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Vaccines targeting the neovasculature of tumors

Agata Matejuk 1 2
Qixin Leng 1
Szu-Ting Chou 1
Archibald J Mixson 1 d @

@ corresponding author, & equal contributor

Vascular Cell. 2011; 3(1):7 | © Matejuk et al

Received: 22 November 2010 | Accepted: 8 March 2011 | Published: 8 March 2011

Vascular Cell ISSN: 2045-824X

DOI: https://doi.org/10.1186/2045-824X-3-7

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1. Department of Pathology - University of Maryland Baltimore, MSTF Building; Baltimore, MD 21201, USA
2. Department of Plastic Surgery, Microsurgery Laboratory - Cleveland Clinic Foundation; Cleveland, Ohio 44195, USA

[d] ude.dnalyramu.mos@nosxiMJ

Holder: Matejuk et al

Licensee: Publiverse Online S.R.L.

License: Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

Abstract

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Angiogenesis has a critical role in physiologic and disease processes. For the growth of tumors, angiogenesis must occur to carry sufficient nutrients to the tumor. In addition to growth, development of new blood vessels is necessary for invasion and metastases of the tumor. A number of strategies have been developed to inhibit tumor angiogenesis and further understanding of the interplay between tumors and angiogenesis should allow new approaches and advances in angiogenic therapy. One such promising angiogenic approach is to target and inhibit angiogenesis with vaccines. This review will discuss recent advances and future prospects in vaccines targeting aberrant angiogenesis of tumors. The strategies utilized by investigators have included whole endothelial cell vaccines as well as vaccines with defined targets on endothelial cells and pericytes of the developing tumor endothelium. To date, several promising anti-angiogenic vaccine strategies have demonstrated marked inhibition of tumor growth in pre-clinical trials with some showing no observed interference with physiologic angiogenic processes such as wound healing and fertility.

Introduction

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Cancer mortality is related to the spread of neoplastic cells to distant loci where the cells, supported by existing blood vessels and angiogenesis, proliferate and give rise to secondary tumors. Tumor angiogenesis is up-regulated by a number of conditions including hypoxia, hypoglycemia, mechanical disruption, and genetic and inflammatory alterations [1] that lead to activation of growth factors and pro-angiogenic genes [2, 3]. The stringent regulation of angiogenesis in normal tissues is often lacking in tumor angiogenesis, resulting in immature and leaky tumor vessels. Furthermore, compared to the tissue-vessel distribution in normal tissue, there is an uneven distribution of vessels within tumors, leading to tumor hypoxia and inefficient transport of chemotherapeutic drugs. In contrast to normal endothelial cells, in which the vast majority are quiescent, tumor endothelial cells actively proliferate, driven by hypoxia and increased levels of angiogenic factors and their cognate receptors. These differences between quiescent and angiogenic endothelial cells resulted in the first clinical anti-angiogenesis trial on human cancer two decades ago. There are now several anti-angiogenic therapies that have received FDA approval including sunitinib, sorafenib, and bevacizumab; and with more than 40 anti-angiogenic drugs in clinical trials [4], further advances are anticipated [5–11].

Differences among tumor endothelial cells and non-malignant endothelial cells may not only be quantitative but in some instances may also be qualitative. With serial analysis of gene expression, investigators compared gene expression from endothelial cells isolated from normal or malignant tissue, and found that several transcripts (e.g., CD276) were specifically elevated in the tumor endothelium [12, 13]. Although most receptors/proteins that are increased in the tumor endothelium are also up-regulated in physiologic angiogenic processes, CD276 is not increased in the vessels of wounds or the corpus luteum [13]. Nevertheless, CD276 is not completely specific for the tumor endothelium because its expression may be induced by cytokines on the cell surfaces of B cells, T cells, and dendritic cells. There are also many proteins/receptors in tumor endothelial cells that are overexpressed (such as VEGFR2 and survivin) compared to expression in quiescent endothelial cells. Proteins differentially expressed on tumor endothelial cells or the supporting matrix are attractive targets for vaccine strategies, with the goal of breaking tolerance to self-antigens.

Targeting the tumor vasculature with vaccines as well as with other immunotherapies may have several potential advantages over targeting tumor cells. First, tumor endothelial cells are more accessible to the immune system than are tumor cells at a distance from the vessels. Second, endothelial cells of the tumor are usually more stable genetically than tumor cells, thereby reducing the risk of resistance developing to immunotherapies [14, 15]. Chromosomal abnormalities, however, have been identified in endothelial cells of solid tumors [16, 17], and in glioblastomas, the tumor cells and its endothelium are derived from common cancer stem-like cells [18, 19]. Third, down-regulation of MHC I in tumor cells occurs less frequently in tumor endothelial cells, thereby leading to a more potent CD8+-mediated response. Fourth, since inhibition of a single endothelial cell can inhibit up to 100 tumor cells [20, 21], immunotherapies directed toward tumor endothelial cells have the potential of an amplifying inhibitory effect.

As a result of these putative advantages and differentially expressed proteins in the tumor endothelium, a number of immunotherapeutic strategies have targeted angiogenesis, including monoclonal antibodies, vaccinations, and adjuvant co-stimulatory therapies [1]. The most successful of these approaches, thus far, has been passive immunotherapy by utilizing monoclonal antibodies. In 2004, the monoclonal antibody bevacizumab which targets angiogenesis through VEGF received approval for treatment of colorectal cancer [22]. Bevacizumab has also shown efficacy against other cancers including lung, renal, and breast cancers [23, 24]. It is likely that the success and ability of bevacizumab to selectively target tumor endothelial cells has provided impetus to development of other forms of angiogenic immunotherapies. Several promising preclinical studies of tumor endothelial vaccines have led to clinical trials that are primarily in phase I. In the burgeoning field of tumor immunotherapies, we will focus on tumor vaccines that have a major anti-angiogenic component.

Delivery Systems of Tumor Endothelial Vaccines

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As this review will highlight, there are many promising tumor endothelial vaccines with demonstrated efficacy in various animal models. These vaccines have been delivered by different approaches/vectors, including direct inoculation of peptides or "naked DNA", gene gun with gold particles, intradermal electroporation, tumor or dendritic cell-based vectors, and attenuated live bacteria vectors. The particular delivery system for anti-angiogenic vaccine therapy is selected at least in part based on whether immunizations are comprised of peptides/proteins, DNA, or RNA. For peptide delivery systems, the peptide can be inoculated directly into the animal model along with an adjuvant, or dendritic cells can be pulsed with the peptides before their inoculation. For gene therapy vaccine approaches, recombinant DNA may be delivered alone ("naked DNA"), by non-viral and viral carriers, or by eukaryotic and prokaryotic cells. Although delivery systems for vaccines targeting tumor endothelial cells generally mirror those targeting tumor cells [25–29], there are exceptions such as the infrequent use of viruses with tumor-endothelial vaccines. Nevertheless, we see no contraindication to using modified herpes simplex or vaccinia viruses to augment the immune response of endothelial vaccines as in tumor cell vaccines.

To date, plasmids encoding angiogenic self-antigens are the most common forms of nucleic acid to demonstrate an anti-angiogenic effect in mouse models. Moreover, bacteria have been the most frequently used delivery system for plasmid-based vaccines (see reviews of [30, 31]). Of the 32 vaccines with specific targets covered in this review, bacteria were the primary delivery vector in 11 studies, whereas direct inoculation of "naked" plasmid DNA was the primary delivery system in 6 studies (see Table 1). Several animal studies have demonstrated that orally administered bacteria-based vectors with attenuated, nonreplicating strains of Listeria or Salmonella have the potential to prevent and treat cancer through inhibition of angiogenesis [32–35]. Although safety concerns are a factor in considering these bacterial delivery systems, it is of note that one Salmonella enterica strain has been approved by the FDA for vaccine use [30, 36]. Moreover, several bacteria-based vaccines that had marked anti-angiogenic and anti-tumor activity showed little to no autoimmune response, at least in the animal studies. Electroporation is also an appealing approach that has been used with DNA or RNA vaccines that target the tumor endothelium [37, 38]. Because of the high number of antigen presenting cells, the skin is a common route of delivery for varied delivery systems including electroporation. The intradermal DNA vaccination approach enables long-term immune protection against tumor angiogenesis and growth. Although electroporation has been used less frequently than direct inoculation of plasmid DNA, it may be more effective. For example, intradermal electroporation of "naked DNA" gave a much stronger anti-angiogenic and anti-tumor immune response to survivin compared to intramuscular DNA injection [37, 39, 40].

Table 1 ( Jump back to reading ◀ )

Different Strategies Utilized With Tumor Endothelial Vaccines

TARGET	FORM OF THE VACCINE	TUMORS	Vector/Route	MECHANISMS	Other Comments	REFERENCES
Endothelial Cell Targets
VEGFR2	mVEGFR2-AP fusion protein	Melanoma and lung carcinoma	DC pulsed	Ab, CTLPrimarily CD8+	P	Li Y et al., 2002[45]
	Autologous DNA vaccine- full-length mVEGFR2	Melanoma, colon carcinoma, non-small cell lung carcinoma, hepatoma	S. typhimurium, oral	CTL	Modest delay in wound healingP, T	Niethammer AG et al., 2002 [59]
	Xenogeneic DNA vaccine	Murine melanoma, carcinoma, fibrosarcoma, lyphoma	"Naked" DNA,SC	Ab, CTL, CD4+(Th1)-mediated	Quail VEGFR2 vaccineIncreased levels of IgG2a and 2bP, T	Liu, J-Y et al., 2003[130]
	Autologous DNA vaccine- mVEGFR2 fragment	Breast tumor-rat Her2 expressing carcinoma; murine p53- deficient breast carcinoma	L. monocytogenes, oral	CD8+ mediated Inf-γ Elispot	Encodes listerolysin-VEGFR2 fragment; No effect on wound healing or pregnancyP, T	Seavey MM et al., 2009 [32]
	Autologous DNA minigene	Murine breast and colon carcinomas	S. typhimurium, oral	CTL	Encodes H-2Kd or H-2Dd restricted peptidesP	Luo Y et al., 2007 [63]
	Autologous DNA minigene	Murine lung, prostate, and breast cancers	S. typhimurium, oral	CTL	Plasmid also encodes HIV-TAT peptideP	Zhou H et al., 2005 [61]
	H-2D^b -restricted Peptides	Murine colon carcinomas	SC	CTL	adjuvant (GM-CSF, CD40 Ab);T	Dong Y et al., 2006[62]
	HLA-A2 or-A24 restricted hVEGFR2 Peptides	Mouse melanoma and colon carcinomas	ID	CTL	HLA-24 restricted Peptide 169 (RFVPDGNRI) induced human PBMC-CTL lysis of endothelial cells	Wada S et al., 2005 [43]
	VEGFR2 Peptide 169 + gemcitabine	Pancreatic cancer(Phase I)	SC	CTL;Reduced Treg cells	Adjuvant (IFA)	Miyazawa M. et al., 2009 [66]
	Xenogeneic DNA vaccine	Murine breast and colon carcinoma	Cationic liposomes, IV	Ab, CTL	Human VEGFR2;P, T	Xie K et al., 2009 [65]
	Autologous DNA vaccine (VEGFR2 fused with β-defensin 2)	Murine lung and colon cancer	Cationic liposomes, IM	Ab, CTL	Antitumor and anti-angiogenic synergy between VEGFR2 and β-defensin-2;P, T	Wang YS et al., 2007 [64]
	Autologous DNA vaccine- Extracellular Domain	Murine Lung	S. typhimurium, oral	Ab, CTL CD4+ (Th1), C8+ mediated	Increased levels of IgG2a and 2bP	Zuo SG et al., 2010 [67]
VEGF	Xenogeneic DNAvaccine	Fibrosarcoma, breast cancer, hepatoma	"Naked" DNA,IM	AbCD4+-mediated	Xenopus VEGF has about 75% homology with humans and miceP, T	Wei YQ et al., 2001 [58]
	Autologous or xenogeneic protein	Murine and human colon caricinoma; human rhadosarcoma	IM	Ab;	h- or mVEGF conjugated to KLHP	Rad FH et al., 2007 [73]
FGFR-1/bFGF	Autologous bFGF peptide	Murine melanoma and lung carcinoma	Lipid A containing liposomesIM	Ab	Effective vaccine against the 44 aa segment of the heparin binding domain; No effect on wound healing or pregancyP	Plum SM et al., 2000 [76]Plum SM et al., 2004 [77]
	Xenogeneic DNAvaccine	Murine fibrosarcoma, hepatoma and breast cancer	"Naked" DNA, IM	Ab	FGFR-1 from Xenopus laevisDelayed wound healingP, T	He QM et al., 2003 [78]
TEM8	Autologous TEM8 with rat Her2 or human tyrosinase-related protein1 DNA vaccine	Rat Her-2 expressing breast carcinoma;Murine melanoma	Gold-particle gene gun	No Ab or CTL response with TEM8 vaccine alone	Synergy observedP	Felicetti P et al., 2007 [82]
	Xenogeneic DNA vaccine	Murine melanoma	S. typhimuriumoral	CTL;	Human TEM8No effect on wound healingT	Ruan Z et al., 2009 [83]
ENDOGLIN (CD105)	Xenogeneic protein	Murine lung, melanoma, colon carcinoma, fibrosarcoma	SC	Ab;	Synergy with cis-platinum; adjuvant (alum)P, T	Tan GH et al., 2004 [87]Tan GH et al., 2004 [88]
ANGIOMOTIN	Xenogeneic DNA vaccine, full-length	Her-2 expressing breast cancer in transgenic mice	Electroporation,TC	Ab	Human angio-motin and Her-2; antitumor synergy when combined with Her-2 DNA vaccine	Holmgren L et al., 2006 [38]
TIE2	Xenogeneic protein vaccine	Murine hepatomas and melanomas	SC	Ab	Chicken Tie2P, T	Luo Y et al., 2006 [94]
	DNA vaccine encoding HLA-restricted peptides	In vitro lysis of endothelial cells expressing Tie-2; Tumor response not tested	Gold-particle gene gun	CTL	HLA-A*0201/Kb transgenic mice; the epitope(FLPATLTMV) had the highest CTL response;	Ramage JM et al., 2004 [95]
HP59/SP55	Xenogeneic peptides	Murine lung carcinoma	Not stated	Ab	HP59 and SP55 peptide mixtureP	Fu C et al., 2001 [96]
Pericyte Targets
HMW-MAA	Xenogeneic DNA vaccine, HMW-MAA fragment	Murine melanoma, renal carcinoma, Her-2 transgenic mice	L monocytogenesIP	Ab, CTL	HMW-MAA (2160-2225 aa) fragment fused to LLOT	Maciag PC et al., 2008 [33]
PDGFRβ	Autologous DNA vaccine, full-length	Murine colon, breast, lung carcinoma	S. typhimuriumoral	CTL	Also, targets activated fibroblastsP, T	Kaplan CD et al., 2006 [34]
Combined Targets
SURVIVIN	Xenogeneic DNA vaccine	Murine melanoma	Electroporation, ID	CTL	Human survivin vaccineP	Lladser A et al., 2010 [37]
	Survivin/CCL21 DNA vaccine	Murine lung carcinoma	S. typhimurium, oral	CTL	Mouse survivin; no effect on wound closure or fertilityP, T	Xiang R et al., 2005 [35]
GRP	Recombinant chimeric HSP-65 -GRP6 fusion protein	Murine breast carcinomas	SC	Ab, CTL	6 tandem repeats of GRP(18-27 aa) fused to HSP-65P, T	Guojun W et al., 2008 [115]
	Chimeric-HSP65-GRP6 DNA Vaccine	Murine melanoma	"Naked" DNA, IM	Ab	chimera also includes tetanus toxoid and HSP70 fragments;P	Fang J et al., 2009 [116]
LEGUMAIN	Allogeneic DNA vaccine	Murine non-small lung, colon and breast cancers	S. typhimurium, oral	CTL	Mutant polyubiquitin incorporatedP, T	Luo Y et al., 2006[119]
	Autologous DNA minigene	Murine breast carcinoma	S. typhimurium, oral	CTL	Angiogenesis inhibited more 90%; H-2K vaccine more potent than H-2DP	Lewen S et al., 2008 [120]
MMP-2	Xenogeneic full-length MMP-2 DNA vaccine	Murine fibrosarcoma, hepatoma, lung carcinoma	"Naked" DNA, IM	Ab	Chicken MMP-2P, T	Su JM et al., 2003 [123]
β3 Integrin	Xenogeneic β3 DNA vaccine	Murine fibrosarcoma, mammary carcinoma	"Naked" DNA, IM	Ab	Chicken β3 ligand binding domainP, T	Lou YY et al., 2002 [129]

Besides tumor cells [41], dendritic cells (DC) pulsed with peptide/protein epitopes (or DNA encoding these epitopes) have also been employed successfully to vaccinate animals against tumor endothelial antigens [42, 43]. DC process and present antigens to T and B cells and produce cytokines and chemokines which in turn activate NK cells [44]. DC-based therapies involve modification with pulsed (loaded) defined peptides, whole protein lysate, and/or transfected DNA or RNA [42, 43]. An interesting anti-cancer and anti-angiogenic approach was the use of a VEGFR2-loaded DCs that led to greater than 80% reduction in lung metastases of two different tumor models [45]. Different forms of nucleic acids have also been used for angiogenic peptides and proteins. In addition to peptides, proteins, and recombinant DNA, mRNA is another promising strategy to enhance cellular immunity [46]. For example, antitumor synergy was observed when dendritic cells were transfected with mRNA from two receptors (VEGFR-2 and Tie2) that are highly expressed on tumor endothelial cells [47]. Varying the routes of pulsed DC administration may also affect the efficacy of tumor vaccines. Pellegatta and colleagues determined that glioblastomas regressed significantly more when mice received both intratumoral and subcutaneous pulsed DC injections compared to those which received subcutaneous injections [48].

Although most authors have not compared different carrier systems with one another, it is evident that the carrier system and route of administration are critical for the success of the vaccine in animal models and in human clinical trials [49]. We have already discussed differences in the immune response to survivin based on whether electroporation or direct injection of DNA was used. In addition, when Lai et al. compared three different delivery approaches (gene gun with non-coated particles, gene gun with coated gold particles, and intramuscular injection) for the EGFR plasmid vaccine, the gene-gun with non-coated particle vaccine had the greatest cytotoxic T-lymphocyte (CTL) response and anti-tumor response [49]. Interestingly, the CD4+ response and the levels of EGFR-specific antibodies were much greater with the coated gold particle method. The required robust immune response to overcome self-tolerance will no doubt eliminate several carriers, and perhaps autoimmunity will eliminate other carriers. Which of the carriers can be translated successfully from the animal models to humans remains to be determined. The delivery vehicle and the immune-adjuvant will likely be as important as the selected angiogenic antigen to obtain a successful tumor response in humans.

Approaches for Anti-Angiogenic Vaccines

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A goal of vaccination in anti-angiogenic therapies targeting tumors is to break immune tolerance to self-antigens and induce specific, strong, and persisting immune response leading to eradication of cancer. Complex networks created by several immune-competent cells such as dendritic cells, B cells, cytotoxic CD8+ T, CD4+ T-helper, and NK cells in combination with cytokines, chemokines and other immune mediators are required for effective vaccines and immune reactions against cancer (Figure 1). Two anti-angiogenic vaccine approaches have shown promising results in reducing tumor growth and/or metastases: endothelial cell vaccines that demonstrate antitumor activity and vaccines targeting specific angiogenic targets.

Figure 1 ( Jump back to reading ◀ )

Figure 1 caption

Major mechanistic immune pathways of anti-angiogenic vaccines and their targets. Vaccine antigens are processed by antigen processing cells such as dendritic cells and presented to T cells. Depending on the antigen, the route of administration, and the vector, peptide presentation to either major histocompatibility complex (MHC) class I or II occurs, with subsequent interaction with T-cell receptors on CD4+ or CD8+ cells. Cytotoxic CD8+ T cells recognize and lyse tumor endothelial cells directly by perforin-mediated and Fas-mediated cytotoxic mechanisms. CD4+ T-helper cells, through release of different cytokines, can induce Th1 or Th2 responses that stimulate B-cells to produce antibodies and/or activate NK cells and macrophages to inhibit tumor endothelium. Representative targets related to endothelial and cancer cells and their environment for anti-angiogenic vaccines are depicted. Reprinted with permission, Cleveland Clinic Center for Medical Art & Photography © 2010. All Rights Reserved.

I. Endothelial Cell Vaccines

II. Vaccines Expressing Defined Targets

Defined endothelial vaccines are based on specific targets and include peptides and nucleic acids (DNA or RNA) that encode these peptides (see Table 1, Figure 2). Suitable angiogenic targets in tumors may be receptors/markers on endothelial cells or alternatively, may be growth factors secreted by cells other than endothelial cells. To date, there has been no target or epitope that is completely specific for tumor endothelial cells. For example, TEM8, one of the more specific tumor endothelial cell markers identified thus far, was originally found in the tumor vasculature and the developing embryo, but it has since been found on cell surfaces of melanomas, breast cancers, and dendritic cells. Despite the overlap in this system, we think that classification of angiogenic vaccines based on preponderance of their targets within most tumors may be useful. As a result, we have divided tumor endothelial vaccines with defined targets into three classes: 1) growth factors/receptors or epitopes that are primarily associated with growth of tumor endothelial cells; 2) growth factors/receptors or epitopes that promote growth of pericytes; and 3) proteins/growth factors/receptors that enhance both tumor and endothelial cell growth or survival. The growth factors were classified, not on their cells of origin, but on the location of their receptors.

Figure 2 ( Jump back to reading ◀ )

Figure 2 caption

Tumor Endothelial Vaccines with Defined Targets. Schematic model of a tumor and its angiogenic vessels are shown with targets of tumor endothelial vaccines. These vaccines may be classified on their specific targets 1) that are primarily associated with tumor endothelial cells, 2) that promote growth of pericytes, or 3) that enhance both tumor and endothelial cell growth or survival. Growth factors were classified based on the location of their receptors. M, Macrophage. Reprinted with permission, Cleveland Clinic Center for Medical Art & Photography © 2011. All Rights Reserved.

Conclusion

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Significant resources including numerous pre-clinical and clinical studies have been devoted to the development of tumor vaccines. Thus far, these results have progressed and culminated in the approval a vaccine targeting advanced prostate cancer (Provenge). Although the benefits with this FDA-approved vaccine are modest, further improved vaccine versions are no doubt on the horizon and will aid with other vaccines approaches, including those against the tumor endothelium. Compared to tumor vaccines, the number of varied approaches for tumor endothelial vaccines is relatively limited and is currently restricted to pre-clinical experiments and primarily phase I trials.

As discussed in this review, several studies with tumor endothelial vaccines show anti-tumor efficacy in both transplantable and transgenic tumor-bearing animal models. Of particular note were the bacteria-based vaccines that showed marked anti-tumor response with varied anti-angiogenic genes and few if any side effects. Nevertheless, major obstacles still remain, including identification and validation of specific targets on the tumor endothelium, inhibition of local suppression mechanisms, and boosting anti-tumor immunity through NK cells [132]. Thus far, there have been few data from the endothelial vaccine studies on the various T-cell subtypes, including regulatory T-cells or myeloid derived suppressor cells [25, 133, 134], and comparison of T-cell subtypes in the tumor and peripheral tissues may be useful in development of more effective vaccines. Other immune cells such as NK cells have not yet shown a direct role in augmenting the efficacy of tumor endothelial vaccines [64, 87, 94, 130], but more research examining interactions among NK cells, dendritic cells, and immunomodulatory agents is needed [132, 135, 136].

Since tumor angiogenesis is a complex process, targeting a single epitope is unlikely to be successful. In many cases, the treated tumor adapts and finds alternative mechanisms of tumorigenesis eventually leading to resistance to therapy. Thus, combinations of anti-angiogenic vaccines with existing chemotherapy or immunomodulatory therapies offer interesting and exciting possibilities. For example, as discussed previously in this review, combinatory treatments between vaccines and IL-12, GM-CSF, CCL21, or β-defensins markedly increased the immune response toward tumor endothelial cells [39, 41, 62, 64]. Nevertheless, these co-stimulatory therapies have been used sparingly and other commonly used cytokines such as IL-2, IFN α or β [137–139] have not been co-administered or transfected into immune and/or endothelial cells to augment vaccine efficacy. Moreover, considerable more research is needed to determine the optimal co-stimulatory therapy to be administered with the vaccine for the different delivery methods.

Another consideration in developing anti-angiogenic vaccines is their potential for causing complications. Cross-reactivity between tumor and non-tumor disease tissues due to tumor endothelial vaccine may result in reduced compensatory biological processes. The classic tumor endothelial target is VEGFR2 up-regulated not only in the endothelial vessels of tumors but also in healing wounds and hypoxic cardiac tissues. Interestingly, at least with 4 vaccine studies (VEGFR2, VEGF-A, bFGF, survivin/CCL21) tumor angiogenesis was markedly inhibited, but these vaccines did not interfere with normal physiologic processes in several studies [32, 35, 47, 76, 77]. The mechanism whereby tolerance to self-angiogenic antigens in tumors but not in normal angiogenic processes is broken remains unknown. It has been suggested that differences in breaking self-angiogenic antigen tolerance between tumors and normal physiological processes may be based on the difference of their vascular organization [32, 140]; determining whether or not this is the mechanism for this difference will require further study.

To ensure effective tumor eradication and reduce autoimmune side effects, intensive efforts are still needed to identify additional targets specific to the tumor endothelium. One such study recently found highly specific and expressed markers of the tumor endothelium that were not expressed in quiescent blood vessels or physiologic angiogenesis [13]. Nevertheless, the efficacy of vaccines against these new markers has not yet been determined. Alternatively, finding tissue-specific vascular targets (e.g., prostate) may enable development of tumor endothelial vaccines with acceptable side effects [141, 142]. There is also the possibility that tailored endothelial vaccines may be developed based on specific endothelial epitopes associated with certain tumors [143]. As new anti-angiogenic targets are discovered, we anticipate that promising new therapeutic approaches are on the horizon.

Acknowledgements

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The authors thank Drs. Pamela Talalay and Paul Anthony for their helpful suggestions and careful reading of this manuscript. This work was supported by the National Institutes of Health (R01-CA136938).

Authors’ original submitted files for images

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References

Rosen LS. Clinical experience with angiogenesis signaling inhibitors: focus on vascular endothelial growth factor (VEGF) blockers. Cancer Control. 2002;9:36-44.
Google Scholar
Gordan JD, Simon MC. Hypoxia-inducible factors: central regulators of the tumor phenotype. Curr Opin Genet Dev. 2007;17:71-77.
Google Scholar
Gruber M, Simon MC. Hypoxia-inducible factors, hypoxia, and tumor angiogenesis. Curr Opin Hematol. 2006;13:169-174.
Google Scholar
Search for Clinical Trials-National Cancer Institute. [http://www.cancer.gov/clinicaltrials/search]
Fens MH, Storm G, Schiffelers RM. Tumor vasculature as target for therapeutic intervention. Expert Opin Investig Drugs. 2010;19:1321-1338.
Google Scholar
Tammela T, Zarkada G, Wallgard E, Murtomaki A, Suchting S, Wirzenius M, Waltari M, Hellstrom M, Schomber T, Peltonen R, et al. Blocking VEGFR-3 suppresses angiogenic sprouting and vascular network formation. Nature. 2008;454:656-660.
Google Scholar
Hu B, Cheng SY. Angiopoietin-2: development of inhibitors for cancer therapy. Curr Oncol Rep. 2009;11:111-116.
Google Scholar
Chen QR, Zhang L, Gasper W, Mixson AJ. Targeting tumor angiogenesis with gene therapy. Mol Genet Metab. 2001;74:120-127.
Google Scholar
Cao Y. Off-tumor target--beneficial site for antiangiogenic cancer therapy?. Nat Rev Clin Oncol. 2010;7:604-608.
Google Scholar
Cao Y. Angiogenesis: What can it offer for future medicine?. Exp Cell Res. 2010;316:1304-1308.
Google Scholar
Cao Y, Langer R. Optimizing the delivery of cancer drugs that block angiogenesis. Sci Transl Med. 2010;2:15ps13-.
Google Scholar
St Croix B, Rago C, Velculescu V, Traverso G, Romans KE, Montgomery E, Lal A, Riggins GJ, Lengauer C, Vogelstein B, Kinzler KW. Genes expressed in human tumor endothelium. Science. 2000;289:1197-1202.
Google Scholar
Seaman S, Stevens J, Yang MY, Logsdon D, Graff-Cherry C, St Croix B. Genes that distinguish physiological and pathological angiogenesis. Cancer Cell. 2007;11:539-554.
Google Scholar
Boehm T, Folkman J, Browder T, O'Reilly MS. Antiangiogenic therapy of experimental cancer does not induce acquired drug resistance. Nature. 1997;390:404-407.
Google Scholar
Huang J, Soffer SZ, Kim ES, McCrudden KW, New T, Manley CA, Middlesworth W, O'Toole K, Yamashiro DJ, Kandel JJ. Vascular remodeling marks tumors that recur during chronic suppression of angiogenesis. Mol Cancer Res. 2004;2:36-42.
Google Scholar
Hida K, Hida Y, Amin DN, Flint AF, Panigrahy D, Morton CC, Klagsbrun M. Tumor-associated endothelial cells with cytogenetic abnormalities. Cancer Res. 2004;64:8249-8255.
Google Scholar
Hida K, Klagsbrun M. A new perspective on tumor endothelial cells: unexpected chromosome and centrosome abnormalities. Cancer Res. 2005;65:2507-2510.
Google Scholar
Ricci-Vitiani L, Pallini R, Biffoni M, Todaro M, Invernici G, Cenci T, Maira G, Parati EA, Stassi G, Larocca LM, De Maria R. Tumour vascularization via endothelial differentiation of glioblastoma stem-like cells. Nature. 2010;468:824-828.
Google Scholar
Wang R, Chadalavada K, Wilshire J, Kowalik U, Hovinga KE, Geber A, Fligelman B, Leversha M, Brennan C, Tabar V. Glioblastoma stem-like cells give rise to tumour endothelium. Nature. 2010;468:829-833.
Google Scholar
Folkman J. Fighting cancer by attacking its blood supply. Sci Am. 1996;275:150-154.
Google Scholar
Folkman J, DeVita VT, Hellman S, Rosenberg SA. Antiangiogenic Therapy. Principles and Practice of Oncology. 1997.:3075-3085.
Google Scholar
Hurwitz H. Integrating the anti-VEGF-A humanized monoclonal antibody bevacizumab with chemotherapy in advanced colorectal cancer. Clin Colorectal Cancer. 2004;4(Suppl 2):S62-68.
Google Scholar
Eskens FA, Sleijfer S. The use of bevacizumab in colorectal, lung, breast, renal and ovarian cancer: where does it fit?. Eur J Cancer. 2008;44:2350-2356.
Google Scholar
Grothey A, Ellis LM. Targeting angiogenesis driven by vascular endothelial growth factors using antibody-based therapies. Cancer J. 2008;14:170-177.
Google Scholar
Chaudhuri D, Suriano R, Mittelman A, Tiwari RK. Targeting the immune system in cancer. Curr Pharm Biotechnol. 2009;10:166-184.
Google Scholar
Palena C, Schlom J. Vaccines against human carcinomas: strategies to improve antitumor immune responses. J Biomed Biotechnol. 2010;2010:380697-.
Google Scholar
Fioretti D, Iurescia S, Fazio VM, Rinaldi M. DNA vaccines: developing new strategies against cancer. J Biomed Biotechnol. 2010;2010:174378-.
Google Scholar
Chiang CL, Benencia F, Coukos G. Whole tumor antigen vaccines. Semin Immunol. 2010;22:132-143.
Google Scholar
Signori E, Iurescia S, Massi E, Fioretti D, Chiarella P, De Robertis M, Rinaldi M, Tonon G, Fazio VM. DNA vaccination strategies for anti-tumour effective gene therapy protocols. Cancer Immunol Immunother. 2010;59:1583-1591.
Google Scholar
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.
Google Scholar
Gravekamp C, Paterson Y. Harnessing Listeria monocytogenes to target tumors. Cancer Biol Ther. 2010;9:257-265.
Google Scholar
Seavey MM, Maciag PC, Al-Rawi N, Sewell D, Paterson Y. An anti-vascular endothelial growth factor receptor 2/fetal liver kinase-1 Listeria monocytogenes anti-angiogenesis cancer vaccine for the treatment of primary and metastatic Her-2/neu+ breast tumors in a mouse model. J Immunol. 2009;182:5537-5546.
Google Scholar
Maciag PC, Seavey MM, Pan ZK, Ferrone S, Paterson Y. Cancer immunotherapy targeting the high molecular weight melanoma-associated antigen protein results in a broad antitumor response and reduction of pericytes in the tumor vasculature. Cancer Res. 2008;68:8066-8075.
Google Scholar
Kaplan CD, Kruger JA, Zhou H, Luo Y, Xiang R, Reisfeld RA. A novel DNA vaccine encoding PDGFRbeta suppresses growth and dissemination of murine colon, lung and breast carcinoma. Vaccine. 2006;24:6994-7002.
Google Scholar
Xiang R, Mizutani N, Luo Y, Chiodoni C, Zhou H, Mizutani M, Ba Y, Becker JC, Reisfeld RA. A DNA vaccine targeting survivin combines apoptosis with suppression of angiogenesis in lung tumor eradication. Cancer Res. 2005;65:553-561.
Google Scholar
Daudel D, Weidinger G, Spreng S. Use of attenuated bacteria as delivery vectors for DNA vaccines. Expert Rev Vaccines. 2007;6:97-110.
Google Scholar
Lladser A, Ljungberg K, Tufvesson H, Tazzari M, Roos AK, Quest AF, Kiessling R. Intradermal DNA electroporation induces survivin-specific CTLs, suppresses angiogenesis and confers protection against mouse melanoma. Cancer Immunol Immunother. 2010;59:81-92.
Google Scholar
Holmgren L, Ambrosino E, Birot O, Tullus C, Veitonmaki N, Levchenko T, Carlson LM, Musiani P, Iezzi M, Curcio C, et al. A DNA vaccine targeting angiomotin inhibits angiogenesis and suppresses tumor growth. Proc Natl Acad Sci USA. 2006;103:9208-9213.
Google Scholar
Lladser A, Parraga M, Quevedo L, Carmen Molina M, Silva S, Ferreira A, Billetta R, AF GQ. Naked DNA immunization as an approach to target the generic tumor antigen survivin induces humoral and cellular immune responses in mice. Immunobiology. 2006;211:11-27.
Google Scholar
Zhu K, Qin H, Cha SC, Neelapu SS, Overwijk W, Lizee GA, Abbruzzese JL, Hwu P, Radvanyi L, Kwak LW, Chang DZ. Survivin DNA vaccine generated specific antitumor effects in pancreatic carcinoma and lymphoma mouse models. Vaccine. 2007;25:7955-7961.
Google Scholar
Nanni P, Nicoletti G, De Giovanni C, Landuzzi L, Di Carlo E, Cavallo F, Pupa SM, Rossi I, Colombo MP, Ricci C, et al. Combined allogeneic tumor cell vaccination and systemic interleukin 12 prevents mammary carcinogenesis in HER-2/neu transgenic mice. J Exp Med. 2001;194:1195-1205.
Google Scholar
Hu B, Wei Y, Tian L, Zhao X, Lu Y, Wu Y, Yao B, Liu J, Niu T, Wen Y, et al. Active antitumor immunity elicited by vaccine based on recombinant form of epidermal growth factor receptor. J Immunother. 2005;28:236-244.
Google Scholar
Wada S, Tsunoda T, Baba T, Primus FJ, Kuwano H, Shibuya M, Tahara H. Rationale for antiangiogenic cancer therapy with vaccination using epitope peptides derived from human vascular endothelial growth factor receptor 2. Cancer Res. 2005;65:4939-4946.
Google Scholar
Tacken PJ, de Vries IJM, Torensma R, Figdor CG. Dendritic-cell immunotherapy: from ex vivo loading to in vivo targeting. Nature Reviews Immunology. 2007;7:790-802.
Google Scholar
Li Y, Wang MN, Li H, King KD, Bassi R, Sun H, Santiago A, Hooper AT, Bohlen P, Hicklin DJ. Active immunization against the vascular endothelial growth factor receptor flk1 inhibits tumor angiogenesis and metastasis. J Exp Med. 2002;195:1575-1584.
Google Scholar
Nair SK, Morse M, Boczkowski D, Cumming RI, Vasovic L, Gilboa E, Lyerly HK. Induction of tumor-specific cytotoxic T lymphocytes in cancer patients by autologous tumor RNA-Transfected dendritic cells. Annals of Surgery. 2002;235:540-549.
Google Scholar
Nair S, Boczkowski D, Moeller B, Dewhirst M, Vieweg J, Gilboa E. Synergy between tumor immunotherapy and antiangiogenic therapy. Blood. 2003;102:964-971.
Google Scholar
Pellegatta S, Poliani PL, Stucchi E, Corno D, Colombo CA, Orzan F, Ravanini M, Finocchiaro G. Intra-tumoral dendritic cells increase efficacy of peripheral vaccination by modulation of glioma microenvironment. Neuro Oncol. 2010;12:377-388.
Google Scholar
Lai MD, Yen MC, Lin CM, Tu CF, Wang CC, Lin PS, Yang HJ, Lin CC. The effects of DNA formulation and administration route on cancer therapeutic efficacy with xenogenic EGFR DNA vaccine in a lung cancer animal model. Genet Vaccines Ther. 2009;7:2-.
Google Scholar
Wei YQ, Wang QR, Zhao X, Yang L, Tian L, Lu Y, Kang B, Lu CJ, Huang MJ, Lou YY, et al. Immunotherapy of tumors with xenogeneic endothelial cells as a vaccine. Nat Med. 2000;6:1160-1166.
Google Scholar
Okaji Y, Tsuno NH, Kitayama J, Saito S, Takahashi T, Kawai K, Yazawa K, Asakage M, Hori N, Watanabe T, et al. Vaccination with autologous endothelium inhibits angiogenesis and metastasis of colon cancer through autoimmunity. Cancer Science. 2004;95:85-90.
Google Scholar
Scappaticci FA, Nolan GP. Induction of anti-tumor immunity in mice using a syngeneic endothelial cell vaccine. Anticancer Res. 2003;23:1165-1172.
Google Scholar
Yoshiura K, Nishishita T, Nakaoka T, Yamashita N, Yamashita N. Inhibition of B16 melanoma growth and metastasis in C57BL mice by vaccination with a syngeneic endothelial cell line. Journal of Experimental & Clinical Cancer Research. 2009;28:13-.
Google Scholar
Okaji Y, Tsuno NH, Tanaka M, Yoneyama S, Matsuhashi M, Kitayama J, Saito S, Nagura Y, Tsuchiya T, Yamada J, et al. Pilot study of anti-angiogenic vaccine using fixed whole endothelium in patients with progressive malignancy after failure of conventional therapy. European Journal of Cancer. 2008;44:383-390.
Google Scholar
Zhang W, Liu JN, Tan XY. Vaccination with xenogeneic tumor endothelial proteins isolated in situ inhibits tumor angiogenesis and spontaneous metastasis. Int J Cancer. 2009;125:124-132.
Google Scholar
Shalaby F, Rossant J, Yamaguchi TP, Gertsenstein M, Wu XF, Breitman ML, Schuh AC. Failure of blood-island formation and vasculogenesis in Flk-1-deficient mice. Nature. 1995;376:62-66.
Google Scholar
Taraboletti G, Margosio B. Antiangiogenic and antivascular therapy for cancer. Curr Opin Pharmacol. 2001;1:378-384.
Google Scholar
Wei YQ, Huang MJ, Yang L, Zhao X, Tian L, Lu Y, Shu JM, Lu CJ, Niu T, Kang B, et al. Immunogene therapy of tumors with vaccine based on Xenopus homologous vascular endothelial growth factor as a model antigen. Proc Natl Acad Sci USA. 2001;98:11545-11550.
Google Scholar
Niethammer AG, Xiang R, Becker JC, Wodrich H, Pertl U, Karsten G, Eliceiri BP, Reisfeld RA. A DNA vaccine against VEGF receptor 2 prevents effective angiogenesis and inhibits tumor growth. Nat Med. 2002;8:1369-1375.
Google Scholar
Hou JM, Liu JY, Yang L, Zhao X, Tian L, Ding ZY, Wen YJ, Niu T, Xiao F, Lou YY, et al. Combination of low-dose gemcitabine and recombinant quail vascular endothelial growth factor receptor-2 as a vaccine induces synergistic antitumor activities. Oncology. 2005;69:81-87.
Google Scholar
Zhou H, Luo Y, Mizutani M, Mizutani N, Reisfeld RA, Xiang R. T cell-mediated suppression of angiogenesis results in tumor protective immunity. Blood. 2005;106:2026-2032.
Google Scholar
Dong Y, Qian J, Ibrahim R, Berzofsky JA, Khleif SN. Identification of H-2Db-specific CD8+ T-cell epitopes from mouse VEGFR2 that can inhibit angiogenesis and tumor growth. J Immunother. 2006;29:32-40.
Google Scholar
Luo Y, Markowitz D, Xiang R, Zhou H, Reisfeld RA. FLK-1-based minigene vaccines induce T cell-mediated suppression of angiogenesis and tumor protective immunity in syngeneic BALB/c mice. Vaccine. 2007;25:1409-1415.
Google Scholar
Wang YS, Wang GQ, Wen YJ, Wang L, Chen XC, Chen P, Kan B, Li J, Huang C, Lu Y, et al. Immunity against tumor angiogenesis induced by a fusion vaccine with murine beta-defensin 2 and mFlk-1. Clin Cancer Res. 2007;13:6779-6787.
Google Scholar
Xie K, Bai RZ, Wu Y, Liu Q, Liu K, Wei YQ. Anti-tumor effects of a human VEGFR-2-based DNA vaccine in mouse models. Genet Vaccines Ther. 2009;7:10-.
Google Scholar
Miyazawa M, Ohsawa R, Tsunoda T, Hirono S, Kawai M, Tani M, Nakamura Y, Yamaue H. Phase I clinical trial using peptide vaccine for human vascular endothelial growth factor receptor 2 in combination with gemcitabine for patients with advanced pancreatic cancer. Cancer Sci. 2010;101:433-439.
Google Scholar
Zuo SG, Chen Y, Wu ZP, Liu X, Liu C, Zhou YC, Wu CL, Jin CG, Gu YL, Li J, et al. Orally administered DNA vaccine delivery by attenuated Salmonella typhimurium targeting fetal liver kinase 1 inhibits murine Lewis lung carcinoma growth and metastasis. Biol Pharm Bull. 2010;33:174-182.
Google Scholar
Yang D, Chertov O, Bykovskaia SN, Chen Q, Buffo MJ, Shogan J, Anderson M, Schroder JM, Wang JM, Howard OM, Oppenheim JJ. Beta-defensins: linking innate and adaptive immunity through dendritic and T cell CCR6. Science. 1999;286:525-528.
Google Scholar
Biragyn A, Ruffini PA, Leifer CA, Klyushnenkova E, Shakhov A, Chertov O, Shirakawa AK, Farber JM, Segal DM, Oppenheim JJ, Kwak LW. Toll-like receptor 4-dependent activation of dendritic cells by beta-defensin 2. Science. 2002;298:1025-1029.
Google Scholar
Lee YH, Tokunaga T, Oshika Y, Suto R, Yanagisawa K, Tomisawa M, Fukuda H, Nakano H, Abe S, Tateishi A, et al. Cell-retained isoforms of vascular endothelial growth factor (VEGF) are correlated with poor prognosis in osteosarcoma. Eur J Cancer. 1999;35:1089-1093.
Google Scholar
Oshika Y, Nakamura M, Tokunaga T, Ozeki Y, Fukushima Y, Hatanaka H, Abe Y, Yamazaki H, Kijima H, Tamaoki N, Ueyama Y. Expression of cell-associated isoform of vascular endothelial growth factor 189 and its prognostic relevance in non-small cell lung cancer. Int J Oncol. 1998;12:541-544.
Google Scholar
Li XH, Tang L, Liu D, Sun HM, Zhou CC, Tan LS, Wang LP, Zhang PD, Zhang SQ. [Antitumor effect of recombinant T7 phage vaccine expressing xenogenic vascular endothelial growth factor on Lewis lung cancer in mice]. Ai Zheng. 2006;25:1221-1226.
Google Scholar
Rad FH, Le Buanec H, Paturance S, Larcier P, Genne P, Ryffel B, Bensussan A, Bizzini B, Gallo RC, Zagury D, Uzan G. VEGF kinoid vaccine, a therapeutic approach against tumor angiogenesis and metastases. Proc Natl Acad Sci USA. 2007;104:2837-2842.
Google Scholar
Harper SJ, Bates DO. VEGF-A splicing: the key to anti-angiogenic therapeutics?. Nat Rev Cancer. 2008;8:880-887.
Google Scholar
Varey AH, Rennel ES, Qiu Y, Bevan HS, Perrin RM, Raffy S, Dixon AR, Paraskeva C, Zaccheo O, Hassan AB, et al. VEGF 165 b, an antiangiogenic VEGF-A isoform, binds and inhibits bevacizumab treatment in experimental colorectal carcinoma: balance of pro- and antiangiogenic VEGF-A isoforms has implications for therapy. Br J Cancer. 2008;98:1366-1379.
Google Scholar
Plum SM, Holaday JW, Ruiz A, Madsen JW, Fogler WE, Fortier AH. Administration of a liposomal FGF-2 peptide vaccine leads to abrogation of FGF-2-mediated angiogenesis and tumor development. Vaccine. 2000;19:1294-1303.
Google Scholar
Plum SM, Vu HA, Mercer B, Fogler WE, Fortier AH. Generation of a specific immunological response to FGF-2 does not affect wound healing or reproduction. Immunopharmacol Immunotoxicol. 2004;26:29-41.
Google Scholar
He QM, Wei YQ, Tian L, Zhao X, Su JM, Yang L, Lu Y, Kan B, Lou YY, Huang MJ, et al. Inhibition of tumor growth with a vaccine based on xenogeneic homologous fibroblast growth factor receptor-1 in mice. J Biol Chem. 2003;278:21831-21836.
Google Scholar
Nanda A, Carson-Walter EB, Seaman S, Barber TD, Stampfl J, Singh S, Vogelstein B, Kinzler KW, St Croix B. TEM8 interacts with the cleaved C5 domain of collagen alpha 3(VI). Cancer Res. 2004;64:817-820.
Google Scholar
Carson-Walter EB, Watkins DN, Nanda A, Vogelstein B, Kinzler KW, St Croix B. Cell surface tumor endothelial markers are conserved in mice and humans. Cancer Res. 2001;61:6649-6655.
Google Scholar
Venanzi FM, Petrini M, Fiammenghi L, Bolli E, Granato AM, Ridolfi L, Gabrielli F, Barucca A, Concetti A, Ridolfi R, Riccobon A. Tumor endothelial marker 8 expression levels in dendritic cell-based cancer vaccines are related to clinical outcome. Cancer Immunol Immunother. 2010;59:27-34.
Google Scholar
Felicetti P, Mennecozzi M, Barucca A, Montgomery S, Orlandi F, Manova K, Houghton AN, Gregor PD, Concetti A, Venanzi FM. Tumor endothelial marker 8 enhances tumor immunity in conjunction with immunization against differentiation Ag. Cytotherapy. 2007;9:23-34.
Google Scholar
Ruan Z, Yang Z, Wang Y, Wang H, Chen Y, Shang X, Yang C, Guo S, Han J, Liang H, Wu Y. DNA vaccine against tumor endothelial marker 8 inhibits tumor angiogenesis and growth. J Immunother. 2009;32:486-491.
Google Scholar
Dales JP, Garcia S, Andrac L, Carpentier S, Ramuz O, Lavaut MN, Allasia C, Bonnier P, Charpin C. Prognostic significance of angiogenesis evaluated by CD105 expression compared to CD31 in 905 breast carcinomas: correlation with long-term patient outcome. Int J Oncol. 2004;24:1197-1204.
Google Scholar
Takahashi N, Kawanishi-Tabata R, Haba A, Tabata M, Haruta Y, Tsai H, Seon BK. Association of serum endoglin with metastasis in patients with colorectal, breast, and other solid tumors, and suppressive effect of chemotherapy on the serum endoglin. Clin Cancer Res. 2001;7:524-532.
Google Scholar
Hofmeister V, Schrama D, Becker JC. Anti-cancer therapies targeting the tumor stroma. Cancer Immunol Immunother. 2008;57:1-17.
Google Scholar
Tan GH, Wei YQ, Tian L, Zhao X, Yang L, Li J, He QM, Wu Y, Wen YJ, Yi T, et al. Active immunotherapy of tumors with a recombinant xenogeneic endoglin as a model antigen. Eur J Immunol. 2004;34:2012-2021.
Google Scholar
Tan GH, Tian L, Wei YQ, Zhao X, Li J, Wu Y, Wen YJ, Yi T, Ding ZY, Kan B, et al. Combination of low-dose cisplatin and recombinant xenogeneic endoglin as a vaccine induces synergistic antitumor activities. Int J Cancer. 2004;112:701-706.
Google Scholar
Troyanovsky B, Levchenko T, Mansson G, Matvijenko O, Holmgren L. Angiomotin: an angiostatin binding protein that regulates endothelial cell migration and tube formation. J Cell Biol. 2001;152:1247-1254.
Google Scholar
Bratt A, Birot O, Sinha I, Veitonmaki N, Aase K, Ernkvist M, Holmgren L. Angiomotin regulates endothelial cell-cell junctions and cell motility. J Biol Chem. 2005;280:34859-34869.
Google Scholar
Jiang WG, Watkins G, Douglas-Jones A, Holmgren L, Mansel RE. Angiomotin and angiomotin like proteins, their expression and correlation with angiogenesis and clinical outcome in human breast cancer. BMC Cancer. 2006;6:16-.
Google Scholar
Peters KG, Coogan A, Berry D, Marks J, Iglehart JD, Kontos CD, Rao P, Sankar S, Trogan E. Expression of Tie2/Tek in breast tumour vasculature provides a new marker for evaluation of tumour angiogenesis. Br J Cancer. 1998;77:51-56.
Google Scholar
Lin P, Buxton JA, Acheson A, Radziejewski C, Maisonpierre PC, Yancopoulos GD, Channon KM, Hale LP, Dewhirst MW, George SE, Peters KG. Antiangiogenic gene therapy targeting the endothelium-specific receptor tyrosine kinase Tie2. Proc Natl Acad Sci USA. 1998;95:8829-8834.
Google Scholar
Luo Y, Wen YJ, Ding ZY, Fu CH, Wu Y, Liu JY, Li Q, He QM, Zhao X, Jiang Y, et al. Immunotherapy of tumors with protein vaccine based on chicken homologous Tie-2. Clin Cancer Res. 2006;12:1813-1819.
Google Scholar
Ramage JM, Metheringham R, Conn A, Spendlove I, Moss RS, Patton DT, Murray JC, Rees RC, Durrant LG. Identification of an HLA-A*0201 cytotoxic T lymphocyte epitope specific to the endothelial antigen Tie-2. Int J Cancer. 2004;110:245-250.
Google Scholar
Fu C, Bardhan S, Cetateanu ND, Wamil BD, Wang Y, Yan HP, Shi E, Carter C, Venkov C, Yakes FM, et al. Identification of a novel membrane protein, HP59, with therapeutic potential as a target of tumor angiogenesis. Clin Cancer Res. 2001;7:4182-4194.
Google Scholar
Rojas J, Green RS, Hellerqvist CG, Olegard R, Brigham KL, Stahlman MT. Studies on group B beta-hemolytic Streptococcus. II. Effects on pulmonary hemodynamics and vascular permeability in unanesthetized sheep. Pediatr Res. 1981;15:899-904.
Google Scholar
Sundell HW, Yan H, Carter CE, Wamil BD, Wu K, Gaddipati R, Li D, Hellerqvist CG. Isolation and identification of the group B streptococcal toxin CM101 from infants with sepsis. J Pediatr. 2000;137:338-344.
Google Scholar
Funa K, Uramoto H. Regulatory mechanisms for the expression and activity of platelet-derived growth factor receptor. Acta Biochim Pol. 2003;50:647-658.
Google Scholar
Ostman A. PDGF receptors-mediators of autocrine tumor growth and regulators of tumor vasculature and stroma. Cytokine Growth Factor Rev. 2004;15:275-286.
Google Scholar
Song S, Ewald AJ, Stallcup W, Werb Z, Bergers G. PDGFRbeta+ perivascular progenitor cells in tumours regulate pericyte differentiation and vascular survival. Nat Cell Biol. 2005;7:870-879.
Google Scholar
Fest S, Huebener N, Bleeke M, Durmus T, Stermann A, Woehler A, Baykan B, Zenclussen AC, Michalsky E, Jaeger IS, et al. Survivin minigene DNA vaccination is effective against neuroblastoma. Int J Cancer. 2009;125:104-114.
Google Scholar
Hajri A, Balboni G, Koenig M, Garaud JC, Damge C. Gastrin-releasing peptide: in vivo and in vitro growth effects on an acinar pancreatic carcinoma. Cancer Res. 1992;52:3726-3732.
Google Scholar
Lango MN, Dyer KF, Lui VW, Gooding WE, Gubish C, Siegfried JM, Grandis JR. Gastrin-releasing peptide receptor-mediated autocrine growth in squamous cell carcinoma of the head and neck. J Natl Cancer Inst. 2002;94:375-383.
Google Scholar
Kim S, Hu W, Kelly DR, Hellmich MR, Evers BM, Chung DH. Gastrin-releasing peptide is a growth factor for human neuroblastomas. Ann Surg. 2002;235:621-629.
Google Scholar
Cuttitta F, Carney DN, Mulshine J, Moody TW, Fedorko J, Fischler A, Minna JD. Bombesin-like peptides can function as autocrine growth factors in human small-cell lung cancer. Nature. 1985;316:823-826.
Google Scholar
Carney DN, Cuttitta F, Moody TW, Minna JD. Selective stimulation of small cell lung cancer clonal growth by bombesin and gastrin-releasing peptide. Cancer Res. 1987;47:821-825.
Google Scholar
Yano T, Pinski J, Groot K, Schally AV. Stimulation by bombesin and inhibition by bombesin/gastrin-releasing peptide antagonist RC-3095 of growth of human breast cancer cell lines. Cancer Res. 1992;52:4545-4547.
Google Scholar
Vangsted AJ, Andersen EV, Nedergaard L, Zeuthen J. Gastrin releasing peptide GRP(14-27) in human breast cancer cells and in small cell lung cancer. Breast Cancer Res Treat. 1991;19:119-128.
Google Scholar
Scott N, Millward E, Cartwright EJ, Preston SR, Coletta PL. Gastrin releasing peptide and gastrin releasing peptide receptor expression in gastrointestinal carcinoid tumours. J Clin Pathol. 2004;57:189-192.
Google Scholar
Martinez A, Zudaire E, Julian M, Moody TW, Cuttitta F. Gastrin-releasing peptide (GRP) induces angiogenesis and the specific GRP blocker 77427 inhibits tumor growth in vitro and in vivo. Oncogene. 2005;24:4106-4113.
Google Scholar
Levine L, Lucci JA, Pazdrak B, Cheng JZ, Guo YS, Townsend CM, Hellmich MR. Bombesin stimulates nuclear factor kappa B activation and expression of proangiogenic factors in prostate cancer cells. Cancer Res. 2003;63:3495-3502.
Google Scholar
Kang J, Ishola TA, Baregamian N, Mourot JM, Rychahou PG, Evers BM, Chung DH. Bombesin induces angiogenesis and neuroblastoma growth. Cancer Lett. 2007;253:273-281.
Google Scholar
Cornelio DB, Roesler R, Schwartsmann G. Gastrin-releasing peptide receptor as a molecular target in experimental anticancer therapy. Ann Oncol. 2007;18:1457-1466.
Google Scholar
Guojun W, Wei G, Kedong O, Yi H, Yanfei X, Qingmei C, Yankai Z, Jie W, Hao F, Taiming L, et al. A novel vaccine targeting gastrin-releasing peptide: efficient inhibition of breast cancer growth in vivo. Endocr Relat Cancer. 2008;15:149-159.
Google Scholar
Fang J, Lu Y, Ouyang K, Wu G, Zhang H, Liu Y, Chen Y, Lin M, Wang H, Jin L, et al. Specific antibodies elicited by a novel DNA vaccine targeting gastrin-releasing peptide inhibit murine melanoma growth in vivo. Clin Vaccine Immunol. 2009;16:1033-1039.
Google Scholar
Liu C, Sun C, Huang H, Janda K, Edgington T. Overexpression of legumain in tumors is significant for invasion/metastasis and a candidate enzymatic target for prodrug therapy. Cancer Res. 2003;63:2957-2964.
Google Scholar
Murthy RV, Arbman G, Gao J, Roodman GD, Sun XF. Legumain expression in relation to clinicopathologic and biological variables in colorectal cancer. Clin Cancer Res. 2005;11:2293-2299.
Google Scholar
Luo Y, Zhou H, Krueger J, Kaplan C, Lee SH, Dolman C, Markowitz D, Wu W, Liu C, Reisfeld RA, Xiang R. Targeting tumor-associated macrophages as a novel strategy against breast cancer. J Clin Invest. 2006;116:2132-2141.
Google Scholar
Lewen S, Zhou H, Hu HD, Cheng T, Markowitz D, Reisfeld RA, Xiang R, Luo Y. A Legumain-based minigene vaccine targets the tumor stroma and suppresses breast cancer growth and angiogenesis. Cancer Immunol Immunother. 2008;57:507-515.
Google Scholar
Rasmussen HS, McCann PP. Matrix metalloproteinase inhibition as a novel anticancer strategy: a review with special focus on batimastat and marimastat. Pharmacol Ther. 1997;75:69-75.
Google Scholar
Anderson IC, Shipp MA, Docherty AP, Teicher BA. Combination therapy including a gelatinase inhibitor and cytoxic agent reduces local invasion and metastasis of murine Lewis lung carcinoma. Cancer Research. 1996;56:715-718.
Google Scholar
Su JM, Wei YQ, Tian L, Zhao X, Yang L, He QM, Wang Y, Lu Y, Wu Y, Liu F, et al. Active immunogene therapy of cancer with vaccine on the basis of chicken homologous matrix metalloproteinase-2. Cancer Res. 2003;63:600-607.
Google Scholar
Smyth E. The Trouble with Inhibitors. Signalling scissors: new perspectives on proteases; Brescia, Italy. 2003.
Google Scholar
Dove A. MMP inhibitors: glimmers of hope amidst clinical failures. Nat Med. 2002;8:95-.
Google Scholar
Overall CM, Kleifeld O. Towards third generation matrix metalloproteinase inhibitors for cancer therapy. Br J Cancer. 2006;94:941-946.
Google Scholar
Overall CM, Kleifeld O. Tumour microenvironment - opinion: validating matrix metalloproteinases as drug targets and anti-targets for cancer therapy. Nat Rev Cancer. 2006;6:227-239.
Google Scholar
Eskens FA, Dumez H, Hoekstra R, Perschl A, Brindley C, Bottcher S, Wynendaele W, Drevs J, Verweij J, van Oosterom AT. Phase I and pharmacokinetic study of continuous twice weekly intravenous administration of Cilengitide (EMD 121974), a novel inhibitor of the integrins alphavbeta3 and alphavbeta5 in patients with advanced solid tumours. Eur J Cancer. 2003;39:917-926.
Google Scholar
Lou YY, Wei YQ, Yang L, Zhao X, Tian L, Lu Y, Wen YJ, Liu F, Huang MJ, Kang B, et al. Immunogene therapy of tumors with a vaccine based on the ligand-binding domain of chicken homologous integrin beta3. Immunol Invest. 2002;31:51-69.
Google Scholar
Liu JY, Wei YQ, Yang L, Zhao X, Tian L, Hou JM, Niu T, Liu F, Jiang Y, Hu B, et al. Immunotherapy of tumors with vaccine based on quail homologous vascular endothelial growth factor receptor-2. Blood. 2003;102:1815-1823.
Google Scholar
Dirix LY, Van Dam PA, Prove PA, Vermeulen PB. Bevacizumab in the Treatment of Patients with Advanced Breast Cancer: Where have We Landed?. Ther Adv Med Oncol. 2010;2:331-342.
Google Scholar
Bielawska-Pohl A, Crola C, Caignard A, Gaudin C, Dus D, Kieda C, Chouaib S. Human NK cells lyse organ-specific endothelial cells: analysis of adhesion and cytotoxic mechanisms. J Immunol. 2005;174:5573-5582.
Google Scholar
Tsuji K, Hamada T, Uenaka A, Wada H, Sato E, Isobe M, Asagoe K, Yamasaki O, Shiku H, Ritter G, et al. Induction of immune response against NY-ESO-1 by CHP-NY-ESO-1 vaccination and immune regulation in a melanoma patient. Cancer Immunol Immunother. 2008;57:1429-1437.
Google Scholar
Ostrand-Rosenberg S. Myeloid-derived suppressor cells: more mechanisms for inhibiting antitumor immunity. Cancer Immunol Immunother. 2010;59:1593-1600.
Google Scholar
Bielawska-Pohl A, Blesson S, Benlalam H, Trenado A, Opolon P, Bawa O, Rouffiac V, Dus D, Kieda C, Chouaib S. The anti-angiogenic activity of IL-12 is increased in iNOS-/- mice and involves NK cells. J Mol Med. 2010;88:775-784.
Google Scholar
Osada T, Clay T, Hobeika A, Lyerly HK, Morse MA. NK cell activation by dendritic cell vaccine: a mechanism of action for clinical activity. Cancer Immunol Immunother. 2006;55:1122-1131.
Google Scholar
Sidky YA, Borden EC. Inhibition of angiogenesis by interferons: effects on tumor- and lymphocyte-induced vascular responses. Cancer Res. 1987;47:5155-5161.
Google Scholar
Majewski S, Szmurlo A, Marczak M, Jablonska S, Bollag W. Synergistic effect of retinoids and interferon alpha on tumor-induced angiogenesis: anti-angiogenic effect on HPV-harboring tumor-cell lines. Int J Cancer. 1994;57:81-85.
Google Scholar
Slaton JW, Perrotte P, Inoue K, Dinney CP, Fidler IJ. Interferon-alpha-mediated down-regulation of angiogenesis-related genes and therapy of bladder cancer are dependent on optimization of biological dose and schedule. Clin Cancer Res. 1999;5:2726-2734.
Google Scholar
Benlalam H, Jalil A, Hasmim M, Pang B, Tamouza R, Mitterrand M, Godet Y, Lamerant N, Robert C, Avril MF, et al. Gap junction communication between autologous endothelial and tumor cells induce cross-recognition and elimination by specific CTL. J Immunol. 2009;182:2654-2664.
Google Scholar
Arap W, Haedicke W, Bernasconi M, Kain R, Rajotte D, Krajewski S, Ellerby HM, Bredesen DE, Pasqualini R, Ruoslahti E. Targeting the prostate for destruction through a vascular address. Proc Natl Acad Sci USA. 2002;99:1527-1531.
Google Scholar
Trepel M, Arap W, Pasqualini R. In vivo phage display and vascular heterogeneity: implications for targeted medicine. Curr Opin Chem Biol. 2002;6:399-404.
Google Scholar
Ruoslahti E, Duza T, Zhang L. Vascular homing peptides with cell-penetrating properties. Curr Pharm Des. 2005;11:3655-3660.
Google Scholar

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