RESEARCH DIRECTIONS IN TUMOR ANGIOGENESIS Edited by Jianyuan Chai Research Directions in Tumor Angiogenesis http://dx.doi.org/10.5772/56020 Edited by Jianyuan Chai Contributors Massimo Mattia Santoro, Vera Mugoni, Takaaki Sasaki, Yoshinori Minami, Yoshinobu Ohsaki, Veronika Sysoeva, Mathias Francois, Jeroen Overman, Mani Valarmathi, Qigui Li, Mark Hickman, Peter Weina, Jianyuan Chai, Ramani Ramchandran, Jill Gershan, Andrew Chan, Magdalena Chrzanowska-Wodnicka, Bryon Johnson, Qing Miao Published by InTech Janeza Trdine 9, 51000 Rijeka, Croatia Copyright © 2013 InTech All chapters are Open Access distributed under the Creative Commons Attribution 3.0 license, which allows users to download, copy and build upon published articles even for commercial purposes, as long as the author and publisher are properly credited, which ensures maximum dissemination and a wider impact of our publications. After this work has been published by InTech, authors have the right to republish it, in whole or part, in any publication of which they are the author, and to make other personal use of the work. Any republication, referencing or personal use of the work must explicitly identify the original source. Notice Statements and opinions expressed in the chapters are these of the individual contributors and not necessarily those of the editors or publisher. No responsibility is accepted for the accuracy of information contained in the published chapters. The publisher assumes no responsibility for any damage or injury to persons or property arising out of the use of any materials, instructions, methods or ideas contained in the book. Publishing Process Manager Iva Lipovic Technical Editor InTech DTP team Cover InTech Design team First published January, 2013 Printed in Croatia A free online edition of this book is available at www.intechopen.com Additional hard copies can be obtained from orders@intechopen.com Research Directions in Tumor Angiogenesis, Edited by Jianyuan Chai p. cm. ISBN 978-953-51-0963-1 free online editions of InTech Books and Journals can be found at www.intechopen.com Contents Preface VII Chapter 1 Transcriptional Modulation of Tumour Induced Angiogenesis 1 Jeroen Overman and Mathias François Chapter 2 Roles of SRF in Endothelial Cells During Hypoxia 29 Jianyuan Chai Chapter 3 Manipulating Redox Signaling to Block Tumor Angiogenesis 47 Vera Mugoni and Massimo Mattia Santoro Chapter 4 Accessory Cells in Tumor Angiogenesis — Tumor-Associated Pericytes 73 Yoshinori Minami, Takaaki Sasaki, Jun-ichi Kawabe and Yoshinobu Ohsaki Chapter 5 Endothelial and Accessory Cell Interactions in Neuroblastoma Tumor Microenvironment 89 Jill Gershan, Andrew Chan, Magdalena Chrzanowska-Wodnicka, Bryon Johnson, Qing Robert Miao and Ramani Ramchandran Chapter 6 T-Cadherin Stimulates Melanoma Cell Proliferation and Mesenchymal Stromal Cell Recruitment, but Inhibits Angiogenesis in a Mouse Melanoma Model 143 K. A. Rubina, E. I. Yurlova, V. Yu. Sysoeva, E. V. Semina, N. I. Kalinina, A. A. Poliakov, I. N. Mikhaylova, N. V. Andronova and H. M. Treshalina Chapter 7 The Use of Artemisinin Compounds as Angiogenesis Inhibitors to Treat Cancer 175 Qigui Li, Peter Weina and Mark Hickman Chapter 8 3-D Microvascular Tissue Constructs for Exploring Concurrent Temporal and Spatial Regulation of Postnatal Neovasculogenesis 261 Mani T. Valarmathi, Stefanie V. Biechler and John W. Fuseler ContentsVI Preface As a process of extension of the vascular network within human body, angiogenesis plays a fundamental role to support cell survival, because all cells need oxygen and nutrients to operate and blood circulation is the only way to provide them. In human adults, angiogenesis mainly takes place in two conditions, wound healing and tumor progression. During wound healing, angiogenesis supports new tissue growth to repair the wound; therefore, it is beneficial to the body and should be promoted. In tumor progression, on the other hand, angiogenesis is hi‐ jacked to serve the mutated cells for their multiplication and therefore, it should be inhibited. This book focuses on the second situation – angiogenesis in tumor progression. However, since the molecular and cellular interactions under both conditions are essentially identical, the con‐ tent of the book is suitable for all the readers who are interested in angiogenesis. The book includes eight chapters written by highly experienced scholars from several na‐ tions. The first chapter, “Transcriptional modulation of tumor induced angiogenesis”, by Overman & Francois (University of Queensland, Australia), gives a comprehensive introduc‐ tion on how angiogenesis at the molecular and cellular levels is initiated and regulated dur‐ ing tumorigenesis as comparing to a normal biological system. Despite the similarity in the molecules involved in both conditions, including transcription factors, angiogenic factors, and cell proliferation/migration factors, the key difference is the balance among these mole‐ cules. In a normal biological system, angiogenesis is highly organized in a spatial-and-tem‐ poral manner. In tumors, however, the uncontrollably replicating cancer cells create an extremely hypoxic environment, which induces a persistent production of angiogenic fac‐ tors that allow angiogenesis to go on and on. As a consequence, the vasculature generated during tumorigenesis is leaky and immature because it never has the time or molecular/ cellular mass to become completed. In a way this makes metastasis easier, because the can‐ cer cells can effortlessly enter into the circulatory system through the porous vessel wall and invade other organs. The imbalance of angiogenic factors during tumorigenesis starts with the disproportional acti‐ vation of transcription factors, which are reviewed in the second chapter, “Role of serum re‐ sponse factor in endothelial cells during hypoxia”, by Chai (University of California, USA). The best known transcription factors in tumor angiogenesis are hypoxia-inducible factor (HIF) and p53. They both can be activated by oxygen shortage. While HIF activates angiogenic factors like vascular endothelial growth factor (VEGF) to promote tumor cell survival, p53 is doomed to kill the cells through up-regulation of apoptotic factors like BAX, which is why p53 is often found mutated in the vast majority of tumor cells. Although these two transcription factors appear to be the enemies to each other, sometimes they also shake hands under the table. For instance, HIF has been reported in several occasions to help p53 to induce cell death under severe hypoxia. I guess, if you can’t beat them, it won’t be a bad idea to join them. In addition to the commonly known transcription factors involved in angiogenesis, this chapter also brings a new member into the light, i.e., Serum Response Factor (SRF). This is a much more powerful regulator than either HIF or p53, and some even call it the master regulator. SRF directly controls nearly 1% of the known human genes, and through these gene derivatives SRF may have influence on a quarter of the entire human genome. This chapter presents convincing data to show that SRF regulates hypoxia-induced angiogenesis through multi-levels and therefore could be an excel‐ lent target for cancer gene therapy. The activation of HIF not only initiates VEGF production, the best known angiogenic stimu‐ lator, but also directs the gene transcription of two other molecules, endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS), both responsible for the gener‐ ation of nitric oxide (NO-), one of the key reactive oxygen species (ROS) in the body. The next chapter, “Manipulating REDOX signaling to block tumor angiogenesis”, by Mugoni & Santoro (University of Torino, Italy), summarizes all the known ROS and dissects how they influence tumor angiogenesis. The level of ROS in the tumor microenvironment can be a determining factor for the fate of a tumor. A moderate amount of these free radicals can help to maintain normal blood pressure, protect endothelial cell integrity, and support angiogen‐ esis, while high level of ROS can cause endothelial cell death and thereby stop tumor angio‐ genesis. Therefore, manipulation of ROS level could be an alternative approach to control tumor progression. Although angiogenesis is performed by endothelial cells, other cells also contribute to the process. In Chapter 4, “Accessory cells in tumor angiogenesis”, Minami et al (Asahikawa Medical University, Japan) introduce a major helper of endothelial cells during angiogenesis, the pericytes. Endothelial cells form the inner lining of the blood vessels, while pericytes wrap around the endothelial cells from the outside and provide molecular and cellular sup‐ port to stabilize the newly formed microvasculature. Although pericytes are usually absent in tumor vasculature due to the accelerating angiogenic activities, this chapter provides sev‐ eral strategies to increase the local population of pericytes to counteract the tumor angiogen‐ esis, which may be advanced to promising therapeutic approaches in the near future. In the following chapter, “Endothelial and accessory cell interactions in neuroblastoma tu‐ mor microenvironment”, Gershan et al (Medical College of Wisconsin, USA) present a special case of tumor biology – neuroblastoma, and give a thorough review on its development, molecular and cellular interactions, and therapeutic strategies. Of particular interest is the point that “tumors are wounds that never heal”, which precisely reflects the truth about tu‐ mors. From molecular and cellular point of view, these two events are almost identical. Mol‐ ecules up-regulated during wound healing are often found elevated in a tumor microenvironment. Wound healing requires cell proliferation, migration and differentiation, and so does tumor progression. Angiogenesis provides fundamental support for wound healing as well as for tumor growth. The only difference, as the team points out, is that wound healing is a highly orchestrated event in which the activations of cells and molecules are regulated spatially and temporally. Once the wound is healed, all of these molecular and cellular activities return to their normal physiological levels. Tumors, on the other hand, sustain the high molecular and cellular activities eternally, which is like an open wound. In the next chapter, “T-cadherin stimulates melanoma cell proliferation and mesenchymal stromal cell recruitment, but inhibits angiogenesis in a mouse melanoma model”, Rubina et al (M.V. Lomonosov Moscow State University, Russia)present original data on the role of T-cad‐ PrefaceVIII herin in melanoma angiogenesis. T-cadherin is a membrane-associated protein and its real function remains largely unknown. While its up-regulation has been associated with high grade astrocytomas, in the majority of cancers including melanoma, T-cadherin is down-regu‐ lated or completely lost. Overexpression of T-cadherin in endothelial cells correlates with a migratory phenotype, which usually suggests a positive role in angiogenesis. However, this study found in a melanoma model that the number of microvessels is reduced when T-cadher‐ in is expressed, supporting an argument that T-cadherin might inhibit angiogenesis. Using natural products to treat chronic diseases is always the top choice in cancer therapy, because they are cheap and less toxic compared to the synthetic drugs. In the next chapter, “The use of artemisinin compounds as angiogenesis inhibitors to treat cancer”, Li et al (Walter Reed Army Institute of Research, USA) introduce such a compound, artemisinin, an extract from the plant sagewort. Artemisinin is the first line treatment recommended by WHO for malaria. However, an increasing amount of data indicates an anti-cancer effect, particularly against tumor angiogenesis. Li et al give a thorough review on artemisinin and its derivatives in cancer and non-cancer context, and provide valuable perspectives for the future research direction. The final chapter of the book, “3-D microvascular tissue constructs for exploring concur‐ rent temporal and spatial regulation of postnatal neovasculogenesis”, by Valarmathi et al (University of South Carolina, USA), demonstrates a marvelous research technique to study neovasculogenesis in vitro, the three-dimensional collagen scaffold. Depending on the cul‐ ture medium provided, bone marrow stromal cells can differentiate into either endothelial cells or smooth muscle cells in front of your eyes and form tube-like network within the scaffold, mimicking the vasculature formation in vivo. Although the study is on neovasculo‐ genesis, meaning generating microvessels from stem cells, the technique can be easily ap‐ plied to angiogenesis studies using differentiated endothelial cells. The beautiful images generated from confocal immunostaining, transmission and scanning electron microscope provide a perfect end for this book. Jianyuan Chai, Ph.D. Laboratory of GI Injury and Cancer VA Long Beach Healthcare System and University of California Long Beach, California USA Preface IX [...]... dymerization or co-receptor (NRPs) interaction adding to the complexity In general, VEGFA binds to VEGFR1 or VEGFR2 with the former interaction being anti-angiogenic to due high affinity but low downstream tyrosine kinase activity, and the latter being pro-angio‐ 13 14 Research Directions in Tumor Angiogenesis genic VEGF-C and VEGF-D on the other hand primarily bind the lymphangiogenic VEGFR3 receptor... Breast tumor kinase (protein tyrosine kinase 6) regulates heregulininduced activation of ERK5 and p38 MAP kinases in breast cancer cells Cancer Res, 2007 67(9): p 4199-209 [125] Hu, W., et al., Biological roles of the Delta family Notch ligand Dll4 in tumor and endothe‐ lial cells in ovarian cancer Cancer Res, 2011 71(18): p 6030-9 [126] Hovinga, K.E., et al., Inhibition of notch signaling in glioblastoma... claudin-5[62] and the vascular adhesion molecule VCAM-1[63], which are both essential for vascular integrity and endothelial activation dur‐ ing angiogenesis SOX18 also directly activates the expression of MMP7, EphrinB2, interleu‐ kin receptor 7 (IL-7R)[64] and Robo4[65] in vitro Robo4 expression in vivo is correspondingly under control of Sox7/18 activity in the mouse caudal vein, and in the intersegmental... mined by vessel type and size Cord hollowing is characterized by the creation of an extracellular luminal space within a cylindrical EC-cord This involves the loss of apical cell adhesion between the central- but not peripheral- ECs, and results in a lumen diameter that is enclosed by multiple ECs[14-16, 18, 19] Cell hollowing on the other hand involves the in tracellular fusion of vacuoles within... tip cell position during angiogenic sprouting Nat Cell Biol, 2010 12(10): p 943-53 [22] Wei, G.H., et al., Genome-wide analysis of ETS-family DNA-binding in vitro and in vivo EMBO J, 2010 29(13): p 2147-60 [23] Pham, V.N., et al., Combinatorial function of ETS transcription factors in the developing vasculature Dev Biol, 2007 303(2): p 772-83 19 20 Research Directions in Tumor Angiogenesis [24] De... beds Intus‐ susception angiogenesis is a process of vessel invagination wherein vessels ultimate divide and split – which requires appreciably high levels of polarization and localized en masse loss of cell junctions Sprouting angiogenesis is visibly distinct from intussusception, and unsurpris‐ ingly involves the sprouting of a subset of ECs from the vascular wall to protrude into a primed ECM In this... where they are dis‐ 17 18 Research Directions in Tumor Angiogenesis torted and exploited to induce chronic angiogenesis and vasculogenesis Although most at‐ tention in therapeutic cancer research over the years has gone to growth factor signalling or other downstream players of proliferation, migration and morphogenesis there seems to be an emerging paradigm shift in studying both prognostic and therapeutic... in the zebrafish embryo Dev Biol, 2008 316(2): p 312-22 [19] Wang, Y., et al., Moesin1 and Ve-cadherin are required in endothelial cells during in vivo tubulogenesis Development, 2010 137(18): p 3119-28 [20] Davis, G.E and C.W Camarillo, An alpha 2 beta 1 integrin-dependent pinocytic mecha‐ nism involving intracellular vacuole formation and coalescence regulates capillary lumen and tube formation in. .. by their highly homologous 79 ami‐ no acid high-mobility group (HMG) domain, which was first discovered in their founding member sex-determining region Y (SRY)[53] This typical SOX element binds the heptameric consensus sequence 5’-(A/T)(A/T)CAA(A/T)G-3’[54], to induce DNA bending and regulate the expression of a broad collection of genes during embryonic development[55] Specificity 9 10 Research Directions. .. transiently in the developing endothelium and then again during patho‐ logical conditions, such as wound healing where SOX18 is reexpressed in the capillary endo‐ thelium[145], and in tumorigenesis where SOX18 is reexpressed in the tumour stroma[146], including the blood and lymphatic vasculature[52, 147] Recently, SOXF transcription factors have emerged as novel prognostic markers during gastric cancer . RESEARCH DIRECTIONS IN TUMOR ANGIOGENESIS Edited by Jianyuan Chai Research Directions in Tumor Angiogenesis http://dx.doi.org/10.5772/56020 Edited by Jianyuan Chai Contributors Massimo. www.intechopen.com Additional hard copies can be obtained from orders@intechopen.com Research Directions in Tumor Angiogenesis, Edited by Jianyuan Chai p. cm. ISBN 978-953-51-0963-1 free online. Army Institute of Research, USA) introduce such a compound, artemisinin, an extract from the plant sagewort. Artemisinin is the first line treatment recommended by WHO for malaria. However, an increasing