Antiangiogenic Efficacy Research Articles

Dehydrocostus Lactone Enhances Chemotherapeutic Potential of Doxorubicin in Lung Cancer by Inducing Cell Death and Limiting Metastasis.

BackgroundNatural compounds have been utilized in inhibiting metastasis alone or in combination with other anti-tumor agents. Dehydrocostus lactone (DHC), a natural sesquiterpene lactone, was used to investigate its effect on proliferation of lung cancer cells and on the anti-angiogenic efficacy of doxorubicin.Material/MethodsCell proliferation was assessed by MTT assay and clonogenic assay. Apoptosis and migration were assessed by flow cytometry and wound-healing assay, respectively. Western blotting and qPCR were performed for gene and protein expression analysis. Matrigel plug assay was performed for angiogenesis assessment.ResultsResults of the study show that DHC inhibited the survival and proliferation of lung cancer cells (A549 and H460) and enhanced the growth-inhibitory properties of DOX. Cotreatment of DHC enhanced the apoptosis-inducing effects of DOX by activating caspase-9 and caspase-3 followed by cleavage of PARP. Treatment of A549 and H460 cells with DHC caused suppression of HIF-1α, Akt and pAkt, GSK-3β and pGSK-3β, as well as ERK, pERK, mTOR, and p-mTOR. DHC enhanced the effect of DOX by inhibiting migration of A549 cells as observed by wound-healing assay. DHC caused synergistic inhibition of MMP-2 and MMP-9 genes when treated in combination with DOX. DHC further enhanced the anti-angiogenic properties of DOX in mice implanted with Matrigel plugs. DHC suppressed the proliferation of lung cancer cells and enhanced the anti-angiogenic properties of DOX.ConclusionsThe putative mechanism behind the metastasis-limiting effects of DHC may involve the suppression of Akt/GSK-3β and inhibition of MMP-2 and MMP-9 in lung cancer cells.

Prevention of corneal neovascularization by subconjunctival injection of avastin® loaded thermosensitive hydrogels in rabbit model

The antibody avastin® (Ava) has been clinically to treat various intraocular neovascular diseases, but suffering from the rapid clearance and short shelf-life of Ava in the requirement of frequent administration. In the present study, we reports the sustained release of Ava from a thermosensitive hydrogel based on poly(ethylene glycol)-poly(ɛ-caprolactone)-poly(ethylene glycol) (PECE) copolymer for the control of corneal neovascularization in rabbit model. Ava were physically mixed with PECE aqueous solution at 4 °C, and resulting Ava-PECE solution showed a sol-gel transition at physiological temperature (37 °C). In vitro release study indicated that Ava-PECE hydrogel provided a sustained release of Ava up to 28 days and the drug release behavior could be finely modulated by the change of PECE concentration. A single subconjunctival injection of PECE hydrogel hardly caused the change of intraocular pressure and corneal endothelial morphology during the entire study period. Intraocular pharmacokinetic analysis suggested that the Ava-PECE hydrogel provided a relatively higher Ava concentration in cornea over Ava solution up to 14 days. In addition, anti-angiogenic effects of the Ava-PECE hydrogel in a suture-induced corneal neovascularization rabbit model indicated that the Ava-PECE hydrogel treatment exhibited superior anti-angiogenic efficacy over Ava solution treatment by decreasing the area ratio of neovascularization on 17 days. Overall, the proposed Ava-PECE hydrogel acting a sustained drug delivery system might be a promising vehicle for the treatment of corneal neovascularization.

Comparison of pharmacodynamics between different batches of recombinant decoy receptor innovative drug RC28-E1 and RC28-E2 in retinal angiogenesis and neovascularization and its mechanism

Objective To compare the pharmacodynamics between different batches of recombinant decoy receptor innovative drug RC28-E1 and RC28-E2 in retinal angiogenesis and neovascularization, and analyze its mechanism. Methods Sixty postnatal Day 4 (P4) C57BL/6J mice were randomly divided into normal control group, vascular endothelial growth factor (VEGF)+ fibroblast growth factor 2 (FGF2) group, VEGF+ FGF2+ RC28-E1 group, VEGF+ FGF2+ RC28-E2 group, VEGF+ FGF2+ conbercept group and VEGF+ FGF2+ FGF trap group by using a random number table, with 10 mice in each group.The mouse retinal explant culture system was established, and stimulated with the corresponding factors and drugs prepared in the starving culture media.The normal controls were treated with the starving media.Then the retinal explants were stained with Isolectin B4 and imaged.The number of filopodia per vascular length was quantified.In addition, ninety-six P7 C57BL/6J mice were randomly divided into normal control group, oxygen-induced retinopathy (OIR) model control group, OIR+ RC28-E1 group, OIR+ RC28-E2 group, OIR+ conbercept group and OIR+ FGF trap group by using a random number table, with 16 mice in each group.The normal controls were raised under normoxia for 10 days, and the rest of the groups were raised under hyperoxia for 5 days, then returned to normoxia for another 5 days.On P17, the retinas were isolated and stained with Isolectin B4.The stained retinas were mounted on the slides and photographed.The relative vessel obliteration and neovascularization in retina were analyzed with computer software.Then the protein levels of VEGF and FGF2 were examined by Western blot in the retinas of each group in the OIR experiment.Finally, in the RF/6A cells stimulated with VEGF and FGF2, the activities of the signaling pathways, including MEK-extracellular regulated protein kinases (Erk), protein kinase C (PKC) and protein kinase B (Akt) pathways, were examined by Western blot.All experimental procedures were evaluated and approved by the Institutional Animal Care and Use Committee of Tianjin Medical University (SYXK 2009-0001), and were in accordance with the ARVO Statement for the Use of Animals in Ophthalmic and Vision Research. Results The results of retinal explant cultures showed that the numbers of filopodia per vascular length in VEGF+ FGF2+ RC28-E1, VEGF+ FGF2+ RC28-E2, VEGF+ FGF2+ conbercept, and VEGF+ FGF2+ FGF trap groups were all significantly less than that in the VEGF+ FGF2 group (all at P < 0.001). The filopodia number in retinal vascular front in RC28-E1 group was similar to that in the RC28-E2 group (P=0.15), whereas the filopodia numbers in both groups were significantly decreased as compared to those in VEGF+ FGF2+ conbercept group and VEGF+ FGF2+ FGF trap group (all at P<0.001). The results from the OIR mouse model showed that the relative vessel obliteration area in OIR model control group was dramatically higher than those in the drug intervention groups (all at P<0.05). There was no statistical significance in the relative vessel obliteration area between OIR+ RC28-E1 group and OIR+ RC28-E2 group (P=0.17), while the obliteration areas in both RC28-E-intervened groups were significantly lower than those in the OIR+ conbercept group and OIR+ FGF trap group (all at P<0.05). The relative neovascular pixels in the intervention groups were significantly lower than those in the OIR model control group (all at P<0.001). The neovascular pixels in OIR+ RC28-E1 group were significantly lower than those in VEGF+ FGF2+ conbercept group and VEGF+ FGF2+ FGF trap group (both at P<0.05), but comparable to those in OIR+ RC28-E2 group (P =0.39). Western blot result showed that, the protein expression of VEGF and FGF2 in the OIR mouse retinas were significantly upregulated compared to those in the normal ones (both at P<0.001). The upregulation of both genes were normalized by both RC28-E1 and RC28-E2.In addition, the stimulation of VEGF and FGF2 induced an enhanced activity in MEK-Erk pathway in RF/6A cells, whereas RC28-E1 inhibited the overactivation. Conclusions RC28-E1 and RC28-E2 both can inhibit angiogenesis in the retinal explants isolated from neonatal mice; they also reduce vessel obliteration and mitigate neovascularization in the OIR mouse model.Therefore, the pharmacology batch and pilot test batch of RC28-E have similar efficacies and reliable stability, and are superior in the anti-angiogenic and anti-neovascular efficacy to the currently clinically available drugs conbercept and FGF trap.RC28-E1 may suppress pathological neovascularization through inhibiting the overactivation of MEK-Erk pathway in retinal vascular endothelial cells. Key words: Retinal neovascularization; Decoy receptor; Basic fibroblast growth factor; Vascular endothelial growth factor; Recombinant protein drugs

Successful single treatment with ziv-aflibercept for existing corneal neovascularization following ocular chemical insult in the rabbit model

PurposeTo evaluate the efficacy of ziv-aflibercept as a treatment for established corneal neovascularization (NV) and to compare its efficacy to that of bevacizumab following ocular chemical insult of sulfur mustard (SM) in the rabbit model. MethodsChemical SM burn was induced in the right eye of NZW rabbits by vapor exposure. Ziv-aflibercept (2 mg) was applied once to neovascularized eyes by subconjunctival injection while subconjunctival bevacizumab (5 mg) was administered twice a week, for 3 weeks. Non-treated exposed eyes served as a control. A clinical follow-up employed by slit-lamp microscope, was performed up to 12 weeks following exposure and digital photographs of the cornea were taken for measurement of blood vessels length using the image analysis software.Eyes were taken for histological evaluation 2, 4 and 8 weeks following treatment for general morphology and for visualization of NV, using H&E and Masson Trichrome stainings, while conjunctival goblet cell density was determined by PAS staining. ResultsCorneal NV developed, starting as early as two weeks after exposure.A single subconjunctival treatment of ziv-aflibercept at 4 weeks post exposure, significantly reduced the extent of existing NV already one week following injection, an effect which lasted for at least 8 weeks following treatment, while NV in the non-treated exposed eyes continued to advance. The extensive reduction in corneal NV in the ziv-aflibercept treated group was confirmed by histological evaluation. Bevacizumab multiple treatment showed a benefit in NV reduction, but to a lesser extent compared to the ziv-aflibercept treatment. Finally, ziv-aflibercept increased the density of conjunctival goblet cells as compared to the exposed non-treated group. ConclusionsSubconjunctival ziv-aflibercept single treatment presented a highly efficient long-term therapeutic benefit in reducing existing corneal NV, following ocular sulfur mustard exposure. These findings show the robust anti-angiogenic efficacy of ziv-aflibercept and demonstrate the advantage of this treatment over the other anti-angiogenic therapies in ameliorating corneal NV and protecting the ocular surface.

Centchroman regulates breast cancer angiogenesis via inhibition of HIF-1α/VEGFR2 signalling axis

AimsAngiogenesis is a recognized hallmark of cancer which promotes cancer cell progression and metastasis. Inhibition of angiogenesis to attenuate cancer growth is becoming desirable strategy for breast cancer management. The present study is aimed to investigate the antiangiogenic efficacy of a novel selective estrogen receptor modulator Centchroman (CC) on human breast cancer cells. Main methodsEffect of CC on cell viability was evaluated using Sulforhodamine B assay. Endothelial cell proliferation, wound healing, Boyden chamber cell invasion, tube formation and chorioallantoic membrane (CAM) assays were performed to assess the effect of CC on migration, invasion and angiogenesis. Apoptosis, reactive oxygen species generation, caspase-3/7 and intracellular calcium ion level were measured through flow cytometry. Expression levels of HIF-1α, VEGF, VEGFR2, AKT and ERK were assessed by western blot analysis. Key findingsCC selectively induces apoptosis in human breast cancer cells without affecting non-tumorigenic breast epithelial cells MCF-10A. Moreover, it inhibits migratory, invasive and mammosphere forming potential of breast cancer. Furthermore, CC also inhibited VEGF-induced migration, invasion and tube formation of HUVECs in vitro. CC effectively inhibited neovasculature formation in chicken CAM. Western blot analysis demonstrated that CC inhibited expression of HIF-1α and its downstream target VEGF. Interestingly, CC also suppressed VEGFR2 phosphorylation and consequently attenuated AKT and ERK phosphorylation. SignificanceOur findings suggest that CC downregulates VEGF-induced angiogenesis by modulating HIF-1α/VEGFR2 pathway and recommend it (CC) as a potential therapeutic drug for breast cancer treatment.

Resveratrol Demonstrated Higher Antiproliferative and Antiangiogenic Efficacy Compared with Oxyresveratrol on Head and Neck Squamous Cell Carcinoma Cell Lines

Resveratrol and its derivative, oxyresveratrol, have various pharmacological effects. Several studies demonstrated the anticancer activity of resveratrol. However, little is known about the anticancer activity of oxyresveratrol. In this study, we compared the antiproliferative and antiangiogenic effects of oxyresveratrol and resveratrol. Three head and neck squamous cell carcinoma cell lines (HSC-3, HN-8, and HN-30) were treated with a range of concentrations of either resveratrol or oxyresveratrol. MTT assays demonstrated that resveratrol and oxyresveratrol significantly inhibited cell survival in a dose-dependent manner. Although ELISA and Real-time PCR revealed that oxyresveratrol inhibited vascular endothelial growth factor (VEGF) expression at both the mRNA and protein level, the reduction was lower than that of resveratrol. Altogether, these findings indicate that oxyresveratrol possesses anticancer properties by inhibiting cancer cell proliferation and VEGF expression. However, its efficacy is lower compared with that of resveratrol.

In vitro human lung microvasculature-on-chip: Anti-angiogenic efficacy of nintedanib

In vitro human lung microvasculature-on-chip: Anti-angiogenic efficacy of nintedanib

Two cyclic hexapeptides from Penicillium sp. FN070315 with antiangiogenic activities.

In the course of searching for angiogenesis inhibitors from microorganisms, two cyclic peptides, PF1171A (1) and PF1171C (2) were isolated from the soil fungus Penicillium sp. FN070315. In the present study, we investigated the antiangiogenic efficacy and associated mechanisms of 1 and 2 in vitro using human umbilical vein endothelial cells (HUVECs). Compounds 1 and 2 inhibited the proliferation of HUVECs at concentrations not exhibiting cytotoxicity. Moreover, 1 and 2 significantly suppressed vascular endothelial growth factor (VEGF)-induced migration, invasion, proliferation and tube formation of HUVECs as well as neovascularization of the chorioallantoic membrane in developing chick embryos. We also identified an association between the antiangiogenic activity of 1 and 2 and the downregulation of both the phosphorylation of VEGF receptor 2 and the expression of hypoxia inducible factor-1α at the protein level. Taken together, these results further suggest that compounds 1 and 2 will be promising angiogenesis inhibitors.

A ketogenic diet supplemented with medium-chain triglycerides enhances the anti-tumor and anti-angiogenic efficacy of chemotherapy on neuroblastoma xenografts in a CD1-nu mouse model.

Neuroblastoma (NB) is a pediatric malignancy characterized by a marked reduction in aerobic energy metabolism. Recent preclinical data indicate that targeting this metabolic phenotype by a ketogenic diet (KD), especially in combination with calorie restriction, slows tumor growth and enhances metronomic cyclophosphamide (CP) therapy of NB xenografts. Because calorie restriction would be contraindicated in most cancer patients, the aim of the present study was to optimize the KD such that the tumors are sensitized to CP without the need of calorie restriction. In a NB xenograft model, metronomic CP was combined with KDs of different triglyceride compositions and fed to CD1-nu mice ad libitum. Metronomic CP in combination with a KD containing 8-carbon medium-chain triglycerides exerted a robust anti-tumor effect, suppressing growth and causing a significant reduction of tumor blood-vessel density and intratumoral hemorrhage, accompanied by activation of AMP-activated protein kinase in NB cells. Furthermore, the KDs caused a significant reduction in the serum levels of essential amino acids, but increased those of serine, glutamine and glycine. Our data suggest that targeting energy metabolism by a modified KD may be considered as part of a multimodal treatment regimen to improve the efficacy of classic anti-NB therapy.

Abstract 3862: In vivo chemopreventive of pseudosemiglabrin via inhibition of tumor angiogenesis and manipulation of hormones in estrogen-responsive breast cancer

Abstract Breast cancer is the most frequently diagnosed form of malignancy and the second leading cause of death in Western women. Mortality and most of the complications associated with breast cancer are due to metastasis developing in regional lymph nodes and in distant organs, including bone, lung, liver and brain. Chemopreventive is administration of chemical agents to prevent the initiational and promotional events associated with carcinogenesis. Some chemopreventive agents can prevent reaction or attacking molecules by different ways, these agents can suppress growth factors or signaling pathway. On this study we examined (-)-Pseudosemiglabrin (SSG) a natural compound extracted from Tephrosia apollinea on breast cancer cells and tumor vascularization in vitro and in vivo. Hormone sensitive breast cancer cell MCF-7 was found subtitle susceptible to SSG, it showed profound antitumorgeneis via inhibiting breast cancer cell migration, invasion and colony formation in vitro settings. In silico investigation of potential PARP inhibitor, SSG showed high binding affinity comparable to Rucaparib (standard PARP inhibitor). The natural compound significantly inhibited the sprouting of new blood vessels in ex vivo rat aorta ring assay; the antiangiogenic efficacy is perturbed by targeting VEGF expression and VEGFR phosphorylation. SSG completely inhibited the onset of breast cancer in animals pretreated with the compound. Molecular docking study showed that SSG binds to active site of Aromatase (the enzyme responsible for a key step in the biosynthesis of estrogens) with binding affinity better than standard aromatase inhibitor (Arimidex), moreover the compound has inhibitory activity against estrogen receptor in the breast cancer cells comparable to Tamoxifen. Our findings reveal that (-)-Pseudosemiglabrin can potentially be beneficial in preventing breast cancer in high-risk women or it can be adjuvant therapy with standard chemotherapy or even can be used for the treatment of women who have been diagnosed with breast cancer. Note: This abstract was not presented at the meeting. Citation Format: Loiy E. Ahmed Hassan. In vivo chemopreventive of pseudosemiglabrin via inhibition of tumor angiogenesis and manipulation of hormones in estrogen-responsive breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3862. doi:10.1158/1538-7445.AM2017-3862

2-(&#969;-Carboxyethyl)pyrrole Antibody as a New Inhibitor of Tumor Angiogenesis and Growth.

Angiogenesis is a fundamental process in the progression, invasion, and metastasis of tumors. Therapeutic drugs such as bevacizumab and ranibuzumab have thus been developed to inhibit vascular endothelial growth factor (VEFG)-promoted angiogenesis. While these anti-angiogenic drugs have been commonly used in the treatment of cancer, patients often develop significant resistance that limits the efficacy of anti-VEGF therapies to a short period of time. This is in part due to the fact that an independent pathway of angiogenesis exists, which is mediated by 2-(ω-carboxyethyl)pyrrole (CEP) in a TLR2 receptor-dependent manner that can compensate for inhibition of the VEGF-mediated pathway. In this work, we evaluated a CEP antibody as a new tumor growth inhibitor that blocks CEP-induced angiogenesis. We first evaluated the effectiveness of a CEP antibody as a monotherapy to impede tumor growth in two human tumor xenograft models. We then determined the synergistic effects of bevacizumab and CEP antibody in a combination therapy, which demonstrated that blocking of the CEP-mediated pathway significantly enhanced the anti-angiogenic efficacy of bevacizumab in tumor growth inhibition indicating that CEP antibody is a promising chemotherapeutic drug. To facilitate potential translational studies of CEP-antibody, we also conducted longitudinal imaging studies and identified that FMISO-PET is a non-invasive imaging tool that can be used to quantitatively monitor the anti-angiogenic effects of CEP-antibody in the clinical setting. That treatment with CEP antibody induces hypoxia in tumor tissue WHICH was indicated by 43% higher uptake of [18F]FMISO in CEP antibody-treated tumor xenografs than in the control PBS-treated littermates.

Growth of MCF-7 breast cancer cells and efficacy of anti-angiogenic agents in a hydroxyethyl chitosan/glycidyl methacrylate hydrogel

BackgroundBreast cancer negatively affects women’s health worldwide. The tumour microenvironment plays a critical role in tumour initiation, proliferation, and metastasis. Cancer cells are traditionally grown in two-dimensional (2D) cultures as monolayers on a flat solid surface lacking cell–cell and cell–matrix interactions. These experimental conditions deviate from the clinical situation. Improved experimental systems that can mimic the in vivo situation are required to discover new therapies, particularly for anti-angiogenic agents that mainly target intercellular factors and play an essential role in treating some cancers.MethodsChitosan can be modified to construct three-dimensional (3D) tumour models. Here, we report an in vitro 3D tumour model using a hydroxyethyl chitosan/glycidyl methacrylate (HECS–GMA) hydrogel produced by a series of chitosan modifications. Parameters relating to cell morphology, viability, proliferation, and migration were analysed using breast cancer MCF-7 cells. In a xenograft model, secretion of angiogenesis-related growth factors and the anti-angiogenic efficacy of Endostar and Bevacizumab in cells grown in HECS–GMA hydrogels were assessed by immunohistochemistry.ResultsHydroxyethyl chitosan/glycidyl methacrylate hydrogels had a highly porous microstructure, mechanical properties, swelling ratio, and morphology consistent with a 3D tumour model. Compared with a 2D monolayer culture, breast cancer MCF-7 cells residing in the HECS–GMA hydrogels grew as tumour-like clusters in a 3D formation. In a xenograft model, MCF-7 cells cultured in the HECS–GMA hydrogels had increased secretion of angiogenesis-related growth factors. Recombinant human endostatin (Endostar), but not Bevacizumab (Avastin), was an effective anti-angiogenic agent in HECS–GMA hydrogels.ConclusionsThe HECS–GMA hydrogel provided a 3D tumour model that mimicked the in vivo cancer microenvironment and supported the growth of MCF7 cells better than traditional tissue culture plates. The HECS–GMA hydrogel may offer an improved platform to minimize the gap between traditional tissue culture plates and clinical applicability. In addition, the anti-angiogenic efficacy of drugs such as Endostar and Bevacizumab can be more comprehensively studied and assessed in HECS–GMA hydrogels.

Inside Cover: Enhancement of Antiangiogenic Efficacy of Iron(II) Complex by Selenium Substitution (Chem. Asian J. 9/2017)

Inside Cover: Enhancement of Antiangiogenic Efficacy of Iron(II) Complex by Selenium Substitution (Chem. Asian J. 9/2017)

Enhancement of Antiangiogenic Efficacy of Iron(II) Complex by Selenium Substitution

Antiangiogenesis therapy is a proven strategy for the treatment of cancers. Herein, we demonstrate that iron(II) complexes containing 1,10-phenanthroline(phen) derivatives were capable of suppressing angiogenesis in vitro in a dose-dependent manner. Interestingly, the introduction of selenium into an iron(II) complex ((Fe(phenSe)3 (ClO4 )2 (phenSe=2-selenoimidazole[4,5-f]1,10-phenanthroline)) could enhance its antiangiogenic efficacy. Mechanistic studies demonstrated that the complex potently induced endothelial cell apoptosis as evidenced by activation of caspases and PARP cleavage. The iron(II) complex activated p53-mediated mitochondrial dysfunction as can be seen by the upregulation in the expression of p53 and proapoptotic Bcl-2 family proteins, and downregulation in the expression of Bcl-2 family proteins. Additionally, the complex inhibited VEGF expression and gave rise to dephosphorylated AKT, which suppressed the transmission of the mitogenic signaling pathway. Taken together, this study could provide a strategy for the rational design of high-efficacy antivascular agents.

Aggretin Venom Polypeptide as a Novel Anti-angiogenesis Agent by Targeting Integrin alpha2beta1

VEGF and VEGFR antibodies have been used as a therapeutic strategy to inhibit angiogenesis in many diseases; however, frequent and repeated administration of these antibodies to patients induces immunogenicity. In previous studies, we demonstrated that aggretin, a heterodimeric snake venom C-type lectin, exhibits pro-angiogenic activities via integrin α2β1 ligation. We hypothesised that small-mass aggretin fragments may bind integrin α2β1 and act as antagonists of angiogenesis. In this study, the anti-angiogenic efficacy of a synthesised aggretin α-chain C-terminus (AACT, residue 106–136) was evaluated in both in vitro and in vivo angiogenesis models. The AACT demonstrated inhibitory effects on collagen-induced platelet aggregation and HUVEC adhesion to immobilised collagen. These results indicated that AACT may block integrin α2β1−collagen interaction. AACT also inhibited HUVEC migration and tube formation. Aortic ring sprouting and Matrigel implant models demonstrated that AACT markedly inhibited VEGF-induced neovascularisation. In addition, induction of FAK/PI3K/ERK1/2 tyrosine phosphorylation and talin 1/2 associated with integrin β1 which are induced by VEGF were blocked by AACT. Similarly, tyrosine phosphorylation of VEFGR2 and ERK1/2 induced by VEGF was diminished in integrin α2-silenced endothelial cells. Our results demonstrate that AACT is a potential therapeutic candidate for angiogenesis related-diseases via integrin α2β1 blockade.

Suppression of VEGF-induced angiogenesis and tumor growth by Eugenia jambolana, Musa paradisiaca, and Coccinia indica extracts

Context: Abnormal angiogenesis and evasion of apoptosis are hallmarks of cancer. Accordingly, anti-angiogenic and pro-apoptotic therapies are effective strategies for cancer treatment. Medicinal plants, namely, Eugenia jambolana Lam. (Myrtaceae), Musa paradisiaca L. (Musaceae), and Coccinia indica Wight & Arn. (Cucurbitaceae), have not been greatly investigated for their anticancer potential.Objective: We investigated the anti-angiogenic and pro-apoptotic efficacy of ethyl acetate (EA) and n-butanol (NB) extracts of E. jambolana (seeds), EA extracts of M. paradisiaca (roots) and C. indica (leaves) with respect to mammary neoplasia.Materials and methods: Effect of extracts (2–200 μg/mL) on cytotoxicity and MCF-7, MDA-MB-231 and endothelial cell (EC) proliferation and in vitro angiogenesis were evaluated by MTT, 3[H]thymidine uptake and EC tube formation assays, respectively. In vivo tumour proliferation, VEGF secretion and angiogenesis were assessed using the Ehrlich ascites tumour (EAT) model followed by rat corneal micro-pocket and chicken chorioallantoic membrane (CAM) assays. Apoptosis induction was assessed by morphological and cell cycle analysis.Results: EA extracts of E. jambolana and M. paradisiaca exhibited the highest cytotoxicity (IC50 25 and 60 μg/mL), inhibited cell proliferation (up to 81%), and tube formation (83% and 76%). In vivo treatment reduced body weight (50%); cell number (16.5- and 14.7-fold), secreted VEGF (∼90%), neoangiogenesis in rat cornea (2.5- and 1.5-fold) and CAM (3- and 1.6-fold) besides EAT cells accumulation in sub-G1 phase (20% and 18.38%), respectively.Discussion and conclusion: Considering the potent anti-angiogenic and pro-apoptotic properties, lead molecules from EA extracts of E. jambolana and M. paradisiaca can be developed into anticancer drugs.

The Potential of Flavonolignans in Prostate Cancer Management

The generic name "flavonolignan" was created in 1968 for a relatively small class of naturally occurring hybrid molecules biogenetically originated from ubiquitous flavonoids and lignans (phenylpropanoids). The first group of flavonolignans was extracted from Silybum marianum that has long been used for hepatoprotection. Recently, the medicinal merit of flavonolignans has been extended to the prostate cancer management. Systematic interpretation and summarization of the relevant literature. Over forty naturally occurring flavonolignans have so far been obtained from various plants. Certain flavonolignans have been demonstrated by in vitro cell-based and in vivo animal-based experiments, and human clinical studies i) to possess effective chemopreventive function against various tumor promoters; ii) to show the anti-angiogenic efficacy; iii) to have potential in treating prostate cancer; iv) to sensitize prostate tumors to chemotherapeutic agents through down-regulation of P-glycoprotein and other mechanisms; and v) to be used by prostate cancer patients to protect or treat the hepatotoxicity caused by several chemotherapies. Certain flavonolignans can synergize with well-established chemotherapeutic agents for prostate cancer. This review provides a systematic and in-depth overview of the promise and potential of flavonolignans in prostate cancer management, which covers their chemopreventive effect, chemotherapeutic treatment, mechanisms of actions, synthetic derivatives, structure-activity relationships, and the difference in inhibiting prostate cancer cell proliferation between certain flavonoligans and their respective flavonoid counterpart. This summarization aims to provide valuable insights into further and rational development of flavonolignans for prostate cancer management by interpreting the data reported in the literature.

Tissue Plasminogen Activator as an Antiangiogenic Agent in Experimental Laser-Induced Choroidal Neovascularization in Mice.

We investigate the antiangiogenic efficacy of tissue plasminogen activator (tPA) on experimental laser-induced choroidal neovascularization (CNV) in mice. After CNV was induced by laser photocoagulation in 92 C57BL/6J wild-type mice, tPA (4 or 40 international units [IU]/μl) or PBS was injected intravitreally immediately after laser injury. Fluorescein angiography was performed on day 7 to grade CNV leakage. The CNV volume was measured by confocal microscopy in eyes enucleated 7 days after laser injury. Immunohistochemical studies were performed 3 days after laser injury to evaluate fibrin/fibrinogen and CD31 expression. The possible adverse effects of tPA were assessed by electroretinography (ERG) and histology on day 7. Intravitreal administration of tPA significantly suppressed CNV leakage and CNV volume in a dose-dependent manner (P < 0.01). Intravitreal injection of tPA suppressed fibrin/fibrinogen and CD31 expression in laser-induced lesions. Histologic examination and ERG showed no evidence of retinal toxicity in eyes injected with tPA. Intravitreal injection of tPA suppressed fibrin/fibrinogen expression and laser-induced CNV. The current results suggested that tPA may be a potential therapeutic adjuvant for treating CNV.

Evaluation of Antiangiogenic Efficacy of Emilia sonchifolia (L.) DC on Tumor-Specific Neovessel Formation by Regulating MMPs, VEGF, and Proinflammatory Cytokines.

Formation of new blood vessels from preexisting vasculature is an indispensable process in tumor initiation, invasion, and metastasis. Novel therapeutic approaches target endothelial cells involved in the process of angiogenesis, due to their genetic stability relative to the rapidly mutating drug-resistant cancer cells. In the present study, we investigated the effect of an active fraction from Emilia sonchifolia, belonging to the family Asteraceae, a plant well known for its anti-inflammatory and antitumor effects, on the inhibition of tumor-specific angiogenesis. Administration of the active fraction from E sonchifolia (AFES; 5 mg/kg, body weight, intraperitoneally) containing the major compound γ-humulene significantly inhibited B16F10 melanoma-induced capillary formation in C57BL/6 mice. The level of serum vascular endothelial growth factor and serum proinflammatory cytokines such as interleukin-1β, interleukin-6, tumor necrosis factor-α, and granulocyte-macrophage colony-stimulating factor were also reduced significantly. At the same time, administration of AFES significantly enhanced the production of antiangiogenic factors such as tissue inhibitor of matrix metalloproteinase-1. Dose-dependent reduction can be seen in the budding and expansion of microvessels from rat thoracic aorta by AFES treatment. Inhibition of the activation of proenzyme to active enzyme of matrix metalloproteinase along with a successful reduction of proliferation, invasion, and migration of human umbilical vein endothelial cells demonstrated the antiangiogenic effect of AFES in vitro. To date, no study has examined the antiangiogenic activity of this plant with already well-known anti-inflammatory and antitumor effects. Results obtained in the present study by using both in vivo and in vitro angiogenic models altogether proved the inhibitory effect of AFES on tumor-specific neovessel formation.

Abstract 3058: Phenotype-based discovery and development of novel therapies for the treatment of colorectal cancer

Abstract Background: Colorectal cancer (CRC) is the third most commonly diagnosed cancer in the world. The treatment of late stage CRC using Bevacizumab®, a targeted anti-VEGF therapy, produces insufficient response rates among patients and inevitable acquired tumour resistance. There is a clinical need for improved treatment options. Methods: Previously, anti-angiogenic screens in Tg[fli1:EGFP] zebrafish identified quininib, a small molecule drug subsequently shown to be as effective as bevacizumab® at reducing tumour volume in vivo and which reduces tumour CD31 expression in xenografted mice. Here, structural analogues of quininib were synthesised to identify novel chemical entities with higher anti-angiogenic and anti-inflammatory efficacy. Analogues were examined for anti-angiogenic effects in the Tg[fli1:EGFP] zebrafish intersegmental-vessel assay. Hits were then progressed for safety analyses in cytotoxic assays, anti-angiogenic efficacy in aortic explants, and effects on cell proliferation and tubule formation using HT29_Luc2 and HMEC cells. Leads were then tested in ex vivo human CRC tumour explants to determine effects on angiogenic and inflammatory factor secretion. Following determination of the maximum tolerated dose (MTD) of the highest ranking analogues, CRC-specific murine xenograft models created by subcutaneous injection of HT29_Luc2 cells were assessed for anti-tumorigenic analysis. Results: Five out of 12 drug candidates (CC16_HCl, CC12_HCl, Z_HCl, CC8_HCl &amp; OS_1) reduced developmental angiogenesis in Tg[fli1:EGFP] zebrafish significantly more than quininib (***P&amp;lt;0.01). These analogues were well tolerated in human endothelial and CRC cell cytotoxic assays and were more effective than quininib at reducing tubule formation and angiogenic factor secretion in HMEC cells. Two analogues reduced aortic ring vessel sprouting equally or more effectively than quininib. Some analogues can reduce inflammatory and angiogenic factor secretion from ex vivo human CRC explants more significantly than quininib. The analogue with the highest efficacy ranking was identified and its maximum tolerated dose study (MTD) determined using balb/c wild type mice. The anti-tumorigenic effects of the highest ranking analogue is being assessed by i/p injection in an optimised model of HT29_Luc2-CRC tumourigenesis in Balb/c nude mice. Conclusions: 5 analogues significantly more effective than quininib at reducing inflammation and angiogenesis were identified. The highest ranking analogue is tolerated by i/p injection in mice up to 50 mg/kg with no obvious adverse effects. The highest ranking analogue is currently being tested in murine xenografts with preliminary data suggests it is more effective than quininib at reducing tumour growth. Citation Format: Clare T. Butler, Breandán Kennedy, William M. Gallagher, Jacintha O’Sullivan. Phenotype-based discovery and development of novel therapies for the treatment of colorectal cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3058.