Sorafenib Decreases Tumor Exposure to an Anti-carcinoembryonic Antigen Monoclonal Antibody in a Mouse Model of Colorectal Cancer

In this investigation, we test the hypothesis that treatment with sorafenib, an anti-angiogenic agent, decreases tumor vascularization and, consequently, hinders the delivery of monoclonal antibodies (mAb) to xenograft tumors. Severe combined immunodeficiency mice bearing carcinoembryonic antigen (CEA) expressing tumor xenografts were divided into control and sorafenib-treated groups. Sorafenib was administered to the latter group at 50 mg/kg IP every 48 h, starting 4 days post-tumor implantation. When tumors attained a size of 200-300 mm(3), mice were evaluated for (a) tumor microvessel density (using immunohistochemical analysis), (b) tumor macromolecular extravasation (using Evans Blue Dye (EBD)), (c) pharmacokinetics of an anti-CEA mAb, T84.66, following an intravenous dose of 10 mg/kg, and (d) intra-tumoral spatial distribution of T84.66 (using autoradiography). Sorafenib treatment resulted in a substantial reduction in tumor growth rate, a visible reduction in tumor microvessel density, and in a 46.4% decrease in EBD extravasation in tumor tissue (p < 0.0455). For control and treated mice, no significant difference was found for the area under the mAb plasma concentration-time curve (AUC(0-7d): 1.67 × 10(3) ± 1.28 × 10(2) vs. 1.76 × 10(3) ± 1.75 × 10(2) nM × day, p = 0.51). However, tumor AUC(0-7d) was reduced by 40.8% in sorafenib-treated mice relative to that observed in control mice (5.61 × 10(2) ± 4.27 × 10(1) vs. 9.48 × 10(2) ± 5.61 × 10(1) nM × day, p < 0.001). Sorafenib therapy was also found to markedly alter mAb tumor spatial distribution. The results collectively suggest that sorafenib treatment causes a significant reduction in mAb delivery to, and distribution within, solid tumors.

Beyond Chemotherapy: An Overview and Review of Targeted Therapy in Cervical Cancer

PURPOSE

The purpose of this study was to provide an overview of current and up and coming targeted therapies in cervical cancer with or without chemotherapy.

METHODS

We reviewed the literature using search terms cervical cancer AND immunotherapy, immune therapy, vaccines, bevacizumab, anti-angiogenic therapy, and PARP inhibitors on PubMed. We included all review articles and prospective trials. We also reviewed ClinicalTrials.gov for trials in progress.

FINDINGS

The addition of bevacizumab has improved the overall survival of women with advanced or recurrent cervical cancer when compared with cytotoxic therapy alone. This advancement has sparked an interest in other anti-angiogenic agents. Additionally, targeted therapies, including tyrosine kinase inhibitors, immunotherapy, and vaccine therapy, are also being evaluated. Another exciting area of study is the role of poly (ADP-ribose) polymerase inhibition in cervical cancer.

IMPLICATIONS

Though the results are promising, the data are preliminary and additional studies evaluating the proper combination of therapy, dosing, and schedules will help inform the ideal regimen.

Niche Regulation of Limbal Epithelial Stem Cells: Relationship between Inflammation and Regeneration

Human limbal palisades of Vogt are the ideal site for studying and practicing regenerative medicine due to their accessibility. Nonresolving inflammation in limbal stroma is common manifestation of limbal stem cell (SC) deficiency and presents as a threat to the success of transplanted limbal epithelial SCs. This pathologic process can be overcome by transplantation of cryopreserved human amniotic membrane (AM), which exerts anti-inflammatory, antiscarring and anti-angiogenic action to promote wound healing. To determine how AM might exert anti-inflammation and promote regeneration, we have purified a novel matrix, HC-HA/PTX3, responsible for the efficacy of AM efficacy. HC-HA complex is covalently formed by hyaluronan (HA) and heavy chain 1 (HC1) of inter-α-trypsin inhibitor by the catalytic action of tumor necrosis factor-stimulated gene-6 (TSG-6) and are tightly associated with pentraxin 3 (PTX3) to form HC-HA/PTX3. In vitro reconstitution of the limbal niche can be established by reunion between limbal epithelial progenitors and limbal niche cells on different substrates. In 3-dimensional Matrigel, clonal expansion indicative of SC renewal is correlated with activation of canonical Wnt signaling and suppression of canonical bone morphogenetic protein (BMP) signaling. In contrast, SC quiescence can be achieved in HC-HA/PTX3 by activation of canonical BMP signaling and non-canonical planar cell polarity (PCP) Wnt signaling, but suppression of canonical Wnt signaling. HC-HA/PTX3 is a novel matrix mitigating nonresolving inflammation and restoring SC quiescence in the niche for various applications in regenerative medicine.

Amentoflavone Induces Anti-angiogenic and Anti-metastatic Effects Through Suppression of NF-κB Activation in MCF-7 cells

The aim of the present study was to investigate whether amentoflavone induces anti-angiogenic and anti-metastatic effects through suppression of NF-κB activation in breast cancer in vitro. Effects of NF-κB inhibitor 4-N-[2-(4-phenoxyphenyl) ethyl] quinazoline-4, 6-diamine (QNZ) and amentoflavone on the expression and secretion of angiogenesis- and metastasis-related proteins and cell invasion were investigated by western blotting, enzyme-linked immunosorbent assay (ELISA), and invasion assays. We also verified the effects of QNZ and amentoflavone on lipopolysaccharides (LPS)-activated cell invasion. Obtained results indicated that both QNZ and amentoflavone reduce NF-κB activation, expression and secretion of angiogenesis- and metastasis-related proteins, and cell invasion. QNZ and amentoflavone also reverse LPS-activated cell invasion. In conclusion, inhibition of NF-κB activation decreases expression and secretion of angiogenesis- and metastasis-related proteins. Amentoflavone may induce anti-angiogenic and anti-metastatic effects through suppression of NF-κB activation.

Synergistic Effect of SN-38 in Combination with Cetuximab on Angiogenesis and Cancer Cell Invasion

BACKGROUND

The combination of irinotecan, a topoisomerase I inhibitor with cetuximab, an antibody against epidermal growth factor receptor, produces synergistic and beneficial effects in patients with irinotecan-refractory colorectal cancer. Our hypothesis was that synergistic effects could be due to anti-angiogenesis and anti-invasion, but not to cytotoxicity.

MATERIALS AND METHODS

Cytotoxicity was assessed by viability test and flow cytometry. Anti-angiogenesis, anti-invasion were studied by the endothelial cell capillary-like network formation and transmigration through an extracellular matrix. Protein kinase B (PKB, frequently cited as AKT), and extracellular signal-regulated kinases (ERK) activation was assayed by cell-based enzyme-linked immunosorbent assay (ELISA).

RESULTS

Combinations of SN-38 (the active of irinotecan) and cetuximab did not induce any synergistic cytotoxicity confirmed by viability test and cell-cycle analyses. Interestingly, their combination produced synergistic anti-angiogenesis and anti-invasion activities revealed by endothelial cell capillary-like network formation and cell invasion tests. Subsequently, their combination attenuated either expression or phosphorylation of AKT and ERK1/2 using cell-based ELISA.

CONCLUSION

SN-38/cetuximab combination has synergistic anti-angiogenesis and anti-invasion activities mediated by down-regulation of phosphatidylinositol-3-kinases/AKT and mitogen-activated protein kinase/ERK pathways.

Anti-angiogenic efficacy of 5'-triphosphate siRNA combining VEGF silencing and RIG-I activation in NSCLCs

Short interfering RNA (siRNA) targeting angiogenic factors and further inhibiting tumor angiogenesis, is one of the potent antitumor candidates for lung cancer treatment. However, this strategy must be combined with other therapeutics like chemotherapy. In this study, we designed a 5'-triphosphate siRNA targeting VEGF (ppp-VEGF), and showed that ppp-VEGF exerted three distinct antitumor effects: i) inhibition of tumor angiogenesis by silencing VEGF, ii) induction of innate immune responses by activating RIG-I signaling pathway, and thus activate antitumor immunity, iii) induction of apoptosis. In a subcutaneous model of murine lung cancer, ppp-VEGF displayed a potent antitumor effect. Our results provide a multifunctional antitumor molecule that may overcome the shortages of traditional antiangiogenic agents.

Nanoparticles Biosynthesized by Fungi and Yeast: A Review of Their Preparation, Properties, and Medical Applications

In the field of nanotechnology, the use of various biological units instead of toxic chemicals for the reduction and stabilization of nanoparticles, has received extensive attention. Among the many possible bio resources, biologically active products from fungi and yeast represent excellent scaffolds for this purpose. Since fungi and yeast are very effective secretors of extracellular enzymes and number of species grow fast and therefore culturing and keeping them in the laboratory are very simple. They are able to produce metal nanoparticles and nanostructure via reducing enzyme intracellularly or extracellularly. The focus of this review is the application of fungi and yeast in the green synthesis of inorganic nanoparticles. Meanwhile the domain of biosynthesized nanoparticles is somewhat novel; the innovative uses in nano medicine in different areas including the delivery of drug, cancer therapy, antibacterial, biosensors, and MRI and medical imaging are reviewed. The proposed signaling pathways of nanoparticles induced apoptosis in cancerous cells and anti-angiogenesis effects also are reviewed. In this article, we provide a short summary of the present study universally on the utilization of eukaryotes like yeast and fungi in the biosynthesis of nanoparticles (NPs) and their uses.

Kinetics of tumor size and peritumoral brain edema before, during, and after systemic therapy in recurrent WHO grade II or III meningioma

BACKGROUND

The efficacy of systemic antineoplastic therapy on recurrent World Health Organization (WHO) grades II and III meningiomas is unclear.

METHODS

We performed a retrospective multicenter analysis of serial cranial MRI in patients with recurrent WHO II and III meningiomas treated with antineoplastic systemic therapies. Growth rates for tumor volume and diameter, as well as change rates for edema size, were calculated for all lesions.

RESULTS

We identified a total of 34 patients (23 atypical, 11 anaplastic meningiomas) with a total of 57 meningioma lesions who had been treated at 6 European institutions. Systemic therapies included bevacizumab, cytotoxic chemotherapy, somatostatin analogues, and tyrosine kinase inhibitors. Overall, tumor growth rates decreased during systemic therapy by 51% for tumor diameter and 14% for tumor volume growth rates compared with the period before initiation of systemic therapy. The most pronounced decrease in meningioma growth rates during systemic therapy was evident in patients treated with bevacizumab, with a reduction of 80% in diameter and 59% in volume growth. Furthermore, a decrease in size of peritumoral edema after initiation of systemic therapy was exclusively observed in patients treated with bevacizumab (-107%).

CONCLUSIONS

Our data indicate that systemic therapy may inhibit growth of recurrent WHO grades II and III meningiomas to some extent. In our small cohort, bevacizumab had the most pronounced inhibitory effect on tumor growth, as well as some anti-edematous activity. Prospective studies are needed to better define the role of medical therapies in this tumor type.

Role of microRNA-520h in 20(R)-ginsenoside-Rg3-mediated angiosuppression

Background

Ginsenoside-Rg3, the pharmacologically active component of red ginseng, has been found to inhibit tumor growth, invasion, metastasis, and angiogenesis in various cancer models. Previously, we found that 20(R)-ginsenoside-Rg3 (Rg3) could inhibit angiogenesis. Since microRNAs (miRNAs) have been shown to affect many biological processes, they might play an important role in ginsenoside-mediated angiomodulation.

Methods

In this study, we examined the underlying mechanisms of Rg3-induced angiosuppression through modulating the miRNA expression. In the miRNA-expression profiling analysis, six miRNAs and three miRNAs were found to be up- or down-regulated in vascular-endothelial-growth-factor-induced human-umbilical-vein endothelial cells (HUVECs) after Rg3 treatment, respectively.

Results

A computational prediction suggested that mature hsa-miR-520h (miR-520h) targets ephrin receptor (Eph) B2 and EphB4, and hence, affecting angiogenesis. The up-regulation of miR-520h after Rg3 treatment was validated by quantitative real-time polymerase chain reaction, while the protein expressions of EphB2 and EphB4 were found to decrease, respectively. The mimics and inhibitors of miR-520h were transfected into HUVECs and injected into zebra-fish embryos. The results showed that overexpression of miR-520h could significantly suppress the EphB2 and EphB4 protein expression, proliferation, and tubulogenesis of HUVECs, and the subintestinal-vessel formation of the zebra fish.

Conclusion

These results might provide further information on the mechanism of Rg3-induced angiosuppression and the involvement of miRNAs in angiogenesis.

Ramucirumab, another anti-angiogenic agent for metastatic colorectal cancer in second-line setting--its impact on clinical practice

The recent FDA approval of ramucirumab (RAISE trial) has added a third agent to our existing armamentarium of angiogenesis inhibitors (bevacizumab and ziv-aflibercept) for the second-line treatment of metastatic colorectal cancer, which may have some impacts in the current clinic practice.

Genetic variants in VEGF pathway genes in neoadjuvant breast cancer patients receiving bevacizumab: Results from the randomized phase III GeparQuinto study

Studies assessing the effect of bevacizumab (BEV) on breast cancer (BC) outcome have shown different effects on progression-free and overall survival, suggesting that a subgroup of patients may benefit from this treatment. Unfortunately, no biomarkers exist to identify these patients. Here, we investigate whether single nucleotide polymorphisms (SNPs) in VEGF pathway genes correlate with pathological complete response (pCR) in the neoadjuvant GeparQuinto trial. HER2-negative patients were randomized into treatment arms receiving either BEV combined with standard chemotherapy or chemotherapy alone. In a pre-planned biomarker study, DNA was collected from 729 and 724 patients, respectively from both treatment arms, and genotyped for 125 SNPs. Logistic regression assessed interaction between individual SNPs and both treatment arms to predict pCR. Five SNPs may be associated with a better response to BEV, but none of them remained significant after correction for multiple testing. The two SNPs most strongly associated, rs833058 and rs699947, were located upstream of the VEGF-A promoter. Odds ratios for the homozygous common, heterozygous and homozygous rare rs833058 genotypes were 2.36 (95% CI, 1.49-3.75), 1.20 (95% CI, 0.88-1.64) and 0.61 (95% CI, 0.34-1.12). Notably, some SNPs in VEGF-A exhibited a more pronounced effect in the triple-negative subgroup. Several SNPs in VEGF-A may be associated with improved pCR when receiving BEV in the neoadjuvant setting. Although none of the observed effects survived correction for multiple testing, our observations are consistent with previous studies on BEV efficacy in BC. Further research is warranted to clarify the predictive value of these markers.

Specific chemotherapeutic agents induce metastatic behaviour through stromal- and tumour-derived cytokine and angiogenic factor signalling

Recent studies reveal that chemotherapy can enhance metastasis due to host responses, such as augmented expression of adhesion molecules in endothelial cells and increased populations of myeloid cells. However, it is still unclear how tumour cells contribute to this process. Here, we observed that paclitaxel and carboplatin accelerated lung metastasis in tumour-bearing mice, while doxorubicin and fluorouracil did not. Mechanistically, paclitaxel and carboplatin induced similar changes in cytokine and angiogenic factors. Increased levels of CXCR2, CXCR4, S1P/S1PR1, PlGF and PDGF-BB were identified in the serum or primary tumour tissues of tumour-bearing mice treated by paclitaxel. The serum levels of CXCL1 and PDGF-BB and the tissue level of CXCR4 were also elevated by carboplatin. On the other hand, doxorubicin and fluorouracil did not induce such changes. The chemotherapy-induced cytokine and angiogenic factor changes were also confirmed in gene expression datasets from human patients following chemotherapy treatment. These chemotherapy-enhanced cytokines and angiogenic factors further induced angiogenesis, destabilized vascular integrity, recruited BMDCs to metastatic organs and mediated the proliferation, migration and epithelial-to-mesenchymal transition of tumour cells. Interestingly, inhibitors of these factors counteracted chemotherapy-enhanced metastasis in both tumour-bearing mice and normal mice injected intravenously with B16F10-GFP cells. In particular, blockade of the SDF-1α-CXCR4 or S1P-S1PR1 axes not only compromised chemotherapy-induced metastasis but also prolonged the median survival time by 33.9% and 40.3%, respectively. The current study delineates the mechanism of chemotherapy-induced metastasis and provides novel therapeutic strategies to counterbalance pro-metastatic effects of chemo-drugs via combination treatment with anti-cytokine/anti-angiogenic therapy.

Anti-Angiogenic Properties of BDDPM, a Bromophenol from Marine Red Alga Rhodomela confervoides, with Multi Receptor Tyrosine Kinase Inhibition Effects

Bis-(2,3-dibromo-4,5-dihydroxy-phenyl)-methane (BDDPM) is a bromophenol first isolated from Rhodomelaceae confervoides. Our previous studies showed that BDDPM exerts PTP1B-inhibiting activity and anti-cancer activity against a wide range of tumor cells while it also showed lower cytotoxicity against normal cells. In the present study, we found that BDDPM exhibits significant activities toward angiogenesis in vitro. BDDPM inhibits multiple angiogenesis processes, including endothelial cell sprouting, migration, proliferation, and tube formation. Further kinase assays investigations found that BDDPM is a potent selective, but multi-target, receptor tyrosine kinase (RTKs) inhibitor. BDDPM (10 μM) inhibits the activities of fibroblast growth factor receptor 2 and 3 (FGFR2, 3), vascular endothelial growth factor receptor 2 (VEGFR2) and platelet-derived growth factor receptor α (PDGFRα) (inhibition rate: 57.7%, 78.6%, 78.5% and 71.1%, respectively). Moreover, BDDPM also decreases the phosphorylation of protein kinase B (PKB/Akt) and endothelial nitric oxide synthase (eNOS), as well as nitric oxide (NO) production in a dose dependent manner. These results indicate that BDDPM can be exploited as an anti-angiogenic drug, or as a lead compound for the development of novel multi-target RTKs inhibitors.

Extraction, Isolation, Structural Characterization and Anti-Tumor Properties of an Apigalacturonan-Rich Polysaccharide from the Sea Grass Zostera caespitosa Miki

An apigalacturonan (AGA)-rich polysaccharide, ZCMP, was isolated from the sea grass Zostera caespitosa Miki. The depolymerized fragments derived from ZCMP were obtained by either acidic degradation or pectinase degradation, and their structures were characterized by electrospray ionization collision-induced-dissociation mass spectrometry (ESI-CID-MS²) and nuclear magnetic resonance (NMR) spectroscopy. The average molecular weight of ZCMP was 77.2 kD and it consisted of galacturonic acid (GalA), apiosefuranose (Api), galactose (Gal), rhamnose (Rha), arabinose (Ara), xylose (Xyl), and mannose (Man), at a molar ratio of 51.4꞉15.5꞉6.0꞉11.8꞉4.2꞉4.4꞉4.2. There were two regions of AGA (70%) and rhamnogalacturonan-I (RG-Ι, 30%) in ZCMP. AGA was composed of an α-1,4-d-galactopyranosyluronan backbone mainly substituted at the O-3 position by single Api residues. RG-Ι possessed a backbone of repeating disaccharide units of →4GalAα1,2Rhaα1→, with a few α-l-arabinose and β-d-galactose residues as side chains. The anti-angiogenesis assay showed that ZCMP inhibited the migratory activity of human umbilical vein endothelial cell (HUVECs), with no influence on endothelial cells growth. ZCMP also promoted macrophage phagocytosis. These findings of the present study demonstrated the potential anti-tumor activity of ZCMP through anti-angiogenic and immunoregulatory pathways.

The role of anti-angiogenesis in non-small-cell lung cancer: an update

Recognition of the vascular endothelial growth factor (VEGF) pathway as a key mediator of angiogenesis has led to the clinical study of several VEGF and VEGF receptor (VEGFR) targeted therapies in non-small-cell lung cancer (NSCLC). These targeted therapies include neutralizing antibodies to VEGF (bevacizumab and aflibercept) and VEGFR-2 (ramucirumab) and tyrosine kinase inhibitors (TKIs) with selectivity for the VEGFRs. Bevacizumab and ramucirumab are associated with survival advantages in the treatment of advanced NSCLC: bevacizumab in the first-line setting in combination with carboplatin/paclitaxel and ramucirumab in combination with docetaxel in the second-line setting. The VEGFR-2 TKIs have been associated with responses and improved progression-free survival in selected NSCLC settings; however, this level of activity has thus far been insufficient to confer significant survival advantages. This review will focus on the current state of VEGF targeted therapies in NSCLC.

Critical appraisal of bevacizumab in the treatment of ovarian cancer

Bevacizumab is the first molecular-targeted agent to be used for the treatment of ovarian cancer. Bevacizumab is a humanized monoclonal antibody targeting vascular endothelial growth factor. Two randomized Phase III trials evaluated the combination of bevacizumab plus standard cytotoxic chemotherapy for first-line treatment of advanced ovarian cancer. Additional Phase III trials evaluated bevacizumab combined with cytotoxic chemotherapy in platinum-sensitive and platinum-resistant recurrent ovarian cancer. All these trials reported a statistically significant improvement in progression-free survival but not in overall survival. Furthermore, bevacizumab effectively improved the quality of life with regard to abdominal symptoms in recurrent ovarian cancer patients. Bevacizumab is associated with adverse events not commonly observed with cytotoxic agents used to treat gynecological cancers, such as hypertension, bleeding, thromboembolism, proteinuria, delayed wound healing, and gastrointestinal events. However, most of these events can be adequately managed by gynecologists. The clinical trial results with bevacizumab have supported its recent approval in Europe and the United States as a treatment for ovarian cancer. This review presents the latest evidence for bevacizumab therapy of ovarian cancer and describes selection of patients for personalized treatment.

An evaluation of the anti-angiogenic effect of the Korean medicinal formula "Sa-mi-yeon-geon-tang" in vitro and in ovo

BACKGROUND

Angiogenesis is a general hallmark of cancer; therefore, the inhibition of tumor-derived angiogenesis is considered to be an attractive target in the development of anti-cancer agents. Sa-mi-yeon-geon-tang (SMYGT), a decoction that consists of four natural medicinal products, has been traditionally prescribed in Oriental medicine to treat diverse diseases, including cancer. In the present study, we investigated the anti-angiogenic potential of SMYGT in vitro and in ovo.

METHODS

The anti-angiogenic potential of SMYGT was evaluated using conventional in vitro assays with human umbilical vein endothelial cells (HUVECs) and chorioallantoic membrane (CAM) assays with fertilized eggs. The expression changes of pro-angiogenic proteins and intracellular signaling in HUVECs following SMYGT treatment were determined by quantitative polymerase chain reaction, gelatinase zymography, and western blot analysis.

RESULTS

SMYGT efficiently inhibited three-dimensional capillary-like tube formation by HUVECs on extracellular matrix supports, as well as new vessel formation on CAMs. SMYGT inhibited cell adhesion to the extracellular matrix and HUVEC cell invasion through Matrigel without affecting cell proliferation, viability, and motility. These anti-angiogenic effects of SMYGT in HUVECs were related to decreases in the phosphorylation of focal adhesion kinase and the expression of matrix metallopeptidase-2 activity.

CONCLUSIONS

SMYGT exhibited an anti-angiogenic potential in both in vitro and in ovo experiments, which may partially contribute to its anti-tumor effect in clinical conditions. We suggest that SMYGT may be a promising source material for the development of anti-cancer chemotherapeutics that target angiogenesis.

Predictive tissue biomarkers for bevacizumab-containing therapy in metastatic colorectal cancer: an update

Bevacizumab is the first anti-angiogenic agent approved for the treatment of metastatic colorectal cancer. The need for patient selection before initiating therapy necessitates the study of various proteins expressed in metastatic colorectal cancer tissue as candidate predictive markers. Immunohistochemistry is a valuable, commonly available and cost-effective method to assess predictive biomarkers. However, it is subject to variations and therefore requires rigorous protocol standardizations. Furthermore, validated quantification methodologies to study these angiogenic elements have to be applied. Based on their function in tumor angiogenesis and their relation to the mechanism of action of bevacizumab, protein markers were divided in four groups: VEGF A-signaling proteins; other relevant angiogenesis factors; factors regarding the tumor microenvironment and tumor intrinsic markers. Conceivably, nimbly selecting a small but relevant group of therapy-guided patients by the appropriate combination of predictive biomarkers may confer great value to this angiogenic inhibitor.

VEGFR3 does not sustain retinal angiogenesis without VEGFR2

Angiogenesis, the formation of new blood vessels, is regulated by vascular endothelial growth factors (VEGFs) and their receptors (VEGFRs). VEGFR2 is abundant in the tip cells of angiogenic sprouts, where VEGF/VEGFR2 functions upstream of the delta-like ligand 4 (DLL4)/Notch signal transduction pathway. VEGFR3 is expressed in all endothelia and is indispensable for angiogenesis during early embryonic development. In adults, VEGFR3 is expressed in angiogenic blood vessels and some fenestrated endothelia. VEGFR3 is abundant in endothelial tip cells, where it activates Notch signaling, facilitating the conversion of tip cells to stalk cells during the stabilization of vascular branches. Subsequently, Notch activation suppresses VEGFR3 expression in a negative feedback loop. Here we used conditional deletions and a Notch pathway inhibitor to investigate the cross-talk between VEGFR2, VEGFR3, and Notch in vivo. We show that postnatal angiogenesis requires VEGFR2 signaling also in the absence of Notch or VEGFR3, and that even small amounts of VEGFR2 are able to sustain angiogenesis to some extent. We found that VEGFR2 is required independently of VEGFR3 for endothelial DLL4 up-regulation and angiogenic sprouting, and for VEGFR3 functions in angiogenesis. In contrast, VEGFR2 deletion had no effect, whereas VEGFR3 was essential for postnatal lymphangiogenesis, and even for lymphatic vessel maintenance in adult skin. Knowledge of these interactions and the signaling functions of VEGFRs in blood vessels and lymphatic vessels is essential for the therapeutic manipulation of the vascular system, especially when considering multitargeted antiangiogenic treatments.

Captopril-polyethyleneimine conjugate modified gold nanoparticles for co-delivery of drug and gene in anti-angiogenesis breast cancer therapy

Captopril-polyethyleneimine (CP) containing low molecular weight polyethyleneimine and anti-angiogenesis drug captopril conjugated via an amide bond was fabricated to modify gold nanoparticles and complex with siRNA to construct siRNA/CP/GNP complexes for the co-delivery of drug and siRNA in anti-angiogenesis breast cancer therapy. The self-assembled siRNA/CP/GNP complexes exhibited desirable and homogenous particle size, reasonable positive charges and condensation ability, and effective gene-silencing property in vitro. In addition, siRNA/CP/GNP complexes co-delivering captopril and siRNA achieved combined angiogenesis suppression by more effectively downregulating the expression of vascular endothelial growth factor mRNA and protein via different pathways in vitro, as compared to mono-delivery systems. In vivo investigation on nude mice bearing MDA-MB435 tumor xenografts revealed that siRNA/CP/GNP complexes possessed satisfying tumor homing ability and strong antitumor activity. These findings suggested that siRNA/CP/GNP complexes could be an ideal system for simultaneous transfer of drug and siRNA, which might be a new promising strategy for effective breast cancer therapy.

Antitumor effects of different administration sequences of cisplatin and Endostar on Lewis lung carcinoma

Angiogenesis plays an essential role in the growth and metastasis of a number of tumors. Anti-angiogenic drugs are able to normalize tumor vasculature and inhibit tumor growth. Therefore, it has been hypothesized that the combination of cytotoxic chemotherapy drugs and angiogenesis inhibitors may exert complementary therapeutic benefits in the treatment of cancer. In the present study, the effect of the angiogenesis inhibitor, recombinant human endostatin (Endostar), in combination with cisplatin, was evaluated in C57/BL/6 mouse xenografts under different administration sequences. The drug combinations and sequences of administration were analyzed within the cancer xenografts for any inhibitory effects. Changes in the cell cycle distribution of the cells were monitored using flow cytometry. The effects of Endostar, particularly a reduction in the density of microvessels, were assessed using a method that employed anti-cluster of differentiation 31 antibodies. The concentration of cisplatin in the blood and tumor tissue at various time-points following administration was detected by high-performance liquid chromatography. The tumor tissues that received simultaneous Endostar and cisplatin exhibited increased inhibition of tumor growth and improved cell cycle distribution compared with those that received cisplatin alone, or those in which Endostar was administered prior to cisplatin. The simultaneous administration of the drugs resulted in the lowest microvessel density in the xenografts. Under these conditions, the concentration of cisplatin was revealed to be the highest in the grafted tumor tissue. The results of the present study suggest that the co-administration of Endostar and cisplatin may aid in the optimization of the antitumor activity of cisplatin.

(99m)Tc-3P-RGD2 micro-single-photon emission computed tomography/computed tomography provides a rational basis for integrin αvβ3-targeted therapy

PURPOSE

This study was to demonstrate the utility of (99m)Tc-3P-RGD2 micro-single-photon emission computed tomography/computed tomography (SPECT/CT) for the integrin αvβ3 expression quantification in NCI-H446 and A549 lung cancer xenografts.

MATERIALS AND METHODS

(99m)Tc-3P-RGD2 was prepared with high radiochemical purity (97%±2%) and showing high in vitro stability. The in vitro affinities of (99m)Tc-3P-RGD2 to NCI-H446 and A549 tumor cells were analyzed with γ-counter, while the in vivo uptakes in NCI-H446 and A549 xenografts were evaluated with micro-SPECT/CT. The region of interest was drawn over the tumor site and contralateral muscle on the SPECT/CT image, and the tumor to nontumor (T/NT) ratio was calculated to estimate αvβ3 expression and tumor uptake. The expressions of integrin αvβ3 in vitro and in vivo were analyzed using a flow cytometer and immunofluorescence.

RESULTS

Micro-SPECT/CT demonstrated focal uptake in the tumors. T/NT ratio in NCI-H446 xenografts was significantly higher compared with the A549 tumor model, as 5.92±0.82 and 3.62±0.91, respectively, with p<0.05. In addition, integrin αvβ3 expression in NCI-H446 cells was significantly higher compared with the A549 cells, which was consistent with the imaging data. A linear relationship was observed between (99m)Tc-3P-RGD2 uptake and αvβ3 expression (R(2)=0.7667, p<0.001).

CONCLUSION

(99m)Tc-3P-RGD2 SPECT/CT could be used to quantify integrin αvβ3 expression within tumors, providing a rational basis for integrin αvβ3-targeted cancer therapy.

Lessons from the Fourth Metronomic and Anti-angiogenic Therapy Meeting, 24-25 June 2014, Milan

The Fourth Metronomic and Anti-angiogenic Therapy Meeting was held in Milan 24–25 June 2014. The meeting was a true translational meeting where researchers and clinicians shared their results, experiences, and insights in order to continue gathering useful evidence on metronomic approaches. Several speakers emphasised that exact mechanisms of action, best timing, and optimal dosage are still not well understood and that the field would learn a lot from ancillary studies performed during the clinical trials of metronomic chemotherapies. From the pre-clinical side, new research findings indicate additional possible mechanisms of actions of metronomic schedule on the immune and blood vessel compartments of the tumour micro-environment. New clinical results of metronomic chemotherapy were presented in particular in paediatric cancers [especially neuroblastoma and central nervous system (CNS) tumours], in angiosarcoma (together with beta-blockers), in hepatocellular carcinoma, in prostate cancer, and in breast cancer. The use of repurposed drugs such as metformin, celecoxib, or valproic acid in the metronomic regimen was reported and highlighted the potential of other candidate drugs to be repurposed. The clinical experiences from low- and middle-income countries with affordable regimens gave very encouraging results which will allow more patients to be effectively treated in economies where new drugs are not accessible. Looking at the impact of metronomic approaches that have been shown to be effective, it was admitted that those approaches were rarely used in clinical practice, in part because of the absence of commercial interest for companies. However, performing well-designed clinical trials of metronomic and repurposing approaches demonstrating substantial improvement, especially in populations with the greatest unmet needs, may be an easier solution than addressing the financial issue. Metronomics should always be seen as a chance to come up with new innovative affordable approaches and not as a cheap rescue strategy.

Generation and characterization of a novel human IgG1 antibody against vascular endothelial growth factor receptor 2

VEGF and its receptors, especially VEGFR2 (KDR), are known to play a critical role in angiogenesis under both physiological and pathological conditions, including cancer and angiogenic retinopathies. This study was aimed at developing a fully human IgG1 antibody (mAb-04) constructed from a phage-derived scFv, targeting the VEGF/VEGFR2 pathway. Firstly, an innovative transfection system, containing two recombinant expression vectors (pMH3 and pCApuro), were introduced into CHO-s cells and clones with higher yield selected accordingly. After an optimal fermentation condition was determined, fed-batch fermentation was performed in 5-L bioreactor with a final yield up to 60 mg/L. Further, cell proliferation, wound healing, transwell invasion, tube formation and chick embryo chorioallantoic membrane assays showed significant anti-angiogenic activity of mAb-04 in vitro and in vivo. In addition, the results of Western blotting indicated the ability of mAb-04 to inhibit VEGF-induced VEGFR2 signaling pathway. Finally, ADCC assay demonstrated that mAb-04 is capable of mediating tumor cell killing in presence of effector cells. This study has therefore proved that the full-length antibody targeting human VEGFR2 has potential clinical applications in the treatment of cancer and other diseases where pathological angiogenesis is involved.

Rapid response to systemic bevacizumab therapy in recurrent respiratory papillomatosis

Recurrent respiratory papillomatosis (RRP) is a primary benign disease, which is characterized by papillomatous growth in the respiratory tract. Malignant transformation occurs in only 3-5% of cases, however, local growth of the benign papillomas is interpreted as clinically malignant in a markedly higher proportion of patients. Local surgical or endoscopic interventional debulking or excision is currently the commonly selected treatment method and antiviral therapy is a potential adjuvant approach. However, the long-term management of RRP patients, who commonly require multiple procedures over numerous years, is challenging and the overall therapeutic armamentarium remains unsatisfactory. The administration of systemic bevacizumab treatment in a series of five patients with long histories of RRP, who required repeated local interventions to control papilloma growth is evaluated. Treatment with the anti-vascular endothelial growth factor (VEGF) antibody bevacizumab was administered at a dose of 5 mg/kg (n=1), 10 mg/kg (n=3) or 15 mg/kg (n=1) intravenously to the five RRP patients, who were clinically classified as exhibiting progressive disease. Endoscopic evaluations were performed prior to the first infusion of bevacizumab and intermittently at variable time points during the course of therapy. Histopathological analyses were performed using pre- and post-treatment papilloma biopsies, including immunohistochemical analyses of VEGF and phosphorylated VEGF receptor (VEGFR)-2 expression. The patients received between three and 16 courses of bevacizumab (median, six courses). The first course was initiated when progression following the previous intervention was observed. An immediate response to bevacizumab treatment was demonstrated in all five RRP patients. While the cumulative number of interventions in the five patients was 18 throughout the 12 months prior to the initiation of bevacizumab treatment, only one patient required interventional treatment due to a malignant transformation during the 12 months following treatment with bevacizumab (18 vs. 1 interventions, P=0.042). Histopathological analyses revealed regressive perivascular edema and normalization of the vascular structure, however, immunohistochemical analyses of the VEGF and phosphorylated VEGFR-2 expression did not demonstrate any changes following therapy. Due to the limited number of alternative treatments, VEGF-targeted therapies may represent a promising novel strategy in the treatment of RRP, which may have the potential to modify the current treatment standards, particularly in patients with poorly accessible papilloma lesions, however, this requires further investigation in clinical trials.

Lessons learned from adult clinical experience to inform evaluations of VEGF pathway inhibitors in children with cancer

Agents targeting the vascular endothelial growth factor (VEGF) pathway have been studied in adults with cancer for nearly two decades. It is important to assess the lessons learned from this adult experience and to see how these lessons can help inform pediatric development of agents in this class. The benefit achieved from the use of VEGF pathway targeted agents for adult cancers has primarily been to delay for several months disease progression and less commonly time to death for conditions in which cure is not a reasonable expectation. VEGF pathway targeted agents have shown no efficacy when applied in the adjuvant setting. For adults with advanced cancer, prolongation of survival by 2-3 months is considered an important achievement in some settings. However, the primary goal of pediatric oncology clinical research is to identify treatments that allow children to be cured of their cancer and to grow to adulthood without treatment-induced limitations that lower their quality of survival. An important question for the pediatric oncology research community, pharmaceutical companies, and regulatory agencies to address in planning for future clinical trials is whether existing data support a role for VEGF pathway targeted agents in contributing to a therapeutic pathway to cure for children with cancer.

Mixed-ligand mononuclear copper(II) complex: crystal structure and anticancer activity

A novel copper(II) complex with mixed ligands including β-[(3-formyl-5-methyl-2-hydroxy-benzylidene)amino]propionic acid anion and 1,10'-phenanthroline was synthesized, and its crystal structure was thoroughly characterized. It exerted excellent inducing apoptosis, anti-angiogenesis and antiproliferative properties in vitro. The complex can bind human serum albumin (HSA) at physiological pH conditions. Remarkably, it can induce formation of the mixed parallel/antiparallel G-quadruplex structures in the G-rich sequence of the proximal vascular endothelial growth factor (VEGF) promoter, and stabilize these G-quadruplex structures, which provide an opportunity for anti-angiogenesis chemotherapeutics. Furthermore, the complex showed a strong uptake, and exhibited multiple anticancer functions by inhibiting the expression of p-Akt and p-Erk1/2 proteins and by upregulating the levels of reactive oxygen species (ROS). Because of the reported results, this new copper(II) complex qualifies itself as a potential anticancer drug candidate.

Clodronate inhibits tumor angiogenesis in mouse models of ovarian cancer

PURPOSE

Bisphosphonates have been shown to inhibit and deplete macrophages. The effects of bisphosphonates on other cell types in the tumor microenvironment have been insufficiently studied. Here, we sought to determine the effects of bisphosphonates on ovarian cancer angiogenesis and growth via their effect on the microenvironment, including macrophage, endothelial and tumor cell populations.

EXPERIMENTAL DESIGN

Using in vitro and in vivo models, we examined the effects of clodronate on angiogenesis and macrophage density, and the overall effect of clodronate on tumor size and metastasis.

RESULTS

Clodronate inhibited the secretion of pro-angiogenic cytokines by endothelial cells and macrophages, and decreased endothelial migration and capillary tube formation. In treated mice, clodronate significantly decreased tumor size, number of tumor nodules, number of tumor-associated macrophages and tumor capillary density.

CONCLUSIONS

Clodronate is a potent inhibitor of tumor angiogenesis. These results highlight clodronate as a potential therapeutic for cancer.

A preclinical evaluation of a novel multikinase inhibitor, SKLB-329, as a therapeutic agent against hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a serious life-threatening malignant disease of liver. Molecular targeted therapies are considered a promising strategy for the treatment of HCC. Sorafenib is the first, and so far the only targeted drug approved by the US Food and Drug Administration (FDA) for clinical therapy of HCC. Despite being effective in some HCC patients, some demerits of sorafenib in the treatment of HCC, such as modest survival benefits, and drug resistance, have also been reported, which highlights the unmet medical need among patients with HCC. Here, we report a novel multikinase inhibitor discovered by us, SKLB-329, which potently inhibits angiogenesis-related kinases including VEGFR1/2/3, and FGFR2, and the Src kinase. SKLB-329 significantly inhibited endothelial cell growth, migration, invasion and tube formation. It showed potent anti-angiogenic activity in a transgenic zebrafish model. Moreover, SKLB-329 could efficiently restrain the proliferation of HCC cells through down-regulation of Src-mediated FAK and Stat3 activity. In vivo, oral administration of SKLB-329 considerably suppressed the tumor growth in HCC xenograft models (HepG2 and SMMC7721) in a dose-dependent manner. In all of the in vitro and in vivo assays of this investigation, sorafenib was used as a positive control, and in most assays SKLB-329 exhibited a higher potency compared with the positive control. In addition, SKLB-329 also bears favorable pharmacokinetic properties. Collectively, the results of preclinical studies presented here demonstrate that SKLB-329 is a promising drug candidate for HCC treatment.

Theasaponin E₁ as an effective ingredient for anti-angiogenesis and anti-obesity effects

Theasaponin E₁ (TSE₁) has been suggested to have higher biological activity than other saponins present in tea seed. Saponins have recently been considered as a potential chemotherapeutic agent for treating cancer. We examined the anti-angiogenic and anti-obesity properties of TSE₁ contributing to anti-cancer efficacy. Treating with a 10 μg/mL concentration of TSE₁ completely inhibited tube formation in human umbilical vein endothelial cells (HUVECs). TSE₁ showed toxicity toward cancer cells and inhibited in vivo growth of the tumor. The vascular endothelial growth factor (VEGF) receptor complex was suppressed, leading to the inhibition of protein kinase B (Akt) expression and down-regulation of nuclear factor-kappa B (NF-kB) activation. The differentiating 3T3-L₁ cells treated with TSE₁ had decreased lipid droplet formation measured by Oil Red O staining. Reduced weight was measured in mice fed with a TSE₁ plus high-fat diet. The results taken together, and particularly the NF-kB inhibition, suggest that TSE₁ may have multi-target action for treating cancer as a novel chemotherapeutic agent.

State of the science in cervical cancer: where we are today and where we need to go

Invasive cervical cancer remains an important global cause of death, despite the declining prevalence within the United States. Definitive therapies, including surgical resection of early-stage disease and chemoradiation for locally advanced disease, can be curative. For women who experience local or distant recurrences, the prognosis remains poor and better treatments are required. On July 18, 2013, The Gynecologic Oncology Group sponsored a State of the Science in Cervical Cancer Symposium with experts, researchers, clinicians, and interested stakeholders. This article summarize the progress that has been made, questions that require further investigation, and contemporary genomic findings and innovative treatments that may help inform the next generation of clinical trials for patients with cervical cancer.

Antibody-based tumor vascular theranostics targeting endosialin/TEM1 in a new mouse tumor vascular model

Tumor endothelial marker 1 (TEM1, endosialin) is a tumor vascular marker with significant diagnostic and therapeutic potential. However, in vivo small animal models to test affinity reagents specifically targeted to human (h)TEM1 are limited. We describe a new mouse tumor model where tumor vascular endothelial cells express hTEM1 protein.

METHODS

Immortalized murine endothelial cells MS1 were engineered to express hTEM1 and firefly luciferase and were inoculated in nude mice either alone, to form hemangioma-like endothelial grafts, or admixed with ID8 ovarian tumor cells, to form chimeric endothelial-tumor cell grafts. MORAb-004, a monoclonal humanized IgG 1 antibody specifically recognizing human TEM1 was evaluated for targeted theranostic applications, i.e., for its ability to affect vascular grafts expressing hTEM1 as well as being a tool for molecular positron emission tomography (PET) imaging.

RESULTS

Naked MORAb-004 treatment of mice bearing angioma grafts or chimeric endothelial-tumor grafts significantly suppressed the ability of hTEM1-positive endothelial cells, but not control endothelial cells, to form grafts and dramatically suppressed local angiogenesis. In addition, highly efficient radioiodination of MORAb-004 did not impair its affinity for hTEM1, and [ (124)I]-MORAb-004-PET enabled non-invasive visualization of tumors enriched with hTEM1-positive, but not hTEM1 negative vasculature with high degree of specificity and sensitivity.

CONCLUSION

The development of a new robust endothelial graft model expressing human tumor vascular proteins will help accelerate the development of novel theranostics targeting the tumor vasculature, which exhibit affinity specifically to human targets but not their murine counterparts. Our results also demonstrate the theranostic potential of MORAb-004 as PET imaging tracer and naked antibody therapy for TEM1-positive tumor.

Synergistic inhibition of angiogenesis and glioma cell-induced angiogenesis by the combination of temozolomide and enediyne antibiotic lidamycin

Present work mainly evaluated the inhibitory effects of lidamycin (LDM), an enediyne antibiotic, on angiogenesis or glioma-induced angiogenesis in vitro and in vivo, especially its synergistic anti-angiogenesis with temozolomide (TMZ). LDM alone efficiently inhibited proliferations and induced apoptosis of rat brain microvessel endothelial cells (rBMEC). LDM also interrupted the tube formation of rat brain microvessel endothelial cells (rBMEC) and rat aortic ring spreading. The blockade of rBMEC invasion and C6 cell-induced rBMEC migration by LDM was associated with decrease of VEGF secretion in a co-culture system. TMZ dramatically potentiated the effects of LDM on anti-proliferation, apoptosis induction, and synergistically inhibited angiogenesis events. As determined by western blot and ELISA, the interaction of tumor cells and the rBMEC was markedly interrupted by LDM plus TMZ with synergistic regulations of VEGF induced angiogenesis signal pathway, tumor cell invasion/migration, and apoptosis signal pathway. Immunofluorohistochemistry of CD31 and VEGF showed that LDM plus TMZ resulted in synergistic decrease of microvessel density (MVD) and VEGF expression in human glioma U87 cell subcutaneous xenograft. This study indicates that the high efficacy of LDM and the synergistic effects of LDM plus TMZ against glioma are mediated, at least in part, by the potentiated anti-angiogenesis.

Phase I study of vinblastine and sirolimus in pediatric patients with recurrent or refractory solid tumors

BACKGROUND

The combination of vinblastine and mammalian target of rapamycin (mTOR) inhibitor sirolimus inhibits the growth of neuroblastoma xenografts through pro-apoptotic and anti-angiogenic mechanisms. This phase I study aimed to explore the safety and toxicity of this combination in pediatric patients with advanced solid tumors.

PROCEDURE

Patients ≤21 years of age with recurrent/refractory solid tumors (including CNS) were eligible. Sirolimus was administered daily by mouth or nasogastric (NG) tube, with doses adjusted to achieve a target trough concentration of 10-15 ng/ml, with weekly intravenous vinblastine (dose escalated 4-6 mg/m(2)/dose according to 3 + 3 phase I design).

RESULTS

Fourteen patients were enrolled (median age 8.7 years; range 2.3-19) of whom 12 were evaluable for toxicity and 11 for response. One patient experienced a dose-limiting toxicity (grade 3 mucositis) at the highest vinblastine dose level. Myelosuppression was the most common toxicity. Dose-adjusted sirolimus trough concentrations were significantly lower in patients receiving drug via NG tube (1.50 ± 0.75 ng/ml/mg vs. 2.25 ± 1.07 ng/ml/mg for oral administration). Correlative biomarker analysis demonstrated a significant reduction in serum concentration of soluble vascular endothelial growth factor receptor (sVEGFR2) at 28 days compared to baseline consistent with inhibition of angiogenesis. One patient had a partial response and three had stable disease for more than 3 months.

CONCLUSIONS

The combination of mTOR inhibitor and vinblastine given over an extended continuous schedule is safe, associated with a reduction in circulating angiogenic factor (CAF) VEGFR2 and resulted in clinical responses. Future studies using the intravenously administered mTOR inhibitor temsirolimus are planned.

Prostate-specific membrane antigen expression in tumor-associated vasculature of breast cancers

Prostate-specific membrane antigen (PSMA) has been found to be expressed in the tumor-associated neovasculature of multiple solid tumor types including breast cancers. However, thus far, the number of cases studied from some tumor types has been limited. In this study, we set out to assess PSMA expression in the tumor-associated vasculature associated with invasive breast carcinomas in a sizable cohort of patients. One hundred and six patients with AJCC stage 0-IV breast cancer were identified. Ninety-two of these patients had primary breast cancer [invasive breast carcinoma with or without co-existing ductal carcinoma in situ (DCIS) (74) or DCIS alone (18)]. In addition, 14 patients with breast cancer metastases to the brain were identified. Immunohistochemical staining for PSMA and CD31 was performed on parallel representative tumor sections in each case. Tumor-associated vascular endothelial cell PSMA immunoreactivity was semi-quantitatively assessed based on two parameters: overall percent of endothelial positivity and staining intensity. PSMA expression for tumor-associated vascular endothelial cells was scored 0 if there was no detectable PSMA expression, 1 if PSMA staining was detectable in 5-50%, and 2 if PSMA expression was positive in >50% of microvessels. CD 31 staining was concurrently reviewed to confirm the presence of vasculature in each case. Tumor-associated vasculature was PSMA-positive in 68/92 (74%) of primary breast cancers and in 14/14 (100%) of breast cancers metastatic to brain. PSMA was not detected in normal breast tissue or carcinoma cells. All but 2 cases (98%) showed absence of PSMA expression in normal breast tissue-associated vasculature. The 10-year overall survival was 88.7% (95% CI = 80.0%, 93.8%) in patients without brain metastases. When overall survival (OS) was stratified based on PSMA score group, patients with PSMA scores of 0, 1, and 2 had 10-year OS of 95.8%, 96.0%, and 79.7%, respectively (p = 0.12). When PSMA scores of 0 and 1 were compared with 2, there was a statistically significant difference in OS (96.0% vs 79.7%, respectively, p = 0.05). Patients with a PSMA score of 2 had a significantly higher median tumor size compared with patients in the lower PSMA score groups (p = 0.04). Patients with higher nuclear grade were more likely to have a PSMA score of 2 compared with patients with lower nuclear grade (p < 0.0001). Patients with a PSMA score of 2 had a significantly higher median Ki-67 proliferation index compared with patients in the lower PSMA score groups (p < 0.0001). Patients with estrogen receptor (ER)-negative tumors were more likely to have a PSMA score of 2 compared with patients with ER-positive tumors (p < 0.0001). Patients with progesterone receptor (PR)-negative tumors were more likely to have a PSMA score of 2 compared with patients with PR-positive tumors (p = 0.03). No significant association was observed between PSMA score group status and lymph node involvement (p = 0.95). Too little variability was present in Human epidermal growth factor receptor-2 (Her2/neu) amplified tumors to correlate with PSMA score group status. To date, this is the first detailed assessment of PSMA expression in the tumor-associated vasculature of primary and metastatic breast carcinomas. Further studies are needed to evaluate whether PSMA has diagnostic and/or potential therapeutic value.

The effects of selected Australian snake venoms on tumour-associated microvascular endothelial cells (TAMECs) in vitro

The effects of various viperid and elapid venoms on the cellular biology of tumour-associated microvascular endothelial cells (TAMECs) were determined in the current study using cells isolated from a rat mammary adenocarcinoma. Previous studies to determine the effects of snake venoms on endothelial cells in vitro have in the main been performed on either human umbilical vein endothelial cells (HUVECs), bovine aortic endothelial cells (BAECs) or endothelial cell lines. These cell populations are accessible and easy to maintain in culture, however, it is well established that endothelial cells display vast heterogeneity depending upon the local microenvironment of the tissue from which they are isolated. Vascular targeting agents have been isolated from a variety of snake venoms, particularly from snakes of the Viperidae family, but it is yet to be established to what extent the venoms from Australian elapids possess similar vascular targeting properties. The present study used endothelial cells (ECs) isolated from the microvasculature of a rat mammary adenocarcinoma to determine the effects of a panel of snake venoms, including viperid venoms with known apoptotic activity and elapid venoms (both exotic and indigenous to Australia), on endothelial morphology and viability, paying specific attention to apoptotic responses. Three of the five Australian snake venoms investigated in this study elicited significant apoptotic responses in ECs which were in many ways similar to responses elicited by the selected viperid venoms. This suggests that these Australian elapids may possess vascular targeting components similar to those found within viperid venoms.

The role of angiogenic factors in fibroid pathogenesis: potential implications for future therapy

BACKGROUND

It is well established that tumors are dependent on angiogenesis for their growth and survival. Although uterine fibroids are known to be benign tumors with reduced vascularization, recent work demonstrates that the vasculature of fibroids is grossly and microscopically abnormal. Accumulating evidence suggests that angiogenic growth factor dysregulation may be implicated in these vascular and other features of fibroid pathophysiology.

METHODS

Literature searches were performed in PubMed and Google Scholar for articles with content related to angiogenic growth factors and myometrium/leiomyoma. The findings are hereby reviewed and discussed.

RESULTS

Multiple growth factors involved in angiogenesis are differentially expressed in leiomyoma compared with myometrium. These include epidermal growth factor (EGF), heparin-binding-EGF, vascular endothelial growth factor, basic fibroblast growth factor, platelet-derived growth factor, transforming growth factor-β and adrenomedullin. An important paradox is that although leiomyoma tissues are hypoxic, leiomyoma feature down-regulation of key molecular regulators of the hypoxia response. Furthermore, the hypoxic milieu of leiomyoma may contribute to fibroid development and growth. Notably, common treatments for fibroids such as GnRH agonists and uterine artery embolization (UAE) are shown to work at least partly via anti-angiogenic mechanisms.

CONCLUSIONS

Angiogenic growth factors play an important role in mechanisms of fibroid pathophysiology, including abnormal vasculature and fibroid growth and survival. Moreover, the fibroid's abnormal vasculature together with its aberrant hypoxic and angiogenic response may make it especially vulnerable to disruption of its vascular supply, a feature which could be exploited for treatment. Further experimental studies are required in order to gain a better understanding of the growth factors that are involved in normal and pathological myometrial angiogenesis, and to assess the potential of anti-angiogenic treatment strategies for uterine fibroids.

YL529, a novel, orally available multikinase inhibitor, potently inhibits angiogenesis and tumour growth in preclinical models

BACKGROUND AND PURPOSE

Targeted chemotherapy using small-molecule inhibitors of angiogenesis and proliferation is a promising strategy for cancer therapy.

EXPERIMENTAL APPROACH

YL529 was developed via computer-aided drug design, de novo synthesis and high-throughput screening. The biochemical, pharmacodynamic and toxicological profiles of YL529 were investigated using kinase and cell viability assays, a mouse tumour cell-containing alginate bead model, a zebrafish angiogenesis model and several human tumour xenograft models in athymic mice.

KEY RESULTS

In vitro, YL529 selectively inhibited the activities of VEGFR2/VEGFR3 and serine/threonine kinase RAF kinase. YL529 inhibited VEGF165 -induced phosphorylation of VEGFR2, as well as the proliferation, migration, invasion and tube formation of human umbilical vascular endothelial cells. It also significantly blocked vascular formation and angiogenesis in the zebrafish model. Moreover, YL529 strongly attenuated the proliferation of A549 cells by disrupting the RAF/mitogen-activated protein (MAP) or extracellular signal-regulated kinase (Erk) kinase (MEK) kinase kinase/MAPK pathway. Oral administration of YL529 (37.5-150 mg(-1) ·kg(-1) ·day(-1) ) to nude mice bearing established tumour xenografts significantly prevented the growth (60-80%) of A549, SPC-A1, A375, OS-RC-2 and HCT116 tumours without detectable toxicity. YL529 markedly reduced microvessel density and increased tumour cell apoptosis in the tumours formed in mice inoculated with the lung cancer cells, SPC-A1 and A549, and the colon carcinoma cells, HCT116.

CONCLUSIONS AND IMPLICATIONS

YL529, an orally active multikinase inhibitor, shows therapeutic potential for solid tumours, and warrants further investigation as a possible anticancer agent.

First-line bevacizumab in combination with chemotherapy for HER2-negative metastatic breast cancer: pooled and subgroup analyses of data from 2447 patients

BACKGROUND

Bevacizumab has consistently demonstrated improved progression-free survival (PFS) and response rate when combined with first-line chemotherapy for HER2-negative metastatic breast cancer (mBC). However, the lack of a significant overall survival (OS) difference continues to attract debate, and identification of patients deriving greatest benefit from bevacizumab remains elusive.

PATIENTS AND METHODS

Individual patient data from three randomised phase III trials in the first-line HER2-negative mBC setting were analysed, focusing specifically on efficacy in poor-prognosis patients.

RESULTS

The meta-analysis (n = 2447) demonstrated a PFS hazard ratio (HR) of 0.64 (95% confidence interval [CI] 0.57-0.71; median 9.2 months with bevacizumab versus 6.7 months with non-bevacizumab therapy) and response rate of 49% versus 32%, respectively. The OS HR was 0.97 (95% CI 0.86-1.08); median 26.7 versus 26.4 months, respectively. In patients with triple-negative mBC, the HRs for PFS and OS were 0.63 (95% CI 0.52-0.76) and 0.96 (95% CI 0.79-1.16), respectively. Median PFS was 8.1 months with bevacizumab versus 5.4 months with chemotherapy alone, median OS was 18.9 versus 17.5 months, respectively, and 1-year OS rates were 71% versus 65%.

CONCLUSIONS

Bevacizumab improves efficacy, including 1-year OS rates, both overall and in subgroups of poor-prognosis patients with limited treatment options.

Targeted anti-vascular therapies for ovarian cancer: current evidence

Ovarian cancer presents at advanced stage in around 75% of women, and despite improvements in treatments such as chemotherapy, the 5-year survival from the disease in women diagnosed between 1996 and 1999 in England and Wales was only 36%. Over 80% of patients with advanced ovarian cancer will relapse and despite a good chance of remission from further chemotherapy, they will usually die from their disease. Sequential treatment strategies are employed to maximise quality and length of life but patients eventually become resistant to cytotoxic agents. The expansion in understanding of the molecular biology that characterises cancer cells has led to the rapid development of new agents to target important pathways but the heterogeneity of ovarian cancer biology means that there is no predominant defect. This review attempts to discuss progress to date in tackling a more general target applicable to ovary cancer-angiogenesis.

A Phase I study of pazopanib in combination with gemcitabine in patients with advanced solid tumors

PURPOSE

Pazopanib plus gemcitabine combination therapy was explored in patients with advanced solid tumors.

METHODS

In a modified 3 + 3 enrollment scheme, oral once-daily pazopanib was administered with intravenous gemcitabine (Days 1 and 8, 21-day cycles). Three protocol-specified dose levels were tested: pazopanib 400 mg plus gemcitabine 1,000 mg/m(2), pazopanib 800 mg plus gemcitabine 1,000 mg/m(2), and pazopanib 800 mg plus gemcitabine 1,250 mg/m(2). Maximum-tolerated dose was based on dose-limiting toxicities during treatment Cycle 1. In the expansion phase, six additional patients were enrolled at the highest tolerable dose level.

RESULTS

Twenty-two patients were enrolled. At the highest dose level tested (pazopanib 800 plus gemcitabine 1,250), patients received >80% of their planned dose and the regimen was deemed safe and tolerable. The most common treatment-related adverse events included fatigue, neutropenia, nausea, and decreased appetite. Neutropenia and thrombocytopenia were the most common events leading to dose modifications. Pharmacokinetic interaction between pazopanib and gemcitabine was not observed. One objective partial response at the highest dose was observed in a patient with metastatic melanoma. Prolonged disease stabilization (>12 cycles) was reported in three patients (metastatic melanoma, cholangiocarcinoma, and colorectal carcinoma).

CONCLUSION

Combination pazopanib plus gemcitabine therapy is tolerable, with an adverse event profile reflective of that associated with the individual agents. There was no apparent pharmacokinetic interaction with pazopanib plus gemcitabine co-administration, although patient numbers were limited. Further investigation of combined pazopanib plus gemcitabine is warranted.

Anti-angiogenic activity of Herba Epimedii on zebrafish embryos in vivo and HUVECs in vitro

Herba Epimedii, an herb commonly used in East Asian medicine, is commonly used for treatment of impotence, osteoporosis and many inflammatory conditions in traditional Chinese medicine. Recent studies revealed that Herba Epimedii also has anti-tumor or anti-cancer activities, which may possibly be mediated through anti-angiogenesis. This study aims to examine and confirm the anti-angiogenic activity in the herb using both in vivo and in vitro approaches. The 95% ethanol extract and four subsequent fractions (n-hexane, ethyl acetate (EA), n-butanol and aqueous fractions) of Herba Epimedii were tested on the zebrafish model by the quantitative assay for endogenous alkaline phosphatase; then, the active fraction was further tested on Tg(fli1a:EGFP)y1 zebrafish embryos and human umbilical vein endothelial cells (HUVECs) for the anti-angiogenic effects. In addition, the action mechanism of Herba Epimedii was further investigated on wild-type zebrafish embryos and HUVECs. The EA fraction showed anti-angiogenic effects in both in vivo and in vitro models. Further experiments demonstrated that it might affect angiogenesis by acting on multiple molecular targets in zebrafish embryos and ERK signaling pathway in HUVECs. In conclusion, Herba Epimedii can inhibit angiogenesis, which may be the mechanism for its anti-inflammatory, anti-tumor and anti-cancer actions.

Antitumor effects of Stat3-siRNA and endostatin combined therapies, delivered by attenuated Salmonella, on orthotopically implanted hepatocarcinoma

Hepatocellular carcinoma (HCC) is one of the most aggressive carcinomas. Limited therapeutic options, mainly due to a fragmented genetic understanding of HCC, and major HCC resistance to conventional chemotherapy are the key reasons for a poor prognosis. Thus, new effective treatments are urgent and gene therapy may be a novel option. Signal transducer and activator of transcription 3 (Stat3) is a highly studied member of the STAT family. Inhibition of Stat3 signaling has been found to suppress tumor growth and improve survival, providing a molecular target for cancer therapy. Furthermore, HCC is a hypervascular tumor and angiogenesis plays a crucial role in tumor growth and metastasis. Thus, anti-angiogenic therapy, combined with inhibition of Stat3, may be an effective approach to combat HCC. We tested the effect that the combination therapy consisting of endostatin (a powerful angiogenesis inhibitor) and Stat3-specific small interfering RNA, using a DNA vector delivered by attenuated S. typhimurium, on an orthotopic HCC model in C57BL/6 mice. Although antitumor effects were observed with either single therapeutic treatment, the combination therapy provided superior antitumor effects. Correlated with this finding, the combination treatment resulted in significant alteration of Stat3 and endostatin levels and that of the downstream gene VEGF, decreased cell proliferation, induced cell apoptosis and inhibited angiogenesis. Importantly, combined treatment also elicited immune system regulation of various immune cells and cytokines. This study has provided a novel cancer gene therapeutic approach.

Deguelin, a novel anti-tumorigenic agent targeting apoptosis, cell cycle arrest and anti-angiogenesis for cancer chemoprevention

Deguelin is a natural compound of the flavonoid family products isolated from Derris trifoliata Lour. or Mundulea sericea (Leguminosae). It exhibited significant anti-tumorigenesis and anti-proliferative activity in various types of cancer both in vitro and in vivo. Deguelin induced cell apoptosis by blocking anti-apoptotic pathways, such as PI3K-Akt, IKK-IκBα-NF-κB and AMPK-mTOR-survivin, while inhibiting tumor cell propagation and malignant transformation through p27-cyclinE-pRb-E2F1 cell cycle control and HIF-1α-VEGF anti-angiogenic pathways. In pre-clinical trials, deguelin markedly decreased the tumor incidence. These biological findings identified deguelin as a novel anti-tumorigenic agent targeting apoptosis, cell cycle arrest and anti-angiogenesis for cancer chemoprevention and chemotherapy.

Aspirin triggered-lipoxin A4 reduces the adhesion of human polymorphonuclear neutrophils to endothelial cells initiated by preeclamptic plasma

INTRODUCTION

Preeclampsia is a disorder of pregnancy, characterized by hypertension and proteinuria after 20 weeks of gestation. Here, we evaluated the role of aspirin triggered-lipoxin A(4) (ATL, 15-epi-LXA(4)) on the modulation of the adhesion of human polymorphonuclear neutrophils (PMN) to endothelial cells initiated by preeclamptic plasma.

MATERIALS AND METHODS

Plasma from preeclamptic, normotensive pregnant, and non-pregnant women were analyzed for factors involved in regulating angiogenesis, inflammation and lipid peroxidation. Plasma from preeclamptic women was added to human umbilical vein endothelial cells, and the adhesion of PMN (incubated with or without ATL) to cells was evaluated.

RESULTS

Preeclampsia was associated with some augmented anti-angiogenic, oxidative and pro-inflammatory markers, as well as increasing human PMN-endothelial cell adhesion. This cell adhesion was reduced when human PMN were incubated with ATL prior to addition to endothelial monolayers.

DISCUSSIONS AND CONCLUSIONS

Our results are the starting point for further research on the efficacy and rational use of aspirin in preeclampsia.

Corticosteroids in brain cancer patients: benefits and pitfalls

Glucocorticoids have been used for decades in the treatment of brain tumor patients and belong to the most powerful class of agents in reducing tumor-associated edema and minimizing side effects and the risk of encephalopathy in patients undergoing radiation therapy. Unfortunately, corticosteroids are associated with numerous and well-characterized adverse effects, constituting a major challenge in patients requiring long-term application of corticosteroids. Novel antiangiogenic agents, such as bevacizumab (Avastin®), which have been increasingly used in cancer patients, are associated with significant steroid-sparing effects, allowing neuro-oncologists to reduce the overall use of corticosteroids in patients with progressive malignant brain tumors. Recent experimental studies have revealed novel insights into the mechanisms and effects of corticosteroids in cancer patients, including modulation of tumor biology, angiogenesis and steroid-associated neurotoxicity. This article summarizes current concepts of using corticosteroids in brain cancer patients and highlights potential pitfalls in their effects on both tumor and neural progenitor cells.

Antitumor activity of placenta-derived mesenchymal stem cells producing pigment epithelium-derived factor in a mouse melanoma model

Mesenchymal stem cells (MSCs) are a new tool that can be used for the delivery of therapeutic agents to tumor cells. Among the various types of MSCs, placenta-derived MSCs (PDMSCs) have emerged as one of the most attractive vehicles for gene therapy due to their high throughput, lack of ethical concerns, non-invasive procedure for their harvesting and ease of isolation. In this study, we evaluated the antitumor activity of human PDMSCs loaded with recombinant adenoviruses expressing pigment epithelium-derived factor (PEDF). PDMSCs were transduced with adenovirus PEDF and the expression of PEDF was confirmed by western blotting and ELISA. The inhibition of angiogenesis mediated by PEDF-expressing PDMSCs (PDMSC-PEDF) was determined using human umbilical vein endothelial cell (HUVEC) proliferation inhibition assay and migration inhibition assay in vitro. In in vivo experiments, C57BL/6 mice bearing B16-F10 melanoma were treated with intratumoral injection of PDMSC-PEDF twice at a 4-day interval. The tumor volume and weight were recorded. The results demonstrated that the administration of PDMSC-PEDF resulted in marked suppression of tumor growth in an established melanoma model, which was associated with a decreased number of microvessels and increased apoptosis of tumor cells compared with the controls. The results suggest that human PDMSCs have potential use as effective delivery vehicles for cancer gene therapy.

Penetration of endothelial cell coated multicellular tumor spheroids by iron oxide nanoparticles

Iron oxide nanoparticles are a useful diagnostic contrast agent and have great potential for therapeutic applications. Multiple emerging diagnostic and therapeutic applications and the numerous versatile parameters of the nanoparticle platform require a robust biological model for characterization and assessment. Here we investigate the use of iron oxide nanoparticles that target tumor vasculature, via the tumstatin peptide, in a novel three-dimensional tissue culture model. The developed tissue culture model more closely mimics the in vivo environment with a leaky endothelium coating around a glioma tumor mass. Tumstatin-iron oxide nanoparticles showed penetration and selective targeting to endothelial cell coating on the tumor in the three-dimensional model, and had approximately 2 times greater uptake in vitro and 2.7 times tumor neo-vascularization inhibition. Tumstatin provides targeting and therapeutic capabilities to the iron oxide nanoparticle diagnostic contrast agent platform. And the novel endothelial cell-coated tumor model provides an in vitro microtissue environment to evaluate nanoparticles without moving into costly and time-consuming animal models.

[Toxicities of targeted therapies and their management in renal cancer: methodology of guidelines]

Advanced renal cell carcinoma (RCC) is associated with a poor prognosis and is refractory to standard chemotherapy. Recent progress in the understanding of molecular biology and pathogenesis of renal cell cancer has been translated into the development of new therapeutic strategies. The management of metastatic RCC has been revolutionized with the development of targeted molecular therapies against VEGF-VEGFR and mTOR. Randomized phase III clinical trials demonstrated clinical benefit for patients with advanced RCC in overall survival and progression free survival. Guidelines for the management of side effects induced by these targeted therapies seem to be warranted.

Integrating individual functional moieties of CXCL10 and CXCL11 into a novel chimeric chemokine leads to synergistic antitumor effects: a strategy for chemokine-based multi-target-directed cancer therapy

The complexity of tumor biology necessitates a multimodality approach that targets different aspects of tumor environment in order to generate the greatest benefit. IFN-inducible T cell alpha chemoattractant (ITAC)/CXCL11 and IFN-inducible protein 10 (IP10)/CXCL10 could exert antitumor effects with functional specificity and thus emerge as attractive candidates for combinatorial strategy. Disappointedly, a synergistic antitumor effect could not be observed when CXCL10 and CXCL11 were pooled together. In this regard, we seek to improve antitumor efficacy by integrating their individual functional moieties into a chemokine chimeric molecule, designated ITIP, which was engineered by substituting the N-terminal and N-loop region of CXCL10 with those of CXCL11. The functional properties of ITIP were determined by chemotaxis and angiogenesis assays. The antitumor efficacy was tested in murine CT26 colon carcinoma, 4T1 mammary carcinoma and 3LL lung carcinoma. Here we showed that ITIP not only exhibited respective functional superiority but strikingly promoted regression of established tumors and remarkably prolonged survival of mice compared with its parent chemokines, either alone or in combination. The chemokine chimera induced an augmented anti-tumor immunity and a marked decrease in tumor vasculature. Antibody neutralization studies indicated that CXCL10 and CXCL11 moieties of ITIP were responsible for anti-angiogenesis and chemotaxis in antitumor response, respectively. These results indicated that integrating individual functional moieties of CXCL10 and CXCL11 into a chimeric chemokine could lead to a synergistic antitumor effect. Thus, this integration strategy holds promise for chemokine-based multiple targeted therapy of cancer.