Angiogenesis--a new target for future therapy

Anti-angiogenic effects of Qingdu granule on breast cancer through inhibiting NFAT signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Qingdu granule (QDG), a traditional Chinese herbal prescription, had anti-tumor effect on breast cancer. However the underlying mechanism of QDG was unclear.

THE AIM OF THIS STUDY

The present study aimed to investigate whether QDG could inhibit angiogenesis of breast cancer via acting on nuclear factor of activated T-cells (NFAT) signaling pathway. This was implicated in human umbilical vein endothelial cells (HUVECs) in vitro and breast cancer xenograft model in vivo.

MATERIALS AND METHODS

The VEGF₁₆₅ (15.58 ng/mL) induced human umbilical vein endothelial cells (HUVECs) were treated with serum samples containing tamoxifen (TAM), tacrolimus (FK506), or QDG with three dosages. The migration and canalization capacities of HUVECs were evaluated by transwell migration and tube formation assay. In 72 h-cultured HUVECs, The gene expression, protein amount, and nuclear translocation of NFATc3 were measured. The anti-tumor and anti-angiogenic effects of QDG in vivo were investigated in breast cancer xenograft model. The serum VEGF levels, microvessel density, and protein expressions (immunohistochemistry and western blot) of VEGF, VEGFR2 and NFATc3 were detected.

RESULTS

The results showed that, QDG significantly inhibited HUVEC migration and tube formation. It downregulated NFATc3 gene expression, decreased NFATc3 protein amount, and reduced the ratio of NFATc3 nuclear translocation in HUVECs. In breast cancer xenograft model, QDG treatment significantly suppressed tumor growth, inhibited VEGF release, and decreased microvessel density. QDG reduced protein expressions of VEGF, VEGFR2 and NFATc3.

CONCLUSION

The results suggested that QDG showed anti-angiogenic effects of breast cancer both in vitro and in vivo. The mechanism might be partially associated with inhibiting NFAT signaling pathway.

Tumor angiogenesis and anti-angiogenic gene therapy for cancer

When Folkman first suggested a theory about the association between angiogenesis and tumor growth in 1971, the hypothesis of targeting angiogenesis to treat cancer was formed. Since then, various studies conducted across the world have additionally confirmed the theory of Folkman, and numerous efforts have been made to explore the possibilities of curing cancer by targeting angiogenesis. Among them, anti-angiogenic gene therapy has received attention due to its apparent advantages. Although specific problems remain prior to cancer being fully curable using anti-angiogenic gene therapy, several methods have been explored, and progress has been made in pre-clinical and clinical settings over previous decades. The present review aimed to provide up-to-date information concerning tumor angiogenesis and gene delivery systems in anti-angiogenic gene therapy, with a focus on recent developments in the study and application of the most commonly studied and newly identified anti-angiogenic candidates for anti-angiogenesis gene therapy, including interleukin-12, angiostatin, endostatin, tumstatin, anti-angiogenic metargidin peptide and endoglin silencing.

Promotion of mammalian angiogenesis by neolignans derived from soybean extracellular fluids

Excessive or insufficient angiogenesis is associated with major classes of chronic disease. Although less studied, small molecules which can promote angiogenesis are being sought as potential therapeutics for cardiovascular and peripheral arterial disease and stroke. Here we describe a bioassay-directed discovery approach utilising size exclusion and liquid chromatography to purify components of soybean xylem sap that have pro-angiogenic activity. Using high resolution accurate mass spectrometry and nuclear magnetic resonance spectroscopy, the structure of two pro-angiogenic molecules (FK1 and FK2) were identified as erythro-guaiacylglycerol-8-O-4'-(coniferyl alcohol) ether (eGGCE), and threo-guaiacylglycerol-8-O-4'-(coniferyl alcohol) ether (tGGCE). These two molecules, which are coniferyl neolignan stereoisomers, promoted in vitro angiogenesis in the μM to nM range. Independently sourced samples of eGGCE and tGGCE exhibited comparable pro-angiogenic activity to the soybean derived molecules. The cellular mode of action of these molecules was investigated by studying their effect on endothelial cell proliferation, migration, tube formation and adhesion to the extracellular matrix (ECM) components, fibronectin and vitronectin. They were found to enhance endothelial cell proliferation and endothelial cell tube formation on Matrigel, but did not affect endothelial cell migration or adhesion to fibronectin and vitronectin. Thus, this study has identified two coniferyl neolignan stereoisomers, eGGCE and tGGCE, as pro-angiogenic molecules, with eGGCE being less active than tGGCE.

Evaluation of Detection Methods and Values of Circulating Vascular Endothelial Growth Factor in Lung Cancer

Lung cancer is the deadliest cancer in the world. Angiogenesis plays a crucial role of the incidence, progression, and metastasis in lung cancer. Angiogenesis inhibitors are used to treat non-small cell lung cancer (NSCLC) patients, and the molecular biomarkers are also being assessed to predict treatment response/therapeutic response and patients' prognosis. Vascular endothelial growth factor (VEGF) is a signal protein produced by cells that stimulates angiogenesis. Due to its predictive values of prognosis on NSCLC, a large number of methods have been developed and evaluated to detect VEGF levels in a variety of studies. In this article, we review the detection methods designed to measure the VEGF levels in different body fluids and prognosticate the value of VEGF in treatment, diagnosis and survival in lung cancer.

MicroRNA-296 mediated corneal neovascularization in an animal model of corneal burns after alkali exposures

Alkali burns of the cornea may lead to permanent visual impairment or complete blindness. In the current study, the role of microRNA 296 (miR-296) was explored in mouse corneal neovascularization induced by alkali burns. An alkali burn model in Balb/c mice was developed to study chemical corneal injuries. The expression of the miR-296 gene was measured by reverse-transcription-quantitative polymerase chain reaction. Fibroblast growth factor 23 (FGF23) protein expression was measured by western blot analysis. Possible impacted pathways were analyzed by Kyoto Encyclopedia of Genes and Genomes pathway analysis. miR-296 gene expression was examined following chemical corneal injury and it was demonstrated that different topical eye medications decreased miR-296 gene expression. miR-296 may participate in cytokine-cytokine receptor interaction pathways to influence corneal inflammatory responses. It was also revealed that FGF23 was expressed following chemical corneal injury and that different treatments with topical eye drops decreased its expression. miR-296 is a novel molecular modulator for alkali burns in the mouse cornea.

Ovarian angiogenesis in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most prevalent endocrine pathology among women in reproductive age. Its main symptoms are oligo or amenorrhea, hyperandrogenism and the presence of ovarian cysts. It is also associated with infertility, obesity and insulin resistance. Mainly due to its heterogeneity, PCOS treatments are directed to manage its symptoms and to prevent associated diseases. The correct formation and regression of blood vessels during each ovarian cycle is indispensable for proper follicular development, ovulation and corpus luteum formation. The importance of these processes opened a new and promising field: ovarian angiogenesis. Vascular alterations characterize numerous pathologies, either with increased, decreased or abnormal angiogenesis. In the last years, several anomalies of ovarian angiogenesis have been described in women with PCOS. Therefore, it has been suggested that these alterations may be associated with the decreased - or lack of - ovulation rates and for the formation of cysts in the PCOS ovaries. Restoration of a proper vessel formation in the ovaries may lead to improved follicular development and ovulation in these patients. In the present review, we attempt to summarize the alterations in ovarian angiogenesis that have been described in women with PCOS. We also discuss the therapeutic approaches aimed to correct these alterations and their beneficial effects on the treatment of infertility in PCOS.

Roles of toll-like receptors: From inflammation to lung cancer progression

Lung cancer is among the most common malignant tumors worldwide, and is characterized by a low survival rate compared with other cancers. Toll-like receptors (TLRs) are highly conserved in evolution and widely expressed on immune cells, where they serve an important role in the innate immune system by evoking inflammatory responses. Evasion of immune destruction is an important hallmark in the development of cancer. There is an established association between chronic inflammation and cancer, with TLRs serving important roles in the immune response against tumor cells. Recently, TLRs have been identified on tumor cells, where their activation may orchestrate the downstream signaling pathways that serve crucial functions in tumorigenesis and tumor progression. The present review summarizes the roles of TLRs as sensors on lung cancer cells that regulate lung cancer progression with regard to cell growth and invasion, angiogenesis and cancer stem cell behavior. This aimed to provide theoretical support for the development of therapies that target TLR signaling pathways for the treatment of lung cancer.

Corneal angiogenesis based on different protocols of alkaline cauterization in murine models

Purpose:

To establish and compare protocols of alkaline cauterization for inducing corneal angiogenesis in murine models.

Methods:

Twenty-four adult Wistar rats were distributed into four groups (G1, G2, G3, and G4). The right eye cornea from each rat was cauterized using filter paper (3 mm), soaked in a solution of silver and potassium nitrates (3:1). Cauterization times were 10 (G1 and G4), or 20 seconds (G2 and G3). Cauterized corneas were washed with Ringer's lactate solution. The filter paper was either removed before washing (G1 and G2), or kept on the corneas (G3 and G4). Corneas were photographed at multiple time points (2, 4, 6, 8, 11, 13, and 15 days after the procedure), and neovascularization parameters were assayed.

Results:

Neovascularization was observed in 66% of G1 corneas, and 100% of G2, G3, and G4 corneas. On day 15, G1 corneas showed smaller vascularized areas (12.63 ± 12.59%) compared to those in the G3 (41.95 ± 17.32%) and G4 (33 ± 11.74%) (P < 0.05) groups.

Conclusions:

The silver and potassium nitrate solution effectively induced corneal angiogenesis. The G2, G3, and G4 protocols showed excellent reproducibility, and induced vascularization in 100% of corneas.

Discovery and evaluation of triple inhibitors of VEGFR-2, TIE-2 and EphB4 as anti-angiogenic and anti-cancer agents

Receptor tyrosine kinases (RTKs), especially VEGFR-2, TIE-2, and EphB4, play a crucial role in both angiogenesis and tumorigenesis. Moreover, complexity and heterogeneity of angiogenesis make it difficult to treat such pathological traits with single-target agents. Herein, we developed two classes of multi-target RTK inhibitors (RTKIs) based on the highly conserved ATP-binding pocket of VEGFR-2/TIE-2/EphB4, using previously reported BPS-7 as a lead compound. These multi-target RTKIs exhibited considerable potential as novel anti-angiogenic and anticancer agents. Among them, QDAU5 displayed the most promising potency and selectivity. It significantly suppressed viability of EA.hy926 and proliferation of several cancer cells. Further investigations indicated that QDAU5 showed high affinity to VEGFR-2 and reduced the phosphorylation of VEGFR-2. We identified QDAU5 as a potent multiple RTKs inhibitor exhibiting prominent anti-angiogenic and anticancer potency both in vitro and in vivo. Moreover, quinazolin-4(3H)-one has been identified as an excellent hinge binding moiety for multi-target inhibitors of angiogenic VEGFR-2, Tie-2, and EphB4.

Effect of Niacin on Inflammation and Angiogenesis in a Murine Model of Ulcerative Colitis

Butyrate and niacin are produced by gut microbiota, however butyrate has received most attention for its effects on colonic health. The present study aimed at exploring the effect of niacin on experimental colitis as well as throwing some light on the ability of niacin to modulate angiogenesis which plays a crucial role of in the pathogenesis of inflammatory bowel disease. Rats were given niacin for 2 weeks. On day 8, colitis was induced by intrarectal administration of iodoacetamide. Rats were sacrificed on day 15 and colonic damage was assessed macroscopically and histologically. Colonic myeloperoxidase (MPO), tumour necrosis factor (TNF)-α, interleukin (IL)-10, vascular endothelial growth factor (VEGF), angiostatin and endostatin levels were determined. Niacin attenuated the severity of colitis as demonstrated by a decrease in weight loss, colonic wet weight and MPO activity. Iodoacetamide-induced rise in the colonic levels of TNF-α, VEGF, angiostatin and endostatin was reversed by niacin. Moreover, niacin normalized IL-10 level in colon. Mepenzolate bromide, a GPR109A receptor blocker, abolished the beneficial effects of niacin on body weight, colon wet weight as well as colonic levels of MPO and VEGF. Therefore, niacin was effective against iodoacetamide-induced colitis through ameliorating pathologic angiogenesis and inflammatory changes in a GPR109A-dependent manner.

The role of bone marrow-derived endothelial progenitor cells and angiogenic responses in chronic obstructive pulmonary disease

Increased vascularity of the bronchial sub-mucosa is a cardinal feature of chronic obstructive pulmonary disease (COPD) and is associated with disease severity. Capillary engorgement, leakage, and vasodilatation can directly increase airway wall thickness resulting in airway luminal narrowing and facilitate inflammatory cell trafficking, thereby contributing to irreversible airflow obstruction, a characteristic of COPD. Airway wall neovascularisation, seen as increases in both the size and number of bronchial blood vessels is a prominent feature of COPD that correlates with reticular basement membrane thickening and airway obstruction. Sub-epithelial vascularization may be an important remodelling event for airway narrowing and airflow obstruction in COPD. Post-natal angiogenesis is a complex process, whereby new blood vessels sprouting from extant microvasculature, can arise from the proliferation of resident mature vascular endothelial cells (ECs). In addition, this may arise from increased turnover and lung-homing of circulating endothelial progenitor cells (EPCs) from the bone marrow (BM). Following lung-homing, EPCs can differentiate locally within the tissue into ECs, further contributing to vascular repair, maintenance, and expansion under pathological conditions, governed by a locally elaborated milieu of growth factors (GFs). In this article, we will review evidence for the role of BM-derived EPCs in the development of angiogenesis in the lug and discuss how this may relate to the pathogenesis of COPD.

Tumstatin regulates the angiogenic and inflammatory potential of airway smooth muscle extracellular matrix

The extracellular matrix (ECM) creates the microenvironment of the tissue; an altered ECM in the asthmatic airway may be central in airway inflammation and remodelling. Tumstatin is a collagen IV‐derived matrikine reduced in the asthmatic airway wall that reverses airway inflammation and remodelling in small and large animal models of asthma. This study hypothesized that the mechanisms underlying the broad asthma‐resolving effects of tumstatin were due to autocrine remodelling of the ECM. Neutrophils and endothelial cells were seeded on decellularized ECM of non‐asthmatic (NA) or asthmatic (A) airway smooth muscle (ASM) cells previously exposed to tumstatin in the presence or absence of a broad matrix metalloproteinase inhibitor, Marimastat. Gene expression in NA and A ASM induced by tumstatin was assessed using RT‐PCR arrays. The presence of tumstatin during ECM deposition affected neutrophil and endothelial cell properties on both NA and A ASM‐derived matrices and this was only partly due to MMP activity. Gene expression patterns in response to tumstatin in NA and A ASM cells were different. Tumstatin may foster an anti‐inflammatory and anti‐angiogenic microenvironment by modifying ASM‐derived ECM. Further work is required to examine whether restoring tumstatin levels in the asthmatic airway represents a potential novel therapeutic approach.

Obesity Downregulates MicroRNA-126 Inducing Capillary Rarefaction in Skeletal Muscle: Effects of Aerobic Exercise Training

Background. We investigated the effects of exercise training (ET) on miR-126 levels and skeletal muscle angiogenesis in obese Zucker rats. Results. Zucker rats were randomly assigned to sedentary and swimming-trained groups: lean sedentary (LS) and trained (LTR); obese sedentary (OB) and trained (OBTR). The OB group displayed capillary rarefaction compared with the LS group. In contrast, ET increased the capillary/fiber ratio by 38% in the LTR group and normalized capillary rarefaction in the OBTR group. VEGF, PI3K, and eNOS levels were reduced in the skeletal muscle of the OB group. ET normalized VEGF, PI3K, and eNOS levels in OBTR, contributing to vascular network homeostasis. PI3KR2 inhibits PI3K, a key mediator of the VEGF signaling pathway. Obesity decreased miR-126 and increased PI3KR2 levels compared with the LS group. However, ET normalized miR-126 levels in the OBTR group versus the LS group and decreased expression of PI3KR2. Conclusion. Our findings show that obesity leads to skeletal muscle capillary rarefaction, which is regulated by decreased miR-126 levels and increased PI3KR2. Inversely, ET normalizes miR-126 levels and VEGF signaling and should be considered an important therapeutic strategy for vascular disorders.

Visualizing dynamics of angiogenic sprouting from a three-dimensional microvasculature model using stage-top optical coherence tomography

Three-dimensional (3D) in vitro microvasculature in a polydimethylsiloxane-based microdevice was developed as a physiologically relevant model of angiogenesis. The angiogenic process is monitored using stage-top optical coherence tomography (OCT). OCT allows non-invasive monitoring of the 3D structures of the prepared host microvasculature and sprouted neovasculature without fluorescence staining. OCT monitoring takes only a few minutes to scan through the several-millimetre scale range, which provides the advantage of rapid observation of living samples. The obtained OCT cross-sectional images capture 3D features of the angiogenic sprouting process and provide information on the dynamics of luminal formation. The stage-top system used in this study enables the observer to visualize the in vitro dynamics of 3D cultured cells simply and conveniently, offering an alternative monitoring method for studies on angiogenesis and providing quantitative information about vascular morphological changes.

Davallia bilabiata exhibits anti-angiogenic effect with modified MMP-2/TIMP-2 secretion and inhibited VEGF ligand/receptors expression in vascular endothelial cells

ETHNOPHARMACOLOGICAL RELEVANCE

Davallia bilabiata Hosokawa (D. bilabiata), also called GuSuiBu, is popularly used as a substitute for Drynaria fortunei J. Sm for rheumatoid and degenerative arthritis in traditional Chinese medicine. Little is known about the underlying mechanisms of anti-angiogenesis responsible for arthritis in D. bilabiata which needs to be elucidated.

AIM OF THE STUDY

The present study is intended to investigate the anti-angiogenic effect of D. bilabiata associated with the modulation of matrix metalloproteinases (MMPs) and down regulation of vascular endothelial growth factor (VEGF) ligand/receptors both in vivo and in vitro.

MATERIALS AND METHODS

We investigated the potential anti-angiogenic effect of D. bilabiata by the in vivo neovascularization of chick chorioallantoic membranes (CAM) assay, and the in vitro migration and matrix-induced tube formation assay using human umbilical vascular endothelial cells (HUVECs). The expressions of MMP-2, TIMP-2, RECK and VEGF/VEGFR were analyzed by real-time RT-PCR or Western blot method.

RESULTS

One major compound from water extract of D. bilabiata was identified as Epicatechin 3-O-β-D-allopyranoside. D. bilabiata was confirmed to inhibit in vivo angiogenesis by CAM assay. D. bilabiata also exhibited in vitro anti-angiogenic and anti-regrowth effects as demonstrated by tube formation assay, transwell migration assay and wound healing assay. The mRNA expressions of MMP-2, and MMP-14 were decreased. On the contrary, tissue inhibitor of metalloproteinase-2 (TIMP-2), reversion-inducing cysteine-rich protein with kazal motifs (RECK) were increased by D. bilabiata. The extracellular MMP-2 activity was found to be reduced both in vitro and in vivo by D. bilabiata as determined by gelatin zymography. Results from western blot analysis and ELISA further demonstrated the decrease of MMP-2 and increase of TIMP-2 secretion after D. bilabiata treatment. The gene expressions of VEGF-A, -B, -C, -D and VEGFR-1, -2, -3 were all inhibited by D. bilabiata.

CONCLUSION

We concluded that the anti-angiogenic effect of D. bilabiata was associated with the decreased MMP-2 activity mediated by the upregulation of TIMP-2 and RECK, and the suppression of VEGF/VEGFRs expression.

Transplantation of bone mesenchymal stem cells promotes angiogenesis and improves neurological function after traumatic brain injury in mouse

Traumatic brain injury (TBI) has emerged as a leading cause of mortality and morbidity worldwide. Transplantation of bone mesenchymal stem cells (BMSCs) has emerged as a promising treatment for various central nervous system diseases. This study aims to evaluate the effect of BMSCs transplantation by intravenous injection on neurological function and angiogenesis of the TBI mice. C57BL/6 male mice were randomly divided into four groups: control, sham, TBI, and BMSC. Functional neurological evaluation was performed 1, 4, 7, 14, and 21 days after TBI using neurological severity scores. The impairment of learning and memory in mice was evaluated 14 days after TBI by Morris water maze experiment. Mice were sacrificed 14 days after TBI, and then brain sections were stained by terminal deoxyribonucleotidyl transferase (TDT)-mediated dUTP-digoxigenin nick end labeling staining to assess brain neuronal apoptosis. Immunohistochemistry was conducted to evaluate caspase-3 activity and identify vascular distribution and microvessel density. Protein and mRNA levels of vascular endothelial growth factor (VEGF) and angiogenin-1 (Ang-1) in brain tissues were analyzed by Western blot and quantitative real-time polymerase chain reaction, respectively. BMSCs transplantation promoted recovery of neurological function, ameliorated impairment of learning and memory, attenuated neuronal apoptosis, and diminished caspase-3 activation in mice after TBI. Also, BMSCs transplantation upregulated expressions of VEGF and Ang-1 and promoted the formation of microvessels in brain tissues after TBI. Our study demonstrated the important role of BMSCs transplantation in TBI mouse and indicated that the underlying mechanism was through promoting angiogenesis and improving neurological function. This provides a novel and effective strategy for cell-based therapy in the treatment of TBI.

Spontaneous Formation of Extensive Vessel-Like Structures in Murine Engineered Heart Tissue

Engineered heart tissue (EHT) from primary heart cells contains endothelial cells (ECs), but the extent to which ECs organize into vessel-like structures or even functional vessels remains unknown and is difficult to study by conventional methods. In this study, we generated fibrin-based mini-EHTs from a transgenic mouse line (Cdh5-CreERT2 × Rosa26-LacZ), in which ECs were specifically and inducibly labeled by applying tamoxifen (EC(iLacZ)). EHTs were generated from an unpurified cell mix of newborn mouse hearts and were cultured under standard serum-containing conditions. Cre expression in 15-day-old EHTs was induced by addition of o-hydroxytamoxifen to the culture medium for 48 h, and ECs were visualized by X-gal staining. EC(iLacZ) EHTs showed a dense X-gal-positive vessel-like network with distinct tubular structures. Immunofluorescence revealed that ECs were mainly associated with cardiomyocytes within the EHT. EC(iLacZ) EHT developed spontaneous and regular contractility with forces up to 0.1 mN. Coherent contractility and the presence of an extensive vessel-like network were both dependent on the presence of animal sera in the culture medium. Contractile EC(iLacZ) EHTs successfully served as grafts in implantation studies onto the hearts of immunodeficient mice. Four weeks after implantation, EHTs showed X-gal-positive lumen-forming vessel structures connected to the host myocardium circulation as they contained erythrocytes on a regular basis. Taken together, genetic labeling of ECs revealed the extensive formation of vessel-like structures in EHTs in vitro. The EC(iLacZ) EHT model could help simultaneously study biological effects of compounds on cardiomyocyte function and tissue vascularization.

Nanomedicine strategies for sustained, controlled, and targeted treatment of cancer stem cells of the digestive system

Cancer stem cells (CSCs) constitute a small proportion of the cancer cells that have self-renewal capacity and tumor-initiating ability. They have been identified in a variety of tumors, including tumors of the digestive system. CSCs exhibit some unique characteristics, which are responsible for cancer metastasis and recurrence. Consequently, the development of effective therapeutic strategies against CSCs plays a key role in increasing the efficacy of cancer therapy. Several potential approaches to target CSCs of the digestive system have been explored, including targeting CSC surface markers and signaling pathways, inducing the differentiation of CSCs, altering the tumor microenvironment or niche, and inhibiting ATP-driven efflux transporters. However, conventional therapies may not successfully eradicate CSCs owing to various problems, including poor solubility, stability, rapid clearance, poor cellular uptake, and unacceptable cytotoxicity. Nanomedicine strategies, which include drug, gene, targeted, and combinational delivery, could solve these problems and significantly improve the therapeutic index. This review briefly summarizes the ongoing development of strategies and nanomedicine-based therapies against CSCs of the digestive system.

Curcumin inhibits angiogenesis by up-regulation of microRNA-1275 and microRNA-1246: a promising therapy for treatment of corneal neovascularization

OBJECTIVE

Curcumin (capable of inhibiting angiogenic growth of human umbilical vein endothelial cells [HUVECs]), can be employed in vitro as a model of pathogenesis of corneal neovascularization (CRNV). The aim of this study was to explore regulatory mechanisms of microRNA (miR) levels after curcumin treatment.

MATERIALS AND METHODS

Expression profiles of miRs in curcumin-treated HUVECs were investigated by miR microassay. Specific mimics and inhibitors of miR-1275 or miR-1246 were transfected into HUVECs. Then, their target genes, vascular endothelial growth factor B (VEGFB) and nuclear transcription factor kappa B acting protein (NKAP) were detected by quantitative real-time PCR, Western blotting assay or immunofluorescence assay. Cell proliferation and cell cycle parameters were measured with the help of CCK-8 assay and flow cytometry.

RESULTS

MiR-1275 and miR-1246 expression levels were up-regulated by curcumin. Administration of the specific mimics and inhibitors of the two miRs led to significant changes in expression of VEGFB and NKAP as well as the indicators related to angiogenesis. Anti-angiogenic effect of curcumin depended on expression patterns of the two miRs in that inhibition of either miR interfered with the effect of curcumin. Furthermore, overexpression of NKAP interrupted effects of curcumin on the cells.

CONCLUSION

Collectively, our findings demonstrate that curcumin inhibited HUVEC proliferation by up-regulation of miR-1275 and miR-1246.

Platelets are versatile cells: New discoveries in hemostasis, thrombosis, immune responses, tumor metastasis and beyond

Platelets are small anucleate blood cells generated from megakaryocytes in the bone marrow and cleared in the reticuloendothelial system. At the site of vascular injury, platelet adhesion, activation and aggregation constitute the first wave of hemostasis. Blood coagulation, which is initiated by the intrinsic or extrinsic coagulation cascades, is the second wave of hemostasis. Activated platelets can also provide negatively-charged surfaces that harbor coagulation factors and markedly potentiate cell-based thrombin generation. Recently, deposition of plasma fibronectin, and likely other plasma proteins, onto the injured vessel wall has been identified as a new "protein wave of hemostasis" that may occur even earlier than the first wave of hemostasis, platelet accumulation. Although no experimental evidence currently exists, it is conceivable that platelets may also contribute to this protein wave of hemostasis by releasing their granule fibronectin and other proteins that may facilitate fibronectin self- and non-self-assembly on the vessel wall. Thus, platelets may contribute to all three waves of hemostasis and are central players in this critical physiological process to prevent bleeding. Low platelet counts in blood caused by enhanced platelet clearance and/or impaired platelet production are usually associated with hemorrhage. Auto- and allo-immune thrombocytopenias such as idiopathic thrombocytopenic purpura and fetal and neonatal alloimmune thrombocytopenia may cause life-threatening bleeding such as intracranial hemorrhage. When triggered under pathological conditions such as rupture of an atherosclerotic plaque, excessive platelet activation and aggregation may result in thrombosis and vessel occlusion. This may lead to myocardial infarction or ischemic stroke, the major causes of mortality and morbidity worldwide. Platelets are also involved in deep vein thrombosis and thromboembolism, another leading cause of mortality. Although fibrinogen has been documented for more than half a century as essential for platelet aggregation, recent studies demonstrated that fibrinogen-independent platelet aggregation occurs in both gene deficient animals and human patients under physiological and pathological conditions (non-anti-coagulated blood). This indicates that other unidentified platelet ligands may play important roles in thrombosis and might be novel antithrombotic targets. In addition to their critical roles in hemostasis and thrombosis, emerging evidence indicates that platelets are versatile cells involved in many other pathophysiological processes such as innate and adaptive immune responses, atherosclerosis, angiogenesis, lymphatic vessel development, liver regeneration and tumor metastasis. This review summarizes the current knowledge of platelet biology, highlights recent advances in the understanding of platelet production and clearance, molecular and cellular events of thrombosis and hemostasis, and introduces the emerging roles of platelets in the immune system, vascular biology and tumorigenesis. The clinical implications of these basic science and translational research findings will also be discussed.

Dysregulation of Vascular Endothelial Progenitor Cells Lung-Homing in Subjects with COPD

Chronic obstructive pulmonary disease (COPD) is characterized by fixed airflow limitation and progressive decline of lung function and punctuated by occasional exacerbations. The disease pathogenesis may involve activation of the bone marrow stimulating mobilization and lung-homing of progenitor cells. We investigated the hypothesis that lower circulating numbers of vascular endothelial progenitor cells (VEPCs) are a consequence of increased lung-sequestration in COPD. Nonatopic, current or ex-smokers with diagnosed COPD and nonatopic, nonsmoking normal controls were enrolled. Blood and induced sputum extracted primitive hemopoietic progenitors (HPCs) and VEPC were enumerated by flow cytometry. Migration and adhesive responses to fibronectin were assessed. In sputum, VEPC numbers were significantly greater in COPD compared to normal controls. In blood, VEPCs were significantly lower in COPD versus normal controls. There were no differences in HPC levels between the two groups in either compartment. Functionally, there was a greater migrational responsiveness of progenitors from COPD subjects to stromal cell-derived factor-1alpha (SDF-1α) compared to normal controls. This was associated with greater numbers of CXCR4⁺ progenitors in sputum from COPD. Increased migrational responsiveness of progenitor cells may promote lung-homing of VEPC in COPD which may disrupt maintenance and repair of the airways and contribute to COPD disease pathogenesis.

Differential Expression of Aquaporins in Cervical Precursor Lesions and Invasive Cervical Cancer

OBJECTIVE

Aquaporins (AQPs) are highly expressed in tumor cells of different origins, particularly the aggressive tumors. The aim of this study was to investigate the expression of AQP isoforms during progression of squamous cervical cancer (SCC) and explore their associations with clinicopathologic variables of SCC.

METHODS

Expression of AQP isoforms (1, 3, 4, 5, and 8) was detected by immunohistochemistry in 47 SCCs, 37 cervical intraepithelial neoplasia (CIN), and 16 normal cervical tissues. Specific expression of AQP protein in SCC was detected by Western blot. Double immunohistochemistry was used to examine whether AQPs and vascular endothelial growth factor (VEGF) are coexpressed in SCC.

RESULTS

Aquaporin 1 showed higher positivity rate in CIN than in SCC and normal cervical tissues (P < .05). The expression intensity of AQP3, 4, 5, and 8 was higher in SCC than that in normal cervical tissues, respectively (P < .05). The expression of AQP3 and 8 was higher in SCC than that in CIN, respectively (P < .05). The AQP4 expression was higher in CIN than in normal cervical tissues (P < .05). The expression of AQP3 in CIN III was higher than that in CIN I and II (P < .05). There was a significant increase in the expression of AQP1 in stage I than that in stage II (P < .05). Aquaporin 3 showed lower positivity in moderately and well-differentiated tumors compared to that in poorly differentiated tumors (P < .05). Finally, double immunohistochemistry illustrated that AQP1/AQP3/AQP8 and VEGF were coexpressed in SCC.

CONCLUSIONS

Different AQP isoforms display specific expression patterns in normal cervical, CIN, and SCC tissues. This and the significant association with the clinicopathologic variables of SCC suggest that AQP isoforms might play different roles in the development of cervical cancer.

Total Synthesis of (-)-Luminacin D

A second-generation synthesis of (-)-luminacin D based on an early stage introduction of the trisubstituted epoxide group is reported, allowing access to the natural product in an improved yield and a reduced number of steps (5.4%, 17 steps vs 2.6%, 19 steps). A full account of the optimization work is provided, with the reversal of stereoselection in the formation of the C4 alcohol in equally excellent diastereoselectivity as the key improvement.

Zebrafish as an Emerging Model Organism to Study Angiogenesis in Development and Regeneration

Angiogenesis is the process through which new blood vessels are formed from preexisting ones and plays a critical role in several conditions including embryonic development, tissue repair and disease. Moreover, enhanced therapeutic angiogenesis is a major goal in the field of regenerative medicine and efficient vascularization of artificial tissues and organs is one of the main hindrances in the implementation of tissue engineering approaches, while, on the other hand, inhibition of angiogenesis is a key therapeutic target to inhibit for instance tumor growth. During the last decades, the understanding of cellular and molecular mechanisms involved in this process has been matter of intense research. In this regard, several in vitro and in vivo models have been established to visualize and study migration of endothelial progenitor cells, formation of endothelial tubules and the generation of new vascular networks, while assessing the conditions and treatments that either promote or inhibit such processes. In this review, we address and compare the most commonly used experimental models to study angiogenesis in vitro and in vivo. In particular, we focus on the implementation of the zebrafish (Danio rerio) as a model to study angiogenesis and discuss the advantages and not yet explored possibilities of its use as model organism.

Suberoylanilide hydroxamic acid suppresses inflammation-induced neovascularization

Histone deacetylases (HDACs) regulate gene transcription by modifying the acetylation of histone and nonhistone proteins. Deregulated expression of HDACs has been implicated in tumorigenesis and angiogenesis. In this study, we examined the effect of suberoylanilide hydroxamic acid (SAHA), a potent inhibitor of HDACs, on inflammatory corneal angiogenesis. In a mouse model of alkali-induced corneal neovascularization (CNV), topical application of SAHA to the injured corneas attenuated CNV. In addition, in vivo treatment with SAHA downregulated the expression of the pro-angiogenic factors vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), transforming growth factor beta 1 (TGFβ1), and epidermal growth factor (EGF), but upregulated the expression of the anti-angiogenic factors thrombospondin (TSP)-1, TSP-2, and ADAMTS-1 in the injured corneas. Furthermore, SAHA inhibited the expression of pro-angiogenic factors, migration, proliferation, and tube formation by human microvascular endothelial cells (HEMC-1) in vitro. These data indicate that SAHA has therapeutic potential for CNV.

Engineering of a disulfide loop instead of a Zn binding loop restores the anti-proliferative, anti-angiogenic and anti-tumor activities of the N-terminal fragment of endostatin: Mechanistic and therapeutic insights

Although considerable effort has been devoted to understanding the molecular mechanism of endostatin's anti-cancer activity, the role of its Zn bound N-terminal loop has not been completely clarified. To investigate whether Zn binding or the N-terminal loop is involved in the anti-cancer properties of endostatin, we compared the structure and biological activity of a native Zn binding endostatin peptide (ES-Zn) with three variants: a Zn free variant (ES), a variant containing both a Zn binding site and a disulfide bond (ES-SSZn), and a variant including a disulfide loop but incapable of Zn binding (ES-SS). Spectroscopic studies indicated that ES-Zn and ES-SS consist of random coil and β structures, whereas ES-SSZn and ES fold into random coils. Theoretical analysis proposed that ES-Zn and ES-SS have a similar binding site to αVβ3 integrin. The anti-proliferative activity of endostatin was retained by all peptides except ES, and the in vitro anti-angiogenic property was preserved in ES-Zn and ES-SS. Remarkably, breast tumor growth and CD31 activity were inhibited more effectively by ES-SS than by ES-Zn. Therefore, a correlation exists between the N-terminal loop and anti-cancer properties of endostatin fragment and a disulfide loop may be more promising than a Zn binding loop for inhibiting tumor growth.

Multiple Mechanisms of Anti-Cancer Effects Exerted by Astaxanthin

Astaxanthin (ATX) is a xanthophyll carotenoid which has been approved by the United States Food and Drug Administration (USFDA) as food colorant in animal and fish feed. It is widely found in algae and aquatic animals and has powerful anti-oxidative activity. Previous studies have revealed that ATX, with its anti-oxidative property, is beneficial as a therapeutic agent for various diseases without any side effects or toxicity. In addition, ATX also shows preclinical anti-tumor efficacy both in vivo and in vitro in various cancer models. Several researches have deciphered that ATX exerts its anti-proliferative, anti-apoptosis and anti-invasion influence via different molecules and pathways including signal transducer and activator of transcription 3 (STAT3), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and peroxisome proliferator-activated receptor gamma (PPARγ). Hence, ATX shows great promise as chemotherapeutic agents in cancer. Here, we review the rapidly advancing field of ATX in cancer therapy as well as some molecular targets of ATX.

In silico database screening of potential targets and pathways of compounds contained in plants used for psoriasis vulgaris

Reviews and meta-analyses of clinical trials identified plants used as traditional medicines (TMs) that show promise for psoriasis. These include Rehmannia glutinosa, Camptotheca acuminata, Indigo naturalis and Salvia miltiorrhiza. Compounds contained in these TMs have shown activities of relevance to psoriasis in experimental models. To further investigate the likely mechanisms of action of the multiple compounds in these TMs, we undertook a computer-based in silico investigation of the proteins known to be regulated by these compounds and their associated biological pathways. The proteins reportedly regulated by compounds in these four TMs were identified using the HIT (Herbal Ingredients' Targets) database. The resultant data were entered into the PANTHER (Protein ANnotation THrough Evolutionary Relationship) database to identify the pathways in which the proteins could be involved. The study identified 237 compounds in the TMs and these retrieved 287 proteins from HIT. These proteins identified 59 pathways in PANTHER with most proteins being located in the Apoptosis, Angiogenesis, Inflammation mediated by chemokine and cytokine, Gonadotropin releasing hormone receptor, and/or Interleukin signaling pathways. All four TMs contained compounds that had regulating effects on Apoptosis regulator BAX, Apoptosis regulator Bcl-2, Caspase-3, Tumor necrosis factor (TNF) or Prostaglandin G/H synthase 2 (COX2). The main proteins and pathways are primarily related to inflammation, proliferation and angiogenesis which are all processes involved in psoriasis. Experimental studies have reported that certain compounds from these TMs can regulate the expression of proteins involved in each of these pathways.

Using Markov Chains to predict the natural progression of diabetic retinopathy

AIM

To study the natural progression of diabetic retinopathy in patients with type 2 diabetes.

METHODS

This was an observational study of 153 cases with type 2 diabetes from 2010 to 2013. The state of patient was noted at end of each year and transition matrices were developed to model movement between years. Patients who progressed to severe non-proliferative diabetic retinopathy (NPDR) were treated. Markov Chains and Chi-square test were used for statistical analysis.

RESULTS

We modelled the transition of 153 patients from NPDR to blindness on an annual basis. At the end of year 3, we compared results from the Markov model versus actual data. The results from Chi-square test confirmed that there was statistically no significant difference (P=0.70) which provided assurance that the model was robust to estimate mean sojourn times. The key finding was that a patient entering the system in mild NPDR state is expected to stay in that state for 5y followed by 1.07y in moderate NPDR, be in the severe NPDR state for 1.33y before moving into PDR for roughly 8y. It is therefore expected that such a patient entering the model in a state of mild NPDR will enter blindness after 15.29y.

CONCLUSION

Patients stay for long time periods in mild NPDR before transitioning into moderate NPDR. However, they move rapidly from moderate NPDR to proliferative diabetic retinopathy (PDR) and stay in that state for long periods before transitioning into blindness.

VEGF transfer based on gene-modified fibroblasts using a hypoxia-induced vector to modulate neoangiogenesis in ischaemic regions of myocutaneous transplants

The effect of a hypoxia-inducible VEGF-expressing on wound healing in an ischaemic hind leg rat model was evaluated in this study. 180 Wistar rats were assigned randomly to three groups. After ligation of the femoral artery, group 1 received pRTP801-VEGF165, group 2 untransfected fibroblasts, group 3 saline; injection was into the subcutaneous tissue, proximal and distal to the artery ligation. Biopsy specimens were obtained on days 3, 5, 7, 14 after implementation. VEGF transgene expression, vessel architecture, the amount and total area of vessel formation were investigated. Results showed a significantly higher level of VEGF protein expression in group 1 compared to group 2 (P≤0.001) throughout the investigational period. Group 1 exhibited a significant growth of CD31-positive blood vessels in the subcutaneous tissue on day 14 compared to groups 2 and 3 (P≤0.001) (group 1, 62.20±1.92; group 2, 20.60±1.67; group 3, 12.40±1.14). Alpha-SMA-positive staining also showed significant vessel growth in group 1 on day 5 (group 1, 27.00±1.87; group 2, 7.20±1.48; group 3, 10.00±1.73). These results were confirmed in the distal muscle tissue. No significant results were obtained for the proximal muscle tissue. The subcutaneous application of pRTP801-VEGF165 showed a long-lasting effect, with an increased expression of VEGF over the entire observation period. It appears that the use of fibroblasts transfected with VEGF is a promising way to increase early angiogenesis in ischaemic tissue.

Diallyl trisulfide inhibits migration, invasion and angiogenesis of human colon cancer HT-29 cells and umbilical vein endothelial cells, and suppresses murine xenograft tumour growth

Angiogenesis inhibitors are beneficial for the prevention and treatment of angiogenesis-dependent diseases including cancer. We examined the cytotoxic, anti-metastatic, anti-cancer and anti-angiogenic effects of diallyl trisulfide (DATS). In HT29 cells, DATS inhibited migration and invasion through the inhibition of focal adhesion kinase (FAK), extracellular signal-regulated kinase, c-Jun N-terminal kinase and p38 which was associated with inhibition of matrix metalloproteinases-2, -7 and -9 and VEGF. In human umbilical vein endothelial cells (HUVEC), DATS inhibited the migration and angiogenesis through FAK, Src and Ras. DATS also inhibited the secretion of VEGF. The capillary-like tube structure formation and migration by HUVEC was inhibited by DATS. The chicken egg chorioallantoic membrane (CAM) assay indicated that DATS treatment inhibited ex-vivo angiogenesis. We investigated the anti-tumour effects of DATS against human colon cancer xenografts in BALB/c^nu/nu mice and its anti-angiogenic activity in vivo. In this in-vivo study, DATS also inhibited the tumour growth, tumour weight and angiogenesis (decreased the levels of haemoglobin) in HT29 cells. In conclusion, the present results suggest that the inhibition of angiogenesis may be an important mechanism in colon cancer chemotherapy by DATS.

Lung-homing of endothelial progenitor cells and airway vascularization is only partially dependant on eosinophils in a house dust mite-exposed mouse model of allergic asthma

Background

Asthmatic responses involve a systemic component where activation of the bone marrow leads to mobilization and lung-homing of progenitor cells. This traffic may be driven by stromal cell derived factor-1 (SDF-1), a potent progenitor chemoattractant. We have previously shown that airway angiogenesis, an early remodeling event, can be inhibited by preventing the migration of endothelial progenitor cells (EPC) to the lungs. Given intranasally, AMD3100, a CXCR4 antagonist that inhibits SDF-1 mediated effects, attenuated allergen-induced lung-homing of EPC, vascularization of pulmonary tissue, airway eosinophilia and development of airway hyperresponsiveness. Since SDF-1 is also an eosinophil chemoattractant, we investigated, using a transgenic eosinophil deficient mouse strain (PHIL) whether EPC lung accumulation and lung vascularization in allergic airway responses is dependent on eosinophilic inflammation.

Methods

Wild-type (WT) BALB/c and eosinophil deficient (PHIL) mice were sensitized to house dust mite (HDM) using a chronic exposure protocol and treated with AMD3100 to modulate SDF-1 stimulated progenitor traffic. Following HDM challenge, lung-extracted EPCs were enumerated along with airway inflammation, microvessel density (MVD) and airway methacholine responsiveness (AHR).

Results

Following Ag sensitization, both WT and PHIL mice exhibited HDM-induced increase in airway inflammation, EPC lung-accumulation, lung angiogenesis and AHR. Treatment with AMD3100 significantly attenuated outcome measures in both groups of mice. Significantly lower levels of EPC and a trend for lower vascularization were detected in PHIL versus WT mice.

Conclusions

This study shows that while allergen-induced lung-homing of endothelial progenitor cells, increased tissue vascularization and development lung dysfunction can occur in the absence of eosinophils, the presence of these cells worsens the pathology of the allergic response.

A novel poly-naphthol compound ST104P suppresses angiogenesis by attenuating matrix metalloproteinase-2 expression in endothelial cells

Angiogenesis, the process of neovascularization, plays an important role in physiological and pathological conditions. ST104P is a soluble polysulfated-cyclo-tetrachromotropylene compound with anti-viral and anti-thrombotic activities. However, the functions of ST104P in angiogenesis have never been explored. In this study, we investigated the effects of ST104P in angiogenesis in vitro and in vivo. Application of ST104P potently suppressed the microvessels sprouting in aortic rings ex vivo. Furthermore, ST104P treatment significantly disrupted the vessels' development in transgenic zebrafish in vivo. Above all, repeated administration of ST104P resulted in delayed tumor growth and prolonged the life span of mice bearing Lewis lung carcinoma. Mechanistic studies revealed that ST104P potently inhibited the migration, tube formation and wound closure of human umbilical endothelial cells (HUVECs). Moreover, ST104P treatment inhibited the secretion and expression of matrix metalloproteinase-2 (MMP-2) in a dose-dependent manner. Together, these results suggest that ST104P is a potent angiogenesis inhibitor and may hold potential for treatment of diseases due to excessive angiogenesis including cancer.

Angiogenin gene polymorphism: A risk factor for diabetic peripheral neuropathy in the northern Chinese Han population

Angiogenin is associated with the pathogenesis of diabetic peripheral neuropathy. Here, we quenced the coding region of the angiogenin gene in genomic DNA from 207 patients with type 2 diabetes mellitus (129 diabetic peripheral neuropathy patients and 78 diabetic non-neuropathy patients) and 268 healthy controls. All subjects were from the Han population of northern China. No mutations were found. We then compared the genotype and allele frequencies of the angiogenin synonymous single nucleotide polymorphism rs11701 between the diabetic peripheral neuropathy patients and controls, and between the diabetic neuropathy and non-neuropathy patients, using a case-control design. We detected no statistically significant genetic associations. Angiogenin may not be associated with genetic susceptibility to diabetic peripheral neuropathy in the Han population of northern China.

Anticancer activities of citrus peel polymethoxyflavones related to angiogenesis and others

Citrus is a kind of common fruit and contains multiple beneficial nutrients for human beings. Flavonoids, as a class of plant secondary metabolites, exist in citrus fruits abundantly. Due to their broad range of pharmacological properties, citrus flavonoids have gained increased attention. Accumulative in vitro and in vivo studies indicate protective effects of polymethoxyflavones (PMFs) against the occurrence of cancer. PMFs inhibit carcinogenesis by mechanisms like blocking the metastasis cascade, inhibition of cancer cell mobility in circulatory systems, proapoptosis, and antiangiogenesis. This review systematically summarized anticarcinogenic effect of citrus flavonoids in cancer therapy, together with the underlying important molecular mechanisms, in purpose of further exploring more effective use of citrus peel flavonoids.

Serum angiostatin levels in patients with Behçet's disease: does angiogenesis play a role in the pathogenesis of Behçet's disease?

Angiogenesis plays an important role in the pathogenesis of inflammatory diseases, but the possible role of angiogenesis in Behçet's disease (BD) has not yet been studied. The aim of this study was to determine angiostatin levels in patients with BD and the role of angiogenesis in the pathogenesis of the disease. Thirty-seven patients with BD (mean age: 28·6±5·4 years, mean disease duration: 9·3±3·7 years) and 18 healthy controls were enrolled to the study. Twenty-four patients were in active and 13 patients were in inactive stage of the disease. The mean serum angiostatin level of patients with BD was 113·9±53·2 and 60·7±20·1 ng/ml in healthy controls. The mean serum angiostatin level was 142·7±43·1 ng/ml in active and 86·9±15·5 ng/ml in inactive patients with BD. Serum angiostatin levels were significantly high in patients with BD compared with healthy controls (P<0·001) and it was significantly high in active patients compared with inactive patients with BD (P<0·001). In inactive patients with BD, serum angiostatin concentrations were found to be higher compared with healthy controls (P<0·01). In active BD patients, the mean serum angiostatin level was correlated with the deep vein thrombosis (r = 0·482, P = 0·05), uveitis (r = 0·582, P = 0·01), and arthritis (r = 0·492, P = 0·05). According to these results; elevated serum angiostatin levels in patients with BD suggest the possible role of angiogenesis in the pathogenesis of the disease and its high levels in inactive Behçet's patients is related with the continuous activation of the disease even in the subclinical period.

Protein expression under sustained activation of signal transducer and activator of transcription-3 in diethylnitrosamine-induced rat liver carcinogenesis

The aim of the present study was to investigate the expression of proteins associated with the sustained activation of the signal transducer and activator of transcription (STAT)-3 pathway during diethylnitrosamine (DEN)-induced rat liver carcinogenesis. DEN was intermittently administered to rats to induce liver cancer, and light and electron microscopy were used to observe the morphological changes in the liver during carcinogenesis. Western blotting and quantitative polymerase chain reaction (qPCR) were used to detect the expression of STAT-3, phosphorylated (p)-STAT-3, matrix metalloproteinase (MMP)-10, vascular endothelial growth factor (VEGF), kinase insert domain receptor (KDR), hypoxia inducible factor (HIF)-1α, basic fibroblast growth factor (bFGF) and interleukin (IL)-10, in order to investigate the association between STAT-3 and p-STAT-3 expression and MMP-10, VEGF, KDR, HIF-1α, bFGF and IL-10. The western blotting and qPCR results revealed that the expression of STAT-3, p-STAT-3, MMP-10, VEGF, KDR, HIF-1α, bFGF and IL-10 proteins gradually increased during carcinogenesis. Furthermore, the STAT-3 and p-STAT-3 levels were found to positively correlate with MMP-10, VEGF, KDR, HIF-1α, bFGF and IL-10 protein expression. During DEN-induced rat liver carcinogenesis, STAT-3 protein continually activated MMP-10, VEGF, KDR, HIF-1α, bFGF and IL-10, and its expression was found to positively correlate with the expression of these proteins.

A novel approach to overcome multidrug resistance: utilization of P-gp mediated efflux of paclitaxel to attack neighboring vascular endothelial cells in tumors

We tried to overcome the paclitaxel (PTX) resistance of cancer cells due to P-glycoprotein (P-gp) overexpression in the in vivo anti-tumor chemotherapy by utilizing polyethylene glycol-modified liposomal paclitaxel (PL-PTX). First of all, established were PTX-resistant Colon-26 cancer cells (C26/PTX) overexpressing P-gp, which provided IC50 value of PTX solution about 30 times larger than that obtained for control C26 (C26/control) in the in vitro MTT assay. Western blot analysis confirmed P-gp expression in C26/PTX 10 times higher than that in C26/control, indicating that the resistance acquisition of C26/PTX to PTX would be ascribed to the enhanced efflux of PTX by P-gp overexpressed in C26/PTX. However, the in vivo anti-tumor effect of PL-PTX in C26/PTX-bearing mice was similar to that in C26/control-bearing mice. Double immunohistochemical staining of vascular endothelial cells and apoptotic cells within tumor tissues demonstrated that the apoptotic cell death was preferentially observed in vascular endothelial cells in C26/PTX tumors after intravenous administration of PL-PTX, while that was in tumor cells in C26/control tumors. These results suggest that the in vivo anti-tumor effect of PL-PTX in C26/PTX-bearing mice would be ascribed to the cytotoxic action of PTX pumped out of tumor cells by overexpressed P-gp to vascular endothelial cells in tumor tissues.

Jaceosidin, a natural flavone, promotes angiogenesis via activation of VEGFR2/FAK/PI3K/AKT/NF-κB signaling pathways in endothelial cells

Angiogenesis, the growth of new blood vessels from pre-existing vasculature, plays an important role in physiological and pathological processes such as embryonic development wound healing and revascularization of tissues after exposure to ischemia. We investigated the effects of jaceosidin, a main constituent of medicinal herbs of the genus Artemisia, on angiogenesis and signaling pathways in endothelial cells. Jaceosidin stimulated proliferation, migration and tubulogenesis of ECs as well as ex vivo sprouting from aorta rings, which are phenomena typical of angiogenesis. Jaceosidin activated vascular endothelial growth factor receptor 2 (VEGFR2, FLk-1/KDR) and angiogenic signaling molecules such as focal adhesion kinase, phosphatidylinositol 3-kinase, and its downstream target, the serine-threonine kinase AKTWe also demonstrated that jaceosidin activated the NF-κB-driven expression of a luciferase reporter gene and NF-κB binding to DNA. Jaceosidin-induced proliferation and migration of human umbilical vascular endothelial cells were strongly inhibited by the phosphatidylinositol 3-kinase inhibitor LY294002 and NF-κB inhibitor BAY11-7082, indicating that the PI3K/AKT/NF-κB signaling pathway is involved in jaceosidin-induced angiogenesis. Our results suggest that jaceosidin stimulates angiogenesis by activating the VEGFR2/FAK/PI3K/AKT/NF-κB signaling pathway and that it may be useful in developing angiogenic agents to promote the growth of collateral blood vessels in ischemic tissues.