC is driven by a number of deregulated signaling pathways and/or epigenetic mechanism. Thus much effort is dedicated to identification of novel agents targeting these dysregulated pathways. Combinations of targeted therapeutics and transarterial chemoembolization (TACE), or different systemic therapeutics also hold the promise to improve treatment outcome beyond sorafenib. This review aims to summarize the current status of clinical development of treatment in HCC. Perspectives on future direction of research will also be discussed.

PMID: 22434314 [PubMed - indexed for MEDLINE]

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Rationale for anti-angiogenic therapy in pheochromocytoma and paraganglioma.

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Rationale for anti-angiogenic therapy in pheochromocytoma and paraganglioma.

Endocr Pathol. 2012 Mar;23(1):34-42

Authors: Favier J, Igaz P, Burnichon N, Amar L, Lib� R, Badoual C, Tissier F, Bertherat J, Plouin PF, Jeunemaitre X, Gimenez-Roqueplo AP

Abstract
Pheochromocytomas and paragangliomas are highly vascularized tumors which are candidates for anti-angiogenic therapies. Several studies have reported the association of vascular endothelial growth factor (VEGF) overexpression with malignancy, but none took into account the genetic status of the patients or tumors, which may have a major influence on such observations. Transcriptome studies indeed revealed that pheochromocytomas and paragangliomas can be classified into two major clusters depending on their gene expression profile: Cluster 1 comprises samples associated with a hypoxic signature such as SDHx- and VHL-related tumors and cluster 2 includes RET, NF1, and TMEM127-mutated tumors, as well as most of sporadic tumors. The aim of this study was to provide a comprehensive rationale for the targeting of angiogenesis in patients with malignant forms of the disease. We used in situ hybridization, immunohistochemistry, and microarray gene expression profiling to evaluate angiogenesis and the expression of several angiogenic factors in a large cohort of pheochromocytomas and paragangliomas. We also studied the activation of mTOR by assessing the phosphorylation of its targets, P70 S6 kinase and 4E-BP1. These results were correlated with both malignancy and transcription signature. Our results reveal that cluster 1 tumors display a marked increase in both vascularization and in the expression of major angiogenic molecules, including VEGF, its receptors, HIF2?, Angiopoietin-2, and the endothelin receptors ETA and ETB. These overexpressions were observed in both benign and malignant samples of cluster 1 and thus appeared to be mainly dependent on the pseudo-hypoxic status of these tumors. The mTOR pathway was potentially activated in half of the tumors studied, with a slight increase in cluster 2 pheochromocytomas. Our results suggest that there is a strong rationale for anti-VEGF-based therapeutic strategies in malignant pheochromocytomas and paragangliomas, in particular in those associated with mutations in the SDHB gene.

PMID: 22183643 [PubMed - indexed for MEDLINE]

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2012年7月19日星期四

Acute Podocyte Vascular Endothelial Growth Factor (VEGF-A) Knockdown Disrupts alpha(V)beta(3) Integrin Signaling in the Glomerulus.

Acute Podocyte Vascular Endothelial Growth Factor (VEGF-A) Knockdown Disrupts alpha(V)beta(3) Integrin Signaling in the Glomerulus.

PLoS One. 2012;7(7):e40589

Authors: Veron D, Villegas G, Aggarwal PK, Bertuccio C, Jimenez J, Velazquez H, Reidy K, Abrahamson DR, Moeckel G, Kashgarian M, Tufro A

Abstract
Podocyte or endothelial cell VEGF-A knockout causes thrombotic microangiopathy in adult mice. To study the mechanism involved in acute and local injury caused by low podocyte VEGF-A we developed an inducible, podocyte-specific VEGF-A knockdown mouse, and we generated an immortalized podocyte cell line (VEGF(KD)) that downregulates VEGF-A upon doxycycline exposure. Tet-O-siVEGF:podocin-rtTA mice express VEGF shRNA in podocytes in a doxycycline-regulated manner, decreasing VEGF-A mRNA and VEGF-A protein levels in isolated glomeruli to ?20% of non-induced controls and urine VEGF-A to ?30% of control values a week after doxycycline induction. Induced tet-O-siVEGF:podocin-rtTA mice developed acute renal failure and proteinuria, associated with mesangiolysis and microaneurisms. Glomerular ultrastructure revealed endothelial cell swelling, GBM lamination and podocyte effacement. VEGF knockdown decreased podocyte fibronectin and glomerular endothelial alpha(V)beta(3) integrin in vivo. VEGF receptor-2 (VEGFR2) interacts with beta(3) integrin and neuropilin-1 in the kidney in vivo and in VEGF(KD) podocytes. Podocyte VEGF knockdown disrupts alpha(V)beta(3) integrin activation in glomeruli, detected by WOW1-Fab. VEGF silencing in cultured VEGF(KD) podocytes downregulates fibronectin and disrupts alpha(V)beta(3) integrin activation cell-autonomously. Collectively, these studies indicate that podocyte VEGF-A regulates alpha(V)beta(3) integrin signaling in the glomerulus, and that podocyte VEGF knockdown disrupts alpha(V)beta(3) integrin activity via decreased VEGFR2 signaling, thereby damaging the three layers of the glomerular filtration barrier, causing proteinuria and acute renal failure.

PMID: 22808199 [PubMed - in process]

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Improved efficacy of a novel anti-angiogenic drug combination (TL-118) against colorectal-cancer liver metastases; MRI monitoring in mice.

Improved efficacy of a novel anti-angiogenic drug combination (TL-118) against colorectal-cancer liver metastases; MRI monitoring in mice.

Br J Cancer. 2012 Jul 17;

Authors: Edrei Y, Gross E, Corchia N, Abramovitch R

Abstract
Background:The poor prognosis of patients with colorectal-cancer liver metastases (CRLM) and the insufficiency of available treatments have raised the need for alternative curative strategies. We aimed to assess the therapeutic potential of TL-118, a new anti-angiogenic drug combination, for CRLM treatment, in a mouse model.Methods:The therapeutic potential of TL-118 was evaluated and compared with B20-4.1.1 (B20; anti-VEGF antibody) and rapamycin in CRLM-bearing mice. Tumour progression and the vascular changes were monitored by MRI. Additionally, mice survival, cell proliferation, apoptosis and vessel density were evaluated.Results:This study demonstrated an unequivocal advantage to TL-118 therapy by significantly prolonging survival (threefold) and reducing metastasis perfusion and vessel density (ninefold). The underlying mechanism for TL-118-treatment success was associated with hepatic perfusion attenuation resulting from reduced nitric-oxide (NO) serum levels as elucidated by using hemodynamic response imaging (HRI, a functional MRI combined with hypercapnia and hyperoxia). Further, systemic hepatic perfusion reduction during the initial treatment phase by adding NO inhibitor has proven to be essential for reaching maximal therapeutic effects for both TL-118 and B20.Conclusion:TL-118 harbours a potential clinical benefit to CLRM patients. Moreover, the reduction of hepatic perfusion at early stages of anti-angiogenic therapies by adding NO inhibitor is crucial for achieving maximal anti-tumour effects.British Journal of Cancer advance online publication, 17 July 2012; doi:10.1038/bjc.2012.322 www.bjcancer.com.

PMID: 22805330 [PubMed - as supplied by publisher]

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