Molecular mechanisms of tumor angiogenesis and tumor progression

The implications of the TNFα-TNFR2 immune checkpoint signaling pathway in cancer treatment: From immunoregulation to angiogenesis

Despite the tremendous advances that have been made in biomedical research, cancer remains one of the leading causes of death worldwide. Several therapeutic approaches have been suggested and applied to treat cancer with impressive results. Immunotherapy based on targeting immune checkpoint signaling pathways proved to be one of the most efficient. In this review article, we will focus on the recently discovered TNFα-TNFR2 signaling pathway, which controls the immunological and pro-angiogenic properties of many immunoregulatory and pro-angiogenic cells such as endothelial progenitor cells (EPCs), mesenchymal stem cells (MSCs), and regulatory T cells (Tregs). Due to their biological properties, these cells can play a major role in cancer progression and metastasis. Therefore, we will discuss the advantages and disadvantages of an anti-TNFR2 treatment that could carry two faces under one hood. It interrupts the immunosuppressive and pro-angiogenic behaviors of the above-mentioned cells and interferes with tumor growth and survival.

When DNA Mutations Interplay with Cellular Proliferation: A Narrative History of Theories of Carcinogenesis

While cancer is one of the most documented diseases, how normal cells become cancerous is still debated. To address this question, in the first part of this review, we investigated the long succession of theories of carcinogenesis since antiquity. Initiated by Hippocrates, Aristotle, and Galen, the humoral theory interpreted cancer as an excess of acid, the black bile. The discovery of the circulation of blood by Harvey in 1628 destroyed the basis of the humoral theory but revived the spontaneous generation hypothesis which was also promoted by Aristotle. In 1859, the theory of microbes promoted by Pasteur demonstrated the irrelevance of this last theory and contributed to the emergence of the germ cancer theory, opposed to the cellular theory of cancer, in which cancer was supposed to be caused by microbes or transformed cells, respectively. These theories were progressively refined by the notions of initiation, promotion, and progression thanks to advances in mutagenesis and cellular proliferation. In the second part of this review, recent discoveries and paradigms in carcinogenesis, notably the role of the protein ATM, a major actor of the stress response involved in both mutagenesis and cellular proliferation, were discussed to better understand the current state of the art of carcinogenesis.

Homeobox D9 drives the malignant phenotypes and enhances the Programmed death ligand-1 expression in non-small cell lung cancer cells via binding to Angiopoietin-2 promoter

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related death worldwide. Homeobox D9 (HOXD9), a member of the HOX family of transcription factors, plays a driver role in development of multiple cancers. Angiopoietin-2 (ANGPT2) is reportedly to facilitate angiogenesis, growth and metastasis in various cancers, including lung cancer. In addition, blocking ANGPT2 can effectively improve cancer immunotherapy via downregulation of Programmed death ligand-1 (PD-L1). The purpose of this study was to elucidate the role of HOXD9 in NSCLC and whether ANGPT2 is required for HOXD9-mediated malignant behaviors of NSCLC cells. By performing a series of in vitro functional experiments, we found that knockdown of HOXD9 induced proliferative inhibition, cell cycle G1 arrest, apoptosis, migratory suppression and invasive repression of NSCLC cells. Reduced PD-L1 expression in NSCLC cells was observed after HOXD9 silencing. Besides, HOXD9 deletion decreased the expression of ANGPT2 in NSCLC cells. In line with this, HOXD9 overexpression led to opposite alteration in NSCLC cells. Mechanistically, ANGPT2 was transcriptionally activated by HOXD9. Forced expression of ANGPT2 significantly regulated HOXD9-mediated malignant phenotypes, and enhanced PD-L1 expression of NSCLC cells. Our results expressing HOXD9 may function as an oncogene in NSCLC via trans-activation of ANGPT2.

Diagnostic and Therapeutic Values of Angiogenic Factors in Endometrial Cancer

Endometrial cancer (EC) is the most frequent gynecological malignancy in developed countries and requires a relatively invasive diagnostic evaluation and operative therapy as the primary therapeutic approach. Angiogenesis is one of the main processes needed for cancer growth and spread. The production of angiogenic factors (AFs) appears early in the process of carcinogenesis. The detection of AFs in plasma and tissue and a better understanding of the angiogenic properties of EC may contribute not only to earlier but also more specific diagnosis and consequently tailored and individual therapeutic approaches. AFs and their receptors also have high potential as binding sites for targeted cancer therapy. In this review, we discuss angiogenesis in EC and the characteristics of the AFs that most contribute to angiogenesis in EC. We also highlight therapeutic strategies that target angiogenesis as potential EC therapy.

Emerging Role of Autophagy in the Development and Progression of Oral Squamous Cell Carcinoma

Autophagy is a cellular catabolic process, which is characterized by degradation of damaged proteins and organelles needed to supply the cell with essential nutrients. At basal levels, autophagy is important to maintain cellular homeostasis and development. It is also a stress responsive process that allows the cells to survive when subjected to stressful conditions such as nutrient deprivation. Autophagy has been implicated in many pathologies including cancer. It is well established that autophagy plays a dual role in different cancer types. There is emerging role of autophagy in oral squamous cell carcinoma (OSCC) development and progression. This review will focus on the role played by autophagy in relation to different aspects of cancer progression and discuss recent studies exploring the role of autophagy in OSCC. It will further discuss potential therapeutic approaches to target autophagy in OSCC.

Optimization of BCG Therapy Targeting Neutrophil Extracellular Traps, Autophagy, and miRNAs in Bladder Cancer: Implications for Personalized Medicine

Bladder cancer (BC) is the ninth most common cancer and the thirteenth most common cause of mortality worldwide. Bacillus Calmette Guerin (BCG) instillation is a common treatment option for BC. BCG therapy is associated with the less adversary effects, compared to chemotherapy, radiotherapy, and other conventional treatments. BCG could inhibit the progression and recurrence of BC by triggering apoptosis pathways, arrest cell cycle, autophagy, and neutrophil extracellular traps (NETs) formation. However, BCG therapy is not efficient for metastatic cancer. NETs and autophagy were induced by BCG and help to suppress the growth of tumor cells especially in the primary stages of BC. Activated neutrophils can stimulate autophagy pathway and release NETs in the presence of microbial pathogenesis, inflammatory agents, and tumor cells. Autophagy can also regulate NETs formation and induce production of reactive oxygen species (ROS) and NETs. Moreover, miRNAs are important regulator of gene expression. These small non-coding RNAs are also considered as an essential factor to control the levels of tumor development. However, the interaction between BCG and miRNAs has not been well-understood yet. Therefore, the present study discusses the roles of miRNAs in regulations of autophagy and NETs formation in BCG therapy in the treatment of BC. The roles of autophagy and NETs formation in BC treatment and efficiency of BCG are also discussed.

Potential Regulatory Roles of GRK2 in Endothelial Cell Activity and Pathological Angiogenesis

G protein-coupled receptor (GPCR) kinase 2 (GRK2) is an integrative node in many signaling network cascades. Emerging evidence indicates that GRK2 can interact with a large number of GPCRs and non-GPCR substrates in both kinase-dependent and -independent modes. Some of these pathways are associated with endothelial cell (EC) activity. The active state of ECs is a pivotal factor in angiogenesis. The occurrence and development of some inflammation-related diseases are accompanied by pathological angiogenesis, but there remains a lack of effective targeted treatments. Alterations in the expression and/or localization of GRK2 have been identified in several types of diseases and have been demonstrated to regulate the angiogenesis process in these diseases. GRK2 as a target may be a promising candidate for anti-angiogenesis therapy.

Luminescent Analysis of Blood Serum for Diagnostics of Pathological and Pre-Pathological States of Cancer Patients

This study is devoted to the development of a methodological approach to mathematical analysis and data interpretation of blood serum phosphorescence intensity in cancer patients for determining the pathological states and differential diagnostics of oncological process stages. The purpose of the study is blood serum phosphorescence research in patients with colorectal cancer (CRC) and stomach adenocarcinoma (SAC) and determination of the ultraweak luminescence role for diagnostics of the disease, determining its stages, control of pathogenetic therapy efficiency and forecast of recovery. The values of phosphorescence intensity of blood serum films in patients with CRC and SAC are significantly higher than the corresponding values for the control group. Contrary to the absolute intensity, the relative intensity increase compared to the control group is much more informative for oncoprocess diagnostics, since it exhibits three times increase even at the first stage of tumoral process. Serum phosphorescence intensity continues to increase with progressing of the disease. As the result of our study, the relative intensity increase compared to the first stage can be recommended as an informative indicator for differential diagnostics of oncological process stages. As a conclusion, determination of blood serum phosphorescence intensity can be considered as a sensitive and specific diagnostic method in oncology. With a correct methodological approach to data processing and interpretation, this method can be used in clinical practice for determining the oncopathological states, differential diagnostics of oncoprocess stages and diagnostics of precancer changes, which precede tumoral process development.

Effect of malignant-associated pleural effusion on endothelial viability, motility and angiogenesis in lung cancer

Malignant pleural effusion (MPE) and paramalignant pleural effusion (PPE) remain debilitating complications in lung cancer patients with poor prognosis and limited treatment options. The role of vascular endothelial cells has not been explored in the pleural environment of lung cancer. By integrating MPE and PPE as malignant-associated pleural fluid (MAPF), the current study aimed to evaluate the effect of MAPF on cell proliferation, migration and angiogenesis of HUVEC. First, increased capillaries were identified in the subpleural layer of lung adenocarcinoma. Compatible with pathological observations, the ubiquitous elevation of HUVEC survival was identified in MAPF culture regardless of the underlying cancer type, the driver gene mutation, prior treatments and evidence of malignant cells in pleural fluid. Moreover, MAPF enhanced HUVEC motility with the formation of lamellipodia and filopodia and focal adhesion complex. Tube formation assay revealed angiogenic behavior with the observation of sheet-like structures. HUVEC cultured with MAPF resulted in a significant increase in MAPK phosphorylation. Accompanied with VEGFR2 upregulation in MAPF culture, there was increased expressions of p-STAT3, HIF-1α and Nf-kB. VEGF/VEGFR2 blockade regressed endothelial migration and angiogenesis but not cell proliferation. Our data indicate the angiogenic activities of MAPF on vascular endothelial cells that revealed increased pleural capillaries in lung cancer. Targeting the VEGF/VEGFR2 pathway might modulate the angiogenic propensity of MAPF in future clinical investigations.

New Technologies in Clinical Trials in Corneal Diseases and Limbal Stem Cell Deficiency: Review from the European Vision Institute Special Interest Focus Group Meeting

To discuss and evaluate new technologies for a better diagnosis of corneal diseases and limbal stem cell deficiency, the outcomes of a consensus process within the European Vision Institute (and of a workshop at the University of Cologne) are outlined. Various technologies are presented and analyzed for their potential clinical use also in defining new end points in clinical trials. The disease areas which are discussed comprise dry eye and ocular surface inflammation, imaging, and corneal neovascularization and corneal grafting/stem cell and cell transplantation. The unmet needs in the abovementioned disease areas are discussed, and realistically achievable new technologies for better diagnosis and use in clinical trials are outlined. To sum up, it can be said that there are several new technologies that can improve current diagnostics in the field of ophthalmology in the near future and will have impact on clinical trial end point design.

α7 nicotinic acetylcholine receptors in lung cancer

Lung cancer has one of the highest mortality rates among malignancies globally, and smoking has been documented as the main cause of lung cancer. Nicotinic acetylcholine receptors (nAChRs) were initially identified as notable regulators of the nervous system. In addition to their function in the brain, accumulating evidence indicates that nAChRs perform a host of diverse functions in almost all non-neuronal mammalian cells. The homomeric α7nAChR, a subtype of nAChRs, is responsible for the proliferative, pro-angiogenic and pro-metastatic effects of nicotine in lung cancer. Provided the association of cigarette smoking with several disease types such as cardiovascular disease, the α7nAChR-mediated signaling pathway has been implicated in the pathophysiology of lung cancer. Currently, strategies that target the α7nAChR including α7nAChR antagonists are considered to be potentially useful anticancer drugs for therapeutic purposes. Thus, the present review assesses current understanding of the function and underlying molecular mechanisms of α7nAChR in lung cancer and evaluates how targeting α7nAChR may result in novel therapeutic methods.

Effect of the monoclonal antibody TRC105 in combination with Sunitinib on renal tumor derived endothelial cells

Anti-angiogenic therapy is an important strategy to limit growth, development and expansion of solid tumors. However, resistance to VEGF-targeting agents may develop, due to activation of alternative pro-angiogenic pathways, indicating the need of multiple target strategy. Here we obtained tumor endothelial cells (TEC) either from total renal carcinomas or from renal cancer stem cells (CSC-TEC) and we tested the effect of a CD105 targeting monoclonal antibody, TRC105, alone or in association with anti-VEGF drugs. We demonstrated that TRC105 impaired the ability of TEC and CSC-TEC to organize in tubular structures, whereas it did not limit proliferation or survival. The combination of TRC105 with different anti-angiogenic drugs showed a synergistic effect of TRC105 only in combination with the tyrosine kinase inhibitor Sunitinib. In particular, TRC105 plus Sunitinib reduced tubulogenesis, proliferation and survival of CSC-TEC and tumor-derived TEC in a similar manner. At a molecular level, we showed that the combination of TRC105 and Sunitinib induced the phosphorylation of Smad 2/3 to promote endothelial cell death. Moreover, TRC105 enhanced the inhibitory effect of Sunitinib on VEGF signaling and reduced VEGFR2-Akt-Creb activation, suggesting a molecular cooperation between the two drugs. Our results highlight that the combined inhibition of VEGF and TGF-β pathway may have a potential use in renal cell carcinoma therapy.

Roles of circulating endothelial progenitor cells and endothelial cells in gastric carcinoma

The present study aimed to investigate the role of endothelial progenitor cells (EPCs) and endothelial cells (ECs) in the peripheral blood of patients with gastric cancer (GC), and to investigate vascular endothelial growth factor (VEGF) expression and microvessel density (MVD) in GC tissues. First, 6 ml peripheral blood with added anticoagulant was collected from each of the 42 patients with GC, followed by determination of the number of EPCs and ECs by flow cytometry using the surface markers cluster of differentiation (CD)34^brightCD133⁺CD31⁺CD45^dim and CD34^dimCD133⁻CD31^brightCD45⁻, respectively. VEGF expression in patients with GC was detected by the streptomycin avidin-peroxidase immunohistochemical method, and MVD was calculated using the marker CD34. EPC and EC levels were positively associated with VEGF expression level, as well as with MVD. VEGF expression was positive in 66.67% GC cases, and its level was significantly associated with tumor-node-metastasis (TNM) stage, invasion depth and lymph-node metastasis (P<0.05). VEGF expression level was also positively associated with MVD. MVD in GC was significantly larger than that in normal tissue (P<0.01), and it was significantly associated with TNM stage (P<0.05), invasion depth (P<0.01) and lymph-node metastasis (P<0.01). EPCs in the peripheral blood have an important role in GC development, and may be a promising indicator of GC diagnosis and prognosis.

Dual role of autophagy in hallmarks of cancer

Evolutionarily conserved across eukaryotic cells, macroautophagy (herein autophagy) is an intracellular catabolic degradative process targeting damaged and superfluous cellular proteins, organelles, and other cytoplasmic components. Mechanistically, it involves formation of double-membrane vesicles called autophagosomes that capture cytosolic cargo and deliver it to lysosomes, wherein the breakdown products are eventually recycled back to the cytoplasm. Dysregulation of autophagy often results in various disease manifestations, including neurodegeneration, microbial infections, and cancer. In the case of cancer, extensive attention has been devoted to understanding the paradoxical roles of autophagy in tumor suppression and tumor promotion. In this review, while we summarize how this self-eating process is implicated at various stages of tumorigenesis, most importantly, we address the link between autophagy and hallmarks of cancer. This would eventually provide a better understanding of tumor dependence on autophagy. We also discuss how therapeutics targeting autophagy can counter various transformations involved in tumorigenesis. Finally, this review will provide a novel insight into the mutational landscapes of autophagy-related genes in several human cancers, using genetic information collected from an array of cancers.

The paradox of Th17 cell functions in tumor immunity

Immune system acts as a host defensive mechanism protecting against attacking pathogens and transformed cells, including cancer cells. Th17 cells are a specific subset of T helper lymphocytes determined by high secretion of IL-17 and other inflammatory cytokines. Th17 cells increase tumor progression by activating angiogenesis and immunosuppressive activities. They can also mediate antitumor immune responses through recruiting immune cells into tumors, stimulating effector CD8+ T cells, or surprisingly by altering toward Th1 phenotype and producing IFN-γ, so Th17 cells are supposed as a double-edged sword in cancer. A comprehensive approach to indicating the activity of Th17 cells in tumor progression could help in the planning of new therapeutic approaches specially targeting Th17 cells in cancer.

A prodrug of green tea polyphenol (-)-epigallocatechin-3-gallate (Pro-EGCG) serves as a novel angiogenesis inhibitor in endometrial cancer

Anti-angiogenesis effect of a prodrug of green tea polyphenol (-)-epigallocatechin-3-gallate (Pro-EGCG) in malignant tumors is not well studied. Here, we investigated how the treatment with Pro-EGCG inhibited tumor angiogenesis in endometrial cancer. Tumor xenografts of human endometrial cancer were established and subjected to microarray analysis after Pro-EGCG treatment. First, we showed Pro-EGCG inhibited tumor angiogenesis in xenograft models through down-regulation of vascular endothelial growth factor A (VEGFA) and hypoxia inducible factor 1 alpha (HIF1α) in tumor cells and chemokine (C-X-C motif) ligand 12 (CXCL12) in host stroma by immunohistochemical staining. Next, we investigated how HIF1α/VEGFA was down-regulated and how the reduction of CXCL12 inhibited tumor angiogenesis. We found that VEGFA secretion from endometrial cancer cells was decreased by Pro-EGCG treatment through inhibiting PI3K/AKT/mTOR/HIF1α pathway. Furthermore, the down-regulation of CXCL12 in stromal cells by Pro-EGCG treatment restricted migration and differentiation of macrophages thereby inhibited infiltration of VEGFA-expressing tumor-associated macrophages (TAMs). Taken together, we demonstrated that treatment with Pro-EGCG not only decreases cancer cell-secreted VEGFA but also inhibits TAM-secreted VEGFA in endometrial cancer. These findings demonstrate that Pro-EGCG is a novel angiogenesis inhibitor for endometrial cancer.

Atherosclerosis and Cancer; A Resemblance with Far-reaching Implications

Atherosclerosis and cancer are chronic diseases considered two of the main causes of death all over the world. Taking into account that both diseases are multifactorial, they share not only several important molecular pathways but also many ethiological and mechanistical processes from the very early stages of development up to the advanced forms in both pathologies. Factors involved in their progression comprise genetic alterations, inflammatory processes, uncontrolled cell proliferation and oxidative stress, as the most important ones. The fact that external effectors such as an infective process or a chemical insult have been proposed to initiate the transformation of cells in the artery wall and the process of atherogenesis, emphasizes many similarities with the progression of the neoplastic process in cancer. Deregulation of cell proliferation and therefore cell cycle progression, changes in the synthesis of important transcription factors as well as adhesion molecules, an alteration in the control of angiogenesis and the molecular similarities that follow chronic inflammation, are just a few of the processes that become part of the phenomena that closely correlates atherosclerosis and cancer. The aim of the present study is therefore, to provide new evidence as well as to discuss new approaches that might promote the identification of closer molecular ties between these two pathologies that would permit the recognition of atherosclerosis as a pathological process with a very close resemblance to the way a neoplastic process develops, that might eventually lead to novel ways of treatment.

Targeting of Tumor Neovasculature with GrB/VEGF121, a Novel Cytotoxic Fusion Protein

Angiogenesis is a critical process in numerous diseases, and intervention in neovascularization has therapeutic value in several disease settings, including ocular diseases, arthritis, and in tumor progression and metastatic spread. Various vascular targeting agents have been developed, including those that inhibit growth factor receptor tyrosine kinases, blocking antibodies that interfere with receptor signal transduction, and strategies that trap growth factor ligands. Limited anti-tumor efficacy studies have suggested that the targeted delivery of the human pro-apoptotic molecule Granzyme B to tumor cells has significant potential for cancer treatment. Here, we review biological vascular targeting agents, and describe a unique vascular targeting agent composed of Granzyme B and the VEGF receptor ligand VEGF₁₂₁. The fusion protein GrB/VEGF₁₂₁ demonstrates cytotoxicity at nanomolar or sub-nanomolar levels, excellent pharmacokinetic and efficacy profiles, and has significant therapeutic potential targeting tumor vasculature.

Bevacizumab significantly increases the risks of hypertension and proteinuria in cancer patients: A systematic review and comprehensive meta-analysis

Published data regarding the overall risks and incidence of hypertension and proteinuria associated with bevacizumab were still unclear. To quantify the precise risks and incidence, we performed this comprehensive meta-analysis of 72 published clinical trials including 21902 cases and 20608 controls. The overall incidence, risk ratios (RRs), and 95% confidence intervals (95% CIs) were calculated using a fixed or random-effect model based on the heterogeneity. The incidence of all-grade and high-grade hypertension were 25.3% (95% CI: 21.5%−29.5%) and 8.2% (95% CI: 7%−9.8%) for patients treated with bevacizumab. And the incidence of all-grade and high-grade proteinuria were 18% (95% CI: 11.7%−26.6%) and 2.4% (95% CI: 1.8%−3.2%), respectively. Compared with controls, bevacizumab significantly increased the risks of all-grade (RR: 3.595, 95% CI: 2.952−4.378) and high-grade hypertension (RR: 5.173, 95% CI: 4.188−6.390). Obviously increased risks of all-grade (RR: 3.369, 95% CI: 2.492−4.556) and high-grade proteinuria (RR: 5.494, 95% CI: 3.991−7.564) were also observed. In the subgroup analysis, the risks of hypertension and proteinuria may significantly vary with bevacizumab dosage, cancer types and concomitant drugs. Whereas, no obvious difference were discovered when stratified based on phase of trials, age of patients, treatment line and duration. So, close monitor and effective management were highly recommended for the safe use of bevacizumab.

68Ga-Chelation and comparative evaluation of N,N'-bis-[2-hydroxy-5-(carboxyethyl)benzyl]ethylenediamine-N,N'-diacetic acid (HBED-CC) conjugated NGR and RGD peptides as tumor targeted molecular imaging probes

Peptides containing RGD and NGR motifs display high affinity towards tumor vasculature molecular markers, integrin α_vβ₃ and CD13 receptors, respectively. In the present study, RGD and NGR peptides were conjugated with the novel acyclic chelator N,N'-bis-[2-hydroxy-5-(carboxyethyl)benzyl]ethylenediamine-N,N'-diacetic acid (HBED-CC) for radiolabeling with ⁶⁸Ga. The radiotracers [⁶⁸Ga-HBED-CC-c(NGR)] and [⁶⁸Ga-HBED-CC-c(RGD)] were quite hydrophilic with respective log P values being -2.8 ± 0.14 and -2.1 ± 0.17. ⁶⁸Ga-HBED-CC-c(RGD) displayed a significantly higher (p < 0.05) uptake in murine melanoma B16F10 tumors as compared to ⁶⁸Ga-HBED-CC-c(NGR) indicating its higher specificity towards integrin α_vβ₃-positive tumors. The two radiotracers showed similar uptake in CD13-positive human fibrosarcoma HT-1080 tumor xenografts (∼1.5 ± 0.2% ID g^-1). The tumor uptake of the two radiotracers was significantly reduced (p < 0.05) in both animal models during blocking studies. The tumor-to-blood ratio was observed to be ∼2-2.5 for the two radiotracers, whereas the tumor-to-muscle ratio was significantly higher (p < 0.005) for ⁶⁸Ga-HBED-CC-c(RGD) in the two animal models. The two radiotracers ⁶⁸Ga-HBED-CC-c(NGR) and ⁶⁸Ga-HBED-CC-c(RGD) exhibited renal excretion with rapid clearance from blood and other non-target organs. Thus, ⁶⁸Ga-chelated HBED-CC conjugated NGR and RGD peptides expressed features conducive towards development as tumor targeted molecular imaging probes. This study further opens avenues for the successful conjugation of different peptides with the acyclic chelator HBED-CC and expansion of ⁶⁸Ga-based radiopharmaceuticals.

The Role of CC-Chemokines in the Regulation of Angiogenesis

Angiogenesis, the formation of new blood vessels, is critical for survival and in the regenerative response to tissue injury or ischemia. However, in diseases such as cancer and atherosclerosis, inflammation can cause unregulated angiogenesis leading to excessive neovascularization, which exacerbates disease. Current anti-angiogenic therapies cause complete inhibition of both inflammatory and ischemia driven angiogenesis causing a range of side effects in patients. Specific inhibition of inflammation-driven angiogenesis would therefore be immensely valuable. Increasing evidence suggests that the CC-chemokine class promotes inflammation-driven angiogenesis, whilst there is little evidence for a role in ischemia-mediated angiogenesis. The differential regulation of angiogenesis by CC-chemokines suggests it may provide an alternate strategy to treat angiogenesis associated pathological diseases. The focus of this review is to highlight the significant role of the CC-chemokine class in inflammation, versus ischemia driven angiogenesis, and to discuss the related pathologies including atherosclerosis, cancer, and rheumatoid arthritis. We examine the pros and cons of anti-angiogenic therapies currently in clinical trials. We also reveal novel therapeutic strategies that cause broad-spectrum inhibition of the CC-chemokine class that may have future potential for the specific inhibition of inflammatory angiogenesis.

Role of metabolic modulator Bet-CA in altering mitochondrial hyperpolarization to suppress cancer associated angiogenesis and metastasis

Solid tumors characteristically reflect a metabolic switching from glucose oxidation to glycolysis that plays a fundamental role in angiogenesis and metastasis to facilitate aggressive tumor outcomes. Hyperpolarized mitochondrial membrane potential is a manifestation of malignant cells that compromise the intrinsic pathways of apoptosis and confer a suitable niche to promote the cancer associated hallmark traits. We have previously reported that co-drug Bet-CA selectively targets cancer cells by inducing metabolic catastrophe without a manifest in toxicity. Here we report that the same molecule at a relatively lower concentration deregulates the cardinal phenotypes associated with angiogenesis and metastasis. In mice syngeneic 4T1 breast cancer model, Bet-CA exhibited effective abrogation of angiogenesis and concomitantly obliterated lung metastasis consistent with altered mitochondrial bioenergetics. Furthermore, Bet-CA significantly lowered vascular endothelial growth factor (VEGF) levels and obviated matrix metalloproteases (MMP-2/9) production directly to the criterion where abrogation of autocrine VEGF/VEGFR2 signalling loop was documented. In vitro studies anticipatedly documented the role of Bet-CA in inhibiting actin remodeling, lamellipodia formation and cell membrane ruffling to constitutively suppress cell motility and invasion. Results comprehensively postulate that Bet-CA, a mitochondria targeting metabolic modulator may serve as an excellent candidate for combating angiogenesis and metastasis.

Interleukin-17 acts as double-edged sword in anti-tumor immunity and tumorigenesis

Interleukin-17 (IL-17), a proinflammatory cytokine, mainly produced by Th17 cells, participates in both innate and adaptive immune responses and is involved in various diseases, including infectious diseases, autoimmune disorders and cancer. Emerging evidence indicates that IL-17 not only has an oncogenic role in tumorigenesis by regulating tumor angiogenesis and enhancing tumor immune evasion but also exerts anti-tumor functions by enhancing natural killer (NK) cells and cytotoxic T lymphocytes (CTLs) activation and through the recruitment of neutrophils, NK cells and CD4⁺ and CD8⁺ T cells to tumor tissue. In this review, we provide an overview on the basic biology of IL-17 and recent findings regarding its enigmatic double-edged features in tumorigenesis, with special attention to the roles of IL-17 produced by tumor cells interacting with other factors in the tumor microenvironment.

In vitro and in vivo antitumoral effects of combinations of polyphenols, or polyphenols and anticancer drugs: perspectives on cancer treatment

Carcinogenesis is a multistep process triggered by genetic alterations that activate different signal transduction pathways and cause the progressive transformation of a normal cell into a cancer cell. Polyphenols, compounds ubiquitously expressed in plants, have anti-inflammatory, antimicrobial, antiviral, anticancer, and immunomodulatory properties, all of which are beneficial to human health. Due to their ability to modulate the activity of multiple targets involved in carcinogenesis through direct interaction or modulation of gene expression, polyphenols can be employed to inhibit the growth of cancer cells. However, the main problem related to the use of polyphenols as anticancer agents is their poor bioavailability, which might hinder the in vivo effects of the single compound. In fact, polyphenols have a poor absorption and biodistribution, but also a fast metabolism and excretion in the human body. The poor bioavailability of a polyphenol will affect the effective dose delivered to cancer cells. One way to counteract this drawback could be combination treatment with different polyphenols or with polyphenols and other anti-cancer drugs, which can lead to more effective antitumor effects than treatment using only one of the compounds. This report reviews current knowledge on the anticancer effects of combinations of polyphenols or polyphenols and anticancer drugs, with a focus on their ability to modulate multiple signaling transduction pathways involved in cancer.

Correlation of tumor-infiltrative lymphocyte subtypes alteration with neoangiogenesis before and after neoadjuvant chemotherapy treatment in breast cancer patients

The two most important factors in tumor-stromal interactions are tumor-infiltrating lymphocytes (TIL) and neoangiogenesis (NAng). While changes of these parameters in responders of neoadjuvant chemotherapy (NCTx) have been reported, their correlation with pathological response in breast cancer (BC) patients treated with NCTx have not been described. We therefore evaluated alterations of the TIL subtypes ratio and alterations of NAng using the vasohibin-1-positive ratio (VPR) in BC patients during the course of NCTx. To this aim we used: (i) double immunohistochemistry of CD8 cytotoxic T cells and T regulatory cells (Treg) with Foxp3, determining the CD8+/Foxp3 ratio; (ii) immunostaining of CD31 and vasohibin-1, yielding the VPR, which reflects the NAng status. Changes between the CD8+/Foxp3 ratio and VPR before and after therapy were then correlated with the pathological response of the patients. A concomitant significant decrement of Foxp3 and NAng, represented by VPR, were detected only in NCTx pathological responders (p<0.001 and p=0.044, respectively). The CD8+/Foxp3 ratio increased in both responders and non-responders, but to greater extent in responders (p=0.02). The changes of VPR in the NCTx-treated group differed from those recorded for the patients treated with aromatase inhibitors and shown in our earlier study; this indicates that the reactions of the tumor-stromal interaction to therapy were different among different treatments in BC patients. Changes in Foxp3 and VPR in responders may reflect the dynamic activity of tumor stroma and host immune response to tumor antigens in the tumor microenvironment in response to the NCTx. VPR can be a potential surrogate marker in BC specimens for predicting the response to NCTx, incorporating both features of carcinoma and stromal cells.

The role of angiogenic factors in endometrial cancer

Endometrial cancer is the most common malignancy within the female reproductive system (37.7%). The incidence increases with age. Frequently this type of cancer is diagnosed in peri- and post-menopausal women. 60-70% of cancers occur in women over 60 years of age, and less than 5% in women below 40 years of age.

Angiogenesis is a process of formation of new microvessels from existing capillaries. There are four different mechanisms of new vessel growth: sprouting, intussusception, vessel elongation and incorporation of endothelial progenitor cells into new microvessels. Angiogenesis plays important roles in growth of endometrial cancers. This process is controlled by many angiogenic factors, for example vascular endothelial growth factor (VEGF). VEGF is the most powerful and most specific endothelial cell growth factor. It plays a crucial role in the initiation of physiological and pathological angiogenesis, lymphangiogenesis, and vasculogenesis. The VEGF family consists of VEGF-A, VEGF-B, VEGF-C, VEGF-D, VEGF-E, VEGF-F and PLGF (placental growth factor). The effects of VEGF are mediated through binding to the two specific and homologous receptors VEGFR-1 (FLT-1) and VEGFR-2 (KDR). Placental growth factor (PLGF) belongs to the VEGF family and it is also a very important growth factor. So far four isoforms of PLGF have been identified: PLGF-1 (PLGF131), PLGF-2 (PLGF152), PLGF-3 (PLGF203) and PLGF-4 (PLGF224).

Molecular neuro-oncology and development of targeted therapeutic strategies for brain tumors. Part 2: PI3K/Akt/PTEN, mTOR, SHH/PTCH and angiogenesis

Brain tumors are a diverse group of malignancies that remain refractory to conventional treatment approaches. Molecular neuro-oncology has now begun to clarify the transformed phenotype of brain tumors and identify oncogenic pathways that might be amenable to targeted therapy. Activity of the phosphoinositide 3; kinase (PI3K)/Akt pathway is often upregulated in brain tumors due to excessive stimulation by growth factor receptors and Ras. Loss of function of the tumor suppressor gene PTEN also frequently contributes to upregulation of PI3K/Akt. Several compounds, such as wortmannin and LY-294002, can target PI3K and inhibit activity of this pathway. The mammalian target of rapamycin (mTOR) is an important regulator of cell growth and metabolism and is often upregulated by Akt. Clinical trials of CCI-779, an inhibitor of mTOR, are ongoing in recurrent malignant glioma patients. The sonic hedgehog/PTCH pathway is involved in the tumorigenesis of some familial and sporadic medulloblastomas. This pathway can be targeted by cyclopamine, which is under evaluation in preclinical studies. Angiogenesis is a critical process for development and progression of brain tumors. Targeted approaches to inhibit angiogenesis include monoclonal antibodies, receptor tyrosine kinase inhibitors, antisense oligonucleotides and gene therapy. Clinical trials are ongoing for numerous angiogenesis inhibitors, including thalidomide, CC-5103 and PTK 787/ZK 222584. Further development of targeted therapies and evaluation of these new agents in clinical trials will be needed to improve survival and quality of life of patients with brain tumors.

Novel delivery system for T-oligo using a nanocomplex formed with an alpha helical peptide for melanoma therapy

Oligonucleotides homologous to 3′-telomere overhang (T-oligos) trigger inherent telomere-based DNA damage responses mediated by p53 and/or ATM and induce senescence or apoptosis in various cancerous cells. However, T-oligo has limited stability in vivo due to serum and intracellular nucleases. To develop T-oligo as an innovative, effective therapeutic drug and to understand its mechanism of action, we investigated the antitumor effects of T-oligo or T-oligo complexed with a novel cationic alpha helical peptide, PVBLG-8 (PVBLG), in a p53 null melanoma cell line both in vitro and in vivo. The uptake of T-oligo by MM-AN cells was confirmed by immunofluorescence, and fluorescence-activated cell sorting analysis indicated that the T-oligo-PVBLG nanocomplex increased uptake by 15-fold. In vitro results showed a 3-fold increase in MM-AN cell growth inhibition by the T-oligo-PVBLG nanocomplex compared with T-oligo alone. Treatment of preformed tumors in immunodeficient mice with the T-oligo-PVBLG nanocomplex resulted in a 3-fold reduction in tumor volume compared with T-oligo alone. This reduction in tumor volume was associated with decreased vascular endothelial growth factor expression and induction of thrombospondin-1 expression and apoptosis. Moreover, T-oligo treatment downregulated procaspase-3 and procaspase-7 and increased catalytic activity of caspase-3 by 4-fold in MM-AN cells. Furthermore, T-oligo induced a 10-fold increase of senescence and upregulated the melanoma tumor-associated antigens MART-1, tyrosinase, and thrombospondin-1 in MM-AN cells, which are currently being targeted for melanoma immunotherapy. Interestingly, siRNA-mediated knockdown of p73 (4–10-fold) abolished this upregulation of tumor-associated antigens. In summary, we suggest a key role of p73 in mediating the anticancer effects of T-oligo and introduce a novel nanoparticle, the T-oligo-PVBLG nanocomplex, as an effective anticancer therapeutic.

The expression of LC-3 is related to tumor suppression through angiogenesis in esophageal cancer

Autophagy is important in the development and remodeling of cells. It is required for cellular adaptation to nutrient deprivation and elimination of damaged organelles. Recently, autophagy has been implicated in carcinogenesis and metastasis. We hypothesized that autophagy-related proteins are initiated until nutrition is supplied by angiogenesis. We evaluated the clinicopathological significance of LC3, an autophagic marker, and its relationship to angiogenesis in patients with esophageal squamous cell carcinoma (ESCC). We immunohistochemically investigated the expression of LC3 as well as endoglin (CD105), a microvessel marker, and vascular endothelial growth factor A (VEGF-A) in 142 patients with ESCC. The high, moderate, and low expression rates of LC3 were 40, 31, and 29 %. LC3 expression inversely correlated with depth of invasion, lymph node metastasis, lymphatic invasion, MVD, VEGF-A expression, and poor prognosis. The overall survival rate was better in patients with high LC3 expression compared to patients with low LC3 expression. We demonstrate that low LC3 expression is related to tumor development as facilitated by angiogenesis and that alteration in LC3 expression is closely related to prognosis. Expression of LC3 proteins is a useful marker for determining tumor prognostic behavior in patients with ESCC.

The role played by the microenvironment in site-specific metastasis

Cancer cells that disseminate to metastatic sites may progress to frank metastasis or persist as dormant micrometastasis. Significant progress has been made in defining the genetic and phenotypic cancer-cell-autonomous determinants of metastasis and in the understanding of the cross-talk between metastasizing tumor cells and the metastatic microenvironment. However several questions remain open, in particular the identity of microenvironmental factors that keep micrometastatic cells in a state of dormancy and those that promote survival, proliferation and progression of such cells. Significantly more information is available on the latter factors than on microenvironmental cells and molecules that restrain micrometastasis. This mini-review summarizes findings suggesting that: In view of the above, it is not unlikely that metastases residing in different microenvironments may require "individualized" treatment modalities.

Risk of liver toxicity with the angiogenesis inhibitor pazopanib in cancer patients

PURPOSE

The angiogenesis inhibitor pazopanib has been approved for the treatment of advanced renal cell cancer (RCC) and soft tissue sarcoma. Severe and fatal hepatotoxicity has been observed in its clinical studies. This analysis was conducted to determine the risk of liver toxicity by a systematic review and meta-analysis of clinical trials.

PATIENTS AND METHODS

Databases from PubMed, Web of Science and abstracts presented at ASCO meetings up to January, 2012 were searched to identify relevant studies. Eligible studies included prospective trials of cancer patients treated with pazopanib starting at 800 mg daily. Summary incidence rates, relative risks, and 95% confidence intervals (CIs) were calculated using a fixed- or random-effects model.

RESULTS

A total of 1478 patients from 10 clinical trials were included. The incidences of all-grade aspartate aminotransferase (AST), alanine transaminase (ALT), and bilirubin elevation were 39.6% (95% CI 31.2-48.6%), 41.4% (95% CI 34.1-49.0%), and 24.8% (95% CI 16.3-35.3%), respectively. The incidences of high-grade (Grade 3 and 4) AST, ALT and bilirubin elevation were 6.9% (95% CI 5.5-8.6%), 9.4% (95% CI 7.8-11.4%), and 3.4% (2.4-5.0%), respectively. In comparison with placebo, pazopanib significantly increased the risk of high-grade AST elevation (RR 6.56, 95% CI 2.04-21.07, p = 0.002) and ALT elevation (RR 4.33, 95% CI 1.88-10.0, p = 0.001). However, the risks of high-grade bilirubin elevation (RR 1.31, 95% CI 0.47-3.64) and fatal hepatotoxicity (RR 2.51, 95% CI 0.12-51.91, p = 0.55) were not significantly elevated.

CONCLUSION

The use of pazopanib was associated with a significantly increased risk of severe non-fatal hepatotoxicity in cancer patients.

Thrombospondin-1 and transforming growth factor-β1 levels in prolactinoma and their clinical significance

OBJECTIVE

To investigate the roles of angiogenesis, thrombospondin-1 (TSP-1) and transforming growth factor-β1 (TGF-β1) in invasive and noninvasive prolactinoma.

METHODS

TSP-1 and TGF-β1 protein were examined using immunohistochemistry and Western blotting in 81 prolactinomas. Angiogenesis was assessed by measuring microvessel density via CD34 immunostaining.

RESULTS

Microvessel density was significantly higher in invasive prolactinomas than in noninvasive prolactinomas. Immunohistochemistry demonstrated that significantly fewer invasive prolactinomas were positive for TSP-1 compared with noninvasive prolactinomas (17.9% versus 50.0%, respectively), and significantly higher numbers of invasive prolactinomas were positive for TGF-β1 compared with noninvasive prolactinomas (82.1% versus 42.9%, respectively). Microvessel density was significantly lower in TSP-1-positive prolactinomas than in TSP-1-negative prolactinomas, and significantly higher in TGF-β1-positive prolactinomas than in TGF-β1-negative prolactinomas.

CONCLUSIONS

These results suggest a close relationship between angiogenesis and tumour invasiveness in prolactinoma. TSP-1 and TGF-β1 may play important roles in the progression of prolactinoma, by affecting angiogenesis.

Regulation of vascular endothelial cell polarization and migration by Hsp70/Hsp90-organizing protein

Hsp70/Hsp90-organizing protein (HOP) is a member of the co-chaperone family, which directly binds to chaperones to regulate their activities. The participation of HOP in cell motility and endothelial cell functions remains largely unknown. In this study, we demonstrate that HOP is critically involved in endothelial cell migration and angiogenesis. Tube formation and capillary sprouting experiments reveal that depletion of HOP expression significantly inhibits vessel formation from endothelial cells. Wound healing and transwell migration assays show that HOP is important for endothelial cell migration. By examination of centrosome reorientation and membrane ruffle dynamics, we find that HOP plays a crucial role in the establishment of cell polarity in response to migratory stimulus. Furthermore, our data show that HOP interacts with tubulin and colocalizes with microtubules in endothelial cells. These findings indicate HOP as a novel regulator of angiogenesis that functions through promoting vascular endothelial cell polarization and migration.

Death inducer-obliterator 1 (Dido1) is a BMP target gene and promotes BMP-induced melanoma progression

Bone morphogenetic proteins (BMPs) are known to play an important role in melanoma development and progression. However, the downstream targets of BMPs have not been investigated thus far. Therefore, we treated melanoma cell lines with the Smad-specific BMP inhibitor Dorsomorphin and performed a cDNA microarray. We identified death inducer-obliterator 1 (Dido1) as a BMP-specific Smad-regulated target gene, which was confirmed by qRT-PCR, immunofluorescence staining and electrophoretic mobility shift assay experiments. An analysis of Dido1 expression revealed an upregulation of Dido1 levels in melanoma cell lines and tissues compared with normal melanocytes. Colony-formation assays showed that siDido1-transfected cells formed significantly smaller colonies when grown in soft agar compared with control cells. In addition, fluorescence-activated cell sorting and western blot experiments revealed that transfection of melanoma cells with Dido1 small interfering RNAs led to an upregulation of apoptosis. Furthermore, cell migratory and invasive potentials were strongly reduced in siDido1-transfected cells compared with control cells. Finally, we demonstrated that Dido1 induces the expression of Integrin αV, thereby promoting the attachment, migration, invasion and apoptosis resistance of melanoma cells.

Lycopene inhibits angiogenesis in human umbilical vein endothelial cells and rat aortic rings

Angiogenesis is important for tumour vascularisation and growth, and is therefore a promising target for cancer therapy. The present study reports inhibition ofin vitroangiogenesis in human umbilical vein endothelial cells (HUVEC) as well as in rat aortic rings at physiological concentrations of lycopene, that is, 1–2 μmol/l. At a final concentration of 1·15 μmol/l, a significant reduction (P < 0·05) in network branching, that is, junction numbers, the number of tubules and tubule length, was observed in both HUVEC as well as in the rat aortic rings. The inhibitory effect of lycopene was independent of the presence of the pro-angiogenic agents, vascular endothelial growth factor and TNF-α. The anti-angiogenic effects of lycopene in the present study were shown at a concentration that should be achievable by dietary means. These results extend our knowledge of one of the putative anti-cancer actions of lycopene.

Glioblastoma multiforme

Patients with newly diagnosed glioblastoma multiforme should undergo a maximal tumor resection and then, whenever possible, should be entered into a clinical trial. The current standard of care consists of external beam irradiation, to a total of 60 Gy over 6 weeks, in combination with low-dose daily temozolomide, followed by at least six cycles of adjuvant temozolomide. If radiotherapy and a temozolomide-based adjuvant regimen fail, the most active treatment approach appears to be bevacizumab and irinotecan. Molecular therapy, with drugs targeting growth factor receptors and critical signal transduction pathway mediators, is also under active investigation.

Production and characterization of a humanized single-chain antibody against human integrin alphav beta3 protein

Anti-angiogenesis therapy is an emerging strategy for cancer treatment. This therapy has many advantages over existing treatments, such as fewer side effects, fewer resistance problems, and a broader tumor type spectrum. Integrin αvβ3 is a heterodimeric transmembrane glycoprotein that has been demonstrated to play a key role in tumor angiogenesis and metastasis. We have used a phage antibody display to humanize a mouse monoclonal antibody (mAb E10) against human integrin αvβ3 with a predetermined CDR3 gene. Three human phage antibodies were developed. Analysis of the humanized phage antibodies by phage ELISA revealed that the antibodies retained high antigen-binding activity and detected the same epitope as the parent mAb E10. A humanized single chain Fv (scFv) antibody was expressed in Escherichia coli in a soluble form. Analysis of the purified scFv indicated that it has the same specificity and affinity as the original mAb. Cell viability assays and xenograft model results suggested that the humanized scFv possesses anti-tumor growth activity in vitro and in vivo. This successful production of a humanized scFv with the ability to inhibit αvβ3-mediated cancer cell growth may provide a novel candidate for integrin αvβ3-targeted therapy.

The inhibitory effects of 5-hydroxy-3,6,7,8,3',4'-hexamethoxyflavone on human colon cancer cells

SCOPE

Previously, we reported that 5-hydroxy-3,6,7,8,3',4'-hexamethoxyflavone (5HHMF), a polymethoxyflavone found in citrus peels, potently inhibited the growth of multiple human colon cancer cells. Herein, we further investigated the anti-cancer mechanisms of 5HHMF in human colon cancer cells.

METHODS AND RESULTS

Colony formation assay revealed that 5HHMF dose dependently inhibited colony formation of multiple colon cancer cells. Western blot analysis demonstrated 5HHMF decreased nuclear β-catenin levels and increased the E-cadherin level in a dose-dependent manner. 5HHMF also modified plasma membrane-associated proteins, such as K-Ras, EGFR, and their downstream effectors, such as Akt. Moreover, treatments with 5HHMF inhibited nuclear translocation of NF-κB, which may contribute to its anti-cancer effects. Add-back study showed that the inhibitory effect of 5HHMF was not associated with the production of reactive oxygen species (ROS). In addition, 5HHMF treatment inhibited the capillary tube formation of human umbilical vein endothelial cells (HUVECs) on matrigel, suggesting a potential anti-tumor angiogenesis effect.

CONCLUSION

Our results demonstrated that 5HHMF suppressed multiple oncogenic molecular events in colon cancer cells.

An integrated experimental and analytical approach to the chemical state imaging of iron in brain gliomas using X-ray absorption near edge structure spectroscopy

X-ray absorption near-edge structure spectroscopy is used for human neoplastic tissues in order to investigate distributions and chemical states of iron. The specimens used in this study were obtained intraoperatively from brain gliomas of different types and various grades of malignancy and from a control subject. An integrated experimental and analytical approach toward topographic and quantitative analysis in thin freeze-dried cryo-sections is presented. The full XANES spectra at the Fe absorption K edge show the presence of both chemical forms of Fe in the analyzed points of the tissues. The main goal of the work is the chemical state imaging of Fe in tissue areas. Topographic analysis of Fe speciation in the tissues investigated with the use of the XANES technique indicates the presence of microstructures where Fe(2+) is dominant as well as those with a high abundance of the oxidized form of Fe. The quantitative analysis shows that for all cases the content of the oxidized form of Fe is significantly higher in comparison with Fe(2+). The highest level of Fe(3+) is found in the control sample, and the lowest one for the glioma of the highest grade of malignancy. The content of either Fe(2+) or Fe(3+) is increased in low grade gliomas in comparison to high-grade malignant tumors.

Nanomaterials: applications in cancer imaging and therapy

The application of nanomaterials (NMs) in biomedicine is increasing rapidly and offers excellent prospects for the development of new non-invasive strategies for the diagnosis and treatment of cancer. In this review, we provide a brief description of cancer pathology and the characteristics that are important for tumor-targeted NM design, followed by an overview of the different types of NMs explored to date, covering synthetic aspects and approaches explored for their application in unimodal and multimodal imaging, diagnosis and therapy. Significant synthetic advances now allow for the preparation of NMs with highly controlled geometry, surface charge, physicochemical properties, and the decoration of their surfaces with polymers and bioactive molecules in order to improve biocompatibility and to achieve active targeting. This is stimulating the development of a diverse range of nanometer-sized objects that can recognize cancer tissue, enabling visualization of tumors, delivery of anti-cancer drugs and/or the destruction of tumors by different therapeutic techniques.

Treatment-related mortality with bevacizumab in cancer patients: a meta-analysis

CONTEXT

Fatal adverse events (FAEs) have been reported in cancer patients treated with the widely used angiogenesis inhibitor bevacizumab in combination with chemotherapy. Currently, the role of bevacizumab in treatment-related mortality is not clear.

OBJECTIVE

To perform a systematic review and meta-analysis of published randomized controlled trials (RCTs) to determine the overall risk of FAEs associated with bevacizumab.

DATA SOURCES

PubMed, EMBASE, and Web of Science databases as well as abstracts presented at American Society of Clinical Oncology conferences from January 1966 to October 2010 were searched to identify relevant studies.

STUDY SELECTION AND DATA EXTRACTION

Eligible studies included prospective RCTs in which bevacizumab in combination with chemotherapy or biological therapy was compared with chemotherapy or biological therapy alone. Summary incidence rates, relative risks (RRs), and 95% confidence intervals (CIs) were calculated using fixed- or random-effects models.

DATA SYNTHESIS

A total of 10,217 patients with a variety of advanced solid tumors from 16 RCTs were included in the analysis. The overall incidence of FAEs with bevacizumab was 2.5% (95% CI, 1.7%-3.9%). Compared with chemotherapy alone, the addition of bevacizumab was associated with an increased risk of FAEs, with an RR of 1.46 (95% CI, 1.09-1.94; P = .01; incidence, 2.5% vs 1.7%). This association varied significantly with chemotherapeutic agents (P = .045) but not with tumor types (P = .13) or bevacizumab doses (P = .16). Bevacizumab was associated with an increased risk of FAEs in patients receiving taxanes or platinum agents (RR, 3.49; 95% CI, 1.82-6.66; incidence, 3.3% vs 1.0%) but was not associated with increased risk of FAEs when used in conjunction with other agents (RR, 0.85; 95% CI, 0.25-2.88; incidence, 0.8% vs 0.9%). The most common causes of FAEs were hemorrhage (23.5%), neutropenia (12.2%), and gastrointestinal tract perforation (7.1%).

CONCLUSION

In a meta-analysis of RCTs, bevacizumab in combination with chemotherapy or biological therapy, compared with chemotherapy alone, was associated with increased treatment-related mortality.

Osteopontin promotes gastric cancer metastasis by augmenting cell survival and invasion through Akt-mediated HIF-1alpha up-regulation and MMP9 activation

Osteopontin (OPN) is a secreted, integrin-binding matrix phosphorylated glycoprotein. OPN has been shown to facilitate the progression and metastasis of malignancies and has prognostic value in several types of cancer, including gastric cancer. However, the functional mechanism of OPN mediated metastatic growth in gastric cancer remains unclear. Here, using multiple in vitro and in vivo models, we report that OPN strongly promoted the progression and metastasis of gastric cancer. Immunohistochemical staining revealed that OPN, matrix metalloproteinase (MMP)9 and hypoxia-inducible factor (HIF)-1alpha have statistically significant different expression patterns between well- and poorly differentiated tissue samples (P < 0.05). Correlations existed between OPN and MMP9, and between OPN and HIF-1 (r(1) = 0.872, p(1) < 0.01 and r(2) = 0.878, p(2) < 0.01). Furthermore, OPN dramatically increased colony formation and invasion of gastric cancer cells in vitro and promoted tumour growth and metastasis in vivo. In addition, OPN potently protected gastric cancer cells from serum depletion-induced apoptosis. Further study shows that OPN activated phosphoinositide 3-kinase/Akt survival pathway and up-regulated HIF-1alpha via binding to v3 integrins in gastric cancer cells. Moreover, we found that OPN could activate MMP9 and upregulate MMP2. Taken together, our results suggest that the survival-promoting function is crucial for OPN to promote the development of gastric cancer, and HIF-1 and MMP9 may play key roles during this process. Thus, targeting OPN and its related signalling network may develop an effective therapeutic approach for the management of gastric cancer.

Bevacizumab increases risk for severe proteinuria in cancer patients

Treatment with the chemotherapeutic agent bevacizumab, a humanized mAb that neutralizes vascular endothelial growth factor, can lead to proteinuria and renal damage. The risk factors and clinical outcomes of renal adverse events are not well understood. We performed a systematic review and meta-analysis of published randomized, controlled trials to assess the overall risk for severe proteinuria with bevacizumab. We analyzed data from 16 studies comprising 12,268 patients with a variety of tumors. The incidence of high-grade (grade 3 or 4) proteinuria with bevacizumab was 2.2% (95% confidence interval [CI] 1.2 to 4.3%). Compared with chemotherapy alone, bevacizumab combined with chemotherapy significantly increased the risk for high-grade proteinuria (relative risk 4.79; 95% CI 2.71 to 8.46) and nephrotic syndrome (relative risk 7.78; 95% CI 1.80 to 33.62); higher dosages of bevacizumab associated with increased risk for proteinuria. Regarding tumor type, renal cell carcinoma associated with the highest risk (cumulative incidence 10.2%). We did not detect a significant difference between platinum- and non-platinum-based concurrent chemotherapy with regard to risk for high-grade proteinuria (P = 0.39). In conclusion, the addition of bevacizumab to chemotherapy significantly increases the risk for high-grade proteinuria and nephrotic syndrome.

Increased risk of high-grade hypertension with bevacizumab in cancer patients: a meta-analysis

BACKGROUND

Hypertension is associated with the use of bevacizumab, an angiogenesis inhibitor widely used in cancer therapy. Currently, the risk of severe hypertension associated with bevacizumab is unclear. We performed a systematic review and meta-analysis of published randomized-controlled clinical trials (RCTs) to assess the risk of high-grade hypertension in cancer patients treated with bevacizumab.

METHODS

Databases from PUBMED, the Web of Science, and abstracts presented at the American Society of Clinical Oncology conferences until May 2009 were searched to identify relevant studies. Eligible studies included prospective RCTs in which bevacizumab was directly compared with controls in cancer patients receiving concurrent antineoplastic therapy. Summary incidence, relative risk (RR), and 95% confidence interval (CI) were calculated employing a fixed- or random-effects model based upon the heterogeneity of the included studies.

RESULTS

A total of 12,656 patients with a variety of tumors from 20 studies were included for the analysis. The incidence of all-grade hypertension in patients receiving bevacizumab was 23.6% (95% CI: 20.5-27.1) with 7.9% (95% CI: 6.1-10.2) being high-grade (grade 3 or 4). Patients treated with bevacizumab had a significantly increased risk of developing high-grade hypertension with an RR of 5.28 (95% CI: 4.15-6.71, P < 0.001) in comparison with controls. Even though not statistically significant, there was a trend suggesting that bevacizumab may increase the risk of hypertensive crisis (grade 4) with an RR of 3.16 (95% CI: 0.91-10.90). The increased risk of high-grade hypertension was observed in patients receiving bevacizumab at 2.5 mg/kg/week (RR = 4.78, 95% CI: 3.59-6.36) as well as 5 mg/kg/week (RR = 5.39, 95% CI: 3.68-7.90). The risk of high-grade hypertension may vary with tumor types, with RRs ranging from 2.49 (95% CI: 0.94-6.59) in patients with mesothelioma to 14.80 (95% CI: 0.92-238.51) in patients with breast cancer.

CONCLUSION

Bevacizumab may significantly increase the risk of high-grade hypertension in cancer patients. Close monitoring and adequate management are highly recommended to decrease cardiovascular complications.

Risk of cardiac ischemia and arterial thromboembolic events with the angiogenesis inhibitor bevacizumab in cancer patients: a meta-analysis of randomized controlled trials

BACKGROUND

The risk of cardiovascular toxicities is a serious concern with the increased application of angiogenesis inhibitors in current cancer therapy. Arterial thromboembolic events (ATE) were associated with bevacizumab, an antibody against vascular endothelial growth factor. To determine the risk of ATE including cardiac ischemia and stroke, a systematic review and meta-analysis of published randomized controlled trials (RCTs) was performed.

METHODS

We searched the databases of PubMed, Web of Science, and American Society of Clinical Oncology conferences to identify relevant clinical trials up to May, 2009. Eligible studies included prospective RCTs in which bevacizumab was compared to a control concurrently in combination with standard anti-neoplastic therapy. Summary incidence rates, relative risks (RRs), and 95% confidence intervals (CIs) were calculated using random-effects or fixed-effects models.

RESULTS

A total of 12 617 patients with a variety of advanced solid tumors from 20 RCTs were included for analysis. The incidences of all-grade and high-grade ATE in patients receiving bevacizumab were 3.3% (95% CI, 2.0-5.6%) and 2.0% (95% CI, 1.7-2.5) respectively. Patients treated with bevacizumab had a significantly increased risk of ATE with an RR of 1.44 (95% CI, 1.08-1.91; p=0.013) compared with controls. The risk similarly increased for bevacizumab at 2.5 and 5 mg/kg/week; in addition, significantly increased risks were observed in patients with renal cell cancer (RR, 3.72, 95% CI, 1.15-12.04; p=0.029) and colorectal cancer (RR, 1.89, 95% CI, 1.28-2.80, p=0.001). Notably, the risk of high-grade cardiac ischemia with bevacizumab was significantly higher than controls with an RR of 2.14 (95% CI, 1.12-4.08, p=0.021); however, the risk of ischemic stroke with bevacizumab was not significantly different from controls (RR, 1.37, 95% CI, 0.67-2.79, p=0.39).

DISCUSSION

Treatment with bevacizumab may significantly increase the risk of cardiac ischemic events in cancer patients.