The ADAM17-directed Inhibitory Antibody MEDI3622 Antagonizes Radiotherapy-induced VEGF Release and Sensitizes Non–Small Cell Lung Cancer for Radiotherapy

The cellular response to ionizing radiation (IR) depends on tumor cell and microenvironmental factors. Here, we investigated the role of IR-induced ADAM17 matrix metalloproteinase activity for the intercellular communication between tumor cells and the tumor vasculature in non–small cell lung cancer (NSCLC) tumor models. Factors shed by ADAM17 from NSCLC tumor cells (A549, H358) and relevant for endothelial cell migration were investigated using transwell migration assays, ELISA, and flow cytometry. Tumor angiogenesis–related endpoints were analyzed with the chorio-allantoic membrane assay and in murine NSCLC tumor models. Efficacy-oriented experiments were performed in a murine orthotopic NSCLC tumor model using irradiation with an image-guided small-animal radiotherapy platform alone and in combination with the novel ADAM17-directed antibody MEDI3622. In vitro, VEGF was identified as the major factor responsible for IR-induced and ADAM17-dependent endothelial cell migration toward attracting tumor cells. IR strongly enhanced tumor cell–associated ADAM17 activity, released VEGF in an ADAM17-dependent manner, and thereby coordinated the communication between tumor and endothelial cells. In vivo, tumor growth and microvessel size and density were strongly decreased in response to the combined treatment modality of IR and MEDI3622 but not by either treatment modality alone and thus suggest that the supra-additive effect of the combined treatment modality is in part due to abrogation of the ADAM17-mediated IR-induced protective effect on the tumor vasculature. Furthermore, we demonstrate that the novel ADAM17-inhibitory antibody MEDI3622 potently improves the radiotherapy response of NSCLC. Significance: The tumor response to radiotherapy is influenced by several factors of the tumor microenvironment. We demonstrate that inhibition of the sheddase ADAM17 by the novel antibody MEDI3622 reduces IR-induced VEGF release from tumor cells relevant for endothelial cell migration and vasculature protection, thereby enhancing radiotherapy treatment outcome of NSCLC.

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PO-93 Very low molecular weight heparins (LMWH) retain the capacity to inhibit endothelial cell migration and capillary-like tube formation induced by tumor cells

Thrombosis Research ◽

10.1016/s0049-3848(10)70143-2 ◽

2010 ◽

Vol 125 ◽

pp. S191

Author(s):

A. Vignoli ◽

M. Marchetti ◽

E. Cantalino ◽

E. Diani ◽

G. Bonacina ◽

...

Keyword(s):

Molecular Weight ◽

Cell Migration ◽

Endothelial Cell ◽

Tumor Cells ◽

Tube Formation ◽

Endothelial Cell Migration ◽

Low Molecular Weight ◽

Low Molecular Weight Heparins

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Enhancement of endothelial cell migration by constitutively active LPA1-expressing tumor cells

Biochemical and Biophysical Research Communications ◽

10.1016/j.bbrc.2012.05.012 ◽

2012 ◽

Vol 422 (2) ◽

pp. 339-343 ◽

Cited By ~ 9

Author(s):

Misaho Kitayoshi ◽

Kohei Kato ◽

Eriko Tanabe ◽

Kyohei Yoshikawa ◽

Rie Fukui ◽

...

Keyword(s):

Cell Migration ◽

Endothelial Cell ◽

Tumor Cells ◽

Endothelial Cell Migration ◽

Constitutively Active

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Physiological and Pathological Agonists Induce Differential Release of Angiogenesis Regulatory Proteins From Platelet Alpha Granules Influencing the Angiogenic Response

Blood ◽

10.1182/blood.v116.21.649.649 ◽

2010 ◽

Vol 116 (21) ◽

pp. 649-649

Author(s):

Elisabeth Battinelli ◽

Joseph Italiano ◽

Beth Markens

Keyword(s):

Cell Migration ◽

Endothelial Cell ◽

Tumor Cells ◽

Capillary Tube ◽

Human Platelets ◽

Tube Formation ◽

Angiogenic Factors ◽

Endothelial Cell Migration ◽

Angiogenic Potential ◽

Granule Release

Abstract Abstract 649 In addition to their primary roles in hemostasis and thrombosis, platelets participate in other physiological and pathological processes, including inflammation, wound healing, and tumor metastasis. Although platelets are presumed to contribute to angiogenesis by providing numerous pro-and anti-angiogenic factors, the cellular and molecular basis by which platelets regulate angiogenesis is poorly understood. Previously, we have shown that platelets differentially package specific angiogenesis regulatory proteins into distinct populations of alpha-granules. Using selective agonists for the PAR1μ and PAR4 receptor, we demonstrated that these distinct subpopulations of alpha-granules are susceptible to differential release upon platelet activation (Italiano et al. Blood 2008). To investigate whether other platelet receptors facilitate differential release of alpha-granules, we treated human platelets with physiological agonists and assayed for differential alpha-granule release. Previously we have shown that activation of human platelets with adenosine diphosphate (ADP) stimulated the release of VEGF (an angiogenesis stimulator) in vitro, but not endostatin (an angiogenesis inhibitor). We now have evidence that the agonist Thromboxane A2 (TXA2) acts in an opposite manner; leading to increased endostatin release, but not VEGF release. To more broadly establish the angiogenic potential of the platelet releasate stimulated by exposure to different platelet agonists, including ADP and TXA2, we used a number of well-established angiogenic assays including endothelial cell migration, capillary tube formation, and also an angiogenic protein array panel. All platelet releasates generated by activating platelets with ADP led to increased angiogenic potential with statistically significant increased cell migration, capillary tube formation, and an overall pro-angiogenic protein content of the releasate. Conversely, treatment with TXA2 led to decreased endothelial cell migration and inhibited the formation of capillary tube structures by human umbilical vein endothelial cells. Although it is established that tumor cells can interact with platelets, the mechanisms involved are not known. This prompted us to investigate the hypothesis that cancer cells may also have the capacity to induce differential alpha-granule release during the pathological angiogenesis associated with tumor growth. To investigate whether tumor cells facilitate differential release of pro-angiogenic alpha-granules, we treated human platelets with different tumor cell lines and assayed for differential alpha-granule release. Exposure of platelets to the breast cancer cell line, MCF-7 cells stimulated significant release of VEGF. The angiogenic potential of this releasate was increased as measured using the endothelial cell migration assay, capillary tube formation assay, and protein arrays. This study provides mechanistic evidence to support an interplay between tumor cells and platelet agonists to orchestrate differential release of angiogenic factors from platelets, and illustrates a key role for platelets in tumor angiogenesis through the delivery of specific angiogenic factors. Disclosures: No relevant conflicts of interest to declare.

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