Vascular endothelial growth factor immunoneutralization plus Paclitaxel markedly reduces tumor burden and ascites in athymic mouse model of ovarian cancer

Effect of bevacizumab in combination with chemotherapy for ovarian cancer on wound healing in patients: A meta-analysis

In this meta-analysis, we reviewed the findings and definitive findings of a new study that assessed the impact of bevacizumab on wound healing following combined chemotherapy for ovarian cancer (OC). The results of a controlled study that assessed the efficacy of bevacizumab in the treatment of ovarian cancer were retrieved from 4 databases, such as the Web of Science and EMBASE. The results of the adverse event associated with wound healing were determined by comparison of the controlled studies of bevacizumab plus chemotherapy in the treatment of ovarian cancer. A meta-analysis was conducted with either a randomized or a fixed-effect model in order to establish an odds ratio for time to event variables and for a binary outcome. In the research literature, 830 trials have been identified and seven have been chosen to be included in a definitive analysis of the trial. Among the 4134 cases who received chemotherapy after operation, 2098 received standard chemotherapy and 2036 received the addition of bevacizumab. A total of 7 trials have shown that the use of bevacizumab in the treatment of ovarian cancer patients has reduced wound healing (OR, 0.55; 95% CI: 0.37, 0.80, p = 0.002). Four trials demonstrated that there was no change in the incidence of haemorrhage in patients with ovarian cancer when administered with or without bevacizumab (OR, 0.48; 95% CI, 0.10, 2.34, p = 0.37). The combined use of bevacizumab and chemotherapy may have a negative effect on the healing of wound.

Platinum-based chemotherapy and bevacizumab instigate the destruction of human ovarian cancers via different signaling pathways

The standard chemotherapy regimens of ovarian cancer are platinum-based chemotherapy (carboplatin and paclitaxel) and bevacizumab (BEV). However, the effects of BEV alone or combined with carboplatin and paclitaxel on mitochondrial dynamics, mitochondrial function, mitophagy, apoptosis, inflammation and vascular endothelial growth factor (VEGF) in human ovarian cancer mitochondria and cells have not yet been investigated. Therefore, we aimed to test the hypothesis that 1) platinum-based chemotherapy and BEV equally damage isolated mitochondria from human ovarian cancers, and ovarian cancer cells through inducing mitochondrial dynamics dysregulation, mitochondrial dysfunction, increased mitophagy and apoptosis, as well as altered inflammation and VEGF; and 2) combined therapies exert greater damage than monotherapy. Each isolated human ovarian cancer mitochondria (n = 16) or CaOV3 cells (n = 6) were treated with either platinum-based chemotherapy (carboplatin 10 μM and paclitaxel 5 μM), BEV (2 mg/mL) or combined platinum-based chemotherapy and BEV for 60 min or 24 h, respectively. Following the treatment, mitochondrial dynamics, mitochondrial function, mitophagy, apoptosis, cytotoxicity, inflammation and VEGF were determined. Platinum-based chemotherapy caused ovarian cancer mitochondria and cell damage through mitochondrial dysfunction, increased cell death with impairment of membrane integrity, and enhanced VEGF reduction, while BEV did not. BEV caused deterioration of ovarian cancer mitochondria and cells through mitochondrial-dependent apoptosis, but it had no effect on cell viability. Interestingly, combined platinum-based chemotherapy and BEV treatments had no addictive effects on all parameters except mitochondrial maximal respiration, when compared to monotherapy. Collectively, these findings suggest that platinum-based chemotherapy and BEV caused human ovarian cancer mitochondrial and cell damage through different mechanisms.

Tumor Microenvironment in Ovarian Cancer: Function and Therapeutic Strategy

Ovarian cancer is one of the leading causes of death in patients with gynecological malignancy. Despite optimal cytoreductive surgery and platinum-based chemotherapy, ovarian cancer disseminates and relapses frequently, with poor prognosis. Hence, it is urgent to find new targeted therapies for ovarian cancer. Recently, the tumor microenvironment has been reported to play a vital role in the tumorigenesis of ovarian cancer, especially with discoveries from genome-, transcriptome- and proteome-wide studies; thus tumor microenvironment may present potential therapeutic target for ovarian cancer. Here, we review the interactions between the tumor microenvironment and ovarian cancer and various therapies targeting the tumor environment.

Epigenetic Crosstalk between the Tumor Microenvironment and Ovarian Cancer Cells: A Therapeutic Road Less Traveled

Metastatic dissemination of epithelial ovarian cancer (EOC) predominantly occurs through direct cell shedding from the primary tumor into the intra-abdominal cavity that is filled with malignant ascitic effusions. Facilitated by the fluid flow, cells distribute throughout the cavity, broadly seed and invade through peritoneal lining, and resume secondary tumor growth in abdominal and pelvic organs. At all steps of this unique metastatic process, cancer cells exist within a multidimensional tumor microenvironment consisting of intraperitoneally residing cancer-reprogramed fibroblasts, adipose, immune, mesenchymal stem, mesothelial, and vascular cells that exert miscellaneous bioactive molecules into malignant ascites and contribute to EOC progression and metastasis via distinct molecular mechanisms and epigenetic dysregulation. This review outlines basic epigenetic mechanisms, including DNA methylation, histone modifications, chromatin remodeling, and non-coding RNA regulators, and summarizes current knowledge on reciprocal interactions between each participant of the EOC cellular milieu and tumor cells in the context of aberrant epigenetic crosstalk. Promising research directions and potential therapeutic strategies that may encompass epigenetic tailoring as a component of complex EOC treatment are discussed.

Treatment response assessment with (R)-[11CPAQ PET in the MMTV-PyMT mouse model of breast cancer

Background

The goal of the study was to assess the potential of the vascular endothelial growth factor receptor (VEGFR)-2-targeting carbon-11 labeled (R)-N-(4-bromo-2-fluorophenyl)-6-methoxy-7-((1-methyl-3-piperidinyl)methoxy)-4-quinazolineamine ((R)-[¹¹C]PAQ) as a positron emission tomography (PET) imaging biomarker for evaluation of the efficacy of anticancer drugs in preclinical models.

Methods

MMTV-PyMT mice were treated with vehicle alone (VEH), murine anti-VEGFA antibody (B20-4.1.1), and paclitaxel (PTX) in combination or as single agents. The treatment response was measured with (R)-[¹¹C]PAQ PET as standardized uptake value (SUV)_mean, SUV_max relative changes at the baseline (day 0) and follow-up (day 4) time points, and magnetic resonance imaging (MRI)-derived PyMT mammary tumor volume (TV) changes. Expression of Ki67, VEGFR-2, and CD31 in tumor tissue was determined by immunohistochemistry (IHC). Non-parametric statistical tests were used to evaluate the relation between (R)-[¹¹C]PAQ radiotracer uptake and therapy response biomarkers.

Results

The (R)-[¹¹C]PAQ SUV_max in tumors was significantly reduced after 4 days in the B20-4.1.1/PTX combinational and B20-4.1.1 monotherapy groups (p < 0.0005 and p < 0.003, respectively). No significant change was observed in the PTX monotherapy group. There was a significant difference in the SUV_max change between the VEH group and B20-4.1.1/PTX combinational group, as well as between the VEH group and the B20-4.1.1 monotherapy group (p < 0.05). MRI revealed significant decreases in TV in the B20-4.1.1/PTX treatment group (p < 0.005) but not the other therapy groups. A positive trend was observed between the (R)-[¹¹C]PAQ SUV_max change and TV reduction in the B20-4.1.1/PTX group. Statistical testing showed a significant difference in the blood vessel density between the B20-4.1.1/PTX combinational group and the VEH group (p < 0.05) but no significant difference in the Ki67 positive signal between treatment groups.

Conclusions

The results of this study are promising. However, additional studies are necessary before (R)-[¹¹C]PAQ can be approved as a predictive radiotracer for cancer therapy response.

Mirvetuximab Soravtansine (IMGN853), a Folate Receptor Alpha-Targeting Antibody-Drug Conjugate, Potentiates the Activity of Standard of Care Therapeutics in Ovarian Cancer Models

Elevated folate receptor alpha (FRα) expression is characteristic of epithelial ovarian cancer (EOC), thus establishing this receptor as a candidate target for the development of novel therapeutics to treat this disease. Mirvetuximab soravtansine (IMGN853) is an antibody-drug conjugate (ADC) that targets FRα for tumor-directed delivery of the maytansinoid DM4, a potent agent that induces mitotic arrest by suppressing microtubule dynamics. Here, combinations of IMGN853 with approved therapeutics were evaluated in preclinical models of EOC. Combinations of IMGN853 with carboplatin or doxorubicin resulted in synergistic antiproliferative effects in the IGROV-1 ovarian cancer cell line in vitro. IMGN853 potentiated the cytotoxic activity of carboplatin via growth arrest and augmented DNA damage; cell cycle perturbations were also observed in cells treated with the IMGN853/doxorubicin combination. These benefits translated into improved antitumor activity in patient-derived xenograft models in vivo in both the platinum-sensitive (IMGN853/carboplatin) and platinum-resistant (IMGN853/pegylated liposomal doxorubicin) settings. IMGN853 co-treatment also improved the in vivo efficacy of bevacizumab in platinum-resistant EOC models, with combination regimens causing significant regressions and complete responses in the majority of tumor-bearing mice. Histological analysis of OV-90 ovarian xenograft tumors revealed that concurrent administration of IMGN853 and bevacizumab caused rapid disruption of tumor microvasculature and extensive necrosis, underscoring the superior bioactivity profile of the combination regimen. Overall, these demonstrations of combinatorial benefit conferred by the addition of the first FRα-targeting ADC to established therapies provide a compelling framework for the potential application of IMGN853 in the treatment of patients with advanced ovarian cancer.

Dysregulation of Aromatase in Breast, Endometrial, and Ovarian Cancers: An Overview of Therapeutic Strategies

Aromatase is the rate-limiting enzyme in the biosynthesis of estrogens, which play crucial roles on a spectrum of developmental and physiological processes. The biological actions of estrogens are classically mediated by binding to two estrogen receptors (ERs), ERα and ERβ. Encoded by the cytochrome P450, family 19, subfamily A, polypeptide 1 (CYP19A1) gene, aromatase is expressed in a wide variety of tissues, as well as benign and malignant tumors, and is regulated in a pathway- and tissue-specific manner. Overexpression of aromatase, leading to elevated systemic levels of estrogen, is unequivocally linked to the pathogenesis and growth of a number malignancies, including breast, endometrium, and ovarian cancers. Aromatase inhibitors (AIs) are routinely used to treat estrogen-dependent breast cancers in postmenopausal women; however, their roles in endometrial and ovarian cancers remain obscure. While AI therapy is effective in hormone sensitive cancers, they diminish estrogen production throughout the body and, thus, generate undesirable side effects. Despite the effectiveness of AI therapy, resistance to endocrine therapy remains a major concern and is the leading cause of cancer death. Considerable advances, toward mitigating these issues, have evolved in conjunction with a number of histone deacetylase (HDAC) inhibitors for countering an assortment of diseases and cancers, including the aforesaid malignancies. HDACs are a family of enzymes that are frequently dysregulated in human tumors. This chapter will discuss the current understanding of aberrant regulation and expression of aromatase in breast, endometrial, and ovarian cancers, and potential therapeutic strategies for prevention and treatment of these life-threatening diseases.

Identification of therapeutic targets in ovarian cancer through active tyrosine kinase profiling

The activation status of a set of pro-oncogenic tyrosine kinases in ovarian cancer patient samples was analyzed to define potential therapeutic targets. Frequent activation of HER family receptor tyrosine kinases, especially HER2, was observed. Studies in ovarian cancer cell lines confirmed the activation of HER2. Moreover, knockdown of HER2 caused a strong inhibition of their proliferation. Analyses of the action of agents that target HER2 indicated that the antibody drug conjugate trastuzumab-emtansine (T-DM1) caused a substantial antitumoral effect in vivo and in vitro, and potentiated the action of drugs used in the therapy of ovarian cancer. T-DM1 provoked cell cycle arrest in mitosis, and caused the appearance of aberrant mitotic spindles in cells treated with the drug. Biochemical experiments confirmed accumulation of the mitotic markers phospho-Histone H3 and phospho-BUBR1 in cells treated with the drug. Prolonged treatment of ovarian cancer cells with T-DM1 provoked the appearance of multinucleated cells which later led to cell death. Together, these data indicate that HER2 represents an important oncogene in ovarian cancer, and suggest that targeting this tyrosine kinase with T-DM1 may be therapeutically effective, especially in ovarian tumors with high content of HER2.

Bevacizumab in ovarian cancer: Focus on clinical data and future perspectives

The past five years have yielded substantial developments in the management of advanced ovarian cancer. Initial promise shown by anti-angiogenic agents has translated into positive phase III trials in the front-line and recurrent settings. Nevertheless, several questions remain unanswered, including the most appropriate timing for initiation of anti-angiogenic therapy and patient selection for the various treatment approaches. This review article summarises the key results (including final overall survival data), from five pivotal phase III trials of bevacizumab, highlights emerging data with new maintenance strategies and considers unanswered questions and ongoing research to address uncertainties in treatment duration, re-exposure to bevacizumab in bevacizumab-pretreated patients and the potential integration of anti-angiogenic therapy into neoadjuvant treatment regimens.

Biological insights into effective and antagonistic combinations of targeted agents with chemotherapy in solid tumors

The potential for synergistic interactions between anticancer drugs has been used to justify combinations of agents in clinical trials. However, most combinations of targeted agents and chemotherapies have been tested in the clinic without previous systematic evaluation of their potential benefit. Preclinical studies may help in the identification of synergistic or antagonistic interactions. For antineoplastic therapies, these studies may reveal synergy or antagonism of the drug combinations. Synergy occurs when two agents given together produce higher antitumoral activity than the sum of each individual drug. This represents the ideal setting for the development of combinations of targeted agents and chemotherapies. On the other side, certain drug combinations have shown adverse results, indicative of an antagonistic effect. In this article, we review the preclinical molecular bases that justify approved combinations of targeted agents with chemotherapy including examples of synergistic and antagonistic combinations. We also discuss scenarios for rational associations of targeted agents based on biological data and propose strategies that may improve the success of combinations of anticancer agents.

Ovarian cancer microenvironment: implications for cancer dissemination and chemoresistance acquisition

Ovarian adenocarcinoma is characterized by a late detection, dissemination of cancer cells into the whole peritoneum, and the frequent acquisition of chemoresistance. If these particularities can be explained in part by intrinsic properties of ovarian cancer cells, an increased number of studies show the importance of the tumor microenvironment in tumor progression. Ovarian cancer cells can regulate the composition of their stroma in promoting the formation of ascitic fluid, rich in cytokines and bioactive lipids, and in stimulating the differentiation of stromal cells into a pro-tumoral phenotype. In return, cancer-associated fibroblasts, cancer-associated mesenchymal stem cells, tumor-associated macrophages, or other peritoneal cells, such as adipocytes and mesothelial cells can regulate tumor growth, angiogenesis, dissemination, and chemoresistance. This review focuses on the current knowledge about the roles of stromal cells and the associated secreted factors on tumor progression. We also summarize the different studies showing that targeting the microenvironment represents a great potential for improving the prognosis of patients with ovarian adenocarcinoma.

Use of bevacizumab in recurrent glioblastoma

Glioblastoma (GBM) is the most common adult primary brain neoplasm. Despite advances in treatment, GBM continues to be associated with considerable morbidity and mortality as compared with other malignancies. Standard treatment for GBM results in survival of 12.9 months (95% CI: 12.3-13.7 months) with a median progression-free survival of 7.2 months (95% CI: 6.4-8.2 months) in a modern GBM cohort. These aggressive tumors recur and treatment for recurrent GBM continues to have very poor outcomes. Prior to the use of bevacizumab, monoclonal antibody to VEGF, 6-month progression-free survival in clinical trials for recurrent GBM ranged from 9 to 15%. Trials utilizing bevacizumab and its subsequent US FDA approval have given more hope to recurrent GBM and this concise review discusses bevacizumab in recurrent GBM. This review focuses on time-to-event outcomes (overall survival, progression-free survival and 6-month progression-free survival) in clinical trials utilizing bevacizumab for the treatment of recurrent GBM. For this review, we have chosen to focus primarily on Phase II clinical trials that have been published and available in the literature (PubMed). While we focused primarily on time-to-event variables, toxicity and safety of bevacizumab is very important and this agent can be associated with serious life-threatening toxicities. We have included a general section of toxicities but for a more lengthy review please see the excellent study by Odia and colleagues.

The emerging role of anti-angiogenic therapy in ovarian cancer (review)

The introduction of new therapeutic agents into clinical practice of ovarian cancer, in addition to the role of surgery and chemotherapy, has been the subject of numerous studies because this tumor remains worldwide the most lethal gynecological cancer. It is now known that angiogenesis plays a vital role for ovarian physiology, but also in ovarian carcinogenesis and so it has become the main target of ovarian cancer treatment. In this review, the most common molecular pathways of angiogenesis have been investigated leading to the identification of novel targets, including monoclonal antibodies and tyrosine kinase inhibitors. The fundamental targets of anti-angiogenic drugs are vascular endothelial growth factor receptor and its ligand, but also platelet-derived growth factor, fibroblast growth factor and angiopoietin. Moreover, improved knowledge of angiogenic process allowed the discovery of other molecules, such as semaphorins, neuropilins, clusterin, some transcriptional factors, and the identification of features, including stemness, epithelial-mesenchymal transition, downregulation of certain microRNAs, the alteration of immune system, that contribute to angiogenesis and possibly to resistance mechanisms. The following patent and literature review aim to highlight recent findings of approved and novel anti-angiogenic drugs that make the treatment of patients with ovarian cancer a rapidly growing field of oncology.

Preliminary safety evaluation of a taurocholate-conjugated low-molecular-weight heparin derivative (LHT7): a potent angiogenesis inhibitor

In our previous studies, taurocholic acid (TA)-conjugated low-molecular-weight heparin derivative (LHT7) has been proven to be a potent anti-angiogenic agent by demonstrated successful blockage capability of vascular endothelial growth factors (VEGF). Preliminary safety evaluations were conducted based on its mechanism of action and chemical behavior. For this purpose, acute toxicity study, and hematological and serological evaluations were carried out. Additionally, in order to evaluate mechanism-related side effects, both blood pressure and the occurrence of proteinuria were measured using a treatment regime of multiple high doses of LHT7 in a biodistribution study. LD50 values for LHT7 in female and male mice were 56.9 and 64.7 mg kg(-1) doses, respectively. There were no vital fluctuations in the serological and hematological parameters, except for the elevated levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) at 100 and 200 mg kg(-1) doses of LHT7, representing vital changes in the liver function. Moreover, the results of mechanism-related studies showed that blood pressure at 50 mg kg(-1) did not change but showed elevated levels of protein in urine. In the biodistribution study, a slight accumulation of LHT7 in the kidney and the liver were observed at the 50 mg kg(-1) repeated dose owing to the presence of bile acid. No fatal damage was observed in this study; most observations were related to the chemical composition or the mechanism of action of the material.

Anti-VEGF therapy: a new approach to colorectal cancer therapy

The purpose of this review is to discuss the inhibition of vascular endothelial growth factor as a treatment for advanced colorectal cancer. The review will begin by summarizing the theory behind vascular endothelial growth factor inhibition and how this affects tumor angiogenesis. The major clinical trials that have examined antivascular endothelial growth factor agents to treat patients with advanced colorectal cancer will then be described. Finally, there is a commentary regarding the status of targeted agents currently in development for the treatment of advanced colorectal cancer and a discussion of the potential future considerations for the use of antivascular endothelial growth factor agents in clinical practice.

Current status and evolution of preclinical drug development models of epithelial ovarian cancer

Epithelial ovarian cancer (EOC) is the most lethal gynecologic malignancy and the fifth most common cause of female cancer death in the United States. Although important advances in surgical and chemotherapeutic strategies over the last three decades have significantly improved the median survival of EOC patients, the plateau of the survival curve has not changed appreciably. Given that EOC is a genetically and biologically heterogeneous disease, identification of specific molecular abnormalities that can be targeted in each individual ovarian cancer on the basis of predictive biomarkers promises to be an effective strategy to improve outcome in this disease. However, for this promise to materialize, appropriate preclinical experimental platforms that recapitulate the complexity of these neoplasms and reliably predict antitumor activity in the clinic are critically important. In this review, we will present the current status and evolution of preclinical models of EOC, including cell lines, immortalized normal cells, xenograft models, patient-derived xenografts, and animal models, and will discuss their potential for oncology drug development.

Where do antiangiogenic agents belong in the treatment algorithm for ovarian cancer?

Although epithelial ovarian cancer responds well to chemotherapy, patients presenting with advanced disease still have a poor prognosis. The clear role of angiogenesis in the development and progression of ovarian tumorigenesis has led to the development of several novel antiangiogenic agents; however, questions remain as how to best incorporate such agents into current treatment algorithms. Searches of PubMed (terms: angiogenesis, VEGF, tyrosine kinase inhibitor, bevacizumab and ovarian cancer) and of recent results from key oncology congresses (terms: drug names and ovarian cancer) were performed to identify relevant articles and abstracts. Clinical trials are ongoing to evaluate investigational antiangiogenic agents as a component of first-line chemotherapy, as a treatment option for recurrent disease, and as maintenance therapy for ovarian cancer. The antiangiogenic monoclonal antibody bevacizumab has demonstrated a progression-free survival benefit in combination with first-line paclitaxel/carboplatin and continued as maintenance therapy, and phase II data suggest therapeutic potential for several multitargeted tyrosine kinase inhibitors in ovarian cancer, with phase III results forthcoming for BIBF 1120, cediranib, and pazopanib. Antiangiogenic therapy remains a promising strategy for ovarian cancer, and it is hoped that results from ongoing trials will inform their optimal placement in the treatment paradigm.

Angiogenesis-related pathways in the pathogenesis of ovarian cancer

Ovarian Cancer represents the most fatal type of gynecological malignancies. A number of processes are involved in the pathogenesis of ovarian cancer, especially within the tumor microenvironment. Angiogenesis represents a hallmark phenomenon in cancer, and it is responsible for tumor spread and metastasis in ovarian cancer, among other tumor types, as it leads to new blood vessel formation. In recent years angiogenesis has been given considerable attention in order to identify targets for developing effective anti-tumor therapies. Growth factors have been identified to play key roles in driving angiogenesis and, thus, the formation of new blood vessels that assist in "feeding" cancer. Such molecules include the vascular endothelial growth factor (VEGF), the platelet derived growth factor (PDGF), the fibroblast growth factor (FGF), and the angiopoietin/Tie2 receptor complex. These proteins are key players in complex molecular pathways within the tumor cell and they have been in the spotlight of the development of anti-angiogenic molecules that may act as stand-alone therapeutics, or in concert with standard treatment regimes such as chemotherapy. The pathways involved in angiogenesis and molecules that have been developed in order to combat angiogenesis are described in this paper.

The role of vascular endothelial growth factor in the pathogenesis, diagnosis and treatment of malignant pleural effusion

Malignant pleural effusions (MPEs) are a significant source of cancer-related morbidity. Over 150,000 patients in the United States suffer from breathlessness and diminished quality of life due to MPE each year. Current management strategies are of mostly palliative value and focus on symptom control; they do not address the pathobiology of the effusion, nor do they improve survival. Further elucidation of the pathophysiological mechanisms, coupled with the development of novel treatments such as intrapleural chemotherapeutics targeting this process, has the potential to greatly improve the efficacy of our current management options. Vascular endothelial growth factor-A (VEGF-A) has been implicated as a critical cytokine in the formation of malignant pleural effusions. Elevated levels of VEGF produced by tumor cells, mesothelial cells, and infiltrating immune cells result in increased vascular permeability, cancer cell transmigration, and angiogenesis. Therefore antiangiogenic therapies such as Bevacizumab, a monoclonal antibody targeting VEGF-A, may have a potential role in the management of malignant pleural effusions. Herein we review the pathogenesis and potential treatment strategies of malignant pleural effusions, with a focus on angiogenesis and antiangiogenic therapeutics.

Measures of biosimilarity in monoclonal antibodies in oncology: the case of bevacizumab

Biosimilars have been available on the European market since 2006 and experience with their use is increasing. The next wave of biopharmaceuticals that are about to lose patent protection consists of more-complicated products, including many monoclonal antibodies. Guidance has been released on the particulars of a biosimilarity exercise involving these products. Considerable challenges exist to establish biosimilarity for anticancer products. An especially challenging product is bevacizumab (Avastin(®)). On the basis of data available for the innovator product (bevacizumab) we will discuss strengths and weaknesses of preclinical and clinical models and explore the application of novel endpoints to the biosimilar comparability exercise.

Novel model for basaloid triple-negative breast cancer: behavior in vivo and response to therapy

INTRODUCTION

The basaloid triple-negative breast cancer (B-TNBC) is one of the most aggressive, therapy-resistant, and metastatic tumors. Current models do not recapitulate the basaloid phenotype of TNBC, thus limiting the understanding of its biology and designing new treatments. We identified HCC1806 as a line expressing typical B-TNBC markers, engineered a subline with traceable reporters, and determined growth, drug sensitivity, recurrence, and vascular and metastatic patterns of orthotopic xenografts in immunodeficient mice.

METHODS

mRNA and protein analyses showed that HCC1806 expresses basal but not luminal or mesenchymal markers. HCC1806-RR subline stably expressing red fluorescent protein and Renilla luciferase was generated and characterized for sensitivity to chemodrugs, orthotopic growth, vascular properties, recurrence, metastasis, and responsiveness in vivo.

RESULTS

The HCC1806 cells were highly sensitive to paclitaxel, but cytotoxicity was accompanied by pro-survival vascular endothelial growth factor-A loop. In vivo, HCC1806-RR tumors display linear growth, induce peritumoral lymphatics, and spontaneously metastasize to lymph nodes (LNs) and lungs. Similarly to human B-TNBC, HCC1806-RR tumors were initially sensitive to taxane therapy but subsequently recur. Bevacizumab significantly suppressed recurrence by 50% and reduced the incidence of LN and pulmonary metastases by, respectively, 50% and 87%.

CONCLUSIONS

The HCC1806-RR is a new model that expresses bona fide markers of B-TNBC and traceable markers for quantifying metastases. Combination of bevacizumab with nab-paclitaxel significantly improved the outcome, suggesting that this approach can apply to human patients with B-TNBC. This model can be used for defining the metastatic mechanisms of B-TNBC and testing new therapies.

Matrix protein of vesicular stomatitis virus: a potent inhibitor of vascular endothelial growth factor and malignant ascites formation

Malignant ascites is common in various types of cancers and is difficult to manage. Vascular endothelial growth factor (VEGF) has a pivotal role in malignant ascites. The matrix protein of vesicular stomatitis virus (VSVMP) has been shown to inhibit host gene expression and induce the apoptosis of cancer cells. The present study was designed to determine whether VSVMP suppresses the formation of ascites in ascites-producing peritoneal carcinomatosis. BALB/c female mice, 6-8 weeks old, bearing peritoneal tumors of H22 or MethA cells received an intraperitoneal administration of 50 μg VSVMP/250 μg liposome complexes, 50 μg empty plasmid/250 μg liposome complexes or 0.9% NaCl solution, respectively, every 2 days for 3 weeks. Administration of VSVMP resulted in a significant inhibition in ascites formation, improvement in health condition and prolonged survival of the treated mice. Decreased peritoneum osmolarity and reduced tumor vascularity coincided with dramatic reductions in the VEGF level in ascites fluid and plasma. Examination of floating tumor cells collected from the peritoneal wash revealed an apparently increased number of apoptotic cells and profound downregulation of VEGF mRNA in the VSVMP-treated mice. Our data indicate for the first time that in BALB/c mice bearing H22 or MethA cell peritoneal tumors, VSVMP may inhibit VEGF production and suppress angiogenesis, consequently abolishing ascites formation.

Screening and identification of biomarkers in ascites related to intrinsic chemoresistance of serous epithelial ovarian cancers

Objective

The ability to predict responses to chemotherapy for serous epithelial ovarian cancer (EOC) would be valuable since intrinsically chemoresistant EOC patients (persistent or recurrent disease within 6 months) gain little benefit from standard chemotherapy. The aim of this study was to screen and identify distinctive biomarkers in ascites of serous EOC associated with intrinsic chemoresistance.

Methods

Protein samples from ascites of 12 chemosensitive and 7 intrinsically chemoresistant serous EOC patients were analyzed using two-dimensional fluorescence difference in gel electrophoresis (2-D DIGE) coupled with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/TOF MS). Furthermore, the identified proteins were validated by ELISA in ascites samples from 19 chemosensitive and 9 intrinsically chemoresistant EOC patients.

Results

The number of spots detected in all 2-D DIGE gels ranged from 1523–1711 using DeCyder software analysis. Thirty-four spots were differentially expressed based on the criteria of an average ratio of more than 1.5 and a student t-test P value <0.05. After MALDI-TOF/TOF MS analysis, 11 differentially expressed proteins, including 3 up-regulated and 8 down-regulated proteins, in ascites of chemoresistant tumors were successfully identified. Of the four selected proteins (ceruloplasmin, apoliprotein A-IV, transthyretin and haptoglobin) in ascites tested by ELISA, only ceruloplasmin was present at significantly different levels between the chemoresistant and chemosensitive ascites samples with average concentrations of 192.2 µg/ml and 157.5 µg/ml, respectively (P = 0.001).

Conclusion

The significantly up-regulated level of ceruloplasmin in the ascites fluid of intrinsic chemoresistant serous EOC patients suggests its potential as a prognostic biomarker for responses to chemotherapy. This finding prompts further investigation with a larger study in order to validate the clinical utility of ceruloplasmin.

Bevacizumab combination therapy: for the first-line treatment of advanced epithelial ovarian, fallopian tube or primary peritoneal cancer

Bevacizumab is a recombinant, humanized anti-vascular endothelial growth factor (VEGF) monoclonal antibody that neutralizes the biological activity of VEGF and inhibits tumour angiogenesis. In two pivotal, well designed, phase III, clinical trials (GOG-0218 and ICON7) in women with advanced epithelial ovarian, fallopian tube or primary peritoneal cancer, first-line treatment with bevacizumab in combination with standard chemotherapy (carboplatin plus paclitaxel) followed by maintenance treatment with bevacizumab alone significantly prolonged progression-free survival relative to standard chemotherapy. A subgroup analysis of ICON7 suggested that bevacizumab therapy may also be beneficial in patients at high risk of disease progression. In GOG-0218, health-related quality of life (HR-QOL) deteriorated temporarily (during the chemotherapy phase) and slightly, although statistically significantly, with bevacizumab in combination with standard chemotherapy followed by bevacizumab maintenance relative to standard chemotherapy plus placebo maintenance. In ICON7, HR-QOL did not differ to a clinically significant extent between patients receiving bevacizumab plus standard chemotherapy followed by bevacizumab maintenance and those receiving standard chemotherapy alone. Bevacizumab combination therapy had generally acceptable tolerability in these studies, with the nature of adverse events generally similar to that observed in previous clinical trials in patients with other solid tumours.

The enhanced antitumor effects of biodegradable cationic heparin-polyethyleneimine nanogels delivering HSulf-1 gene combined with cisplatin on ovarian cancer

HSulf-1 (heparan sulfate 6-O-endosulfatase 1), a commonly downregulated gene in the majority of ovarian cancer cell lines, has been identified to play an important role in regulating tumorigenesis. Our previous studies demonstrated that HSulf-1 could inhibit angiogenesis and tumorigenesis in vivo. The employment of polymeric nanoparticles to deliver functional gene holds much promise as an effective therapeutic strategy against ovarian cancer. To develop more effective therapy, in this study, we investigated the antitumor effect of heparin-polyethyleneimine (HPEI) nanogels delivering HSulf-1 combined with cisplatin (DDP) on ovarian cancer. Expression of HSulf-1 in vitro and in vivo was determined by reverse transcription polymerase chain reaction (RT-PCR) and western blot analysis. A SKOV3 intraperitoneal ovarian carcinomatosis model in nude mice was established to assess the antitumor efficacy. Mice were treated with NS, pEP/HPEI complexes, pHSulf-1/HPEI complexes, DDP or pHSulf-1/HPEI plus DDP, respectively. Intraperitoneal tumors were weighed. Antiangiogenic effect in vivo was evaluated by CD31 immunostaining and alginate-encapsulate tumor cell assay. Detection of the proliferative cells and apoptotic cells in tumor tissues were performed by Ki-67 staining and TUNEL assay. Stable expression of HSulf-1 was detected in the pHSulf-1/HPEI and pHSulf-1/HPEI plus DDP groups. The combination of pHSulf-1/HPEI complexes with DDP exhibited enhanced antitumor activity, compared with the monotherapy of HSulf-1 or DDP alone (P<0.01). the combination therapy exerted significant antitumor activity through enhanced antiangiogenesis, induction of apoptosis and suppression of cell proliferation. Collectively, these observations provide evidence that HPEI nanogels delivering HSulf-1 combined with DDP may have a promising application in the therapy of human ovarian cancer.

Cisplatin plus paclitaxel and maintenance of bevacizumab on tumour progression, dissemination, and survival of ovarian carcinoma xenograft models

Background:

Bevacizumab is being incorporated as first-line therapy with standard-of-care chemotherapy on epithelial ovarian carcinoma (EOC). We investigated bevacizumab combined with chemotherapy on tumour progression and mouse survival in EOC xenograft models.

Methods:

Bevacizumab was administered concomitantly with cisplatin plus paclitaxel (DDP+PTX), continued after induction (maintenance) or started after chemotherapy. The effect on tumour progression was monitored by bioluminescence imaging (BLI) (1A9-luc xenograft). Tumour dissemination into the peritoneal organs and ascites formation (HOC22 xenograft) was evaluated by histological analysis at the end of treatment (interim) and at euthanasia (survival). The effects on overall survival (OS) were investigated in both EOC models.

Results:

Bevacizumab with PTX+DDP delayed tumour progression in mice bearing EOC xenografts. OS was significantly extended, with complete responses, by bevacizumab continued after stopping chemotherapy in the HOC22 xenograft. Bevacizumab alone inhibited ascites formation, with only limited effect on tumour burden, but combined with PTX+DDP reduced ascites and metastases. Bevacizumab started after induction with PTX+DDP and maintained was equally effective on tumour progression and survival on 1A9-luc xenograft.

Conclusion:

Bevacizumab combined with chemotherapy not only affected tumour progression, but when administered as maintenance regimen significantly prolonged survival, reducing ascites, and tumour dissemination. We believe our findings are consistent with the clinical results and shed light on the potential effects of this kind of treatment on tumour progression.

Significance of vascular endothelial growth factor in growth and peritoneal dissemination of ovarian cancer

Vascular endothelial growth factor (VEGF) is a key regulator of angiogenesis which drives endothelial cell survival, proliferation, and migration while increasing vascular permeability. Playing an important role in the physiology of normal ovaries, VEGF has also been implicated in the pathogenesis of ovarian cancer. Essentially by promoting tumor angiogenesis and enhancing vascular permeability, VEGF contributes to the development of peritoneal carcinomatosis associated with malignant ascites formation, the characteristic feature of advanced ovarian cancer at diagnosis. In both experimental and clinical studies, VEGF levels have been inversely correlated with survival. Moreover, VEGF inhibition has been shown to inhibit tumor growth and ascites production and to suppress tumor invasion and metastasis. These findings have laid the basis for the clinical evaluation of agents targeting VEGF signaling pathway in patients with ovarian cancer. In this review, we will focus on VEGF involvement in the pathophysiology of ovarian cancer and its contribution to the disease progression and dissemination.

Molecular targeted therapy in ovarian cancer: what is on the horizon?

Over the past two decades, empirical optimization of cytotoxic chemotherapy combinations and surgical debulking procedures have improved outcomes and survival in epithelial ovarian cancer. Yet, this disease remains the fifth leading cause of cancer-related deaths in the US, as cure rates seem to have reached a plateau at approximately 20% with conventional chemotherapy. Novel high-throughput genomic and proteomic analyses have improved the molecular understanding of ovarian carcinogenesis, thereby providing a vast array of new potential drug targets with complex signalling interactions. In order to yield the most significant impact on disease outcome, it is necessary to carefully select, and subsequently target, the driving molecular pathway(s) within a tumour or tumour subtype, which are most likely to correspond to high-frequency mutations and genomic aberrations. The identification of biomarkers predictive of response to targeted therapy is essential to avoid poor responses to potentially useful drugs in unselected trial populations. With some promising, albeit early, phase III data on the angiogenesis inhibitor bevacizumab, exciting new opportunities lie ahead with the ultimate goal of personalizing therapies to individual tumour profiles.

Systemic administration of bevacizumab prolongs survival in an in vivo model of platinum pre-treated ovarian cancer

Ovarian cancer patients often suffer from malignant ascites and pleural effusion. Apart from worsening the outcome, this condition frequently impairs the quality of life in patients who are already distressed by ovarian cancer. This study investigated whether single intraperitoneal administration of the anti-VEGF antibody bevacizumab is capable of reducing the ascites-related body surface and prolonging survival. The study was performed in an orthotopic murine model of peritoneal disseminated platin-resistant ovarian cancer. Mice were treated with bevacizumab and/or paclitaxel or buffer (control). Reduction of body surface and increased survival rates were assessed as therapeutic success. Survival of mice in all treatment groups was significantly enhanced when compared to the non-treatment control group. The combination of paclitaxel plus bevacizumab significantly improved body surface as well as overall survival in comparison to a treatment with only one of the drugs. Treatment of malignant effusion with a single dose of bevacizumab as an intraperitoneal application, with or without cytostatic co-medication, may be a powerful alternative to systemic treatment.

Reducing endothelial NOS activation and interstitial fluid pressure with n-3 PUFA offset tumor chemoresistance

The aim of this study was to determine how n-3 polyunsaturated fatty acid (PUFAs) counteracted tumor chemoresistance by restoring a functional vascularization. Rats with chemically induced mammary tumors were divided into two nutritional groups: a control group and a group fed with an n-3 PUFA-enriched diet. Both groups were treated with docetaxel. Functional vascular parameters (ultrasounds, interstitial fluid pressure) were determined for both nutritional groups before (W(0)) and during docetaxel treatment [every 2 h up to 1 week (W(+1)) for interstitial fluid pressure, at W(+1) for Evans blue extravasation and at W(+2) and W(+6) for ultrasounds]. In vitro n-3 PUFA-induced changes in endothelial cell migration, permeability and phosphorylation of endothelial nitric oxide synthase were evaluated using human umbilical vein endothelial cells. Whereas docetaxel stabilized tumor growth in the rat control group, it induced a 50% tumor regression in the n-3 PUFA group. Ultrasounds parameters were consistently lower in the n-3 PUFA group at all time points measured, down to ∼50% at W(+6). A single dose of docetaxel in the n-3 PUFA group markedly reduced interstitial fluid pressure from 2 h after injection up to W(+1) when Evans blue extravasation was increased by 3-fold. A decreased activation of endothelial nitric oxide synthase in tumors of the n-3 PUFA group, and in human umbilical vein endothelial cell cultured with n-3 PUFA, points toward a PUFA-induced disruption of nitric oxide signaling pathway. This normalization of tumor vasculature functions under n-3 PUFA diet indicates that such a supplementation, by improving drug delivery in mammary tumors, could be a complementary clinical strategy to decrease anticancer drug resistance.

Bevacizumab plus microtubule targeting agents in heavily pre-treated ovarian cancer patients: a retrospective study

OBJECTIVES. As vascular endothelial growth factor (VEGF) is expressed in ovarian cancer, we assessed the efficacy and safety of bevacizumab (a monoclonal antibody targeting VEGF) plus microtubule targeting agents for heavily pre-treated ovarian carcinoma patients. METHODS. We retrospectively reviewed 43 patients with recurrent epithelial ovarian carcinoma. Combined treatment included bevacizumab with paclitaxel in 32 (74%), docetaxel in 10 (23%), and vinorelbine in one (2.3%) patients, respectively. RESULTS. The median number of combined treatment was six cycles (range 1-29). On RECIST criteria, the objective response rate (ORR) was 40% (16% CR and 24% PR). Clinical benefit (complete response [CR] plus partial response [PR] and stable disease [SD] lasting ≥ 3 months) was 74% (CI95%: 46.7-77%). Median duration of treatment and overall survival were 3.9 months (range 0.2-14.4 months) and 20.1 months (CI95%: 13.8-20.1) respectively. No toxic death was reported. Grade 3-4 toxicity occurred in 30% of patients. Gastrointestinal perforations and fistula occurred in 3 (7%) and 6 (14%) patients, respectively. CONCLUSION. Although being active in terms of ORR, bevacizumab plus microtubule targeting agents - mainly taxanes - leads to a high rate of gastro-intestinal perforations and fistula in heavily pre-treated ovarian carcinoma patients.

Utility of vascular endothelial growth factor inhibitors in the treatment of ovarian cancer: from concept to application

Despite recent advances in the management of ovarian cancer, it remains the most lethal gynecologic malignancy. Vascular endothelial growth factor (VEGF) has been shown to play a pivotal role in the progression of ovarian cancer leading to the eventual development of malignant ascites. On this basis, agents rendering VEGF ineffective by neutralizing VEGF (bevacizumab), blocking its receptors (aflibercept), or interfering with the postreceptor signaling pathways (sunitinib) provide us with the rational treatment options. These agents are generally used in combination with the standard chemotherapeutic drugs. Here, we discuss the basis of and the logic behind the use of these agents in the treatment of epithelial ovarian cancer, as well as their evaluation in different preclinical and clinical studies.

Vascular endothelial growth factor (VEGF), produced by feline infectious peritonitis (FIP) virus-infected monocytes and macrophages, induces vascular permeability and effusion in cats with FIP

Feline infectious peritonitis virus (FIPV) causes a fatal disease called FIP in Felidae. The effusion in body cavity is commonly associated with FIP. However, the exact mechanism of accumulation of effusion remains unclear. We investigated vascular endothelial growth factor (VEGF) to examine the relationship between VEGF levels and the amounts of effusion in cats with FIP. Furthermore, we examined VEGF production in FIPV-infected monocytes/macrophages, and we used feline vascular endothelial cells to examine vascular permeability induced by the culture supernatant of FIPV-infected macrophages. In cats with FIP, the production of effusion was related with increasing plasma VEGF levels. In FIPV-infected monocytes/macrophages, the production of VEGF was associated with proliferation of virus. Furthermore, the culture supernatant of FIPV-infected macrophages induced hyperpermeability of feline vascular endothelial cells. It was suggested that vascular permeability factors, including VEGF, produced by FIPV-infected monocytes/macrophages might increase the vascular permeability and the amounts of effusion in cats with FIP.

Differential effect of intraperitoneal albendazole and paclitaxel on ascites formation and expression of vascular endothelial growth factor in ovarian cancer cell-bearing athymic nude mice

OBJECTIVES

The purposes of our study were to evaluate the effect of intraperitoneal albendazole on tumor growth, ascites formation, and vascular endothelial growth factor (VEGF) mRNA expression, and to assess the synergistic effect of paclitaxel in OVCAR-3-bearing nude mice.

METHODS

In all, 4 groups of mice were injected intraperitoneally with weekly albendazole (450 mg/kg per week), paclitaxel (30 mg/kg per week), albendazole plus paclitaxel, or normal saline for 4 weeks.

RESULTS

Ascitic fluid accumulation (2.47, 2.65, 2.88, and 5.90 mL, respectively) and in ascitic VEGF levels were significantly reduced in the 3 treatment groups compared to the control group (170.83, 229.16, 267, and 1625 pg/mL, respectively). However, complete tumor suppression was more prominent in the paclitaxel group, and VEGF mRNA expression was more strongly inhibited in the albendazole group (P < .05). No synergistic effect of albendazole and paclitaxel was observed.

CONCLUSION

We demonstrated a differential effect of albendazole and paclitaxel in a xenograft model of ovarian carcinoma; albendazole suppressed ascites formation by inhibiting VEGF secretion, and paclitaxel exerted its effects by direct cytotoxicity.

TGF-beta blockade controls ascites by preventing abnormalization of lymphatic vessels in orthotopic human ovarian carcinoma models

PURPOSE

Ovarian cancer patients with malignant ascites have poor prognosis. The accumulation of ascites is caused by an imbalance between fluid extravasation from the blood vessels and reabsorption by lymphatic vessels. Whereas, the role of TGF-β in tumor progression has been well studied, the role of TGF-β in lymphatic vessel function is far from understood. Here, we sought to dissect the role of TGF-β blockade in the formation of ascites.

EXPERIMENTAL DESIGN

We used soluble TGF-β Receptor II (sTβRII) to block TGF-β signaling in two orthotopic human ovarian carcinoma models: SKOV3ip1 and Hey-A8. We measured tumor proliferation, apoptosis, lymphangiogenesis, and angiogenesis by immunohistochemical staining, and examined diaphragm lymphatic vessel network by intraperitoneal injection of a fluorescent dye. Diaphragm lymphatic vessel function was assessed by tracking fluorescent beads in the diaphragm and measuring their drainage rate.

RESULTS

TGF-β blockade impaired tumor growth in both models, accompanied by a decreased tumor cell proliferation and angiogenesis. More strikingly, TGF-β blockade almost completely abolished ascites formation. TGF-β blockade significantly inhibited the expression of VEGF, which is the major contributor to ascites formation. At the same time, TGF-β blockade prevent 'abnormalization' of diaphragm lymphatic vessels and improved ascites drainage.

CONCLUSIONS

TGF-β blockade decreased ascites by both inhibiting ascites formation and improving ascites drainage. Based on our finding, it is reasonable to consider the use of TGF-β blockade as a palliative treatment for symptomatic ascites.

Overview of anti-angiogenic agents in development for ovarian cancer

OBJECTIVE

To review the rationale for targeting the vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), and fibroblast growth factor (FGF) pathways for anti-angiogenic therapy in patients with ovarian cancer and to summarize the currently available data with agents that block these pathways.

METHODS

Relevant papers and studies were identified by searches conducted on Medline using the terms angiogenesis, ovarian cancer, VEGF, PDGF, FGF, receptor, kinase, and inhibitor alone or in combination as well as by searches by drug name and by review of abstracts presented at recent oncology meetings.

RESULTS

The VEGF pathway is considered to be the key driver of angiogenesis, but the PDGF and FGF pathways also play important roles and may contribute to resistance to VEGF-specific blockade. Each pathway may also promote tumorigenesis; tumor cell overexpression of these growth factors and their receptors have been detected in ovarian tumor specimens, suggesting that autocrine loops may lead to tumor growth and progression. Selective inhibitors of the VEGF pathway (e.g., bevacizumab and VEGF Trap) as well as VEGF/PDGF pathway inhibitors (e.g., sorafenib and sunitinib) and VEGF/PDGF/FGF pathway inhibitors (e.g., cediranib, pazopanib, and BIBF 1120) have shown single-agent activity in women with ovarian cancer in phase II trials. Response rates of up to 21% have been reported with several agents in patients with recurrent ovarian cancer. Phase III trials with many anti-angiogenic agents in the treatment of ovarian cancer are currently ongoing.

CONCLUSIONS

Anti-angiogenic agents may provide an improvement in the treatment of patients with recurrent ovarian cancer and may be useful when incorporated into first-line platinum/taxane therapy. It remains to be determined whether multitargeted agents will offer greater clinical benefit than specific VEGF pathway inhibitors.

Vascular endothelial growth factor as an anti-angiogenic target for cancer therapy

New blood vessel formation (angiogenesis) is fundamental to tumor growth, invasion, and metastatic dissemination. The vascular endothelial growth factor (VEGF) signaling pathway plays pivotal roles in regulating tumor angiogenesis. VEGF as a therapeutic target has been validated in various types of human cancers. Different agents including antibodies, aptamers, peptides, and small molecules have been extensively investigated to block VEGF and its pro-angiogenic functions. Some of these agents have been approved by FDA and some are currently in clinical trials. Combination therapies are also being pursued for better tumor control. By providing comprehensive real-time information, molecular imaging of VEGF pathway may accelerate the drug development process. Moreover, the imaging will be of great help for patient stratification and therapeutic effect monitoring, which will promote effective personalized molecular cancer therapy. This review summarizes the current status of tumor therapeutic agents targeting to VEGF and the applications of VEGF related molecular imaging.

Epithelial ovarian cancer: focus on targeted therapy

Ovarian cancer remains the leading cause of gynecological cancer-related mortality in the Western World despite the advances in surgical techniques and chemotherapy regimens over the past three decades. Although response rates and complete responses in advanced disease are >80% and 40-60%, respectively, after first-line treatment with carboplatin and paclitaxel, most of the patients will eventually relapse with a median progression-free survival of 18 months. Currently, research efforts have improved our understanding on the molecular biology of ovarian cancer and novel targeted treatment strategies are likely to contribute to the management of the disease and give the chance to an individualized therapeutic approach.

VEGF -460T → C polymorphism and its association with VEGF expression and outcome to FOLFOX-4 treatment in patients with colorectal carcinoma

The -460T → C polymorphism of vascular endothelial growth factor (VEGF) gene significantly increases its promoter activity. A pilot study was conducted to assess the influence of this polymorphism on clinicopathological features of patients with colorectal carcinoma. In total, 228 patients were enrolled, including 100 with stage II/III colorectal carcinoma receiving curative surgery and 128 with metastatic disease. An excellent correlation in VEGF -460 genotypes based on white blood cells and tumor tissues existed, but there was no between-group difference in patients with or without colorectal carcinoma. A marked increase in intratumor and circulating VEGF levels were observed in patients with the T/C or C/C genotypes (P < 0.01), which was associated with increased extent of invasion, nodal involvement, poor histological differentiation, subsequent metastasis and shorter survival in stage II/III patients treated with curative surgery (P < 0.01). For patients with metastatic disease, this polymorphism was associated with a lower response rate to FOLFOX-4 (P = 0.03) and shorter survival (P < 0.001). By multivariate analysis, this polymorphism was identified as an independent prognostic factor (P = 0.01). These data suggest that -460T → C polymorphism of VEGF gene, by increasing VEGF expression and subsequent angiogenesis, could be a key determinant for increased tumor recurrence and a poor prognosis of patients with colorectal carcinoma. However, this study is exploratory and is not adjusted for multiple comparisons, requiring independent replication.

Advances in combination of antiangiogenic agents targeting VEGF-binding and conventional chemotherapy and radiation for cancer treatment

Despite great efforts and resources being devoted to treatment, the incidence and mortality of numerous cancers have not decreased in recent decades. This is a result of the resistance of cancer cells to chemotherapeutic agents and radio-therapy. The development of antiangiogenic agents that target vascular endothelial growth factor (VEGF) provides a new option for treatment of cancer. Major advances have been achieved with cancer therapy based on antiangiogenic VEGF-targeted agents in the past few years, and some of the recently approved therapies are now being used in daily clinical practice. A further challenge is finding a more efficacious combination of antiangiogenic VEGF-targeted therapies and conventional radio- and chemotherapies. This review outlines the current preclinical and clinical cancer treatments using optimized combinations of antiangiogenic VEGF-targeted agents and conventional radiochemotherapy and highlights that better scheduling for the combination of radiochemotherapy and antiangiogenic VEGF-targeted agents should be developed to achieve better treatment outcomes.