301
|
Abstract
When the FDA commissioner announced in February 2004 the approval of Avastin for the treatment of patients with colon cancer, he called angiogenesis inhibitors a fourth modality of anti-cancer therapy. Because angiogenesis inhibitors are relatively less toxic than conventional chemotherapy and have a lower risk of drug resistance, they may also represent a new class of anti-cancer agents, some of which have sufficiently reduced toxicity that they may be safely used long term. These include immunotherapy, vaccines, telomerase inhibitors, apoptosis inducers, low dose metronomic chemotherapy, novel hormonal therapies, gene therapy and others. However, at least 16 endogenous angiogenesis inhibitors have been discovered in the circulation, and/or in the extracellular matrix. These may become the safest and least toxic of anti-cancer therapies. Four are already being administered by injection in clinical trials for cancer. Recently, it has been reported that at least two endogenous angiogenesis inhibitors can be significantly increased in humans (endostatin), and in mice (thrombospondin), by oral administration of small molecules which themselves are already FDA approved for other uses. This finding suggests several new clinical applications for the future, including the possibility of guiding the use of angiogenesis inhibitors by blood or urinary biomarkers, currently being developed, that may detect the presence of cancer before it is symptomatic, or before it can be located by conventional methods.
Collapse
Affiliation(s)
- Judah Folkman
- Departments of Surgery, Children's Hospital and Harvard Medical School and Vascular Biology Program, Children's Hospital, Boston, Massachusetts 02115, USA.
| |
Collapse
|
302
|
Shaked Y, Bertolini F, Man S, Rogers MS, Cervi D, Foutz T, Rawn K, Voskas D, Dumont DJ, Ben-David Y, Lawler J, Henkin J, Huber J, Hicklin DJ, D'Amato RJ, Kerbel RS. Genetic heterogeneity of the vasculogenic phenotype parallels angiogenesis; Implications for cellular surrogate marker analysis of antiangiogenesis. Cancer Cell 2005; 7:101-11. [PMID: 15652753 DOI: 10.1016/j.ccr.2004.11.023] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2004] [Revised: 10/25/2004] [Accepted: 11/18/2004] [Indexed: 10/25/2022]
Abstract
Development of antiangiogenic therapies would be significantly facilitated by quantitative surrogate pharmacodynamic markers. Circulating peripheral blood endothelial cells (CECs) and/or their putative progenitor subset (CEPs) have been proposed but not yet fully validated for this purpose. Herein, we provide such validation by showing a striking correlation between highly genetically heterogeneous bFGF- or VEGF-induced angiogenesis and intrinsic CEC or CEP levels measured by flow cytometry, among eight different inbred mouse strains. Moreover, studies using genetically altered mice showed that levels of these cells are affected by regulators of angiogenesis, including VEGF, Tie-2, and thrombospondin-1. Finally, treatment with a targeted VEGFR-2 antibody caused a dose-dependent reduction in viable CEPs that precisely paralleled its previously and empirically determined antitumor activity.
Collapse
Affiliation(s)
- Yuval Shaked
- Department of Molecular and Cellular Biology, Sunnybrook and Women's College Health Sciences Centre, Toronto, Ontario M3N 4M5, Canada
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
303
|
Greenaway J, Gentry PA, Feige JJ, LaMarre J, Petrik JJ. Thrombospondin and vascular endothelial growth factor are cyclically expressed in an inverse pattern during bovine ovarian follicle development. Biol Reprod 2004; 72:1071-8. [PMID: 15616224 DOI: 10.1095/biolreprod.104.031120] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Angiogenesis does not normally occur in most adult tissues. However, in the ovary, there are cyclical vascular changes including angiogenesis that involve the interaction of numerous cytokines and growth factors. Angiogenic processes are regulated by a balance between pro- and antiangiogenic factors. The purpose of this study was to determine the expression of the antiangiogenic thrombospondin family and proangiogenic vascular endothelial growth factor (VEGF) in various sizes of healthy bovine follicles. Ovaries were collected from slaughterhouse animals and healthy follicles were sorted based on size (< 0.5 cm, small; 0.5-1.0 cm, medium; >1.0 cm, large). Thrombospondin (TSP) protein levels were significantly higher in small follicles. Immunohistochemistry confirmed the granulosa layer as the primary area within the follicle involved in TSP generation and that small follicles had the highest proportion of immunopositive cells. TSP-1 and -2 mRNA levels were significantly higher in small follicles than either medium or large follicles. TSP colocalized with CD36 on granulosa cells (GC) in the follicle and in cultured cells. In contrast with TSP, VEGF expression increased during growth and development of the follicle. FSH stimulated GC expression of TSP, while LH had no effect. In summary, TSP-1 and -2 were coordinately expressed in the extravascular compartment of the ovary during early follicle development. VEGF was inversely expressed, with expression increasing as follicles developed. Regulated expression and localization of these proteins suggests that they may be involved in regulating growth and development of the follicle in a novel fashion.
Collapse
Affiliation(s)
- James Greenaway
- Department of Biomedical Sciences, University of Guelph, Guelph, Ontario, Canada N1G 2W1
| | | | | | | | | |
Collapse
|
304
|
Lawler J, Detmar M. Tumor progression: the effects of thrombospondin-1 and -2. Int J Biochem Cell Biol 2004; 36:1038-45. [PMID: 15094119 DOI: 10.1016/j.biocel.2004.01.008] [Citation(s) in RCA: 176] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2004] [Revised: 01/12/2004] [Accepted: 01/13/2004] [Indexed: 11/23/2022]
Abstract
The thrombospondins (TSPs) are a family of proteins that regulate tissue genesis and remodeling. In many tumors, down-regulation of TSPs accompanies activation of oncogenes or inactivation of tumor suppresser genes and appears to be a prerequisite for the aquisition of a pro-angiogenic phenotype. The normal suppression of angiogenesis by TSP-1 and -2 involves multiple mechanisms including direct interaction with vascular endothelial cell growth factor (VEGF), inhibition of matrix metalloproteinase 9 (MMP9) activation, inhibition of endothelial cell migration and induction of endothelial cell apoptosis. The importance of down-regulation of TSPs for tumor progression is further established by the fact that several different approaches that are designed to increase the levels of TSP-1 or -2 in tumor tissue inhibit tumor growth. These approaches include cell-based gene therapy, low dose chemotherapeutics and systemic delivery of recombinant proteins or synthetic peptides that include type 1 repeat (TSR) sequences. Initial studies indicate that these reagents, in combination with established approaches for the treatment of cancer, will offer more efficacious therapies.
Collapse
Affiliation(s)
- Jack Lawler
- Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, 99 Brookline Avenue, Boston, MA 02215, USA.
| | | |
Collapse
|
305
|
Abstract
Angiogenesis is regulated in large part by the balance of various proangiogenic stimulators, such as VEGF, and a diverse group of endogenous inhibitors of angiogenesis, most of which are extrinsic to endothelial cells. With respect to the latter, until recently, none have appeared to be induced as a consequence of a specific, self-regulating, feedback inhibition response. A new inhibitor, called vasohibin, has been uncovered. Vasohibin is selectively induced in endothelial cells by proangiogenic stimulatory growth factors such as VEGF; it appears to operate as an intrinsic and highly specific feedback inhibitor of activated endothelial cells engaged in the process of angiogenesis.
Collapse
Affiliation(s)
- Robert S Kerbel
- Sunnybrook and Women's College Health Sciences Centre and the University of Toronto, Ontario, Canada.
| |
Collapse
|
306
|
de Vos FYFL, Willemse PHB, de Vries EGE, Gietema JA. Endothelial cell effects of cytotoxics: balance between desired and unwanted effects. Cancer Treat Rev 2004; 30:495-513. [PMID: 15325031 DOI: 10.1016/j.ctrv.2004.05.003] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Since Folkman defined angiogenesis more than 25 years ago as the most important process in tumour growth and metastasis, specific anti-angiogenic agents have been developed. One obvious route to block this process was until recently overlooked, however. Tumour endothelial cells are different from normal endothelial cells and may respond differently to conventional cytotoxics. Chemotherapeutic-induced vascular toxicity has been observed in various clinical studies and seems to be based on endothelial cell damage as seen in vitro in human umbilical vein endothelial cells (HUVEC) models with protracted low-dose cytostatic exposure. Translated into the clinical setting, such "metronomically" administered chemotherapy could lead to anti-angiogenesis enhancing anti-tumour efficacy of cytostatic drugs. This paper reviews the desired anti-tumour endothelial activity versus the unwanted general vascular toxicity of cytostatic drugs. Several ways to enhance the anti-tumour activity and to circumvent the unwanted vascular toxicity of these "accidental" anti-angiogenic drugs will be discussed.
Collapse
Affiliation(s)
- F Y F L de Vos
- Department Internal Medicine, Division Medical Oncology, University Hospital Groningen, P.O. Box 30.001, 9700 RB Groningen, The Netherlands
| | | | | | | |
Collapse
|
307
|
Huang H, Campbell SC, Bedford DF, Nelius T, Veliceasa D, Shroff EH, Henkin J, Schneider A, Bouck N, Volpert OV. Peroxisome Proliferator-Activated Receptor γ Ligands Improve the Antitumor Efficacy of Thrombospondin Peptide ABT510. Mol Cancer Res 2004. [DOI: 10.1158/1541-7786.541.2.10] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
An expanding capillary network is critical for several pathologic conditions. In cancer, the decrease of antiangiogenic thrombospondin-1 (TSP1) often enables an angiogenic switch, which can be reversed with exogenous TSP1 or its peptide derivative ABT510. TSP1 acts by inducing endothelial cell apoptosis via signaling cascade initiated at CD36, a TSP1 antiangiogenic receptor. Here, we show that the ligands of nuclear receptor peroxisome proliferator-activated receptor γ (PPARγ), 15-deoxy-Δ12,14-prostaglandin J2, troglitazone, and rosiglitazone increased PPARγ and CD36 expression in endothelial cells and improved the efficacy of TSP1 and ABT510 in a CD36-dependent manner. The ABT510 and PPARγ ligands cooperatively blocked angiogenic endothelial functions in vitro and neovascularization in vivo. In tumor xenografts, 15-deoxy-Δ12,14-prostaglandin J2 and troglitazone synergistically improved antiangiogenic and antitumor effects of ABT510. Our data provide one mechanism for the in vivo angioinhibitory effect of PPARγ ligands and show fine-tuning of the antiangiogenic efficacy via targeted up-regulation of the endothelial receptor.
Collapse
Affiliation(s)
| | - Steven C. Campbell
- 4Department of Urology, Loyola University Medical Center, Maywood, Illinois
| | - Dhugal F. Bedford
- 3Bioinformatics Core, Robert H. Lurie Comprehensive Cancer Center, Northwestern University Medical School, Chicago, Illinois
| | - Thomas Nelius
- 1Urology and Departments of
- 5Department of Urology, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany; and
| | | | | | | | | | | | | |
Collapse
|
308
|
Abstract
The fact that a single blood vessel can support the life of thousands of tumor cells has been known for a long time. However, therapeutic strategies that aim to impair vascular development in tumors are only slowly emerging in the clinics. Nevertheless, the accumulation of data from many successful preclinical studies of the effects of a variety of drugs that target tumor vasculature provides clues that should help rationalize future treatment modalities for human tumors. Indeed, the 'old' view of an immature and non-functional vascular network within tumors has evolved and, in this article, we will show that the concept of tumor heterogeneity should be extended to the vascular compartment. In addition, we will review recent data documenting that both mature and immature vessels coexist within tumors and, importantly, that their relative density responds to a dynamic process that evolves with time and treatments.
Collapse
Affiliation(s)
- Olivier Feron
- University of Louvain Medical School, Unit of Pharmacology and Therapeutics, UCL-FATH 5349, 53 Avenue E. Mounier, B-1200 Brussels, Belgium.
| |
Collapse
|
309
|
Pasquier E, Carré M, Pourroy B, Camoin L, Rebaï O, Briand C, Braguer D. Antiangiogenic activity of paclitaxel is associated with its cytostatic effect, mediated by the initiation but not completion of a mitochondrial apoptotic signaling pathway. Mol Cancer Ther 2004. [DOI: 10.1158/1535-7163.1301.3.10] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Angiogenesis is a critical event in tumor growth and metastasis, which can be inhibited by conventional anticancer drugs such as the microtubule-damaging agent paclitaxel (Taxol). In this study, we investigate the mechanism of action of paclitaxel on human endothelial cells. We characterize two distinct effects of paclitaxel on human umbilical vein endothelial cell and human microvascular endothelial cell-1 proliferation according to drug concentration: a cytostatic effect at low concentrations and a cytotoxic effect at concentrations 10 nmol/L. The cytotoxic effect involves signaling pathways similar to those described in tumor cells (i.e., microtubule network disturbance, G2-M arrest, increase in Bax/Bcl-2 ratio, and mitochondria permeabilization) that result in apoptosis. In sharp contrast, the cytostatic effect involves an inhibition of endothelial cell proliferation without apoptosis induction and without any structural modification of the microtubule network. This cytostatic effect is due to a slowing of the cell cycle rather than to an arrest in a specific phase of the cell cycle. In addition, paclitaxel, at cytostatic concentrations, early initiates an apoptotic signaling pathway associated with increases in the mitochondrial reducing potential, mitochondrial membrane potential, p53 expression, and Bax/Bcl-2 ratio. However, this apoptotic pathway is stopped upstream of mitochondria permeabilization and it does not lead to endothelial cell death. Finally, we found that paclitaxel inhibits endothelial cell morphogenesis on Matrigel at all tested concentrations. In conclusion, we describe the mechanism of action of low concentrations of paclitaxel related to the antiangiogenic properties of this drug.
Collapse
Affiliation(s)
- Eddy Pasquier
- 1FRE-Centre National de la Recherche Scientifique 2737, ISPDCT,
| | - Manon Carré
- 1FRE-Centre National de la Recherche Scientifique 2737, ISPDCT,
| | | | - Laurence Camoin
- 2UMR Institut National de la Sante et de la Recherche Medicale 608, and
| | - Ouafa Rebaï
- 3Institut National de la Sante et de la Recherche Medicale 559, Université de la Méditerranée, Marseille, France
| | | | - Diane Braguer
- 1FRE-Centre National de la Recherche Scientifique 2737, ISPDCT,
| |
Collapse
|
310
|
Calzada MJ, Annis DS, Zeng B, Marcinkiewicz C, Banas B, Lawler J, Mosher DF, Roberts DD. Identification of novel beta1 integrin binding sites in the type 1 and type 2 repeats of thrombospondin-1. J Biol Chem 2004; 279:41734-43. [PMID: 15292271 DOI: 10.1074/jbc.m406267200] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In addition to the three known beta(1) integrin recognition sites in the N-module of thrombospondin-1 (TSP1), we found that beta(1) integrins mediate cell adhesion to the type 1 and type 2 repeats. The type 1 repeats of TSP1 differ from typical integrin ligands in that recognition is pan-beta(1)-specific. Adhesion of cells that express one dominant beta(1) integrin on immobilized type 1 repeats is specifically inhibited by antagonists of that integrin, whereas adhesion of cells that express several beta(1) integrins is partially inhibited by each alpha-subunit-specific antagonist and completely inhibited by combining the antagonists. beta(1) integrins recognize both the second and third type 1 repeats, and each type 1 repeat shows pan-beta(1) specificity and divalent cation dependence for promoting cell adhesion. Adhesion to the type 2 repeats is less sensitive to alpha-subunit antagonists, but a beta(1) blocking antibody and two disintegrins inhibit adhesion to immobilized type 2 repeats. beta(1) integrin expression is necessary for cell adhesion to the type 1 or type 2 repeats, and beta(1) integrins bind in a divalent cation-dependent manner to a type 1 repeat affinity column. The widely used TSP1 function blocking antibody A4.1 binds to a site in the third type 2 repeat. A4.1 proximally inhibits beta(1) integrin-dependent adhesion to the type 2 repeats and indirectly inhibits integrin-dependent adhesion mediated by the TSP1 type 1 repeats. Although antibody A4.1 is also an antagonist of CD36 binding to TSP1, these data suggest that some biological activities of A4.1 result from antagonism of these novel beta(1) integrin binding sites.
Collapse
Affiliation(s)
- Maria J Calzada
- Laboratory of Pathology, NCI, National Institutes of Health, Bethesda, Maryland 20892-1500, USA
| | | | | | | | | | | | | | | |
Collapse
|
311
|
Abstract
PURPOSE OF REVIEW The purpose of this review is not to provide an extensive overview of well-established mechanisms of angiogenesis and lymphangiogenesis but rather to highlight several recent key studies that constituted a significant conceptual or medical advancement to the field during the past year or so. The authors apologize for their inability, because of space restrictions, to reference all other relevant work of the past or previous years. RECENT FINDINGS In 1993, fewer than 400 studies on angiogenesis were published. During the past year alone, more than 4000 angiogenesis studies were reported, making angiogenesis one of the most rapidly growing fields. Moreover, the first studies on lymphangiogenesis were published only a couple of years ago. A milestone in the field in the past year has been the first successful report that the angiogenesis inhibitor bevacizumab (Avastin), an antibody against vascular endothelial growth factor, prolonged the survival of colorectal and renal cancer patients in phase 3 clinical trials. This remarkable achievement provides great promise and hope for the future development of therapeutic strategies to inhibit or stimulate angiogenesis. SUMMARY The intensive search for antiangiogenic and proangiogenic mechanisms during the past decade is starting to translate into clinical promise. Further discovery of novel pathways and concepts in angiogenesis may lead to the optimization and refinement of current strategies to improve the clinical benefit and therapeutic safety for a vast number of patients with angiogenesis-related disease.
Collapse
Affiliation(s)
- Aernout Luttun
- Center for Transgene Technology and Gene Therapy, Flanders Interuniversity Institute for Biotechnology, Leuven, Belgium
| | | |
Collapse
|
312
|
Takano S, Kamiyama H, Tsuboi K, Matsumura A. Angiogenesis and antiangiogenic therapy for malignant gliomas. Brain Tumor Pathol 2004; 21:69-73. [PMID: 15700836 DOI: 10.1007/bf02484513] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Angiogenesis is crucial to the growth of malignant gliomas. Therefore, antiangiogenic therapy represents a new, promising therapeutic modality for malignant gliomas. This study was designed to define the malignant glioma cases most suitable for antiangiogenic therapy in humans and to demonstrate the efficacy of antiangiogenic therapy in animals. Protein expression of the most potent angiogenic factor, vascular endothelial growth factor (VEGF), and its specific natural inhibitor, soluble Flt-1, as well as vessel architecture, including vessel density, area, and diameter, was evaluated in human malignant glioma samples (24 glioblastomas, 13 anaplastic astrocytomas). Among these, VEGF >1000ng/ml, VEGF/soluble Fltl ratio >1, vessel density >30, and vessel area >7% were prognostic factors for malignant gliomas. Based on these results, we performed three different antiangiogenic experiments targeted to inhibit VEGF expression in a human malignant glioma (U87) mouse model: anti-VEGF neutralized antibody intraperitoneal injection; interferon-beta intramusclar injection; and transfection of an endogenous nonspecific angiogenesis inhibitor, thrombospondin-1, into glioma cells caused inhibition of VEGF secretion and/or mRNA expression and resulted in glioma growth inhibition of 70%, 84%, and 50%, respectively, compared with control. We conclude that malignant gliomas with high degrees of VEGF expression and vessel areas are good candidates for antiangiogenic therapy, especially that designed to inhibit VEGF expression.
Collapse
Affiliation(s)
- Shingo Takano
- Department of Neurosurgery, Institute of Clinical Medicine, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8575, Japan.
| | | | | | | |
Collapse
|
313
|
Reisfeld RA, Niethammer AG, Luo Y, Xiang R. DNA vaccines suppress tumor growth and metastases by the induction of anti-angiogenesis. Immunol Rev 2004; 199:181-90. [PMID: 15233734 DOI: 10.1111/j.0105-2896.2004.00137.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Four novel oral DNA vaccines provide long-lived protection against melanoma, colon, breast, and non-small cell lung carcinoma in mouse model systems. The vaccines are delivered by attenuated Salmonella typhimurium to secondary lymphoid organs and are directed against targets such as carcinoembryonic antigen, tyrosine-related protein, vascular endothelial growth factor receptor-2 [also called fetal liver kinase-1 (FLK-1)], and transcription factor Fos-related antigen-1 (Fra-1). The FLK-1 and Fra-1 vaccines are effective in suppressing angiogenesis in the tumor vasculature. All four vaccines are capable of inducing potent cell-mediated protective immunity, breaking peripheral T-cell tolerance against these self-antigens resulting in effective suppression of tumor growth and metastasis. It is anticipated that such research efforts will contribute toward the rational design of future DNA vaccines that will be effective for prevention and treatment of human cancer.
Collapse
|
314
|
Emmenegger U, Man S, Shaked Y, Francia G, Wong JW, Hicklin DJ, Kerbel RS. A comparative analysis of low-dose metronomic cyclophosphamide reveals absent or low-grade toxicity on tissues highly sensitive to the toxic effects of maximum tolerated dose regimens. Cancer Res 2004; 64:3994-4000. [PMID: 15173013 DOI: 10.1158/0008-5472.can-04-0580] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The survival benefits of traditional maximum tolerated dose (MTD) cytotoxic therapy have been modest for the treatment of most types of metastatic malignancy and, moreover, often come with increased acute and chronic toxicity. Recent studies have demonstrated that the frequent administration of comparatively low doses of cytotoxic agents, with no extended breaks [low-dose metronomic (LDM) chemotherapy], may not only be at least as efficient as MTD therapy but also less toxic. This coincides with an apparent selectivity for "activated" endothelial cells of the tumor vasculature. However, the impact of LDM chemotherapy on the most sensitive target cell populations normally affected by MTD therapy (i.e., bone marrow progenitors, gut mucosa, and hair follicle cells) has not been analyzed in experimental detail. Therefore, we compared effects of LDM and MTD cyclophosphamide (CTX) on bone marrow and gut mucosa. Furthermore, we studied the potential impact of LDM CTX on angiogenesis in the context of wound healing and evidence of organ toxicity. We show absent or moderate hematologic and intestinal toxicity of LDM as opposed to MTD CTX. Of note was the finding of sustained lymphopenia, which is not unexpected given the use of CTX as immunosuppressive drug. There was no negative impact on wound healing or evidence of organ toxicity. LDM offers clear safety advantages over conventional MTD chemotherapy and therefore would appear to be ideal for long-term combination therapy with targeted antiangiogenic drugs.
Collapse
Affiliation(s)
- Urban Emmenegger
- Molecular and Cellular Biology Research, Sunnybrook and Women's College Health Sciences Centre, Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
| | | | | | | | | | | | | |
Collapse
|
315
|
Affiliation(s)
- Robert S Kerbel
- Molecular and Cellular Biology Research, Sunnybrook and Women's College Health Sciences Centre, S-217, 2075 Bayview Avenue, Toronto, Ontario M4N 3M5, Canada.
| | | |
Collapse
|
316
|
Miller KD. Recent translational research: antiangiogenic therapy for breast cancer - where do we stand? Breast Cancer Res 2004; 6:128-32. [PMID: 15084233 PMCID: PMC400679 DOI: 10.1186/bcr782] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2004] [Accepted: 03/04/2004] [Indexed: 01/13/2023] Open
Abstract
The central importance of angiogenesis and our understanding of how new blood vessels are formed have led to the development of novel antiangiogenic therapies. Although the number of agents in development has grown exponentially, only one phase III trial in breast cancer has been completed. In that study the addition of bevacizumab to capecitabine did not extend the progression-free survival of patients with refractory disease as compared with capecitabine monotherapy. Early enthusiasm for antiangiogenic therapy must give way to clinical reality. Our challenge now is to exploit better the activity of antiangiogenic agents seen in the early clinical studies.
Collapse
|
317
|
Reisfeld RA, Niethammer AG, Luo Y, Xiang R. DNA vaccines designed to inhibit tumor growth by suppression of angiogenesis. Int Arch Allergy Immunol 2004; 133:295-304. [PMID: 14988601 DOI: 10.1159/000077009] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The development of new blood vessels, i.e. angiogenesis, is a rate-limiting step in the development of tumors since tumor growth is generally limited to 1-2 mm3 in the absence of a blood supply. Thus, the inhibition of tumor growth by attacking the tumor's vascular supply offers a primary target for antiangiogenic intervention by DNA-based vaccines. Here, we describe two novel orally delivered DNA vaccines which suppress tumor angiogenesis and induce a robust cell-mediated immune response that provides for long-lived protection against melanoma, colon, breast and non-small-cell lung carcinoma in mouse model systems. These vaccines, which are delivered by attenuated Salmonella typhimurium to secondary lymphoid organs, are directed against such targets as vascular endothelial growth factor receptor 2 (FLK-1) and transcription factor Fos-related antigen 1 (Fra-1). Both vaccines break peripheral T cell tolerance against these self-antigens and induce a robust T cell-mediated immune response leading to suppression of tumor angiogenesis and resulting in effective suppression of tumor growth and metastases. Such research efforts may open up new possibilities for the rational design of future DNA vaccines effective for the prevention and treatment of cancer.
Collapse
|