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A stem cell type supposed to be crucial for angiogenesis and cancer growth does not exist?
April 23, 2008
Angiogenesis, the growth of new blood vessels, is a central process in diverse physiological and pathological situations such as healing of wounds and traumas, cardiovascular disorders, inflammatory conditions such as rheumatoid arthritis, and in cancer growth. The current belief about the source of blood vessel wall endothelial cells (ECs) responsible for vascular growth in adults is that a significant and crucial part of neovascular ECs originate from circulating stem and progenitor cells that are first mobilized from the bone marrow (BM), and subsequently differentiate to mature bona fide ECs and incorporate in the vasculature. This concept has become textbook material, and a common theme in modem vascular and cancer biology. Importantly, it is widely believed that tumor angiogenesis and cancer growth critically depend on BM derived circulating endothelial precursor cells. Endothelial precursors would thus provide a powerful novel approach to block tumor angiogenesis and cure cancer. Correspondingly, therapeutic transplantation of such stem cells would be a promising approach to restore tissue vascularization after ischemic events. Clinical trials with human patients are currently ongoing based on the circulating endothelial precursor cell dogma.
Now, researchers lead by Dr. Petri Salvén at the University of Helsinki, Finland, and the stem cell research pioneer Dr. Irving Weissman at Stanford University, California, have shown that circulating endothelial precursor cells actually do not exist, and that angiogenesis and cancer growth do not involve or depend on such hypothetical stem cells. (PNAS, in press; online 21.-25.4.). By using endothelial cell specific genomic mouse models and most modern three dimensional cellular imaging technologies, they show that endothelial differentiation is not a typical function of BM derived stem cells, and it has to be an extremely rare event if it occurs at all. However, angiogenic and tumor tissues contain large numbers of BM derived cells such as ordinary white blood cells that often are very close to blood vessel walls, and may therefore have been misinterpreted as blood vessel wall ECs in earlier studies utilizing less advanced technologies.
The results have great practical significance when researchers are trying to focus on novel approaches to cure cancer by targeting the normal cells of the body which supply tumors with blood and nutrients. "Our results will help the researchers to concentrate their efforts on molecular and cellular targets that actually exist" says Dr. Salvén, leader of the Helsinki team.
"It has been a learning experience to try to publish results that demonstrate that a number of fellow research have for years been studying nonexistent cells", Dr. Salven comments. "Issues concerning publication bias and nonaccessibility of negative data are really becoming more and more relevant, just as recently seen also in other fields of biomedicine."
University of Helsinki
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From Local Invasion to Metastatic Cancer: Involvement of Distant Sites Through the Lymphovascular System (Current Clinical Oncology)
by Stanley P.L. Leong (Editor)
In human solid tumors, nodal status is the most important prognostic indicator for patient outcome. Recent developments in the sentinel lymph node concept have resulted in new procedures to define the first draining node as the primary gateway through which the cancer will spread. In From Local Invasion to Metastatic Cancer: Involvement of Distant Sites Through the Lymphovascular System, a panel of international authorities takes an in-depth look at the role of the lymphovascular system in the spread of cancer. The authors summarize the findings of the Second International Symposium on Cancer Metastasis: Basis for Rational Therapy summit. Specifically, the book presents important developments in the biology and clinical understanding of cancer metastasis, describes the relationship...
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Angiostop 250 mg - 60 capsules | Slows Angiogenesis
by Chi's Enterprise
Angiostop is extracted from a special sea cucumber in the South China seas. Its active fraction has been shown through in vitro and in vivo studies to inhibit angiogenesis (new blood vessel formation) and also inhibit receptor tyrosine kinases (RTKs). Studies show that the active fraction inhibits 4 different angiogenesis-related RTKs. By stopping the cytokines from binding to their corresponding RTKs, factors such as angiogenesis and proliferation are inhibited and apoptosis (programmed cell death) is induced.
* Inhibits 4 receptor tyrosine kinases (RTKs):VEGFR, FGFR, PDGR, EGFR
* Inhibits new blood vessel formation
* Induces apoptosis
Inhibiting the vascular endothelial growth factor receptor (VEGFR) is the most important because it stops angiogenesis, cutting off nutrient and...
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Tumor Angiogenesis: Basic Mechanisms and Cancer Therapy
by Dieter Marmé (Author), Dieter Marmé (Editor), Norbert Fusenig (Editor)
Tumor angiogenesis is one of the most prominent mechanisms driving tumor development and progression. In the past 30 years some of the most important signaling pathways linking specific angiogenic activities of tumor cells to fatal reactions of the patient s vascular system have been elucidated. Crucial targets for therapeutic intervention have been identified and validated. Based on these achievements targeted drug development programs have been implemented to interfere with tumor angiogenesis as an attractive strategy in cancer treatment. The first targeted anti-angiogenic drugs have been approved for a variety of solid metastasizing cancers. Part 1 describes the basic mechanisms. Tumor-angiogenic signaling pathways are presented as new potential targets for...
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Angiogenesis Inhibition (Recent Results in Cancer Research)
by Rüdiger Liersch (Editor), Wolfgang E. Berdel (Editor), Torsten Kessler (Editor)
Angiogenesis is attracting increased scientific and clinical interest. The identification of novel mediators and targeting molecules has led to significant progress in our understanding of tumor angiogenesis and tumor vessel targeting. Important advances in cancer treatment have already emerged, and in the future, blood vessel targeting will play a significant role within individualized therapeutic strategies. This volume provides a general overview of the latest developments in angiogenesis inhibition in cancer. All aspects from the bench to the bedside are considered, with detailed attention both to basic research and to its translation into clinical practice. Individual chapters are devoted to the roles of angiopoietins, HIF-1a, chemokines, PDGF and VEGF, and vascular integrins. The...
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Angiogenesis in Brain Tumors (Cancer Treatment and Research)
by Matthias Kirsch (Editor), Peter McL. Black (Editor)
The mutual relationship between tumor growth and concomitant neovascularization offers important insight into the biology of brain tumors and the development of new treatment strategies. Many of the early findings in the biology of angiogenesis have been investigated using brain tumor models. Angiogenesis in Brain Tumors is part of the "Cancer Treatment and Research" book series and this volume provides an overview of the biology of angiogenesis in the central nervous system, the role of angiogenesis in brain tumor development and growth, and therapeutic applications including clinical trials. `Angiogenesis is a critical component of tumor growth. This text evaluates the role of neovascularization in brain tumor development and growth, and presents therapeutic applications...
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AngioGenetics AB and Tumour Biology Centre Freiburg collaborate on the exploration of angiogenesis inhibitors for cancer treatment.: An article from: BIOTECH Patent News
by Biotech Patent News (Publisher)
This digital document is an article from BIOTECH Patent News, published by Biotech Patent News on May 1, 2004. The length of the article is 2286 words. The page length shown above is based on a typical 300-word page. The article is delivered in HTML format and is available in your Amazon.com Digital Locker immediately after purchase. You can view it with any web browser.
Citation Details Title: AngioGenetics AB and Tumour Biology Centre Freiburg collaborate on the exploration of angiogenesis inhibitors for cancer treatment. Publication: BIOTECH Patent News (Newsletter) Date: May 1, 2004 Publisher: Biotech Patent News Volume: 18 Issue: 5
Distributed by Thomson...
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CE test on markers of Angiogenesis in Breast Cancer.(CONTINUING EDUCATION): An article from: Medical Laboratory Observer
by Gale Reference Team (Author)
This digital document is an article from Medical Laboratory Observer, published by Thomson Gale on August 1, 2006. The length of the article is 779 words. The page length shown above is based on a typical 300-word page. The article is delivered in HTML format and is available in your Amazon.com Digital Locker immediately after purchase. You can view it with any web browser.
Citation Details Title: CE test on markers of Angiogenesis in Breast Cancer.(CONTINUING EDUCATION) Author: Gale Reference Team Publication: Medical Laboratory Observer (Magazine/Journal) Date: August 1, 2006 Publisher: Thomson Gale Volume: 38 Issue: 8 Page: 18(2)
Distributed by Thomson...
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The NPY Family of Peptides in Immune Disorders, Inflammation, Angiogenesis, and Cancer (Progress in Inflammation Research)
by Zofia Zukowska (Editor), Giora Z. Feuerstein (Editor)
Recent research indicates that the immune system and inflammatory reactions are governed and regulated by powerful neuronal mediators derived from the central and peripheral nervous system. The NPY family of peptides is a diverse group of neuropeptides that acts via multiple receptors, Y1-Y5, which are widespread not only in neurons but also in a variety of non-neural and immune cells. These peptides have been known as important regulators of many essential systems, such as blood pressure and cardiac function, food consumption and energy homeostasis. However, in recent years, they have also become recognized for their role as potent modulators of cell growth and immune functions with broad implications in chronic inflammatory diseases, cancer and angiogenesis.In this book, experts in the...
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Gale Encyclopedia of Cancer: Angiogenesis inhibitors
by RPh.,BCOP Nancy J. Beaulieu (Author)
The article is excerpted from Gale Encyclopedia of Cancer The resource students and researchers will turn to for reliable, up-to-date and clearly written information, the Gale Encyclopedia of Cancer is a comprehensive survey of 120 cancers, cancer drugs, traditional and alternative treatments and diagnostic procedures. The Encyclopedia includes entries covering cancers, cancer drugs, treatments, side effects and diagnostic procedures. Entries typically include the following elements: Causes and Symptoms Definition Description Diagnosis Prevention Resources Risks Special Concerns And more An appendix provides complete contact information for cancer centers, national support groups, government agencies and research groups. Features include...
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Chi's Enterprise Angiostop - 120 capsules
by Chi's Enterprise
Angiostop is extracted from a special sea cucumber in the South China seas. Its active fraction has been shown through in vitro and in vivo studies to inhibit angiogenesis (new blood vessel formation) and also inhibit receptor tyrosine kinases (RTKs). Studies show that the active fraction inhibits 4 different angiogenesis-related RTKs. By stopping the cytokines from binding to their corresponding RTKs, factors such as angiogenesis and proliferation are inhibited and apoptosis (programmed cell death) is induced. * Inhibits 4 receptor tyrosine kinases (RTKs):VEGFR, FGFR, PDGR, EGFR * Inhibits new blood vessel formation * Induces apoptosis Inhibiting the vascular endothelial growth factor receptor (VEGFR) is the most important because it stops angiogenesis, cutting off nutrient and blood...
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