TRAIL inhibits angiogenesis stimulated by VEGF expression in human glioblastoma cells

Role of MEF2C in the Endothelial Cells Derived from Human Induced Pluripotent Stem Cells

Human induced pluripotent stem cells (hiPSCs) not only provide an abundant source of vascular cells for potential therapeutic applications in vascular disease but also constitute an excellent model for understanding the mechanisms that regulate the differentiation and the functionality of vascular cells. Here, we reported that myocyte enhancer factor 2C (MEF2C) transcription factor, but not any other members of the MEF2 family, was robustly upregulated during the differentiation of vascular progenitors and endothelial cells (ECs) from hiPSCs. Vascular endothelial growth factors (VEGF) strongly induced MEF2C expression in endothelial lineage cells. The specific upregulation of MEF2C during the commitment of endothelial lineage was dependent on the extracellular signal regulated kinase (ERK). Moreover, knockdown of MEF2C with shRNA in hiPSCs did not affect the differentiation of ECs from these hiPSCs, but greatly reduced the migration and tube formation capacity of the hiPSC-derived ECs. Through a chromatin immunoprecipitation-sequencing, genome-wide RNA-sequencing, quantitative RT-PCR, and immunostaining analyses of the hiPSC-derived endothelial lineage cells with MEF2C inhibition or knockdown compared to control hiPSC-derived ECs, we identified TNF-related apoptosis inducing ligand (TRAIL) and transmembrane protein 100 (TMEM100) as novel targets of MEF2C. This study demonstrates an important role for MEF2C in regulating human EC functions and highlights MEF2C and its downstream effectors as potential targets to treat vascular malfunction-associated diseases.

Glioblastoma multiforme targeted delivery of docetaxel using bevacizumab-modified nanostructured lipid carriers impair in vitro cell growth and in vivo tumor progression

Glioblastoma multiforme (GBM) is the most common malignant brain cancer, characterized by high invasiveness and poor prognosis. Docetaxel (DTX) is a chemotherapeutic drug with promising anti-tumor properties. However, conventional intravenous formulations exhibit side effects of systemic biodistribution and low brain bioavailability, limiting their clinical use. The current work aimed to evaluate the effect of DTX-loaded nanostructured lipid carriers (NLC) functionalized with bevacizumab (BVZ-NLC-DTX) against GBM using in vitro and in vivo models. The NLC was obtained by the fusion-emulsification method followed by sonication, with narrow size distribution, negative zeta potential, and low polydispersity index. NLC showed DTX entrapment efficiency above 90%. BVZ coupling efficiency was 62% and BVZ integrity after functionalization was confirmed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Calorimetry studies confirmed thermal stability and molecular dispersion of DTX in the lipid matrix. NLC showed a sustained DTX release over 84 h. In vitro anti-tumor assays shown that BVZ-NLC-DTX selectively increased the cytotoxic of DTX in cells overexpressing VEGF (U87MG and A172), but not in peripheral blood mononuclear cells (PMBCs), promoting cell death by apoptosis. BVZ functionalization did not impair cellular uptake. An in vivo orthotopic rat model demonstrated that free-DTX was not capable of reducing tumor growth whereas BVZ-NLC-DTX reduced up to 70% tumor volume after 15-days of treatment. Therefore, this study contributes to understanding new nanotechnology-based vehicles capable of reaching the brain more efficiently and repurposing the use of anti-cancer drugs in GBM treatment.

G-CSF and IL-6 may be involved in formation of endometriosis lesions by increasing the expression of angiogenic factors in neutrophils

Evidence accumulated in recent years has revealed that neutrophils are involved in the initial establishment of endometriosis, which is well-known as a chronic inflammatory disease. So far, why and how neutrophils promote the formation of early endometriosis are still unclear. In this study, using a mouse model of endometriosis, we demonstrated that endometriosis mice (EMs mice) had a significantly increased number of neutrophils in peritoneal fluids and lesions, and increased levels of granulocyte colony-stimulating factor (G-CSF) and IL-6 in serum and peritoneal fluids compared to the control group. In the neutrophils and uterine fragments co-injection experiment, neutrophils regulated by G-CSF and IL-6 had a similar effect to neutrophils from EMs mice, increasing the number, area, weight and microvessel density (MVD) of endometriotic lesions. Blocking the effect of G-CSF and IL-6 in EMs mice resulted in a decrease in the number, area and weight of endometriotic lesions. Following the depletion of neutrophils in vivo using a anti-Ly6G antibody, the MVD in the lesions of mice treated with neutrophils from EMs mice and neutrophils from pG/pI6 mice were significantly reduced. Neutrophils from EMs mice and neutrophils from pG/pI6 mice altered the expression levels of Mmp9, Bv8 and Trail genes compared to the neutrophils from PBS-treated mice. IL-6 together with G-CSF induced a higher expression of phospho-STAT3 and STAT3 in neutrophils. These findings suggest that neutrophils modulated by G-CSF and IL-6 through the STAT3 pathway alter the expression levels of the angiogenesis-related genes Mmp9, Bv8 and Trail, and may promote the establishment of early endometriosis.

Leveling Up the Controversial Role of Neutrophils in Cancer: When the Complexity Becomes Entangled

Neutrophils are the most abundant immune cell in the circulation of human and act as gatekeepers to discard foreign elements that have entered the body. They are essential in initiating immune responses for eliminating invaders, such as microorganisms and alien particles, as well as to act as immune surveyors of cancer cells, especially during the initial stages of carcinogenesis and for eliminating single metastatic cells in the circulation and in the premetastatic organs. Since neutrophils can secrete a whole range of factors stored in their many granules as well as produce reactive oxygen and nitrogen species upon stimulation, neutrophils may directly or indirectly affect carcinogenesis in both the positive and negative directions. An intricate crosstalk between tumor cells, neutrophils, other immune cells and stromal cells in the microenvironment modulates neutrophil function resulting in both anti- and pro-tumor activities. Both the anti-tumor and pro-tumor activities require chemoattraction towards the tumor cells, neutrophil activation and ROS production. Divergence is seen in other neutrophil properties, including differential secretory repertoire and membrane receptor display. Many of the direct effects of neutrophils on tumor growth and metastases are dependent on tight neutrophil–tumor cell interactions. Among them, the neutrophil Mac-1 interaction with tumor ICAM-1 and the neutrophil L-selectin interaction with tumor-cell sialomucins were found to be involved in the neutrophil-mediated capturing of circulating tumor cells resulting in increased metastatic seeding. On the other hand, the anti-tumor function of neutrophils was found to rely on the interaction between tumor-surface-expressed receptor for advanced glycation end products (RAGE) and Cathepsin G expressed on the neutrophil surface. Intriguingly, these two molecules are also involved in the promotion of tumor growth and metastases. RAGE is upregulated during early inflammation-induced carcinogenesis and was found to be important for sustaining tumor growth and homing at metastatic sites. Cathepsin G was found to be essential for neutrophil-supported lung colonization of cancer cells. These data level up the complexity of the dual role of neutrophils in cancer.

Synergistic Effect of Gefitinib and Temozolomide on U87MG Glioblastoma Angiogenesis

One of the most common and deadly brain tumors is Glioblastoma multiforme (GBM). Due to recent advances in angiogenesis and its related key factors, this process as a hallmark in glioblastoma has attracted more consideration from the research community. Temozolomide (TMZ) as the first-line treatment used to treat GBM but, resistance to TMZ limits its effectiveness and the need for better treatments is still felt. Therefore, we aimed to examine the Synergistic effects of Gefitinib (GFI) in combination with Temozolomide on VEGF and MMPs in glioma cell line (U87MG). Our results displayed that GFI could induce cytotoxic effects in U87MG with IC50 values of 11 μM. U87MG cells produced large amounts of VEGF without any stimuli, and the results showed that GFI in combination with TMZ caused a significant decrease in VEGF production in these cells. In this study, we demonstrated that after treating with TMZ and GFI, there was more decrease in the levels of MMP 2 and 9 secretions in cells than treatment with GFI and TMZ doses alone. This study indicates synergistic effects of GFI plus TMZ against glioma are mediated by the potentiated anti-angiogenesis. Therefore, it can be considered as a promising plan for future studies.

Endothelial Recovery in Bare Metal Stents and Drug-Eluting Stents on a Single-Cell Level

[Figure: see text].

Advances and potential pitfalls of oncolytic viruses expressing immunomodulatory transgene therapy for malignant gliomas

Glioblastoma (GBM) is an immunosuppressive, lethal brain tumor. Despite advances in molecular understanding and therapies, the clinical benefits have remained limited, and the life expectancy of patients with GBM has only been extended to ~15 months. Currently, genetically modified oncolytic viruses (OV) that express immunomodulatory transgenes constitute a research hot spot in the field of glioma treatment. An oncolytic virus is designed to selectively target, infect, and replicate in tumor cells while sparing normal tissues. Moreover, many studies have shown therapeutic advantages, and recent clinical trials have demonstrated the safety and efficacy of their usage. However, the therapeutic efficacy of oncolytic viruses alone is limited, while oncolytic viruses expressing immunomodulatory transgenes are more potent inducers of immunity and enhance immune cell-mediated antitumor immune responses in GBM. An increasing number of basic studies on oncolytic viruses encoding immunomodulatory transgene therapy for malignant gliomas have yielded beneficial outcomes. Oncolytic viruses that are armed with immunomodulatory transgenes remain promising as a therapy against malignant gliomas and will undoubtedly provide new insights into possible clinical uses or strategies. In this review, we summarize the research advances related to oncolytic viruses that express immunomodulatory transgenes, as well as potential treatment pitfalls in patients with malignant gliomas.

Soluble TRAIL Armed Human MSC As Gene Therapy For Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is still one of the most aggressive adult cancers with an unacceptable prognosis. For this reason novel therapies accounting for PDAC peculiarities, such as the relevant stromal reaction, are urgently needed. Here adipose mesenchymal stromal/stem cells (AD-MSC) have been armed to constantly release a soluble trimeric and multimeric variant of the known anti-cancer TNF-related apoptosis-inducing ligand (sTRAIL). This cancer gene therapy strategy was in vitro challenged demonstrating that sTRAIL was thermally stable and able to induce apoptosis in the PDAC lines BxPC-3, MIA PaCa-2 and against primary PDAC cells. sTRAIL released by AD-MSC relocated into the tumor stroma was able to significantly counteract tumor growth in vivo with a significant reduction in tumor size, in cytokeratin-7+ cells and by an anti-angiogenic effect. In parallel, histology on PDAC specimens form patients (n = 19) was performed to investigate the levels of TRAIL DR4, DR5 and OPG receptors generating promising insights on the possible clinical translation of our approach. These results indicate that adipose MSC can very efficiently vehicle a novel TRAIL variant opening unexplored opportunities for PDAC treatment.

Nucleus-enriched Ruthenium Polypyridine Complex Acts as a Potent Inhibitor to Suppress Triple-negative Breast Cancer Metastasis In vivo

Polypyridine Ru(II) complexes have long been deemed to excellent antitumor agents that inhibit the proliferation of breast cancer cells. Nevertheless, their effects on the metastatic potency of breast cancer cells need further research. Herein, a class of polypyridine Ru(II) complexes coordinated with phenazine derivates (DPPZ) ([Ru(bpy)₂(DPPZ-R)](ClO₄)₂, Ru(bpy)₂DPPZ: R = -H, Ru(bpy)₂BrDPPZ: R = -Br, Ru(bpy)₂MDPPZ: R = -CH₃, Ru(bpy)2BnDPPZ: R = −acene, Ru(bpy)₂BEDPPZ: R = -C ≡ C(C₆H₅)) was synthesized by introducing different substituent groups to regulate the electron cloud density and planarity of the main ligands. Results indicated that this class of DPPZ-based Ru(II) complexes exhibited promising inhibitory effect against MDA-MB-231 triple-negative breast cancer cells, especially for Ru(bpy)₂BEDPPZ, which is comparable with that of cisplatin. In addition, Ru(bpy)₂BEDPPZ effectively inhibited the migration and invasion of MDA-MB-231 cells in vitro and suppressed focal adhesion and stress fiber formation. Moreover, it effectively blocked MDA-MB-231 cell metastasis in blood vessels and restrained angiogenesis formation in a zebrafish xenograft breast cancer model. Further studies showed that the mechanisms may involve DNA damage-mediated apoptosis probably due to Ru(bpy)₂BEDPPZ, which was enriched in the cell nucleus and induced DNA damage. All these results suggested that the DPPZ-based Ru(II) complexes can act as potent anti-metastasis agents.

Divergent Roles for TRAIL in Lung Diseases

The tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) is a widely expressed cytokine that can bind five different receptors. TRAIL has been of particular interest for its proposed ability to selectively induce apoptosis in tumour cells. However, it has also been found to regulate a wide variety of non-canonical cellular effects including survival, migration and proliferation via kinase signalling pathways. Lung diseases represent a wide range of conditions affecting multiple tissues. TRAIL has been implicated in several biological processes underlying lung diseases, including angiogenesis, inflammation, and immune regulation. For example, TRAIL is detrimental in pulmonary arterial hypertension—it is upregulated in patient serum and lungs, and drives the underlying proliferative pulmonary vascular remodelling in rodent models. However, TRAIL protects against pulmonary fibrosis in mice models—by inducing apoptosis of neutrophils—and reduced serum TRAIL is found in patients. Conversely, in the airways TRAIL positively regulates inflammation and immune response. In COPD patients and asthmatic patients challenged with antigen, TRAIL and its death receptors are upregulated in serum and airways. Furthermore, TRAIL-deleted mouse models have reduced airway inflammation and remodelling. In the context of respiratory infections, TRAIL assists in immune response, e.g., via T-cell toxicity in influenza infection, and neutrophil killing in S. pneumoniae infection. In this mini-review, we examine the functions of TRAIL and highlight the diverse roles TRAIL has in diseases affecting the lung. Disentangling the facets of TRAIL signalling in lung diseases could help in understanding their pathogenic processes and targeting novel treatments.

Proangiogenic effects of tumor cells on endothelial progenitor cells vary with tumor type in an in vitro and in vivo rat model

Endothelial progenitor cells (EPCs) contribute to neovascularization in tumors. However, the relationship of EPCs and tumor-induced angiogenesis still remains to be clarified. The present study aimed at investigating the influence of 4 different tumor types on angiogenic properties of EPCs in an in vitro and in vivo rat model. It could be demonstrated that in vitro proliferation, migration, and angiogenic abilities and genetic modifications of EPCs are controlled in a tumor-type-dependent manner. The proangiogenic effect of mammary carcinoma, osteosarcoma, and rhabdomyosarcoma cells was more pronounced compared to colon carcinoma cells. Coinjection of encapsulated tumor cells, especially mammary carcinoma cells, and EPCs in a rat model confirmed a contributing effect of EPCs in tumor vascularization. Cytokines secreted by tumors such as monocyte chemoattractant protein 1, macrophage inflammatory protein 2, and TNF-related apoptosis-inducing ligand play a pivotal role in the tumor cell-EPC interaction, leading to enhanced migration and angiogenesis. With the present study, we were able to decipher possible underlying mechanisms by which EPCs are stimulated by tumor cells and contribute to tumor vascularization. The present study will contribute to a better understanding of tumor-induced vascularization, thus facilitating the development of therapeutic strategies targeting tumor-EPC interactions.-An, R., Schmid, R., Klausing, A., Robering, J. W., Weber, M., Bäuerle, T., Detsch, R., Boccaccini, A. R., Horch, R. E., Boos, A. M., Weigand, A. Proangiogenic effects of tumor cells on endothelial progenitor cells vary with tumor type in an in vitro and in vivo rat model.

IL-35 induces N2 phenotype of neutrophils to promote tumor growth

IL-35 is an immunosuppressive cytokine and exerts regulatory effects on T cells, B cells, macrophages and dendritic cells. Neutrophils are important innate immune cells that play key roles in tumor development. The effect of IL-35 on neutrophils remains unknown. Here, we report that IL-35 can induce N2 neutrophil polarization (protumor phenotype) by increasing G-CSF and IL-6 production, and promote neutrophil infiltration into tumor microenvironment. The sustained expression of IL-35 could promote chronic inflammation to augment the proangiogenic and immunosuppressive function of neutrophils. IL-35 stimulated macrophages to secrete proinflammatory cytokines IL-1β and IL-6. IL-1β stimulated γδ T cells to produce IL-17, which in turn increased the production of G-CSF. By increasing the expression of G-CSF and IL-6, IL-35 could up-regulate the expression of MMP-9 and Bv8, and down-regulate TRAIL expression in neutrophils, thus augmenting the proangiogenic function of neutrophils. Moreover, G-CSF/IL-6 induced the enhanced activation of STAT3 and ERK pathways in neutrophils, thus increasing the expression of iNOS to suppress T cell activation. Our findings suggest that IL-35 can promote tumor progression by functioning as an up-stream cytokine to promote cancer-associated inflammation and control neutrophil polarization. Targeting IL-35 might be an important approach for designing new strategy of tumor therapy.

Scutellarin suppresses human colorectal cancer metastasis and angiogenesis by targeting ephrinb2

Tumor induced angiogenesis is an attractive target for anti-cancer drug treatment. Scutellarin, which is a native compound derived from scutellaria altissima leaves, has already been proved to possess anti-tumor activities. Nevertheless, their effects in colorectal cancer metastasis and angiogenesis have not been evaluated. In order to reveal the anti-angiogenic and anti-metastasis capacity of scutellarin, wound healing and Transwell chamber inserts invasion were done in colorectal cancer cells, and cell proliferation as wells colony formation were conducted to identify the proliferation inhibition of colorectal cancer in vitro. The growth inhibition of scutellarin was further definite by a mouse colorectal xenograft model in vivo. Herein, we demonstrated scutellarin suppressed colorectal cancer cell viability and colony formation in vitro, and remarkably reduced tumor growth in vivo mouse xenografts. Additionally, scutellarin restrained colorectal cancer cells-induced angiogenesis, inhibited human umbilical vascular endothelial cells (HUVECs) migration, tube formation of HUVECs, and micro-vessel formation in chick embnyo chorioallantoic menbreme (CAM) assay. Altogether, our results exhibited the evidence that scutellarin inhibit colorectal cancer angiogenesis and metastasis via targeting ephrinb2 signaling, with the potential of an anti-tumor agent for cancer treatment.

Unbalanced Vitreous Levels of Osteoprotegerin, RANKL, RANK, and TRAIL in Proliferative Diabetic Retinopathy

PURPOSE

We investigated the expression of the proinflammatory and proangiogenic factor osteoprotegerin (OPG) and its ligands, receptor activator of nuclear factor-κB ligand (RANKL), tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), and the receptor RANK in proliferative diabetic retinopathy (PDR).

MATERIALS AND METHODS

Vitreous samples from PDR and nondiabetic control patients and epiretinal membranes from PDR patients were studied by enzyme-linked immunosorbent assay, immunohistochemistry, and Western blot analysis.

RESULTS

Vascular endothelial growth factor, OPG, and soluble RANK levels in vitreous samples from PDR patients were significantly higher than that in nondiabetic controls. Soluble TRAIL levels were significantly lower in PDR patients than that in nondiabetic control, whereas soluble RANKL levels did not differ significantly. RANKL, RANK, and TRAIL were expressed in vascular endothelial cells, myofibroblasts, and CD45-expressing leukocytes in PDR epiretinal membranes.

CONCLUSIONS

Dysregulated expression of OPG/RANKL/RANK pathway and TRAIL might be related to inflammation and angiogenesis in PDR.

Fms related tyrosine kinase 1 (Flt1) functions as an oncogene and regulates glioblastoma cell metastasis by regulating sonic hedgehog signaling

Studies have shown that the abnormal expression of Fms related tyrosine kinase 1 (Flt1) is associated with multiple malignancies, yet its role in glioblastoma pathology remains to be elucidated. In this study, we investigated the role of Flt1 in regulating proliferation, migration and invasion of glioblastoma cells by establishing glioblastoma cell strains with constitutively silenced or elevated Flt1 expression. We demonstrate that ectopic expression of Flt1 promotes glioblastoma cells migration, invasion through cell scratching and Transwell assays. Further study has indicated that Flt1 knockdown prevents the spread of glioblastoma cells in vivo. Conversely, we also show that suppression of Flt1 expression inhibits migration and invasion of glioblastoma cells. Finally, our findings demonstrate that Flt1 promotes invasion and migration of glioblastoma cells through sonic hedgehog (SHH) signaling pathway. Our study suggests that galectin-1 represents a crucial regulator of glioblastoma cells metastasis. Thus, the detection and targeted treatment of Flt1-expressing cancer serves as a new therapeutic target for glioblastoma.

Circulating tumor cells promote the metastatic colonization of disseminated carcinoma cells by inducing systemic inflammation

Circulating tumor cells (CTCs) have been studied well in the prognosis for malignant diseases as liquid biopsy, but their contribution to tumor metastasis is not clearly defined. Here we report that CTCs could promote the metastatic colonization of disseminated carcinoma cells by inducing systemic inflammation and neutrophil recruitment to pre-metastatic organs. Depletion of neutrophils in vivo could effectively abrogate the promoting effect of CTCs on tumor cell metastasis. In the presence of CTCs, the pro-tumor function of neutrophils was augmented, whereas the antitumor function of neutrophils was suppressed. Mechanically, CTC-derived ligands for TLR2 and TLR4 (TLR2/4) induced the systemic inflammation, thus increasing the production of proinflammatory cytokines such as G-CSF and IL-6 that could induce the conversion of neutrophil function from tumor-suppressing to tumor-promoting. Moreover, CTCs induced the production of endogenous TLR2/4 ligands such as S100A8, S100A9, and SAA3, which may amplify the stimulating effect that induces the expression of proinflammatory cytokines. The promoting effect of CTCs on tumor cell metastasis could be abrogated by suppressing inflammatory response with IL-37, an anti-inflammatory cytokine, or blocking CTC-derived ligands for TLR2/4. Identification of the metastatic axis of CTCs/systemic inflammation/neutrophils may provide potential targets for preventing tumor cell metastasis.

Targeting NRASQ61K mutant delays tumor growth and angiogenesis in non-small cell lung cancer

Tumor cells require vascular supply for their growth, and they express proangiogenic growth factors that promote the formation of vascular networks. Many oncogenic mutations that may potentially lead to tumor angiogenesis have been identified. Somatic mutations in the small GTPase NRAS are the most common activating lesions found in human cancer and are generally associated with poor response to standard therapies. However, the mechanisms by which NRAS mutations affect tumor angiogenesis are largely unknown. Therefore, we investigated the role of NRAS^Q61K oncogene in tumor angiogenesis and analyzed tumors harboring NRAS^Q61K for potential sensitivity to a kinase inhibitor. Knock-in of the NRAS^Q61K allele in human normal epithelial cells triggered the angiogenic response in these cells. In cancer cells harboring oncogenic NRAS, a mitogen-activated protein kinase (MEK) inhibitor down-regulated the extracellular regulated protein kinase (ERK) pathway and inhibited the expression of proangiogenic molecules. In tumor xenografts harboring the NRAS^Q61K, the MEK inhibitor extensively modified tumor growth, causing abrogation of angiogenesis. Overall, our results provide a functional link between oncogenic NRAS and angiogenesis, and imply that tumor vasculature could be indirectly altered by targeting a genetic lesion on which cancer cells are dependent.

PTEN and TRAIL genes loaded zein nanoparticles as potential therapy for hepatocellular carcinoma

Gene therapy is one of the recent approaches in treatment of hepatocellular carcinoma (HCC). Development of a vector or vehicle that can selectively and efficiently deliver the gene to target cells with minimal toxicity is an urgent demand. In the present study, phosphatase and tensin homolog (PTEN) and tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) genes were loaded to zein nanoparticles (ZNPs). The formulated PTEN and TRAIL-loaded ZNPs were tested for their in vitro and in vivo potential antitumor efficacy using liver tumor cells (HepG2) and HCC-induced rats as animal model. Also, mRNA expression of p53, VGEF and MMP-2 were carried out as markers of apoptosis, angiogenesis and metastasis in animal liver tissues. The results of the study showed that both PTEN and TRAIL-loaded ZNPs proved anti-proliferative activity against HepG2 cell lines with IC₅₀ values of 0.09, 0.25 µg/ml, respectively. In vivo assay confirmed decrease in mRNA expression of both VEGF and MMP-2 with increased in P53 expression level in liver tissues of the treated animals. Therefore, authors introduced new integration between gene therapy and nanotechnology in the form of PTEN and TRAIL-loaded ZNPs that proved potential to be used in gene therapy for the treatment of HCC.

Comparative Evaluation of TRAIL, FGF-2 and VEGF-A-Induced Angiogenesis In Vitro and In Vivo

Tumor necrosis-factor-related apoptosis-inducing ligand (TRAIL) has been implicated in angiogenesis; the growth of new blood vessels from an existing vessel bed. Our aim was to compare pro-angiogenic responses of TRAIL, vascular endothelial growth-factor-A (VEGF-A) and fibroblast growth-factor-2 (FGF-2) either separately (10 ng/mL) or in combination, followed by the assessment of proliferation, migration and tubule formation using human microvascular endothelial-1 (HMEC-1) cells in vitro. Angiogenesis was also measured in vivo using the Matrigel plug assay. TRAIL and FGF-2 significantly augmented HMEC-1 cell proliferation and migration, with combination treatment having an enhanced effect on cell migration only. In contrast, VEGF-A did not stimulate HMEC-1 migration at 10 ng/mL. Tubule formation was induced by all three factors, with TRAIL more effective compared to VEGF-A, but not FGF-2. TRAIL at 400 ng/mL, but not VEGF-A, promoted CD31-positive staining into the Matrigel plug. However, FGF-2 was superior, stimulating cell infiltration and angiogenesis better than TRAIL and VEGF-A in vivo. These findings demonstrate that each growth factor is more effective at different processes of angiogenesis in vitro and in vivo. Understanding how these molecules stimulate different processes relating to angiogenesis may help identify new strategies and treatments aimed at inhibiting or promoting dysregulated angiogenesis in people.

Targeting Tumor-Associated Fibroblasts for Therapeutic Delivery in Desmoplastic Tumors

The off-target distribution of anticancer nanoparticles to fibroblasts creates a barrier to the effective treatment of desmoplastic tumors. However, we hypothesized that this nanoparticle detriment might be exploited to target the expression of secreted cytotoxic proteins from tumor-associated fibroblasts (TAF) as an anticancer strategy. In addressing this hypothesis, plasmids encoding the secretable TNF-related factor sTRAIL were loaded into lipid-coated protamine DNA complexes and administered by infusion in a murine xenograft model of human desmoplastic bladder carcinoma. Three doses were sufficient to generate approximately 70% of TAFs as sTRAIL-producing cells. sTRAIL triggered apoptosis in tumor cell nests adjacent to TAFs. Furthermore, it reverted residual fibroblasts to a quiescent state due to insufficient activation, further compromising tumor growth and remodeling the microenvironment to favor second-wave nanotherapy. We confirmed the efficacy of this strategy in an orthotopic xenograft model of human pancreatic cancer, where the desmoplastic stroma is well known to be a major barrier to the delivery of therapeutic nanoparticles. Collectively, our results offer a proof of concept for the use of nanoparticles to modify TAFs as an effective strategy to treat desmoplastic cancers. Cancer Res; 77(3); 719-31. ©2016 AACR.

Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand (TRAIL) Promotes Angiogenesis and Ischemia-Induced Neovascularization Via NADPH Oxidase 4 (NOX4) and Nitric Oxide-Dependent Mechanisms

BACKGROUND

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has the ability to inhibit angiogenesis by inducing endothelial cell death, as well as being able to promote pro-angiogenic activity in vitro. These seemingly opposite effects make its role in ischemic disease unclear. Using Trail(-/-) and wildtype mice, we sought to determine the role of TRAIL in angiogenesis and neovascularization following hindlimb ischemia.

METHODS AND RESULTS

Reduced vascularization assessed by real-time 3-dimensional Vevo ultrasound imaging and CD31 staining was evident in Trail(-/-) mice after ischemia, and associated with reduced capillary formation and increased apoptosis. Notably, adenoviral TRAIL administration significantly improved limb perfusion, capillary density, and vascular smooth-muscle cell content in both Trail(-/-) and wildtype mice. Fibroblast growth factor-2, a potent angiogenic factor, increased TRAIL expression in human microvascular endothelial cell-1, with fibroblast growth factor-2-mediated proliferation, migration, and tubule formation inhibited with TRAIL siRNA. Both fibroblast growth factor-2 and TRAIL significantly increased NADPH oxidase 4 (NOX4) expression. TRAIL-inducible angiogenic activity in vitro was inhibited with siRNAs targeting NOX4, and consistent with this, NOX4 mRNA was reduced in 3-day ischemic hindlimbs of Trail(-/-) mice. Furthermore, TRAIL-induced proliferation, migration, and tubule formation was blocked by scavenging H2O2, or by inhibiting nitric oxide synthase activity. Importantly, TRAIL-inducible endothelial nitric oxide synthase phosphorylation at Ser-1177 and intracellular human microvascular endothelial cell-1 cell nitric oxide levels were NOX4 dependent.

CONCLUSIONS

This is the first report demonstrating that TRAIL can promote angiogenesis following hindlimb ischemia in vivo. The angiogenic effect of TRAIL on human microvascular endothelial cell-1 cells is downstream of fibroblast growth factor-2, involving NOX4 and nitric oxide signaling. These data have significant therapeutic implications, such that TRAIL may improve the angiogenic response to ischemia and increase perfusion recovery in patients with cardiovascular disease and diabetes.

Investigating the Influence of HUVECs in the Formation of Glioblastoma Spheroids in High-Throughput Three-Dimensional Microwells

Glioblastoma (GBM) is the most common form of primary brain tumor with a high infiltrative capacity, increased vascularity, and largely elusive tumor progression mechanism. The current GBM treatment methods do not increase the patient survival rate and studies using two-dimensional (2D) cell cultures and in vivo animal models to investigate GBM behavior and mechanism have limitations. Therefore, there is an increasing need for in vitro three-dimensional (3D) models that closely mimic in vivo microenvironment of the GBM tumors to understand the underlying mechanisms of the tumor progression. In this study we propose to use a 3D in vitro model to overcome these limitations, using poly (ethylene glycol) dimethyl acrylate (PEGDA) hydrogel-based microwells and co-culture GBM (U87) cells and endothelial cells (HUVEC) in the 3D microwells to provide a 3D in vitro simulation of the tumor microenvironment. Furthermore, we investigated the gene expression differences of co-cultures by quantitative real-time PCR. Our results suggested that the relative expression profiles of tumor angiogenesis markers, PECAM1/CD31, and VEGFR2, in co-cultures are consistent with in vivo GBM studies. Furthermore, we suggest that our microwell platform could provide robust and useful 3D co-culture models for high-throughput drug screening and treatment of the GBM.

Neutrophils with protumor potential could efficiently suppress tumor growth after cytokine priming and in presence of normal NK cells

In tumor-bearing state, the function of neutrophils is converted from tumor-suppressing to tumor-promoting. Here we report that priming with IFN-γ and TNF-α could convert the potential of neutrophils from tumor-promoting to tumor-suppressing. The neutrophils with protumor potential have not lost their responsiveness to IFN-γ and TNF-α. After priming with IFN-γ and TNF-α, the potential of the neutrophils to express Bv8 and Mmp9 genes was reduced. Conversely, the tumor-promotional neutrophils recovered the expression of Rab27a and Trail, resumed the activation levels of PI3K and p38 MAPK pathways in response to stimuli, and expressed higher levels of IL-18 and NK-activating ligands such as RAE-1, MULT-1, and H60. Therefore, the anti-tumor function of the neutrophils was augmented, including the cytotoxicity to tumor cells, the capability of degranulation, and the capacity to activate NK cells. Since the function of NK cells is impaired in tumor-bearing state, the administration of normal NK cells could significantly augment the efficiency of tumor therapy based on neutrophil priming. These findings highlight the reversibility of neutrophil function in tumor-bearing state, and suggest that neutrophil priming by IFN-γ/TNF-α might be a potential approach to eliminate residual tumor cells in comprehensive strategy for tumor therapy.

TNF-related apoptosis inducing ligand in ocular cancers and ocular diabetic complications

TNF-related apoptosis inducing ligand (TRAIL) is an intensively studied cytokine, in particular for its anticancer activity. The discovery that conjunctival sac fluid contains extremely high levels of soluble TRAIL as compared to other body fluids suggested important implications in the context of the immunological surveillance of the eye, in particular of the anterior surface. In this review, we discuss the potential physiopathologic and therapeutic role of the TRAIL/TRAIL receptor system in a variety of ocular cancers. Moreover, since an increasing amount of data has indicated the important biological activities of the TRAIL/TRAIL receptor systems also in a completely different pathologic context such as diabetes mellitus, in the second part of this review we summarize the currently available data on the involvement of TRAIL in the ocular complications of diabetes mellitus as modulator of the inflammatory and angiogenic response in the eye.

Relationship between tumour necrosis factor-related apoptosis inducing ligand (TRAIL) and vascular endothelial growth factor in human multiple myeloma patients

Tumour necrosis factor-alfa (TNF-α) is an inflammatory cytokine with a wide spectrum of biological activity, including angiogenesis. Tumour necrosis factor-related apoptosis inducing ligand (TRAIL), which belongs to the TNF family of proteins, plays a role in the regulation of vascular responses, but its effect on the formation of new blood vessels (angiogenesis) is unclear. We analysed TRAIL concentrations in parallel with pro-angiogenic cytokines in serum and their expression in trephine biopsy (TB) in 56 patients with newly diagnosed IgG MM and 24 healthy volunteers. The study showed statistically higher concentrations of TRAIL and TNF-α, as well as of VEGF and its receptor, in MM patients compared to healthy volunteers and patients in advanced stages of the disease. Furthermore, we observed a significant decrease in all studied pro-angiogenic cytokines and significant increase of TRAIL concentration after anti-angiogenic therapy, with meaningful differences between responders (at least partial remission) and patients with progression during the induction treatment. It was also established that TRAIL correlated statistically and negatively with pro-angiogenic cytokines such as VEGF with its receptor and expression of VEGF and syndecan-1 in TB. In summary, our data indicate that in MM patients, both clinical course and treatment responsiveness are associated with dynamic yet corresponding changes of levels of TRAIL parallel pro-angiogenic mediators such as VEGF with its receptor and expression of VEGF and syndecan-1 in TB.

Involvement of caspase 8 and c-FLIPL in the proangiogenic effects of the tumour necrosis factor-related apoptosis-inducing ligand (TRAIL)

Tumour necrosis factor-related apoptosis-inducing ligand (TRAIL), a cytokine of the tumour necrosis factor superfamily, is a potent cell-apoptosis inducer, although its effects vary as a function of concentration. In fact, low concentrations of TRAIL are associated with non-apoptotic effects, such as cell proliferation. Here, the effects of TRAIL at different concentrations have been evaluated on mitogenesis and migration on human umbilical vein endothelial cells (HUVEC) in vitro, as well as in the chick embryo chorioallantoic membrane (CAM) angiogenesis model in vivo. At low concentrations, TRAIL promoted either mitogenesis or migration of HUVEC, evaluated using the wound healing method. Cleavage of caspase 8 was evaluated along with expression of the caspase 8-like molecule, cellular FLICE-inhibitory protein (long form) (c-FLIPL ). Low concentrations of TRAIL failed to induce caspase 8 processing, whereas high concentrations induced apoptosis of HUVEC and activation of caspase 8. Moreover, TRAIL induced a significant angiogenic response in the CAM assay in vivo, comparable with that of vascular endothelial growth factor. These data suggest that the non-apoptotic effects of TRAIL include mitogenesis and increased mobility of endothelial cells, and eventually angiogenesis. In addition, the results demonstrate that the c-FLIPL level is also modulated by differences in TRAIL concentration, suggesting its involvement in the divergent effects of TRAIL. In conclusion, this study envisions a proangiogenic role of TRAIL, suggesting that TRAIL may represent a target for pharmacological manipulation.

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.

Effects of AG490 and S3I-201 on regulation of the JAK/STAT3 signaling pathway in relation to angiogenesis in TRAIL-resistant prostate cancer cells in vitro

The aim of the present study was to analyze the molecular mechanisms involved in blocking the signaling pathway and the effects of this on the progression of prostate cancer (CaP) cells in vitro. LNCaP human CaP cell line was stimulated with interleukin-6 (IL-6) in the presence/absence of Janus kinase (JAK) 2 (AG490), signal transducer and activator of transcription 3 [(STAT3) S3I-201] inhibitors and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). Cytotoxic activity, the activation of phosphorylated (p)-STAT3 protein, caspase (CASP) 3 activity at protein level, vascular endothelial growth factor (VEGF) A, VEGFC, vascular endothelial growth factor receptor 2, STAT3, matrix metalloproteinase-2, myeloid cell leukemia sequence 1 (MCL-1), CASP8 and CASP9 messenger RNA (mRNA) levels were determined. Morphology and apoptosis were confirmed by DAPI staining and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assay. IL-6 rapidly induced the phosphorylation of STAT3 in a dose- and time-dependent manner with a peak expression at 3 h at a concentration of 25 ng/ml. In addition, AG490 (50 μM) and S3I-201 (300 μM) inhibited STAT3 activation. Western blotting results revealed that p-STAT3 protein expression decreased significantly with AG490 and S3I-201 treatment in LNCaP cells. AG490 and S3I-201 induced the downregulation of VEGFA, MCL-1 and STAT3 and the upregulation of CASP8 and CASP9 mRNA transcription levels. In addition, the inhibitors increased the level of CASP3 protein. Combinations of AG490- and S3I-201-TRAIL did not result in an increase in this effect. Parallel results were found by DAPI staining and TUNEL assay. To the best of our knowledge, this is the first study to investigate the possible clinical use of AG490 or S3I-201, together with the reduced use of chemotherapeutic agents with high cytotoxicity, for their ability to exert an apoptotic effect, targeting the JAK/STAT3 pathway.

Level of TNF-related apoptosis-inducing-ligand and CXCL8 correlated with 2-[18F]Fluoro-2-deoxy-D-glucose uptake in anti-VEGF treated colon cancers

BACKGROUND

The changes and correlations of TRAIL (TNF-related apoptosis-inducing-ligand) and CXCL8 (IL8) prior to treatment and three months following therapy as well as the corresponding Positron emission tomography (PET/CT) (SUV(max): standardized uptake maximum values) results were evaluated.

MATERIAL AND METHODS

The measurements were taken before and after treatment for comparison purposes. The study population comprised 29 patients with Metastatic Colorectal cancer (MCRC), undergoing PET/CT scanning prior to treatment.

RESULTS

There were significant changes prior to treatment and three months later for sTRAIL (p=0.0080) and CXCL8 (p=0.0001)values. Generally, sTRAIL values were increasing during therapy, while a decrease was observed for CXCL8. Correlation analysis was applied to the data and revealed significant correlations for the SUV(max) in the primary tumor prior to treatment and CXCL8 prior to therapy (p=0.0303). Furthermore, significant correlations were observed for the SUV(max) and sTRAIL (p=0.0237) as well as CXCL8 (p=0.0002) three months after treatment initiation. CXCL8 prior to treatment was also correlated with the SUV three months after onset of treatment (p=0.0072). A significant correlation was noted for one combination of two variables, the SUV(max) in the metastases and CXCL8 prior to treatment (p=0.0175). These results are supported when we group the SUV(max) in the metastases following treatment into two groups with SUV(max) <5 and SUV(max) >5.

CONCLUSIONS

This study provides evidence that proteomics patterns of sTRAIL and CXCL8 predict tumor response und survival in MCRC patients treated with bevacizumab and within a high concordance of FDG-PET/CT findings.

TRAIL negatively regulates VEGF-induced angiogenesis via caspase-8-mediated enzymatic and non-enzymatic functions

Solid tumors supply oxygen and nutrients required for angiogenesis by producing vascular endothelial growth factor (VEGF). Thus, inhibitors of VEGF signaling abrogate tumor angiogenesis, resulting in the suppression of tumor growth and metastasis. We here investigated the effects of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) on VEGF-induced angiogenesis. TRAIL inhibited VEGF-induced in vitro angiogenesis of human umbilical vein endothelial cells (HUVECs) and in vivo neovascularization in chicken embryos and mice. TRAIL blocked VEGF-induced angiogenic signaling by inhibiting ERK, Src, FAK, paxillin, Akt, and eNOS. Further, TRAIL blocked intracellular Ca(2+) elevation and actin reorganization in HUVECs stimulated with VEGF, without inhibiting VEGF receptor-2 tyrosine phosphorylation. TRAIL increased caspase-8 activity, without inducing caspase-9/-3 activation and apoptosis. Moreover, TRAIL resulted in cleavage of FAK into FAK-related non-kinase-like fragments in VEGF-stimulated HUVECs, which was blocked by a caspase-8 inhibitor and cellular caspase-8-like inhibitory protein. Biochemical and pharmacological inhibition of caspase-8 and FAK blocked the inhibitory effects of TRAIL on VEGF-stimulated anti-angiogenic signaling and events. In addition, caspase-8 knockdown also suppressed VEGF-mediated signaling and angiogenesis, suggesting that procaspase-8 plays a role of a non-apoptotic modulator in VEGF-induced angiogenic signaling. These results suggest that TRAIL inhibits VEGF-induced angiogenesis by increasing caspase-8 activity and subsequently decreasing non-apoptotic signaling functions of procaspase-8, without inducing caspase-3 activation and endothelial cell cytotoxicity. These data indicate that caspase-8 may be used as an anti-angiogenic drug for solid tumors resistant to TRAIL and anti-tumor drugs.

Ad-KDRscFv:sTRAIL displays a synergistic antitumor effect without obvious cytotoxicity to normal tissues

AIM

To investigate the antitumor activities and safety of Ad-KDRscFv, Ad-sTRAIL (114-281) and Ad-KDRscFv:sTRAIL in vivo and in vitro.

METHODS

Recombinant replication-defective adenovirus vectors encoding either the extracellular domain (114-281 aa) of TRAIL, the KDRscFv (single chain antibody (scFv) against human vascular endothelial growth factor (VEGF) receptor KDR) or the fusion gene of KDRscFv:sTRAIL were constructed and transfected into HEK 293 cells for virus packaging. The recombinant virus particles were then infected human tumor cell lines of liver cancer (HepG2), gastric cancer (SGC-7901), colorectal cancer (SW480) and normal human liver cell line (LO2) to investigate the antitumor activities. Nude mice of the subcutaneous tumor models were established with HepG2 cells and were randomly divided into different groups to investigate the therapeutic effect and safety of these adenovirus particles on hepatocellular carcinoma. The expression of foreign proteins and the effect on microvascular number were also evaluated.

RESULTS

All three adenovirus particles could induce apoptosis of cancer cells lines HepG2, SGC-7901 and SW480, but had no obvious lethal effect on LO2 cells. Ad-KDRscFv:sTRAIL showed the strongest tumoricidal effect. After intratumoral injection with these adenovirus particles on nude mice model, all the three adenoviruses could inhibit the tumor growth and angiogenesis, and the expression of foreign proteins (sTRAIL, KDRscFv and KDRscFv:sTRAIL fusion protein) was restricted to liver and tumor tissues. In coincidence with the result in vitro, Ad-KDRscFv:sTRAIL also had the strongest antitumor activity in vivo. No obvious pathological changes were detected in vivo.

CONCLUSIONS

Replication-defective recombinant adenovirus of Ad-KDRscFv, Ad-sTRAIL and Ad-KDRscFv:sTRAIL all had tumoricidal activities and Ad-KDRscFv:sTRAIL showed the strongest effect. All three adenoviruses had no obvious toxicity to normal cells and tissues in vitro and in vivo.

Increased serum sTRAIL levels were correlated with survival in bevacizumab-treated metastatic colon cancer

BACKGROUND

Colorectal cancer is the third most common cancer and the third leading cause of cancer-related death. Bevacizumab is a humanized monoclonal antibody developed against vascular endothelial growth factor (VEGF) for the treatment of metastatic cancer. The parameters of RECIST (Response Evaluation Criteria for Solid Tumors) are not adequate to detect important treatment effects and response. Our goal was to evaluate the possibility of using sTRAIL (serum-soluble TNF-related apoptosis-inducing ligand) and VEGF as markers of treatment efficacy and prognosis in patients with metastatic colon cancer.

METHODS

sTRAIL and VEGF levels were measured by ELISA in the sera of 16 bevacizumab-treated metastatic colon cancer patients and 10 presumably healthy age-matched controls. The measurements were taken before and after treatment for comparison purposes.

RESULTS

Elevated levels of sTRAIL were found in seven out of 16 patients after bevacizumab treatment. Although these patients had a median survival time of 20.6 months, the remaining bevacizumab-treated patients who did not show an increase in sTRAIL had a median survival time of 9.4 months. As expected, serum VEGF levels were decreased in all patients who received bevacizumab therapy and showed no correlation between serum VEGF levels and patient survival (data not shown).

CONCLUSIONS

Serum sTRAIL levels might be a useful predictor of prognosis in metastatic colon cancer, in the early evaluation stages following bevacizumab treatment.

Biodegradable poly(amine-co-ester) terpolymers for targeted gene delivery

Many synthetic polycationic vectors for non-viral gene delivery show high efficiency in vitro, but their usually excessive charge density makes them toxic for in vivo applications. Here we describe the synthesis of a series of high molecular weight terpolymers with low charge density, and show that they exhibit efficient gene delivery, some surpassing the efficiency of the commercial transfection reagents Polyethylenimine and Lipofectamine 2000. The terpolymers were synthesized via enzyme-catalyzed copolymerization of lactone with dialkyl diester and amino diol, and their hydrophobicity adjusted by varying the lactone content and by selecting a lactone comonomer of specific ring size. Targeted delivery of the pro-apoptotic TRAIL gene to tumour xenografts by one of the terpolymers results in significant inhibition of tumour growth, with minimal toxicity both in vitro and in vivo. Our findings suggest that the gene delivery ability of the terpolymers stems from their high molecular weight and increased hydrophobicity, which compensates for their low charge density.

TRAIL and doxorubicin combination induces proapoptotic and antiangiogenic effects in soft tissue sarcoma in vivo

PURPOSE

Novel therapeutic approaches for complex karyotype soft tissue sarcoma (STS) are crucially needed. Consequently, we assessed the efficacy of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), in combination with chemotherapy, on local and metastatic growth of human STS xenografts in vivo.

EXPERIMENTAL DESIGN

TRAIL was evaluated alone and combined with low-dose doxorubicin in two human STS severe combined immunodeficient mouse xenograft models using fibrosarcoma (HT1080; wild-type p53) and leiomyosarcoma (SKLMS1; mutated p53), testing for effects on local growth, metastasis, and overall survival. Magnetic resonance imaging was used to evaluate local growth and bioluminescence was used to longitudinally assess lung metastases. Tissues were evaluated through immunohistocemistry and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling staining for treatment effects on tumor cell proliferation, apoptosis, angiogenesis, angiogenic factors, and TRAIL receptor expression. Quantitative real-time polymerase chain reaction (QRTPCR) angiogenesis array was used to assess therapy-induced gene expression changes.

RESULTS

TRAIL/doxorubicin combination induced marked STS local and metastatic growth inhibition in a p53-independent manner. Significantly increased (P < 0.001) host survival was also demonstrable. Combined therapy induced significant apoptosis, decreased tumor cell proliferation, and increased TRAIL receptor (DR4 and DR5) expression in all treated tumors. Moreover, decreased microvessel density was observed, possibly secondary to increased expression of the antiangiogenic factor CXCL10 and decreased proangiogenic interleukin-8 cytokine in response to TRAIL/doxorubicin combination, as was also observed in vitro.

CONCLUSIONS

Given the urgent need for better systemic approaches to STS, clinical trials evaluating TRAIL in combination with low-dose chemotherapy are potentially warranted.

TRAIL, DR5 and caspase 3-dependent apoptosis in vessels of diseased human temporomandibular joint disc. An immunohistochemical study

To evaluate the apoptosis involvement in the angiogenesis as a self-limiting process in patients with temporomandibular joint (TMJ) degenerated disc vessels, we assessed, by immunohistochemistry, the detection of TRAIL, its death receptor DR5 and caspase 3. TRAIL, its death receptor DR5 and caspase 3 expression were studied by immunohistochemistry in 15 TMJ discs displaced without reduction and in 4 unaffected discs. These apoptosis molecules were detected in the intima and media layers of newly formed vessels affected discs. In conclusion, vessels apoptosis activation in TMJ disc with ID could be regarded as a self-limiting process that try to leads to vessel regression; in this way an inhibition of angiogenic vessels may prove a key strategy in limiting pathological angiogenesis, by cutting off blood supply to tumors, or by reducing harmful inflammation.

Evidence that tumor necrosis factor-related apoptosis inducing ligand (TRAIL) inhibits angiogenesis by inducing vascular endothelial cell apoptosis

Tumor necrosis factor (TNF) and its related ligands TNF-related apoptosis inducing ligand (TRAIL) and Fas ligand (FasL) play roles in the regulation of vascular responses, but their effect on the formation of new blood vessels (angiogenesis) is unclear. Therefore, we have examined the effects of these ligands on angiogenesis modeled with primary cultures of human umbilical vein endothelial cells (HUVEC). To examine angiogenesis in the context of the central nervous system, we have also modeled cerebral angiogenesis with the human brain endothelial cell line hCMEC/D3. Parameters studied were bromodeoxyuridine (BrdU) incorporation and cell number (MTT) assay (to assess endothelial proliferation), scratch assay (migration) and networks on Matrigel (tube formation). In our hands, neither TRAIL nor FasL (1, 10, and 100 ng/ml) had an effect on parameters of angiogenesis in the HUVEC model. In hCMEC/D3 cells by contrast, TRAIL inhibited all parameters (10-100 ng/ml, 24h). This was due to apoptosis, since its action was blocked by the pan-caspase inhibitor zVADfmk (5 x 10(-5) mol/l) and TRAIL increased caspase-3 activity 1h after application. However FasL (100 ng/ml) increased BrdU uptake without other effects. We conclude that TRAIL has different effects on in vitro angiogenesis depending on which model is used, but that FasL is generally ineffective when applied in vitro. The data suggest that TRAIL primarily influences angiogenesis by the induction of vascular endothelial apoptosis, leading to vessel regression.

Fn14-TRAIL, a chimeric intercellular signal exchanger, attenuates experimental autoimmune encephalomyelitis

Hallmarks of the pathogenesis of autoimmune encephalomyelitis include perivascular infiltration of inflammatory cells into the central nervous system, multifocal demyelination in the brain and spinal cord, and focal neuronal degeneration. Optimal treatment of this complex disease will ultimately call for agents that target the spectrum of underlying pathogenic processes. In the present study, Fn14-TRAIL is introduced as a unique immunotherapeutic fusion protein that is designed to exchange and redirect intercellular signals within inflammatory cell networks, and, in so doing, to impact multiple pathogenic events and yield a net anti-inflammatory effect. In this soluble protein product, a Fn14 receptor component (capable of blocking the pro-inflammatory TWEAK ligand) is fused to a TRAIL ligand (capable of inhibiting activated, pathogenic T cells). Sustained Fn14-TRAIL expression was obtained in vivo using a transposon-based eukaryotic expression vector. Fn14-TRAIL expression effectively prevented chronic, nonremitting, paralytic disease in myelin oligodendrocyte glycoprotein-challenged C57BL/6 mice. Disease suppression in this model was reflected by decreases in the clinical score, disease incidence, nervous tissue inflammation, and Th1, Th2, and Th17 cytokine responses. Significantly, the therapeutic efficacy of Fn14-TRAIL could not be recapitulated simply by administering its component parts (Fn14 and TRAIL) as soluble agents, either alone or in combination. Its functional pleiotropism was manifest in its additional ability to attenuate the enhanced permeability of the blood-brain barrier that typically accompanies autoimmune encephalomyelitis.

The role of the matricellular protein SPARC in the dynamic interaction between the tumor and the host

Tumor growth is essentially the result of an evolving cross-talk between malignant and surrounding stromal cells (fibroblasts, endothelial cells and inflammatory cells). This heterogeneous mass of extracellular matrix and intermingled cells interact through cell-cell and cell-matrix contacts. Malignant cells also secrete soluble proteins that reach neighbor stromal cells, forcing them to provide the soil on which they will grow and metastasize. Different studies including expression array analysis identified the matricellular protein SPARC as a marker of poor prognosis in different cancer types. Further evidence demonstrated that high SPARC levels are often associated with the most aggressive and highly metastatic tumors. Here we describe the most recent evidence that links SPARC with human cancer progression, the controversy regarding its role in certain human cancers and the physiological processes in which SPARC is involved: epithelial-mesenchymal transition, immune surveillance and angiogenesis. Its relevance as a potential target in cancer therapy is also discussed.

Inhibition of tumor-induced edema by antisense VEGF is mediated by suppressive vesiculo-vacuolar organelles (VVO) formation

Vascular endothelial growth factor (VEGF) is an important regulator of angiogenesis, vasculogenesis and vascular permeability. Edema in glioma tumors is considered one of the most pathological characteristics, but the mechanism of regulating vascular permeability is still unclear. In the present study, tumorigenic mice were generated by subcutaneous injection of glioma cell lines, C6-null cells and stable transfected-C6 cells overexpressing mock vector (C6-mock) and antisense VEGF (C6-VEGF(-/-)). Overexpression of antisense VEGF (C6-VEGF(-/-) mice) significantly suppressed tumor growth, decreased angiogenesis and reduced tumoral edema. Further studies by electron microscope revealed that tumor-induced hyperpermeability was mediated by formation of vesiculo-vacuolar organelles (VVO), specifically reducing the number of vesicle and caveolae in VVO, and this effect was blocked, at least partially, by antisense VEGF. These data show a possible mechanism of tumor-induced hyperpermeability and indicate that blockage of VEGF might contribute to therapeutical strategies for tumor edema.

The role of the matricellular protein SPARC in the dynamic interaction between the tumor and the host

Tumor growth is essentially the result of an evolving cross-talk between malignant and surrounding stromal cells (fibroblasts, endothelial cells and inflammatory cells). This heterogeneous mass of extracellular matrix and intermingled cells interact through cell-cell and cell-matrix contacts. Malignant cells also secrete soluble proteins that reach neighbor stromal cells, forcing them to provide the soil on which they will grow and metastasize. Different studies including expression array analysis identified the matricellular protein SPARC as a marker of poor prognosis in different cancer types. Further evidence demonstrated that high SPARC levels are often associated with the most aggressive and highly metastatic tumors. Here we describe the most recent evidence that links SPARC with human cancer progression, the controversy regarding its role in certain human cancers and the physiological processes in which SPARC is involved: epithelial-mesenchymal transition, immune surveillance and angiogenesis. Its relevance as a potential target in cancer therapy is also discussed.

Using extracellular biomarkers for monitoring efficacy of therapeutics in cancer patients: an update

Rapidly detectable and easily accessible markers of tumor cell death are needed for evaluating early therapeutic efficacy for immunotherapy and chemotherapy so that patients and their physicians can decide whether to remain with a given therapeutic strategy. Currently, image-based tests such as computed tomography scans and magnetic resonance imaging are used to visualize the response of a patient's tumor, but often these evaluations are not conducted for weeks to months after treatment begins. While serum levels of secreted proteins such as carcinoembryonic antigen and prostate specific antigen are commonly monitored to gauge tumor status during therapy and between image evaluations, the levels of these proteins do not always correlate well with the actual tumor response. In laboratory studies, it has been shown that tumor cells undergoing apoptosis can release cellular components into cell culture media such as cytochrome c, nucleosomes, cleaved cytokeratin-18 and E-cadherin. Studies of patient sera have found that these and other macromolecules can be found in circulation during cancer therapy, providing a potential source of material for monitoring treatment efficacy. In the future, analysis of biofluids from severe combined immunodeficiency mice bearing patient tumor specimens treated with a targeted therapy such as Apo2L/tumor necrosis factor-related apoptosis-inducing ligand will be useful in the preclinical identification of therapy response markers. In this review, the current status of the identification of serum markers of tumor cell apoptosis is provided, as well as a discussion of critical research questions that must be addressed and the considerations necessary when identifying a marker that reflects true clinical outcome.

Green tea polyphenol EGCG sensitizes human prostate carcinoma LNCaP cells to TRAIL-mediated apoptosis and synergistically inhibits biomarkers associated with angiogenesis and metastasis

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL/Apo2L) is a promising candidate for cancer therapy, however, emergence of drug resistance limits its potential use. Here, we report for the first time that epigallocatechin-3-gallate (EGCG), the major polyphenolic constituent of green tea, sensitizes TRAIL-resistant LNCaP cells to TRAIL-mediated apoptosis through modulation of intrinsic and extrinsic apoptotic pathways. When combined with EGCG, Apo2L/TRAIL exhibited enhanced apoptotic activity in LNCaP cells characterized by three major molecular events. First, apoptosis induction was accompanied by the upregulation of poly(ADP-ribose) polymerase cleavage and modulation of pro- and antiapoptotic Bcl2 family of proteins. A synergistic inhibition of inhibitors of apoptosis with concomitant increase in caspase cleavage was observed. Second, pretreatment of cells with EGCG resulted in modulation of death-inducing signaling cascade complex involving DR4/TRAIL R1, Fas-associated death domain and FLICE-inhibitory protein proteins. Last, we observed a synergistic inhibition in the invasion and migration of LNCaP cells. This effect was observed to be mediated through inhibition in the protein expression of vascular endothelial growth factor, uPA and angiopoietin 1 and 2. Further, the activity and protein expression of MMP-2, -3 and -9 and upregulation of TIMP1 in cells treated with a combination of EGCG and TRAIL was observed. These data might have implications for developing new strategies aimed at eliminating prostate cancer cells resistant to TRAIL.

SNS-032 prevents tumor cell-induced angiogenesis by inhibiting vascular endothelial growth factor

Cell proliferation, migration, and capillary network formation of endothelial cells are the fundamental steps for angiogenesis, which involves the formation of new blood vessels. The purpose of this study is to investigate the effect of a novel aminothiazole SNS-032 on these critical steps for in vitro angiogenesis using a coculture system consisting of human umbilical vein endothelial cells (HUVECs) and human glioblastoma cells (U87MG). SNS-032 is a potent selective inhibitor of cyclin-dependent kinases 2, 7, and 9, and inhibits both transcription and cell cycle. In this study, we examined the proliferation and viability of HUVECs and U87MG cells in the presence of SNS-032 and observed a dose-dependent inhibition of cellular proliferation in both cell lines. SNS-032 inhibited threedimensional capillary network formations of endothelial cells. In a coculture study, SNS-032 completely prevented U87MG cell-mediated capillary formation of HUVECs. This inhibitor also prevented the migration of HUVECs when cultured alone or cocultured with U87MG cells. In addition, SNS-032 significantly prevented the production of vascular endothelial growth factor (VEGF) in both cell lines, whereas SNS-032 was less effective in preventing capillary network formation and migration of endothelial cells when an active recombinant VEGF was added to the medium. In conclusion, SNS-032 prevents in vitro angiogenesis, and this action is attributable to blocking of VEGF.

Comparison of topical interleukin-1 vs tumor necrosis factor-alpha blockade with corticosteroid therapy on murine corneal inflammation, neovascularization, and transplant survival (an American Ophthalmological Society thesis)

PURPOSE

Interleukin-1 (IL-1) and tumor necrosis factor-alpha (TNF-alpha) play critical roles in mediating corneal inflammation. In this study, topical blockade of IL-1 and TNF-alpha, alone or in combination, was compared to conventional corticosteroid anti-inflammatory therapy in suppressing infiltration of the cornea by antigen-presenting Langerhans cells (LCs) and in promoting corneal transplant survival in a mouse model of keratoplasty.

METHODS

Study drugs included topical 2% IL-1 receptor antagonist (IL-1Ra), 1.5% soluble TNF-alpha receptor (sTNFR), and 1% prednisolone phosphate (Pred), all formulated in hyaluronic acid vehicle. Fifty eyes of BALB/c mice were used for LC studies where the numbers of LCs were determined 1 week after electrocautery to the corneal surface or transplantation of C57BL/6 corneas. Additionally, 65 BALB/c mice received corneal allografts and were randomized to receive one of the following for 8 weeks: (1) IL-1Ra, (2) sTNFR, (3) Pred, (4) combined IL-1Ra and Pred, or (5) vehicle alone.

RESULTS

Mean suppression of LC infiltration after electrocautery or transplantation was 67% and 71%, respectively, for IL-1Ra, 40% and 62% for sTNFR, 70% and 72% for sTNFR+IL-1Ra, and 77% and 78% for Pred alone. Rejection rates were 15% for IL-1Ra (P = .01), 38% for sTNFR (P = .1), 17% for Pred (P = .02), and 7% for combined IL-1Ra+Pred (P = .002) as compared to 69% for the vehicle-treated group. IL-1Ra and Pred, but not sTNFR, significantly inhibited post-transplantation neovascularization.

CONCLUSIONS

Topical IL-1Ra and prednisolone are comparable in their capacity to promote graft survival. sTNFR therapy, though effective, has much lower efficacy as compared to IL-1Ra or Pred. Combination IL-1Ra and steroid therapy offers only minimal added efficacy over either agent used alone.