Angiogenesis in hepatocellular carcinoma:mechanisms and anti-angiogenic therapies

Hepatocellular carcinoma(HCC)is the fourth leading cause of cancer-associated death worldwide.Angiogenesis,the process of formation of new blood vessels,is required for cancer cells to obtain nutrients and oxygen.HCC is a typical hypervascular solid tumor with an aberrant vascular network and angiogenesis that contribute to its growth,progression,invasion,and metastasis.Current anti-angiogenic therapies target mainly tyrosine kinases,vascular endothelial growth factor receptor(VEGFR),and plateletderived growth factor receptor(PDGFR),and are considered effective strategies for HCC,particularly advanced HCC.However,because the survival benefits conferred by these anti-angiogenic therapies are modest,new anti-angiogenic targets must be identified.Several recent studies have determined the underlying molecular mechanisms,including pro-angiogenic factors secreted by HCC cells,the tumor microenvironment,and cancer stem cells.In this review,we summarize the roles of pro-angiogenic factors;the involvement of endothelial cells,hepatic stellate cells,tumor-associated macrophages,and tumor-associated neutrophils present in the tumor microenvironment;and the regulatory influence of cancer stem cells on angiogenesis in HCC.Furthermore,we discuss some of the clinically approved anti-angiogenic therapies and potential novel therapeutic targets for angiogenesis in HCC.A better understanding of the mechanisms underlying angiogenesis may lead to the development of more optimized anti-angiogenic treatment modalities for HCC.

Identification of bioactive anti-angiogenic constitutes targeting tumor endothelial cells in Shenmai Injection using multidimensional pharmacokinetics

OBJECTIVE To identify the bioactive anti-angiogenic constitutes targeting tumor endothelial cells(TECs)in Shenmai Injection(SMI).METHEODS For pharmacokinetic(PK)studies,Balb/c mice harboring human colorectal cancer(LoVo)xenografts were treated with SMI 10 mL·kg^-1 daily for 1 or 8 d.Multidimensional PK profiles of ginsenosides in plasma,subcutaneous tumors,and TECs were investigated.For PD studies,the tumor-bearing mice Intravital multi-photon imaging and CD31 immunofluorescence staining were used to evaluate the number of microves⁃sels and braches.Double staining of CD31 and α-SMA was performed to evaluate pericytes coverage ratios around vessels.ELISA was performed to determine the concentrations of VEGF and FGF in tumor tissues.For synergistic anti-tumor study,the tumor-bearing mice were treated with SMI 10 mL·kg^-1 daily,Rd 5 mg·kg^-1 daily with or without 5-FU 15 mg·kg^-1 every 3 d for 20 d.HPLC-MS/MS was used to determine the concentrations of 5-FU in plasma and tumor tissues.RESULTS SMI decreased the number of microvessels(P<0.05)and vessel branches(P<0.05)and improved vascular pericytes coverage(P<0.05).PK studies showed that the concentrations of protopanaxadiol-type(PPD)ginsenosides(Rb1,Rb2/Rb3,Rc,and Rd)in both,plasma and tumors,were higher than those of protopanaxatriol-type(Rg1 and Re)and oleanane-type(Ro)ginsenosides.Among PPD ginsenosides,Rd exhibited the greatest concentrations in tumors and TECs after repeated injection.In fact,the proportion of Rd in the detectable components of SMI gradually increased in the following order:SMI formula(2.8%),plasma(16.0%),tumor tissues(34.3%),and TECs(40.3%).In vivo bioactivity results showed that Rd 5 mg·kg^-1 daily significantly decreased the number of microvessels(P<0.05)and vessel branches(P<0.05)and increased pericytes coverage(P<0.05)while Rd 0.5 mg·kg^-1 daily,Rb1 and Rg1 had no significant effect on them.Rd 5 mg·kg^-1 suppressed the expression of VEGF and FGF simultaneously.Rd 5 mg·kg^-1 enhanced the antitumor effect of 5-FU via increasing the distribution of 5-FU in tumor tissues(P<0.05)in xenograft mice.CONCLUSION Ginsenoside Rd may be the major bioactive anti-angiogenic constituent targeting TECs after SMI treatment.

Numerical simulation of inhibiting effects on solid tumour cells in anti-angiogenic therapy: application of coupled mathematical model of angiogenesis with tumour growth

To investigate the inhibiting effects of the anti-angiogenic factor andostatin and the anti-angiogenic drug endostatin on turnout angiogenesis and turnout cells, a coupled mathematical model of tumor angiogenesis with tumour growth and blood perfusion is developed. Simulation results show that angiostatin and endostatin can improve the abnormal microenvironment inside the tumour tissue by effectively inhibiting the process of tumor angiogenesis and decreasing tumour cells. The present model can be used as a valid theoretical method in the investigation of the tumour anti-angiogenic therapy.

Vascular damage and anti-angiogenic effects of tumor vessel-targeted adenovirus-mediated herpes simplex virus thymidine kinase gene

AIM： To explore the therapeutic efficacy and mechanism of herpes simplex virus-thymidine kinase （HSV-tk） targeting angiogenesis against hepatocellular carcinoma in vivio and in vitro. METHODS： Recombinant adenovirus containing kinase domain insert with receptor （KDR） or cytomegalovirus （CMV） promoter-controlled HSV-tk gene （AdKDR-tk and AdCMV-tk） was constructed using pAdeasy system. The expression of KDR antigen in human umbilical venous endothelial cells （HUVEC） and HepG2 was detected with histological analysis of cells. The virus was used to infect HUVEC and HepG2. Following administration of ganciclovir （GCV）, the survival rate of gene-transfected HUVEC and HepG2 was evaluated by MTT method. To develop hepatocarcinomas in 32 Balb/C mice with HepG2 cells, the mice were divided into four groups： ganciclovir group （Ⅰ）, Ad group （Ⅱ）, AdCMV-tk group （Ⅲ） and AdKDR-tk group （Ⅳ）. Then selective administration of recombinant adenovirus or Ad via the intratumorial was given to all rats. Ganciclovir （GCV） was given at a dose of 100 mg·kg^-1·d^-1 （ip） started on the following day and lasted 10 d. Microvessel density （MVD） of tumor in all the treated animals were examined by the immunohistochemical methods and tumor burden was evaluated 10 d before and alter the last GCV dose.RESULTS： Immunocytochemical staining indicated the expression of KDR antigen in HUVEC. Under adenovirus infection index of 100, with increasing GCV concentration from 0 up to 50 mg/L, the survival rate of AdKDR-tk- transfected HUVEC and HepG2 decreased from 100% to （28.94 ± 5.67）% and （75.45 ± 2.91）% at proper order, respectively （P 〈 0.01）, while the survival rate of AdCMV- tk-transfected HUVEC and HepG2 declined from 100% to （17.56 ± 2.48）% and （23.15± 5.72）%, respectively （P 〉 0.05）. Compared with group I, there was a decrease of tumor weight by 14.7% in group Ⅲ and by 23.6% in group Ⅳ. And there was a distinct difference between group M and Ⅳ （P 〈 0.05）. The median MVD for all groups was 37.4 ± 8.6, 30.6 ± 7.8, 27.6 ± 7.1, and 10.7 ± 4.1 （microvessels/mm^2） in group Ⅰ, Ⅱ, M and IV, respectively. And there was a marked difference between group M and Ⅱ （P 〈 0.05）, Ⅳ and Ⅱ （P 〈 0.01）, and Ⅳ and M （P 〈 0.01）. CONCLUSION： KDR promoter-HSV-tk gene may effectually restrain the growth of tumor via targeting angiogenesis for hepatocellular carcinoma with treatment of GCV.

Anti-angiogenic agents in metastatic colorectal cancer

Colorectal cancer(CRC) is a major public health concern being the third leading cause of cancer mortality in the United States. The availability of better therapeutic options has led to a decline in cancer mortality in these patients. Surgical resection should be considered in all stages of the disease. The use of conversion therapy has made surgery a potentially curative option even in patients with initially unresectable metastatic disease. In this review we discuss the role of various antiangiogenic agents in patients with metastatic CRC(m CRC). We describe the mechanism of action of these agents, and the rationale for their use in combination with chemotherapy. We also review important clinical studies that have evaluated the safety and efficacy of these agents in m CRC patients. Despite the discovery of several promising anti-angiogenic agents, m CRC remains an incurable disease with a median overall survival of just over 2 years in patients exposed to all available treatment regimens. Further insights into tumor biology and tumor microenvironment may help improve outcomes in these patients.

Identification of bioactive anti-angiogenic components targeting tumor endothelial cells in Shenmai injection using multidimensional pharmacokinetics

Shenmai injection(SMI)is a well-defined herbal preparation that is widely and clinically used as an adjuvant therapy for cancer.Previously,we found that SMI synergistically enhanced the activity of chemotherapy on colorectal cancer by promoting the distribution of drugs in xenograft tumors.However,the underlying mechanisms and bioactive constituents remained unknown.In the present work,the regulatory effects of SMI on tumor vasculature were determined,and the potential anti-angiogenic components targeting tumor endothelial cells(TECs)were identified.Multidimensional pharmacokinetic profiles of ginsenosides in plasma,subcutaneous tumors,and TECs were investigated.The results showed that the concentrations of protopanaxadiol-type(PPD)ginsenosides(Rb1,Rb2/Rb3,Rc,and Rd)in both plasma and tumors,were higher than those of protopanaxatriol-type(Rg1 and Re)and oleanane-type(Ro)ginsenosides.Among PPD-type ginsenosides,Rd exhibited the greatest concentrations in tumors and TECs after repeated injection.In vivo bioactivity results showed that Rd suppressed neovascularization in tumors,normalized the structure of tumor vessels,and improved the anti-tumor effect of 5-fluorouracil(5 FU)in xenograft mice.Furthermore,Rd inhibited the migration and tube formation capacity of endothelial cells in vitro.In conclusion,Rd may be an important active form to exert the anti-angiogenic effect on tumor after SMI treatment.

1-Methoxycarbony-β-carboline from Picrasma quassioides exerts anti-angiogenic properties in HUVECs in vitro and zebrafish embryos in vivo

Angiogenesis is a crucial process in the development of inflammatory diseases,including cancer,psoriasis and rheumatoid arthritis.Recently,several alkaloids from Picrasma quassioides had been screened for angiogenic activity in the zebrafish model,and the results indicated that 1-methoxycarbony-β-carboline(MCC) could effectively inhibit blood vessel formation.In this study,we further confirmed that MCC can inhibit,in a concentration-dependent manner,the viability,migration,invasion,and tube formation of human umbilical vein endothelial cells(HUVECs) in vitro,as well as the regenerative vascular outgrowth of zebrafish caudal fin in vivo.In the zebrafish xenograft assay,MCC inhibited the growth of tumor masses and the metastatic transplanted DU145 tumor cells.The proteome profile array of the MCC-treated HUVECs showed that MCC could down-regulate several angiogenesis-related self-secreted proteins,including ANG,EGF,b FGF,GRO,IGF-1,PLG and MMP-1.In addition,the expression of two key membrane receptor proteins in angiogenesis,TIE-2 and u PAR,were also down-regulated after MCC treatment.Taken together,these results shed light on the potential therapeutic application of MCC as a potent natural angiogenesis inhibitor via multiple molecular targets.

Anti-angiogenic drugs in cancer therapeutics:a review of the latest preclinical and clinical studies of anti-angiogenic agents with anticancer potential

Cancer is a group of diseases with significant morbidity and mortality.In cancer cells,where energy requirements are exceptionally high,angiogenesis,which is the sprouting of new blood vessels from pre-existing ones,is an important process for tumour survival and progression.Hence,extensive research in recent years focuses on the discovery of new anticancer drugs that target angiogenesis.Several methodologies have been developed preclinically,including the inhibition of pro-angiogenic factors and their receptors via micromolecular agents or monoclonal antibodies and the inhibition of other compensatory pathways beyond the traditional angiogenic ones.The purpose of the literature review is to present new anticancer drugs that target the process of angiogenesis and have been under preclinical or clinical investigation during the last five years.Many new anticancer drugs targeting angiogenesis are identified in the literature.The results of the in vitro and in vivo evaluation of these drugs show that,apart from inhibiting angiogenesis,they also affect cancer cell proliferation and tumour growth.Recent clinical studies show that these drugs increase the overall or disease-free survival of patients,even those with persistent,chemotherapy-resistant and metastatic types of cancer,although treatment-related side effects are not uncommon.Drugs that target the process of angiogenesis are likely to be the future of anticancer therapy,especially in cases where more traditional treatments do not produce the desired results and where combination regimens of anti-angiogenic agents with standard chemotherapeutics increase patient survival.

NOVEL ANTI-ANGIOGENIC ACTIVITIES OF A TRITERPENOID DEOXYACTEIN FROM CIMICIFUGA FOETIDA

Deoxyactein(DA)is a triterpenoid isolated from the root of Cimicifuga foetida which is a source of traditional Chinese herb'shengma'and is traditionally used as an antipyretic and analgesic agent.Previous studies showed that DA exhibited anti-proliferative effect in human breast cancer cells.Hence,the objectives of this study were to

Mechanisms of resistance to anti-angiogenic treatments

Hailed as the cancer treatment to end all the resistance to treatment,anti-angiogenic therapy turned out to be not quite what was promised.The hope that this therapeutic approach would not have suffered by the phenomenon of resistance was based on the fact that was targeting normal vessels rather than tumour cells prone to mutation and subject to drug induced selection.However,reality turned out to be more complex and since 1997,several mechanisms of resistance have been described to the point that the study of resistance to these drugs is now a very large field.Far from being exhaustive,this paper presents the main mechanisms discovered trough some examples.

Progress of Immunotherapy Combined with Anti-Angiogenesis Therapy in Lung Cancer

Lung cancer is the most prevalent and fatal cancer in China and even around the world, and many patients are found in the late stage of lung cancer. For the treatment of advanced lung cancer, in addition to traditional chemotherapy modalities, many emerging treatments are increasingly significant, such as immunotherapy, anti-angiogenic therapy, and targeted therapy. An increasing number of studies have now shown that anti-angiogenic therapy improves the immune microenvironment by enhancing tumor immunity through normalization of tumor vessels. Immunization combined with anti-angiogenic therapy can exert synergistic effects and improve the prognosis of patients. This article summarizes the extent of benefit, current clinical study data, and future prospects of immunotherapy combined with anti-angiogenic agents in the treatment of advanced NSCLC.

Role of bevacizumab in colorectal cancer growth and its adverse effects:A review

Angiogenesis affects both wound healing and malignant cell growth through nutrients and oxygen.Vascular endothelial growth factor(VEGF) is the most important element involved in this complex process.Inhibition of VEGF influences angiogenesis and may restrict tumor growth and metastatic ability.Modern antiangiogenic therapy is based on this theory.Bevacizumab is a recombinant humanized monoclonal antibody(immunoglobulin G1) which binds with VEGF-A forming a large molecule.It can not be bound with VEGF tyrosine kinase receptors preventing VEGF-A incorporation;thus its activity is inhibited inducing blockage of VEGFmediated angiogenesis.Bevacizumab,in combination with chemotherapy or other novel targeted therapeutic agents,is currently used more frequently in clinical practice,mainly for managing advanced colorectal cancer.It is also used for managing other malignancies,such as breast cancer,pancreatic cancer,prostate cancer,non small-cell lung cancer,metastatic renal carcinoma and ovarian tumors.Although it is generally considered a safe treatment,there are reports of some rare side effects which should be taken into account.Recent experiments in rats and mice show promising results with a wider therapeutic range.

Perfusion computed tomography in renal cell carcinoma

Various imaging modalities are available for the diagnosis, staging and response evaluation of patients with renal cell carcinoma(RCC). While contrast enhanced computed tomography(CT) is used as the standard of imaging for size, morphological evaluation and response assessment in RCC, a new functional imaging technique like perfusion CT(p CT), goes down to the molecular level and provides new perspectives in imaging of RCC. p CT depicts regional tumor perfusion and vascular permeability which are indirect parameters of tumor angiogenesis and thereby provides vital information regarding tumor microenvironment. Also response evaluation using p CT may predate the size criteria used in Response Evaluation Criteria in Solid Tumors, as changes in the perfusion occurs earlier following tissue kinase inhibitors before any actual change in size. This may potentially help in predicting prognosis, better selection of therapy and more accurate and better response evaluation in patients with RCC. This article describes the techniques and role of p CT in staging and response assessment in patients with RCCs.

Fucoidan-Based Theranostic Nanogel for Enhancing Imaging and Photodynamic Therapy of Cancer

In this study, a fucoidan-based theranostic nanogel(CFN-gel) consisting of a fucoidan backbone, redox-responsive cleavable linker and photosensitizer is developed to achieve acti-vatable near-infrared fluorescence imaging of tumor sites and an enhanced photodynamic therapy(PDT) to induce the com-plete death of cancer cells. A CFN-gel has nanomolar a nity for P-selectin, which is overexpressed on the surface of tumor neovascular endothelial cells as well as many other cancer cells. Therefore, a CFN-gel can enhance tumor accumulation through P-selectin targeting and the enhanced permeation and retention e ect. Moreover, a CFN-gel is non-fluorescent and non-phototoxic upon its systemic administration due to the aggregation-induced self-quenching in its fluorescence and singlet oxygen generation. After internalization into cancer cells and tumor neovascular endothelial cells, its photoactivity is recovered in response to the intracellular redox potential, thereby enabling selective near-infrared fluorescence imaging and an enhanced PDT of tumors. Since a CFN-gel also shows nanomolar a nity for the vascular endothelial growth factor, it also provides a significant anti-tumor e ect in the absence of light treatment in vivo. Our study indicates that a fucoidan-based theranostic nanogel is a new theranostic material for imaging and treating cancer with high e cacy and specificity.

Atezolizumab and bevacizumab as first line therapy in advanced hepatocellular carcinoma:Practical considerations in routine clinical practice

Hepatocellular carcinoma(HCC)is the most common primary liver cancer.For advanced HCC,sorafenib was considered the standard of care for more than ten years.Recently the atezolizumab and bevacizumab combination has become standard of care for these patients without contraindications to either immune checkpoint inhibitors or antiangiogenic therapy.We now review the practical aspects of the atezolizumab and bevacizumab combination,including current evidence,indications,contraindications,management of adverse events,sequencing of this combination,areas of current knowledge gaps and future areas of active clinical research of this combination for busy clinicians in clinical practice.

Flk-1 specific kinase inhibitor SU5416 blocked angiogenesis of Lewis carcinoma in mouse and prolonged the survival

Objective: To reveal the mechanism and effect of SU5416 in the treatment of mouse Lewis cancer in vivo. Methods: Lewis cell was transplanted into groin of C57/B6 mouse by subcutaneous injection, then SU5416 was administrated intraperitoneally to investigate the impact of SU5416 on tumor angiogenesis and growth in vivo. 32 mice were treated with SU5416 at two different doses every day until the end-point. As a control, 8 mice received no treatment and 8 mice were treated with vehicle (DMSO) only after implantation. Results: Median survival in the treated group was statistically longer compared to that in the control groups (P < 0.05) and no significant systemic adverse was observed. Histological analysis of the treated tumors showed an increase in necroses and reduced in angiogenesis compared to the control tumors. Furthermore, the percent of apoptotic cells increased in the treated tumors by FCM, the expressions of VEGF and KDR had no change after SU5416 administration by western blot. Conclusion: SU5416 may be useful therapeutics drug that specifically inhibits the enzymatic activity of KDR kinase and could down regulate the tumor angiogenesis.

Combined Ang-2 and VEGF Targeting Therapies in Renal Cell Carcinoma

Angiogenesis, the growth of new vessels from pre-existing ones, is an important feature of tumor growth that has been exploited as a therapeutic target in oncology. Given its key role in facilitating blood vessel sprouting, VEGF has been a major focus of anti-angiogenic strategies, but the observation of resistance in some clinical trials utilizing such agents has led to a search for new or complementary targets in angiogenesis process. The Angiopoietin/Tie2 pathway and in particular the Angiopoietin-2 (Ang-2) ligand which is critically involved in the destabilization of normal vasculature, has been identified as one such target. The current study investigated the potential benefits of combining an Ang-2 targeted therapy with small molecule VEGF targeted agents (Sunitinib, Cediranib) in a human renal cell carcinoma model. The results showed that while both Ang-2 and VEGF interference on their own impaired tumor growth and new blood vessel formation, the combination of agents that targeted both pathways resulted in significantly superior anti-tumor and anti-angiogenic effects.

Research Progress of Anti-Tumor Angiogenesis in Traditional Chinese Medicine

In recent years,seeking effective anti-angiogenic components and therapeutic methods from traditional Chinese Medicine(TCM)has been a hot spot in the treatment of malignant tumors.In particular,the active ingredients found in Chinese herbal extracts have shown strong inhibition of tumor neovascularization.

Apatinib for treatment of a pseudomyxoma peritonei patient after surgical treatment and hyperthermic intraperitoneal chemotherapy:A case report

BACKGROUND Pseudomyxoma peritonei(PMP)is a rare benign,but progressive,disease according to myxoma histopathology.Surgical resection is the preferred and most effective treatment,but the outcomes are often unsatisfactory.CASE SUMMARY A 63-year-old Chinese woman with PMP received apatinib at a daily dose of 0.5 mg for 15 d per cycle and at a daily dose of 0.4 mg to date for recurrent abdominal distension after surgical treatment and hyperthermic intraperitoneal chemotherapy.During the follow-up period,apatinib was the maintenance treatment with a progression-free period of 10 mo and the toxicity of apatinib was controllable and tolerable.Unfortunately,recurrence occurred 10 mo after administration.After two operations,the patient gave up treatment at the 18th mo and eventually died of intestinal obstruction and multiple organ failure.CONCLUSION Apatinib may be an option for recurrent PMP after surgical treatment,but this conclusion remains to be confirmed.

Type XIX collagen: a promising biomarker from the basement membranes

Among collagen members in the collagen superfamily,type XIX collagen has raised increasing interest in relation to its structural and biological roles.Type XIX collagen is a Fibril-Associated Collagen with Interrupted Triple helices member,one main subclass of collagens in this superfamily.This collagen contains a triple helix composed of three polypeptide segments aligned in parallel and it is associated with the basement membrane zone in different tissues.The molecular structure of type XIX collagen consists of five collagenous domains,COL1 to COL5,interrupted by six non-collagenous domains,NCI to NC6.The most relevant domain by which this collagen exerts its biological roles is NCI domain that can be cleavage enzymatically to release matricryptins,exerting anti-tumor and anti-angiogenic effect in murine and human models of cancer.Under physiological conditions,type XIX collagen expression decreases after birth in different tissues although it is necessary to keep its basal levels,mainly in skeletal muscle and hippocampal and telencephalic interneurons in brain.Notwithstanding,in amyotrophic lateral sclerosis,altered transcript expression levels show a novel biological effect of this collagen beyond its structural role in basement membranes and its anti-tumor and anti-angiogenic properties.Type XIX collagen can exert a compensatory effect to ameliorate the disease progression under neurodegenerative conditions specific to amyotrophic lateral sclerosis in transgenic SOD1 G93 A mice and amyotrophic lateral sclerosis patients.This novel biological role highlights its nature as prognostic biomarker of disease progression in and as promising therapeutic target,paving the way to a more precise prognosis of amyotrophic lateral sclerosis.