Antiangiogenic Response Research Articles

PET imaging in urology: a rapidly growing successful collaboration.

To discuss and highlight the recent findings in urological oncology focusing on nuclear medicine advances on imaging and therapy. Testicular tumors: F-FDG as the standard positron emission tomography (PET) tracer with proven good accuracy in detecting metastatic testicular cancer; urothelial cancer: good accuracy of F-FDG PET in detecting distant metastases but poor results in detecting local disease; prostate cancer: prostate-specific membrane antigen (PSMA) is a promising target for imaging prostate cancer with unprecedented accuracy in both staging and restaging and prospective studies were recently published. In castration-resistant prostate cancer, PSMA-targeting radionuclide therapy is showing potential as a curative possibility (e.g. using Lu-PSMA); renal cell cancer (RCC): besides FDG other PET radiotracers are under clinical evaluation (e.g. antibody-based molecular imaging, metabolic radiotracers and PSMA-based tracers). PSMA-based imaging may have applications in staging clear-cell RCC and in the selection and in the antiangiogenic treatment's response assessment. Possible role of PSMA-targeting radionuclide therapy? In urological oncology, the use of F-FDG has been limited by a generally low tumor uptake and physiological F-FDG excretion by the urinary system. Other radiotracers are increasing the urologist's portfolio allowing imaging of several biochemical pathways. Theragnostic possibilities are also under investigation thanks to PSMA-based tracers.

Bevacizumab dose adjustment to improve clinical outcomes of glioblastoma

BackgroundGlioblastoma (GBM) is one of the most aggressive and vascularized brain tumors in adults, with a median survival of 20.9 months. In newly diagnosed and recurrent GBM, bevacizumab demonstrated an increase in progression-free survival, but not in overall survival.MethodsWe conducted an in silico analysis of VEGF expression, in a cohort of 1082 glioma patients. Then, to determine whether appropriate bevacizumab dose adjustment could increase the anti-angiogenic response, we used in vitro and in vivo GBM models. Additionally, we analyzed VEGFA expression in tissue, serum, and plasma in a cohort of GBM patients before and during bevacizumab treatment.ResultsWe identified that 20% of primary GBM did not express VEGFA suggesting that these patients would probably not respond to bevacizumab therapy as we proved in vitro and in vivo. We found that a specific dose of bevacizumab calculated based on VEGFA expression levels increases the response to treatment in cell culture and serum samples from mice bearing GBM tumors. Additionally, in a cohort of GBM patients, we observed a correlation of VEGFA levels in serum, but not in plasma, with bevacizumab treatment performance.ConclusionsOur data suggest that bevacizumab dose adjustment could improve clinical outcomes in Glioblastoma treatment.

Hypoxia: Turning vessels into vassals of cancer immunotolerance.

Hypoxia is a universal feature of solid cancers caused by a mismatch between cellular oxygen supply and consumption. To meet the increased demand for oxygen, hypoxic cancer cells (CCs) induce a multifaceted process known as angiogenesis, wherein new vessels are formed by the sprouting of pre-existing ones. In addition to providing oxygen for growth and an exit route for dissemination, angiogenic vessels and factors are co-opted by CCs to enable the generation of an immunotolerant, hypoxic tumor microenvironment, leading to therapeutic failure and mortality. In this review, we discuss how hypoxia-inducible factors (HIFs), the mechanistic target of rapamycin (mTOR), and the unfolded protein response (UPR) control angiogenic factors serving both vascular and immunomodulatory functions in the tumor microenvironment. Possible therapeutic strategies, wherein targeting oxygen sensing might enhance anti-angiogenic and immunologically-mediated anti-cancer responses, are suggested.

Elevated cell-free fetal DNA contributes to placental inflammation and antiangiogenesis via AIM2 and IFI16 during pre-eclampsia.

Accumulated evidence has shown that pre-eclampsia (PE) is related to both maternal and utero-placental antiangiogenesis and inflammation. Remarkably, an elevated cell-free fetal DNA (cffDNA) level has been found in maternal circulation; however, it remains unclear whether this DNA can induce activation of cytosolic DNA sensor signaling pathways and lead to the development of PE. In this study, we found that trophoblast cells constitutively expressed the cytosolic DNA sensors, absent in melanoma 2 (AIM2) and interferon-inducible protein 16 (IFI16). The cffDNA and pro-inflammatory and antiangiogenic factors were present at higher concentrations in PE compared with the control group and correlated with the severity of PE. DNA stimulation significantly increased the AIM2 and IFI16 levels, consistent with the elevated AIM2 and IFI16 expression in women with PE, and elicited increased production of AIM2-mediatedinterleukin IL-8 (IL-8), IL-6 and CC chemokine ligand 2 (CCL2) and IFI16-mediated sEndoglin, sFlt-1 and CXCL10. Furthermore, enhancement of the inflammatory response was found to be induced by DNA exposure, but DNA exposure did not induce PE-like symptoms in pregnant mice. It is possible that elevated cffDNA could reflect the degree of placental damage and trigger cytosolic DNA sensoractivation, which disrupts the immunity balance and, consequently, contributes to inflammatory and antiangiogenic responses. In conclusion, the results of this study suggest that circulating cffDNA levels are increased in preeclamptic women and act through AIM2 and IFI16 activation to promote the production of pro-inflammatory and antiangiogenic factors, which correlate with the severity of the disease, and may offer insights into the etiology and pathogenesis of PE.

Intratumoral Gene Electrotransfer of Plasmid DNA Encoding shRNA against Melanoma Cell Adhesion Molecule Radiosensitizes Tumors by Antivascular Effects and Activation of an Immune Response.

In this study, radiotherapy was combined with the gene electrotransfer (GET) of plasmid encoding shRNA against melanoma cell adhesion molecule (pMCAM) with dual action, which was a vascular-targeted effect mediated by the silencing of MCAM and an immunological effect mediated by the presence of plasmid DNA in the cytosol-activating DNA sensors. The effects and underlying mechanisms of therapy were evaluated in more immunogenic B16F10 melanoma and less immunogenic TS/A carcinoma. The silencing of MCAM potentiated the effect of irradiation (IR) in both tumor models. Combined therapy resulted in 81% complete responses (CR) in melanoma and 27% CR in carcinoma. Moreover, after the secondary challenge of cured mice, 59% of mice were resistant to challenge with melanoma cells, and none were resistant to carcinoma. Combined therapy reduced the number of blood vessels; induced hypoxia, apoptosis, and necrosis; and reduced cell proliferation in both tumor models. In addition, the significant increase of infiltrating immune cells was observed in both tumor models but more so in melanoma, where the expression of IL-12 and TNF-α was determined as well. Our results indicate that the combined therapy exerts both antiangiogenic and immune responses that contribute to the antitumor effect. However, tumor immunological status is crucial for a sufficient immune system contribution to the overall antitumor effect.

Allopurinol inhibits excess glucose-induced trophoblast IL-1β and ROS production.

Pre-gestational diabetes is a risk factor for preeclampsia, a condition associated with inflammatory markers, a dysregulated angiogenic profile, and impaired placentation. Using an in vitro model, we previously reported that hyperglycemic levels of glucose induced a pro-inflammatory (IL-1β, IL-8, RANTES, GRO-α), anti-angiogenic (sFlt-1) and anti-migratory profile in a human trophoblast cell line. The IL-1β response to excess glucose was mediated by uric acid-induced activation of the NLRP3 inflammasome. Allopurinol is a xanthine oxidase inhibitor that inhibits uric acid and reactive oxygen species (ROS) production. Thus, we sought to test the effects of allopurinol on the IL-1β and other inflammatory, angiogenic and migratory responses that are triggered in the trophoblast by excess glucose. Under excess glucose conditions, allopurinol significantly inhibited trophoblast secretion of inflammatory IL-1β; caspase-1 activity; IL-8; RANTES; and GRO-α. Allopurinol also significantly inhibited excess glucose-induced trophoblast secretion of anti-angiogenic sFlt-1. The presence of IL1Ra significantly inhibited excess glucose-induced trophoblast IL-8 and GRO-α secretion but had no effect on RANTES or sFlt-1. Conversely, DPI, a ROS inhibitor, significantly inhibited excess glucose-induced trophoblast GRO-α and sFlt-1 secretion, but had no effect on IL-8 or RANTES. Together, our findings indicate that the xanthine oxidase inhibitor allopurinol inhibited excess glucose-induced trophoblast IL-1β secretion. Additionally, through its inhibition of both IL-1β and ROS production by the trophoblast, allopurinol reduced the additional pro-inflammatory and anti-angiogenic responses to excess glucose. Thus, allopurinol may be a candidate medication to prevent placental dysfunction and adverse pregnancy outcomes, such as preeclampsia, in pregnant women with diabetes.

Intravoxel Incoherent Motion of Colon Cancer Liver Metastases for the Assessment of Response to Antiangiogenic Treatment: Results from a Pilot Study

Objective: This study was aimed at evaluating the intravoxel incoherent motion (IVIM) parameter alterations of liver metastases of colorectal carcinoma (CRC) during antiangiogenic bevacizumab combination therapy. Methods: Twenty-five patients with CRC liver metastases treated with bevacizumab in combination with FOLFOX-or-FOLFIRI protocols were enrolled in the study. MRI was performed using a 1.5-tesla scanner pre-treatment (PT) and at 3, 6, and 9 months of therapy. Routine abdominal MRI sequences and an IVIM-DWI (diffusion-weighted imaging) sequence were obtained. The IVIM-DWI sequence was executed with 16 b-values varying from 0 to 1,400 s/mm². The mean values of apparent diffusion coefficient (ADC), true diffusion (D), pseudodiffusion (D*), and perfusion fraction (f) of each metastasis were obtained for all b-values, and the time-related changes were recorded to analyze the chronologic responses to antiangiogenic therapy. The RECIST 1.1 criteria were used for the evaluation of treatment response. Results: The diameters of the metastases diminished significantly at 9 months when compared with PT (p = 0.03). The D (p = 0.10) and ADC (p = 0.21) values of the metastases increased at 9 months of therapy. D* was the highest at 3 months (p =0.24); it decreased at 6 (p =0.97) and 9 months (p =0.87) of therapy. The f value had peaked at 3 months (p =0.51) and started to decrease thereafter. At 6 months, f decreased to the lowest values (p =0.12). Conclusion: IVIM parameters, particularly the perfusion fraction, may quantitatively reflect the response to antiangiogenic treatment. The antiangiogenic response manifests after 3 months of therapy before the RECIST-related response.

Monitoring Dual VEGF Inhibition in Human Pancreatic Tumor Xenografts With Dynamic Contrast-Enhanced Ultrasound.

Background:Association of drugs acting against different antiangiogenic mechanisms may increase therapeutic effect and reduce resistance. Noninvasive monitoring of changes in the antiangiogenic response of individual tumors could guide selection and administration of drug combinations. Noninvasive detection of early therapeutic response during dual, vertical targeting of the vascular endothelial growth factor pathway was investigated in an ectopic subcutaneous xenograft model for human pancreatic tumor.Methods:Dynamic contrast-enhanced ultrasound 12 MHz was used to monitor tumor-bearing Naval Medical Research Institute mice beginning 15 days after tumor implantation. Mice received therapy from 15 to 29 days with sorafenib (N = 9), ziv-aflibercept (N = 11), combined antiangiogenic agents (N = 11), and placebo control (N = 14). Sorafenib (BAY 43-9006; Nexavar), a multikinase inhibitor acting on Raf kinase and receptor tyrosine kinases—including vascular endothelial growth factor receptors 2 and 3—was administered daily (60 mg/kg, per os). Ziv-aflibercept (ZALTRAP), a high-affinity ligand trap blocking the activity of vascular endothelial growth factor A, vascular endothelial growth factor B, and placental growth factor was administered twice per week (40 mg/kg, intraperitoneally).Results:Functional evaluation with dynamic contrast-enhanced ultrasound indicated stable tumor vascularization for the control group while revealing significant and sustained reduction after 1 day of therapy in the combined group (P = .007). There was no survival benefit or penalty due to drug combination. The functional progression-free survival assessed with dynamic contrast-enhanced ultrasound was significantly higher for the 3 treated groups; whereas, the progression-free survival based on tumor size did not discriminate therapeutic effect.Conclusions:Dynamic contrast-enhanced ultrasound, therefore, presents strong potential to monitor microvascular modifications during antiangiogenic therapy, a key role to monitoring antiangiogenic combining therapy to adapt dose range drug.

Angioregulatory microRNAs in Colorectal Cancer.

Colorectal cancer (CRC) is one of the leading causes of cancer mortality. Angiogenesis is a rate-determining step in CRC development and metastasis. The balance of angiogenic and antiangiogenic factors is crucial in this process. Angiogenesis-related genes can be regulated post-transcriptionally by microRNAs (miRNAs) and some miRNAs have been shown to shuttle between tumor cells and the tumor microenvironment (TME). MiRNAs have context-dependent actions and can promote or suppress angiogenesis dependent on the type of cancer. On the one hand, miRNAs downregulate anti-angiogenic targets and lead to angiogenesis induction. Tumor suppressor miRNAs, on the other hand, enhance anti-angiogenic response by targeting pro-angiogenic factors. Understanding the interaction between these miRNAs and their target mRNAs will help to unravel molecular mechanisms involved in CRC progression. The aim of this article is to review the current literature on angioregulatory miRNAs in CRC.

18F]Fluciclatide PET as a biomarker of response to combination therapy of pazopanib and paclitaxel in platinum-resistant/refractory ovarian cancer

BackgroundAngiogenesis is a driver of platinum resistance in ovarian cancer. We assessed the effect of combination pazopanib and paclitaxel followed by maintenance pazopanib in patients with platinum-resistant/refractory ovarian cancer. Integrins αvβ3 and αvβ5 are both upregulated in tumor-associated vasculature. [18F]Fluciclatide is a novel PET tracer that has high affinity for integrins αvβ3/5, and was used to assess the anti-angiogenic effect of pazopanib.Patients and methodsWe conducted an open-label, phase Ib study in patients with platinum-resistant/refractory ovarian cancer. Patients received 1 week of single-agent pazopanib (800 mg daily) followed by combination therapy with weekly paclitaxel (80 mg/m2). Following completion of 18 weeks of combination therapy, patients continued with single-agent pazopanib until disease progression. Dynamic [18F]fluciclatide-PET imaging was conducted at baseline and after 1 week of pazopanib. Response (RECIST 1.1), toxicities, and survival outcomes were recorded. Circulating markers of angiogenesis were assessed with therapy.ResultsFourteen patients were included in the intention-to-treat analysis. Complete and partial responses were seen in seven patients (54%). Median progression-free survival (PFS) was 10.63 months, and overall survival (OS) was 18.5 months. Baseline [18F]fluciclatide uptake was predictive of long PFS. Elevated baseline circulating angiopoietin and fibroblast growth factor (FGF) were predictive of greater reduction in SUV60,mean following pazopanib. Kinetic modeling of PET data indicated a reduction in K1 and Ki following pazopanib indicating reduced radioligand delivery and retention.ConclusionsCombination therapy followed by maintenance pazopanib is effective and tolerable in platinum-resistant/refractory ovarian cancer. [18F]Fluciclatide-PET uptake parameters predict clinical outcome with pazopanib therapy indicating an anti-angiogenic response.

Insights into the Regulation of Tumor Angiogenesis by Micro-RNAs.

One of the hallmarks of cancer is angiogenesis, a series of events leading to the formation of the abnormal vascular network required for tumor growth, development, progression, and metastasis. MicroRNAs (miRNAs) are short, single-stranded, non-coding RNAs whose functions include modulation of the expression of pro- and anti-angiogenic factors and regulation of the function of vascular endothelial cells. Vascular-associated microRNAs can be either pro- or anti-angiogenic. In cancer, miRNA expression levels are deregulated and typically vary during tumor progression. Experimental data indicate that the tumor phenotype can be modified by targeting miRNA expression. Based on these observations, miRNAs may be promising targets for the development of novel anti-angiogenic therapies. This review discusses the role of various miRNAs and their targets in tumor angiogenesis, describes the strategies and challenges of miRNA-based anti-angiogenic therapies and explores the potential use of miRNAs as biomarkers for anti-angiogenic therapy response.

The Antiangiogenic Effects of Tamoxifen might be Attributed to Receptor Binding Capacity of its Solvent Dimethylsulfoxide in Breast Cancer: A Molecular Docking Study

Aim: Tamoxifen, a Dimethyl sulfoxide (DMSO)-soluble chemotherapeutic, is widely used in the treatment of breast cancer. Tamoxifen has an anti-angiogenic effect especially on breast tumor cells by blocking VEGF(Vascular Endothelial Growth Factor) production. On the other hand, according to our previously studies, we demonstrated that DMSO could mimics the cytotoxic effects of Thalidomide in 4T1 mouse breast cancer cells and is related with the anti-angiogenic response of HeLa cells. At this point of view, the aim of this study was to determine the possible binding effects of DMSO on certain cell surface receptors.
 Methods: The in silico studies were implemented using the Docking Server. X-ray structures of receptor proteins’ PDB files were obtained from Protein Data Bank [Human Progesteron Receptor (PDB ID: 1A28, Human Tumor Necrosis Factor Receptor-1 (PDB ID: 1EXT), Human Interferon Gamma Receptor-1 (PDB ID: 1FG9), Human Epidermal Growth Factor Receptor (PDB ID: 1IVO)]. Docking simulations were performed using the Lamarckian genetic algorithm (LGA) and the Solis & Wets local search method.
 Results: According to the molecular docking results of this study, DMSO, the general solvent of Tamoxifen, has a 90% binding capacity to the Interferon Gamma (IFNɣ) receptor and 100% to Tumor Necrosis Factor alfa (TNFα) receptor, respectively.
 Conclusion: These receptors have significant effects on the proliferation and angiogenesis of cancer cells which leads to the metastasis of breast cancer. In conclusion, the antiangiogenic effects of Tamoxifen might be reduced due to its solvent DMSO's angiogenic effects.

The Tumor Microenvironment in Colorectal Cancer Therapy.

The current standard-of-care for metastatic colorectal cancer (mCRC) includes chemotherapy and anti-angiogenic or anti-epidermal growth factor receptor (EGFR) monoclonal antibodies, even though the addition of anti-angiogenic agents to backbone chemotherapy provides little benefit for overall survival. Since the approval of anti-angiogenic monoclonal antibodies bevacizumab and aflibercept, for the management of mCRC over a decade ago, extensive efforts have been devoted to discovering predictive factors of the anti-angiogenic response, unsuccessfully. Recent evidence has suggested a potential correlation between angiogenesis and immune phenotypes associated with colorectal cancer. Here, we review evidence of interactions between tumor angiogenesis, the immune microenvironment, and metabolic reprogramming. More specifically, we will highlight such interactions as inferred from our novel immune-metabolic (IM) signature, which groups mCRC into three distinct clusters, namely inflamed-stromal-dependent (IM Cluster 1), inflamed-non stromal-dependent (IM Cluster 2), and non-inflamed or cold (IM Cluster 3), and discuss the merits of the IM classification as a guide to new immune-metabolic combinatorial therapeutic strategies in mCRC.

Abstract 3115: High-capacity adenoviral vectors with controlled expression of interleukin 12 as a new strategy against pediatric osteosarcoma

Abstract Osteosarcoma (OS) is the most frequent and aggressive primary bone tumor in children and young adults, with a high propensity to metastasize to the lungs. Despite therapeutic efforts, the survival rate for metastatic or relapsed patients in under 30%. For this reason, we need new strategies to halt the progression of primary bone tumor and impede the metastatic stage. Interleukin-12 (IL12) is a cytokine implicated in a variety of immune activities including the stimulation of T and natural killer (NK) cells and the production of high levels of IFNγ. In addition, this process triggers an anti-angiogenic response leading to T reg inhibition and tumor death. This cytokine has shown significant antitumor activity in several animal models and clinical trials. The aim of this work was to evaluate the antisarcoma effect of a high-capacity adenovirus vector carrying the mouse IL12 (mIL12). This vector harbours a mifepristone (RU486)-inducible system for controlled expression of IL12 (HCA-EFZP-IL12) in order to improve the treatment of OS and reduced the systemic toxicity associated with IL12. The murine K7M2 OS cell line was injected intratibially in Balbc mice to induce bone tumor. HCA-EFZP-IL12 was administered intratumorally (two doses 2 days apart) in the orthotopic model with mifepristone induction during two weeks. Blood samples were collected 10 h after the first RU486 induction; mIL12 protein level was measured by ELISA, and tumor volumes were measured using a calliper. At the end of the experiment we collected tibias, lungs and livers for immunohistochemical studies. Our results showed a reduction of local tumor growth and also a significant extended overall survival. Importantly, the treatment led to long-term survivors free of disease. We performed a re-challenge experiment to assess the generation of antitumor memory and we are currently waiting for those results. Immunohistochemical analyses showed an increase in CD3, mainly CD4 and CD8 and a decrease of T-reg cells. Moreover, splenocytes from treated mice produced significant higher amounts of IFNγ than those of control mice. In summary, the role of the microenvironment and the potent antitumor immune response mediated by controlled expression of IL12 by an HC-Ad equipped with a drug-inducible system can be a real therapeutic option for primary pediatrics OS. Citation Format: Marta Zalacain, Virginia Laspieda, Naiara Martinez-Vélez, Lucía Marrodán, María Buñuales, Marisol Gonzalez-Huarriz, Maider Varela, Montserrat Puigdelloses, Manuela Gonzalez-Aparicio, Marta María Alonso, Rubén Hernandez, Ana Patiño-García. High-capacity adenoviral vectors with controlled expression of interleukin 12 as a new strategy against pediatric osteosarcoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3115.

Fucoidan from Fucus vesiculosus inhibits new blood vessel formation and breast tumor growth in vivo

Fucoidan is a marine-origin sulfated polysaccharide that can show anticancer activity, to which both pro- and anti-angiogenic responses have been reported. Due to this unpredictability, the angiogenic potential of an effective anticancer crude fucoidan (CF), at a concentration of 0.5 mg mL−1, was evaluated. Tube formation assays demonstrated that CF, either administered while endothelial cells seeding or after their adhesion, migration and organization, inhibited or disrupted the formation of tubular-like structures, respectively. Although CF did not significantly reduced vascular endothelial growth factor (VEGF) secretion, it significantly reduced the expression of platelet-derived growth factor (PDGF), compromising the blood vessels maturation. Two chicken embryo chorioallantoic membrane (CAM) assays were performed: one without tumor (CAM I) and the other with an onplanted tumor mass (CAM II); the CF injection reduced the number of blood of vessels and significantly decreased the tumor size, respectively. In vitro and in vivo results support the effectiveness of fucoidan as a natural antitumor therapeutic agent.

Nanoparticle exposure driven circulating bioactive peptidome causes systemic inflammation and vascular dysfunction

BackgroundThe mechanisms driving systemic effects consequent pulmonary nanoparticle exposure remain unclear. Recent work has established the existence of an indirect process by which factors released from the lung into the circulation promote systemic inflammation and cellular dysfunction, particularly on the vasculature. However, the composition of circulating contributing factors and how they are produced remains unknown. Evidence suggests matrix protease involvement; thus, here we used a well-characterized multi-walled carbon nanotube (MWCNT) oropharyngeal aspiration model with known vascular effects to assess the distinct contribution of nanoparticle-induced peptide fragments in driving systemic pathobiology.ResultsData-independent mass spectrometry enabled the unbiased quantitative characterization of 841 significant MWCNT-responses within an enriched peptide fraction, with 567 of these factors demonstrating significant correlation across animal-paired bronchoalveolar lavage and serum biofluids. A database search curated for known matrix protease substrates and predicted signaling motifs enabled identification of 73 MWCNT-responsive peptides, which were significantly associated with an abnormal cardiovascular phenotype, extracellular matrix organization, immune-inflammatory processes, cell receptor signaling, and a MWCNT-altered serum exosome population. Production of a diverse peptidomic response was supported by a wide number of upregulated matrix and lysosomal proteases in the lung after MWCNT exposure. The peptide fraction was then found bioactive, producing endothelial cell inflammation and vascular dysfunction ex vivo akin to that induced with whole serum. Results implicate receptor ligand functionality in driving systemic effects, exemplified by an identified 59-mer thrombospondin fragment, replete with CD36 modulatory motifs, that when synthesized produced an anti-angiogenic response in vitro matching that of the peptide fraction. Other identified peptides point to integrin ligand functionality and more broadly to a diversity of receptor-mediated bioactivity induced by the peptidomic response to nanoparticle exposure.ConclusionThe present study demonstrates that pulmonary-sequestered nanoparticles, such as multi-walled carbon nanotubes, acutely upregulate a diverse profile of matrix proteases, and induce a complex peptidomic response across lung and blood compartments. The serum peptide fraction, having cell-surface receptor ligand properties, conveys peripheral bioactivity in promoting endothelial cell inflammation, vasodilatory dysfunction and inhibiting angiogenesis. Results here establish peptide fragments as indirect, non-cytokine mediators and putative biomarkers of systemic health outcomes from nanoparticle exposure.

Natural killer cells and pigment epithelial-derived factor control the infiltrative and nodular growth of hepatic metastases in an Orthotopic murine model of ocular melanoma

BackgroundMetastases account for 90% of all cancer-related deaths, becoming a therapeutic problem. Approximately 50% of all uveal melanoma (UM) patients will develop metastases, mainly in the liver. Post-mortem analyses of livers from metastatic UM patients showed two different metastatic growth patterns: infiltrative and nodular. The infiltrative pattern exhibits tumor infiltration directly to the hepatic lobule and minimal angiogenesis. The nodular pattern shows clusters of tumor cells around the portal venules that efface the liver parenchyma. We recently demonstrated Natural Killer (NK) cells play a pivotal role in the control of hepatic metastases and the pigment epithelial-derived factor (PEDF) controls angiogenesis in the liver using our established ocular melanoma animal model. In this study we investigated the role of NK cells and PEDF in the development of metastatic growth patterns, as this can contribute to the development of novel therapeutics specific towards each growth pattern.MethodsWe utilize our established ocular melanoma animal model by inoculation of B16-LS9 melanoma cells into C57BL/6 J mice (WT), anti-asialo GM1-treated C57BL/6 J mice (NK-depleted), and PEDF−/− C57BL/6 J mice. Three weeks after inoculation we evaluated the metastatic growth patterns and stratified them based of the numbers of tumor cells. To evaluate angiogenesis the mean vascular density (MVD) was calculated. The immune compartment of the liver was analyzed by flow cytometry.ResultsOur in vivo work showed two distinct metastatic growth patterns, the infiltrative and nodular, recapitulating the post-mortem analyses on human liver tissue. We discovered NK cells control the infiltrative growth. In contrast, PEDF controlled anti-angiogenic responses, showing higher MVD values compared to NK-depleted and WT animals. The myeloid lineage, comprised of monocytes, macrophages, and myeloid-derived suppressor cells, was reduced in the absence of NK cells or PEDF.ConclusionsOur animal model recapitulates the metastatic growth patterns observed in the human disease. We demonstrated a role for NK cells in the development of the infiltrative growth pattern, and a role for PEDF in the development of the nodular pattern. The understanding of the complexity associated with the metastatic progression has profound clinical implications in the diagnostic and disease-management as we can develop and direct more effective therapies.

18F] Fluciclatide PET as a biomarker of clinical response to combination therapy of pazopanib and paclitaxel in patients with platinum-resistant or platinum-refractory advanced ovarian cancer: Results of a phase Ib study.

3070 Background: Angiogenesis has been shown to be a driver of platinum resistance in ovarian cancer. We assessed the effect of combination pazopanib and paclitaxel followed by maintenance pazopanib in patients with platinum resistant/refractory ovarian cancer. Integrins αvβ3 and αvβ5 are both up-regulated in tumour-associated vasculature. [18F]Fluciclatide is a novel PET tracer that has high affinity for integrins αvβ3/5, and was used to assess the anti-angiogenic effect of pazopanib. Methods: We conducted an open-label, phase Ib study in patients with platinum resistant/refractory ovarian cancer. Patients received 1 week of single agent pazopanib (800mg daily) followed by combination therapy with weekly paclitaxel 80mg/m2. Following completion of 18 weeks of therapy, patients continued with single agent pazopanib until disease progression. Dynamic [18F]Fluciclatide-PET imaging was conducted at baseline and after 1 week of pazopanib. Response (RECIST 1.1), toxicities and survival outcomes were recorded. Circulating markers of angiogenesis were assessed with therapy. Results: Fourteen patients were included in the intention-to-treat analysis. Complete and partial response was seen in 7 patients (54%). Median progression free survival (PFS) was 7.97 months, and overall survival (OS) was 18.5 months. A reduction in [18F]fluciclatide uptake was observed following 1 week of pazopanib, and the reduction in uptake was predictive of long PFS. Elevated baseline circulating angiopoietin and FGF were predictive of greater reduction in SUV60,mean following pazopanib. Kinetic modelling indicated a reduction in K1 and Ki following pazopanib indicating reduced radiotracer delivery and retention. Conclusions: Combination therapy followed by maintenance pazopanib is effective and tolerable in patients with platinum resistant/refractory ovarian cancer. We have shown that [18F]fluciclatide-PET uptake parameters alter with pazopanib therapy indicating an anti-angiogenic response. Clinical trial information: NCT01608009.

18F-alfatide PET may predict anti-angiogenic drugs toxicity.

e14608 Background: Identifying predictive markers for toxicity could decrease the number of patients experiencing dose-limiting toxicity. The study aims to investigate whether 18F-Alfatide positron emission tomography (PET) can predict the antiangiogenic drugs toxicity. Methods: A549 xenografted mice underwent 18F-Alfatide PET at baseline when tumor volume reached 100-200 mm3 and after treatment with apatinib (100mg/kg once daily), bevacizumab (20mg/kg every four days), endostar (20mg/kg once daily) or vehicle. Tumor growth and body weight were monitored every two days. The changed rate of tumor volume (TV) and organ uptake (OU) after therapy were calculated using the formula: [mean value(negative control) – each value(experimental)]/mean value(negative control)×100%, and [each value(experimental) – mean value(negative control)]/mean value(negative control)×100% for pathological injury degree of organs (PID) after therapy. We compared the antiangiogenic response and organs PID among three groups. Then, linear correlation was analyzed between mean OU and mean TV or mean PID, and between organ uptakes before treatment and PIDs in all model group. Results: TVs treated by endostar was lower than that of bevacizumab, both of which were lower than that of apatinib (mean IR±SD: endostar (13.56±11.78)%, bevacizumab (37.19±12.50)% and apatinib (48.43±8.71)%, respectively, P > 0.05 for the three groups, but P < 0.05 for the comparison of endastar and apatinib groups). The same is true for the PIDs (mean PID±SD for livers: endostar (32.58±11.81) %, bevacizumab (36.12±11.01)% and apatinib (41.12±9.99)%, P > 0.05; mean PID±SD for kidneys: endostar (39.54±4.80)%, bevacizumab (43.24±5.46)% and apatinib (52.90±8.75)%, P > 0.05). There was an excellent linear relationship between mean OU and mean PID (Liver: R2= 0.93, P > 0.05 for OUSUVmean; R2= 0.80, P > 0.05 for OUSUVmax; Kidney: R2= 0.85, P > 0.05 for OUSUVmean; R2= 0.97, P > 0.05 for OUSUVmax) and an excellent linear relationship between mean OU and mean IR (Liver: R2= 0.99, P < 0.05 for OUSUVmean; R2 = 0.97, P > 0.05 for OUSUVmax; Kidney: R2= 0.99, P < 0.05 for OUSUVmean; R2= 0.93, P > 0.05 for OUSUVmax). There was a significantly moderate linear association between the uptakes of organs prior to treatment and the PIDs (Liver: R2= 0.49, P < 0.001 for OUSUVmean; R2= 0.45, P < 0.001 for OUSUVmax; Kidney: R2= 0.57, P < 0.0001 for OUSUVmean; R2= 0.53, P < 0.001 for OUSUVmax). Conclusions: 18F-Alfatide PET may be a useful molecular imaging tool for individual selection with toxicity before antiangiogenic therapy.

Antiangiogenic Iridoids from Stachys ocymastrum and Premna resinosa.

In this paper, the isolation of one new iridoid glucoside, 6β-acetoxyipolamiide (1: ), and thirteen (2: - 14: ) known congeners from two Lamiaceae species, Stachys ocymastrum and Premna resinosa, leaf extracts is reported. The structural determination of the isolated compounds was performed by mono- and bidimensional NMR spectroscopic analysis as well as MS experiments. The isolates were assayed for their antiangiogenic activity by two in vivo models, zebrafish embryos and chick chorioallantoic membrane assays. The compounds with a significant antiangiogenic activity in both assays were β-hydroxyipolamiide (2: ), ipolamiide (3: ), and buddlejoside A5 (8: ). 6-O-α-l-(3″-O-p-Methoxycinnamoyl-4″-O-acetyl)rhamnopyranosyl catalpol (13: ) and 6-O-α-l-(2″-trans-caffeoyl)rhamnopyranosyl catalpol (6: ) showed the best antiangiogenic response on blood vessel growth in zebrafish embryos, whereas saccatoside (10: ) and 6-O-α-l-(2″-O - : p-methoxycinnamoyl-3″-O-acetyl)rhamnopyranosyl catalpol (14: ) resulted in a strong reduction of capillary formation in the chorioallantoic membrane assay.