Expression of angiopoietins, Tie2 and vascular endothelial growth factor in angiogenesis and progression of hepatocellular carcinoma

Vasomics of the liver

Chronic liver disease is a cluster of disorders associated with complex haemodynamic alterations, which is characterised by structural and functional disruptions of the intrahepatic and extrahepatic vasculature. 'Vasomics' is an emerging omics discipline that comprehensively analyses and models the vascular system by integrating pathophysiology of disease, biomechanics, medical imaging, computational science and artificial intelligence. Vasomics is further typified by its multidimensional, multiscale and high-throughput nature, which depends on the rapid and robust extraction of well-defined vascular phenotypes with clear clinical and/or biological interpretability. By leveraging multimodality medical imaging techniques, vascular functional assessments, pathological image evaluation, and related computational methods, integrated vasomics provides a deeper understanding of the associations between the vascular system and disease. This in turn reveals the crucial role of the vascular system in disease occurrence, progression and treatment responses, thereby supporting precision medicine approaches. Pathological vascular features have already demonstrated their key role in different clinical scenarios. Despite this, vasomics is yet to be widely recognised. Therefore, we furnished a comprehensive definition of vasomics providing a classification of existing hepatic vascular phenotypes into the following categories: anatomical, biomechanical, biochemical, pathophysiological and composite.

Machine Learning-Based Pathomics Model Predicts Angiopoietin-2 Expression and Prognosis in Hepatocellular Carcinoma

Angiopoietin-2 (ANGPT2) shows promise as prognostic marker and therapeutic target in hepatocellular carcinoma (HCC). However, assessing ANGPT2 expression and prognostic potential using histopathology images viewed with naked eye is challenging. Herein, machine learning was employed to develop a pathomics model for analyzing histopathology images to predict ANGPT2 status. HCC cases obtained from The Cancer Genome Atlas (TCGA-HCC; n = 267) were randomly assigned to the training or testing set, and cases from a single center were employed as a validation set (n = 91). In the TCGA-HCC cohort, the group with high ANGPT2 expression had a significantly lower overall survival compared with the group with low ANGPT2. Histopathologic features in the training set were extracted, screened, and incorporated into a gradient-boosting machine model that generated a pathomics score, which successfully predicted ANGPT2 expression in the three data sets and showed remarkable risk stratification for overall survival in both the TCGA-HCC (P < 0.0001) and single-center cohorts (P = 0.001). Multivariate analysis suggested that the pathomics score could serve as a predictor of prognosis (P < 0.001). Bioinformatics analysis illustrated a distinction in tumor growth and development related gene-enriched pathways, vascular endothelial growth factor-related gene expression, and immune cell infiltration between high and low pathomics scores. This study indicates that the use of histopathology image features can enhance the prediction of molecular status and prognosis in HCC. The integration of image features with machine learning may improve prognosis prediction in HCC.

Fibrosis and Hepatocarcinogenesis: Role of Gene-Environment Interactions in Liver Disease Progression

The liver is a complex organ that performs vital functions in the body. Despite its extraordinary regenerative capacity compared to other organs, exposure to chemical, infectious, metabolic and immunologic insults and toxins renders the liver vulnerable to inflammation, degeneration and fibrosis. Abnormal wound healing response mediated by aberrant signaling pathways causes chronic activation of hepatic stellate cells (HSCs) and excessive accumulation of extracellular matrix (ECM), leading to hepatic fibrosis and cirrhosis. Fibrosis plays a key role in liver carcinogenesis. Once thought to be irreversible, recent clinical studies show that hepatic fibrosis can be reversed, even in the advanced stage. Experimental evidence shows that removal of the insult or injury can inactivate HSCs and reduce the inflammatory response, eventually leading to activation of fibrolysis and degradation of ECM. Thus, it is critical to understand the role of gene-environment interactions in the context of liver fibrosis progression and regression in order to identify specific therapeutic targets for optimized treatment to induce fibrosis regression, prevent HCC development and, ultimately, improve the clinical outcome.

Angiopoietin-2 and the Vascular Endothelial Growth Factor Promote Migration and Invasion in Hepatocellular Carcinoma- and Intrahepatic Cholangiocarcinoma-Derived Spheroids

Aggressive hepatocellular carcinoma (HCC) overexpressing Angiopoietin-2 (ANG-2) (a protein linked with angiogenesis, proliferation, and epithelial-mesenchymal transition (EMT)), shares 95% of up-regulated genes and a similar poor prognosis with the proliferative subgroup of intrahepatic cholangiocarcinoma (iCCA). We analyzed the pro-invasive effect of ANG-2 and its regulator vascular endothelial growth factor (VEGF) on HCC and CCA spheroids to uncover posUsible common ways of response. Four cell lines were used: Hep3B and HepG2 (HCC), HuCC-T1 (iCCA), and EGI-1 (extrahepatic CCA). We treated the spheroids with recombinant human (rh) ANG-2 and/or VEGF and then observed the changes at the baseline, after 24 h, and again after 48 h. Proangiogenic stimuli increased migration and invasion capability in HCC- and iCCA-derived spheroids and were associated with a modification in EMT phenotypic markers (a decrease in E-cadherin and an increase in N-cadherin and Vimentin), especially at the migration front. Inhibitors targeting ANG-2 (Trebananib) and the VEGF (Bevacizumab) effectively blocked the migration ability of spheroids that had been stimulated with rh-ANG-2 and rh-VEGF. Overall, our findings highlight the critical role played by ANG-2 and the VEGF in enhancing the ability of HCC- and iCCA-derived spheroids to migrate and invade, which are key processes in cancer progression.

Nanosecond pulse effectively ablated hepatocellular carcinoma with alterations in the gut microbiome and serum metabolites

Background: Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related death in the world. Nanosecond pulsed electric fields (nsPEFs) have emerged as a new treatment for cancer. This study aims to identify the effectiveness of nsPEFs in the treatment of HCC and analyze the alterations in the gut microbiome and serum metabonomics after ablation. Methods: C57BL/6 mice were randomly divided into three groups: healthy control mice (n = 10), HCC mice (n = 10), and nsPEF-treated HCC mice (n = 23). Hep1-6 cell lines were used to establish the HCC model in situ. Histopathological staining was performed on tumor tissues. The gut microbiome was analyzed by 16S rRNA sequencing. Serum metabolites were analyzed by liquid chromatography-mass spectrometry (LC-MS) metabolomic analysis. Spearman's correlation analysis was carried out to analyze the correlation between the gut microbiome and serum metabonomics. Results: The fluorescence image showed that nsPEFs were significantly effective. Histopathological staining identified nuclear pyknosis and cell necrosis in the nsPEF group. The expression of CD34, PCNA, and VEGF decreased significantly in the nsPEF group. Compared with normal mice, the gut microbiome diversity of HCC mice was increased. Eight genera including Alistipes and Muribaculaceae were enriched in the HCC group. Inversely, these genera decreased in the nsPEF group. LC-MS analysis confirmed that there were significant differences in serum metabolism among the three groups. Correlation analysis showed crucial relationships between the gut microbiome and serum metabolites that are involved in nsPEF ablation of HCC. Conclusion: As a new minimally invasive treatment for tumor ablation, nsPEFs have an excellent ablation effect. The alterations in the gut microbiome and serum metabolites may participate in the prognosis of HCC ablation.

Immune Aging and How It Works for Inflammation and Fibrosis

Almost all mature cells that undergo apoptosis in an age-dependent or an accidental manner are completely recovered in tissue-specific microenvironments without any physiological changes. After peripheral blood leukocytes are released into the local region, fibroblast cells and new blood vessels commonly proliferate during wound healing. Inducible repair tools mainly supplied from blood vessels are cleared by peripheral blood phagocytic macrophages. Finally, hematopoietic stem cell (HSC)-derived precursor cells migrate from bone marrow (BM) to the microenvironment to rebuild damaged tissues (the mature immune system). In contrast to the mature immune system, the effects of aging on HSCs (long-term HSCs) and peripheral blood lymphocytes (long-term PBLs) are not clearly understood in the BM and thymus niches with tissue-specific microenvironments with some physiological changes (the aged BM niche) for incomplete rebuilding of damaged tissues (the aged immune system). In this review, the roles of the aged immune system in both a delay of acute inflammation and the development of chronic inflammation or fibrosis are discussed.

Combinatorial therapy in tumor microenvironment: Where do we stand?

The tumor microenvironment plays a pivotal role in tumor initiation and progression by creating a dynamic interaction with cancer cells. The tumor microenvironment consists of various cellular components, including endothelial cells, fibroblasts, pericytes, adipocytes, immune cells, cancer stem cells and vasculature, which provide a sustained environment for cancer cell proliferation. Currently, targeting tumor microenvironment is increasingly being explored as a novel approach to improve cancer therapeutics, as it influences the growth and expansion of malignant cells in various ways. Despite continuous advancements in targeted therapies for cancer treatment, drug resistance, toxicity and immune escape mechanisms are the basis of treatment failure and cancer escape. Targeting tumor microenvironment efficiently with approved drugs and combination therapy is the solution to this enduring challenge that involves combining more than one treatment modality such as chemotherapy, surgery, radiotherapy, immunotherapy and nanotherapy that can effectively and synergistically target the critical pathways associated with disease pathogenesis. This review shed light on the composition of the tumor microenvironment, interaction of different components within tumor microenvironment with tumor cells and associated hallmarks, the current status of combinatorial therapies being developed, and various growing advancements. Furthermore, computational tools can also be used to monitor the significance and outcome of therapies being developed. We addressed the perceived barriers and regulatory hurdles in developing a combinatorial regimen and evaluated the present status of these therapies in the clinic. The accumulating depth of knowledge about the tumor microenvironment in cancer may facilitate further development of effective treatment modalities. This review presents the tumor microenvironment as a sweeping landscape for developing novel cancer therapies.

A Correlative Study Between IVIM-DWI Parameters and the Expression Levels of Ang-2 and TKT in Hepatocellular Carcinoma

BACKGROUND

Noninvasive evaluation of the expression of angiopoietin-2 (Ang-2) and transketolase (TKT) in hepatocellular carcinoma (HCC) is of great significance for the clinical development of individualized treatment plans. However, the correlation between intravoxel incoherent motion diffusion weighted imaging (IVIM-DWI) and the expression of Ang-2 and TKT has not been reported. We sought to investigate the correlations between IVIM-DWI parameters and Ang-2 and TKT expression levels in HCCs.

METHODS

Conventional non-enhanced magnetic resonance imaging (MRI) and IVIM-DWI and dynamic contrast MRI were performed for 61 patients with HCC before surgical treatment. Various IVIM-DWI parameters, such as apparent diffusion coefficient (ADC), slow apparent diffusion coefficient (D), fast apparent diffusion coefficient (D*) and fraction of fast apparent diffusion coefficient (f), were calculated using Function-MADC software. Expression levels of Ang-2 and TKT in HCC were detected via immunohistochemical staining and classified into two grades. Independent sample t tests were used to compare differences in parameters between the two groups. The Spearman rank correlation test was used to analyze the correlations between IVIM-DWI parameters and Ang-2 and TKT expression levels in HCCs.

RESULTS

The D* and f values were significantly higher in the high Ang-2 group than in the low Ang-2 group; there were no obvious between-group differences in ADC and D. Ang-2 expression was positively correlated with D* and f but not with ADC and D. The ADC and D values were significantly lower in the high TKT group than in the low TKT group, whereas the between-group differences for D* and f were not significant. TKT expression was negatively correlated with ADC and D but not with D* and f.

CONCLUSIONS

IVIM-DWI can be used to evaluate Ang-2 and TKT expression in HCC.

The Angiopoietin/Tie2 Pathway in Hepatocellular Carcinoma

Due to the usually late diagnosis and lack of effective therapies, hepatocellular carcinoma (HCC), which poses a growing global health problem, is characterized by a poor prognosis. Angiogenesis plays an important role in HCC progression, and vascular endothelial growth factor (VEGF) and angiopoietins (Angs) are key drivers of HCC angiogenesis. VEGF-targeting strategies already represent an important component of today’s systemic treatment landscape of HCC, whereas targeting the Ang/Tie2 signaling pathway may harbor future potential in this context due to reported beneficial anticancer effects when targeting this pathway. In addition, a better understanding of the relation between Angs and HCC angiogenesis and progression may reveal their potential as predictive factors for post-treatment disease progression and prognosis. In this review, we give a comprehensive overview of the complex role of Ang/Tie2 signaling in HCC, pinpointing its potential value as biomarker and target for HCC treatments, aiding HCC diagnosis and therapy.

Targeting the Tie2-αvβ3 integrin axis with bi-specific reagents for the inhibition of angiogenesis

BACKGROUND

Increased activity of the receptor tyrosine kinase Tie2 has been implicated in the promotion of pathological angiogenesis. This activity is mainly mediated through angiopoietin (Ang)1- and Ang2-dependent activation of integrins by Tie2, rendering the Ang/Tie2/integrin axis an attractive putative target for cancer therapeutics.

RESULTS

To target this axis, we developed single domain, non-immunoglobulin high-affinity bi-specific protein inhibitors against both Tie2 and αvβ3 integrin. We have previously engineered the Ang2-binding domain of Tie2 (Ang2-BD) as a Tie2 inhibitor. Here, we engineered an exposed loop in Ang2-BD to generate variants that include an integrin-binding Arg-Gly-Asp (RGD) motif and used flow cytometry screening of a yeast-displayed Ang2-BD RGD loop library to identify the integrin antagonists. The bi-specific antagonists targeting both Tie2 and αvβ3 integrin inhibited adhesion and proliferation of endothelial cells cultured together with the αvβ3 integrin ligand vitronectin, as well as endothelial cell invasion and tube formation. The bi-specific reagents inhibited downstream signaling by Tie2 intracellularly in response to its agonist Ang1 more effectively than the wild-type Ang2 BD that binds Tie2 alone.

CONCLUSIONS

Collectively, this study-the first to describe inhibitors targeting all the known functions resulting from Tie2/integrin αvβ3 cross-talk-has created new tools for studying Tie2- and integrin αvβ3-dependent molecular pathways and provides the basis for the rational and combinatorial engineering of ligand-Tie2 and ligand-integrin αvβ3 receptor interactions. Given the roles of these pathways in cancer angiogenesis and metastasis, this proof of principle study paves the route to create novel Tie2/integrin αvβ3-targeting proteins for clinical use as imaging and therapeutic agents.

Hepatocellular carcinoma treatment: hurdles, advances and prospects

Hepatocellular carcinoma (HCC) is one of the major causes of cancer-related mortality and is particularly refractory to the available chemotherapeutic drugs. Among various etiologies of HCC, viral etiology is the most common, and, along with alcoholic liver disease and nonalcoholic steatohepatitis, accounts for almost 90% of all HCC cases. HCC is a heterogeneous tumor associated with multiple signaling pathway alterations and its complex patho-physiology has made the treatment decision challenging. The potential curative treatment options are effective only in small group of patients, while palliative treatments are associated with improved survival and quality of life for intermediate/advanced stage HCC patients. This review article focuses on the currently available treatment strategies and hurdles encountered for HCC therapy. The curative treatment options discussed are surgical resection, liver transplantation, and local ablative therapies which are effective for early stage HCC patients. The palliative treatment options discussed are embolizing therapies, systemic therapies, and molecular targeted therapies. Besides, the review also focuses on hurdles to be conquered for successful treatment of HCC and specifies the future prospects for HCC treatment. It also discusses the multi-modal approach for HCC management which maximizes the chances of better clinical outcome after treatment and identifies that selection of a particular treatment regimen based on patients' disease stage, patients' ages, and other underlying factors will certainly lead to a better prognosis.

The Selective Tie2 Inhibitor Rebastinib Blocks Recruitment and Function of Tie2Hi Macrophages in Breast Cancer and Pancreatic Neuroendocrine Tumors

Tumor-infiltrating myeloid cells promote tumor progression by mediating angiogenesis, tumor cell intravasation, and metastasis, which can offset the effects of chemotherapy, radiation, and antiangiogenic therapy. Here, we show that the kinase switch control inhibitor rebastinib inhibits Tie2, a tyrosine kinase receptor expressed on endothelial cells and protumoral Tie2-expressing macrophages in mouse models of metastatic cancer. Rebastinib reduces tumor growth and metastasis in an orthotopic mouse model of metastatic mammary carcinoma through reduction of Tie2⁺ myeloid cell infiltration, antiangiogenic effects, and blockade of tumor cell intravasation mediated by perivascular Tie2^Hi/Vegf-A^Hi macrophages in the tumor microenvironment of metastasis (TMEM). The antitumor effects of rebastinib enhance the efficacy of microtubule inhibiting chemotherapeutic agents, either eribulin or paclitaxel, by reducing tumor volume, metastasis, and improving overall survival. Rebastinib inhibition of angiopoietin/Tie2 signaling impairs multiple pathways in tumor progression mediated by protumoral Tie2⁺ macrophages, including TMEM-dependent dissemination and angiopoietin/Tie2-dependent angiogenesis. Rebastinib is a promising therapy for achieving Tie2 inhibition in cancer patients. Mol Cancer Ther; 16(11); 2486-501. ©2017 AACR.

Oncogenic function of angiopoietin-2 in vitro and its modulation of tumor progression in colorectal carcinoma

Angiopoietin-2 (Ang-2) has been investigated in cancer primarily in terms of its angiogenic function, and its role as an oncogene has yet to be elucidated. The current study hypothesized that Ang-2 may be an oncogene and have a function in tumor progression. An investigation of the function of Ang-2 in the LoVo colorectal cancer (CRC) cell line in vitro, which expresses a high level of Ang-2, was performed by knocking down endogenous expression with a targeted short hairpin RNA. The aggressive phenotypic effects of Ang-2 on experimental and control group cells were assessed using cell proliferation, migration and invasion assays. The association between Ang-2 expression levels and clinicopathological factors was evaluated in 415 CRC tissues using immunohistochemistry. Suppressing Ang-2 expression decreased cellular proliferation, invasion and migration in an in vitro study. Ang-2 overexpression was observed in 46% of patients with CRC and was significantly associated with pT (P=0.048), pN (P<0.001), venous invasion (P=0.023), lymphatic invasion (P<0.001) and tumor-node-metastasis stage (P=0.022). Furthermore, Ang-2 overexpression was an independent prognostic factor in pN stages 1 and 2. These results reveal that Ang-2 may be an oncogene in colorectal carcinogenesis and its expression may exert aggressive phenotypic effects during tumor progression. In addition, Ang-2 expression may serve as a prognostic marker and a potential drug target.

Morusin shows potent antitumor activity for human hepatocellular carcinoma in vitro and in vivo through apoptosis induction and angiogenesis inhibition

Hepatocellular carcinoma (HCC) is one of the most aggressive cancers with high mortality worldwide. Research and development of novel agents for HCC therapy is in demand, urgently. Morusin has been reported to exhibit potential cytotoxic activity in several cancer cell lines. However, whether it has potential antiangiogenic activity especially in HCC remains unclear. In the current study, we found that morusin exerted growth inhibition effects on human HCC cells (HepG2 and Hep3B) in vitro and human HCC cell (HepG2) xenografts in vivo. Moreover, apoptosis induction was observed in a dose-dependent manner after morusin treatment along with an increase in the expression of active caspase-3 and the Bax/Bcl-2 expression ratio. More importantly, morusin inhibited proliferation, migration, and tube formation of human umbilical vein endothelial cells (HUVECs) in vitro and downregulated angiogenic proteins in HCC cells and HUVECs. In vivo, tumor angiogenesis was also attenuated after morusin treatment. In addition, morusin suppressed constitutive as well as IL-6-induced STAT3 phosphorylation in HCC cells and corresponding tumor tissues. Overall, morusin has a potential anticancer effect on human HCC cells in vitro and in vivo by inducing apoptosis and inhibiting anti-angiogenesis. The corresponding mechanism might be associated with the attenuation of the IL-6/STAT3 signaling pathway. Morusin might serve as a promising novel anticancer agent in HCC therapy, and requires further study.

The Role of Cancer-Associated Fibroblasts and Fibrosis in Liver Cancer

Liver cancer is the second leading cause of cancer mortality worldwide, causing more than 700,000 deaths annually. Because of the wide landscape of genomic alterations and limited therapeutic success of targeting tumor cells, a recent focus has been on better understanding and possibly targeting the microenvironment in which liver tumors develop. A unique feature of liver cancer is its close association with liver fibrosis. More than 80% of hepatocellular carcinomas (HCCs) develop in fibrotic or cirrhotic livers, suggesting an important role of liver fibrosis in the premalignant environment (PME) of the liver. Cholangiocarcinoma (CCA), in contrast, is characterized by a strong desmoplasia that typically occurs in response to the tumor, suggesting a key role of cancer-associated fibroblasts (CAFs) and fibrosis in its tumor microenvironment (TME). Here, we discuss the functional contributions of myofibroblasts, CAFs, and fibrosis to the development of HCC and CCA in the hepatic PME and TME, focusing on myofibroblast- and extracellular matrix-associated growth factors, fibrosis-associated immunosuppressive pathways, as well as mechanosensitive signaling cascades that are activated by increased tissue stiffness. Better understanding of the role of myofibroblasts in HCC and CCA development and progression may provide the basis to target these cells for tumor prevention or therapy.

Clinical significance of vascular endothelial growth factor in hepatitis C related hepatocellular carcinoma in Egyptian patients

Background and aims

Several angiogenic factors are involved in the development and progression of hepatocellular carcinoma (HCC), a hypervascular tumor. Vascular endothelial growth factor (VEGF) is a primary driving force for angiogenesis, and its overexpression has been reported in HCC. However, the significance of plasma and tissue VEGF levels in HCC in Egyptian patients with chronic hepatitis C (CHC) infection is understudied. The aim of this study was to evaluate the role of VEGF (measured in plasma and liver tissue) in patients with hepatitis C virus-related HCC and to assess its significance in the diagnosis and prognosis of HCC.

Materials and methods

A total of 90 subjects were studied. Among 90 subjects, 60 with CHC were examined and were subdivided into two groups: 30 patients with CHC-related HCC (HCC group) and 30 patients with CHC without HCC (non-HCC group). Thirty apparently healthy subjects served as the control group. VEGF was estimated in plasma by enzyme-linked immunosorbent assay and its expression in liver tissue was evaluated by real-time polymerase chain reaction. VEGF expression level and its relationship to tumor parameters, patients’ liver function profile, and patients’ clinical parameters were also investigated.

Results

Plasma VEGF levels in the HCC group were significantly higher than those of the non-HCC group, and both groups had significantly higher plasma VEGF levels than did the control group. Liver tissue VEGF expression was significantly higher in the HCC group than in the non-HCC group and positively correlated with plasma VEGF in the HCC group. The plasma VEGF levels were positively correlated with patients’ age, aspartate aminotransferase levels, serum alpha-fetoprotein levels, the presence of portal vein thrombosis, and the number of hepatic focal lesions in the HCC group. However, plasma VEGF levels were not significantly correlated with the Child-Pugh score, alanine aminotransferase levels, the size of focal lesions, and Okuda stage. Using both the VEGF and alpha-fetoprotein levels to detect HCC maximizes the sensitivity and specificity.

Conclusion

Plasma levels of VEGF may be a useful diagnostic and prognostic marker for HCC in patients who have been diagnosed with CHC.

The effect of Setarud (IMOD(TM)) on angiogenesis in transplanted human ovarian tissue to nude mice

BACKGROUND

One of the promising methods in fertility preservation among women with cancer is cryopreservation of ovarian cortex but there are many drawbacks such as apoptosis and considerable reduction of follicular density in the transplanted ovary. One solution to reduce ischemic damage is enhancing angiogenesis after transplantation of ovarian cortex tissue.

OBJECTIVE

The aim of this study was to investigate the effect of Setarud, on angiogenesis in transplanted human ovarian tissue.

MATERIALS AND METHODS

In this case control study, twenty four nude mice were implanted subcutaneously, with human ovarian tissues, from four women. The mice were randomly divided into two groups (n=12): the experimental group was treated with Setarud, while control group received only vehicle. Each group was divided into three subgroups (n=4) based on the graft recovery days post transplantation (PT). The transplanted fragments were removed on days 2, 7, and 30 PT and the expression of Angiopoietin-1, Angiopoietin-2, and Vascular endothelial growth factor at both gene and protein levels and vascular density were studied in the grafted ovarian tissues.

RESULTS

On the 2(nd) and 7(th) day PT, the level of Angiopoietin-1 gene expression in case group was significantly lower than that in control group, while the opposite results were obtained for Angiopoietin-2 and Vascular endothelial growth factor. These results were also confirmed at the protein level. The density of vessels in Setarud group elevated significantly on day 7 PT compared to pre-treatment state.

CONCLUSION

Our results showed that administration of Setarud may stimulates angiogenesis in transplanted human ovarian tissues, although further researches are needed before a clear judgment is made.

Evaluation of antiangiogenic efficacy in advanced hepatocellular carcinoma: Biomarkers and functional imaging

Many years after therapeutic wilderness, sorafenib finally showed a clinical benefit in patients with advanced hepatocellular carcinoma. After the primary general enthusiasm worldwide, some disappointments emerged particularly since no new treatment could exceed or at least match sorafenib in this setting. Without these new drugs, research focused on optimizing care of patients treated with sorafenib. One challenging research approach deals with identifying prognostic and predictive biomarkers of sorafenib in this population. The task still seems difficult; however appropriate investigations could resolve this dilemma, as observed for some malignancies where other drugs were used.

Fingolimod prevents blood-brain barrier disruption induced by the sera from patients with multiple sclerosis

Objective

Effect of fingolimod in multiple sclerosis (MS) is thought to involve the prevention of lymphocyte egress from lymphoid tissues, thereby reducing autoaggressive lymphocyte infiltration into the central nervous system across blood-brain barrier (BBB). However, brain microvascular endothelial cells (BMECs) represent a possible additional target for fingolimod in MS patients by directly repairing the function of BBB, as S1P receptors are also expressed by BMECs. In this study, we evaluated the effects of fingolimod on BMECs and clarified whether fingolimod-phosphate restores the BBB function after exposure to MS sera.

Methods

Changes in tight junction proteins, adhesion molecules and transendothelial electrical resistance (TEER) in BMECs were evaluated following incubation in conditioned medium with or without fingolimod/fingolimod-phosphate. In addition, the effects of sera derived from MS patients, including those in the relapse phase of relapse-remitting (RR) MS, stable phase of RRMS and secondary progressive MS (SPMS), on the function of BBB in the presence of fingolimod-phosphate were assessed.

Results

Incubation with fingolimod-phosphate increased the claudin-5 protein levels and TEER values in BMECs, although it did not change the amount of occludin, ICAM-1 or MelCAM proteins. Pretreatment with fingolimod-phosphate restored the changes in the claudin-5 and VCAM-1 protein/mRNA levels and TEER values in BMECs after exposure to MS sera.

Conclusions

Pretreatment with fingolimod-phosphate prevents BBB disruption caused by both RRMS and SPMS sera via the upregulation of claudin-5 and downregulation of VCAM-1 in BMECs, suggesting that fingolimod-phosphate is capable of directly modifying the BBB. BMECs represent a possible therapeutic target for fingolimod in MS patients.

Histopathological characteristics of hypervascular cholangiocellular carcinoma as an early stage of cholangiocellular carcinoma

AIM

Prognosis of hypervascular cholangiocellular carcinoma (h-CCC) is reportedly better than that of ordinary hypovascular CCC (o-CCC). The aim of this study is to clarify the histopathological characteristics of h-CCC.

METHODS

On the basis of the findings in the arterial phase of contrast-enhanced computed tomography, 16 cases of mass-forming-type CCC were divided into two groups (h-CCC, n = 8; o-CCC, n = 8). Areas of high (Area H-a) and low (Area H-b) attenuation in h-CCC cases and areas of low attenuation in o-CCC cases (Area O) were delineated. These areas were then evaluated histopathologically to determine the proportion of tumor cells, fibrous stroma, arterial vessel density, and immunohistochemical expression of Vascular endothelial growth factor; angiopoietin-2; cytokeratin 7, CK19, SOX9 and SOX17 genes; epithelial cell adhesion molecule; and the Bmi-1, Ki-67, epithelial membrane antigen and polyclonal carcinoembryonic antigen.

RESULTS

The areal ratio of tumor cells decreased and that of fibrous stroma increased in the following order: Area H-a, Area H-b and Area O. Values for AVD and neural cell adhesion molecule positivity rate were significantly higher in Area H-a than in Areas H-b or O. Expressions of vascular endothelial growth factor and angiopoietin-2 were significantly higher in Areas H-a and H-b than in Area O. The Ki-67 labeling index increased in the following order: Area H-a, Area H-b and Area O.

CONCLUSION

A high areal ratio of tumor cells and AVD as well as a high expression of stem cells and angiogenic markers were observed in cases of h-CCC, whereas the areal ratio of fibrous stroma and malignant potential were low. These results suggest that h-CCC may represent the early stage of CCC.

Suppression of angiogenesis and tumor growth in vitro and in vivo using an anti-angiopoietin-2 single-chain antibody

Hepatocellular carcinomas (HCCs) are tumors with a highly developed vascular architecture. HCC cells require access to blood vessels for growth and metastasis; therefore, the inhibition of angiogenesis represents a potential therapeutic target for HCC that may reduce the mortality and morbidity from HCC. Various attempts to develop an anti-angiogenic therapy have been made in past decades; however, modest results have been achieved in clinical trials and the challenge of HCC treatment remains. Single-chain antibodies (scFv) are characterized by low molecular weight, low immunogenicity, high penetration and a short half-life, and are easy to produce on a large scale by genetic engineering. Accordingly, an scFv against a specific angiogenic regulator, such as angiopoietin (Ang), may be a promising anti-angiogenic therapy for HCC. Our previous study indicated that an imbalanced expression of angiopoietin-2 (Ang-2) vs. angiopoietin-1 (Ang-1) in HCCs contributes to initiation of neovascularization and promotes the angiogenesis and progression of HCCs. Therefore, we suggest that specific Ang-2-targeting interventions may be valuable in the treatment of HCC via remodeling the neovascular network and changing the tumor microenvironment. In this study, a prokaryotic expression vector of Ang-2 was constructed and purified human Ang-2 protein was isolated. An scFv against human Ang-2 (scFv-Ang2) was identified and purified via phage display technology, and the effects of scFv-Ang2 in vitro and in vivo on HCC in nude mice were evaluated. The results show that scFv-Ang2 inhibits vascular endothelial growth factor (VEGF) and Ang-2 induces the proliferation, migration and tubule formation of human umbilical vein endothelial cells (HUVECs) in vitro. In the in vivo assay, statistical indices, including tumor weight and volume, metastases to lungs, CD31 expression and the microvessel density (MVD) count in the scFv-Ang2-treated group of mice were significantly lower than those in the control group (P<0.05). In conclusion, the successfully generated scFv-Ang2 showed significant inhibitory effects on the angiogenesis and tumor growth of human HCC in vitro and in vivo.

Sunitinib versus sorafenib in advanced hepatocellular cancer: results of a randomized phase III trial

PURPOSE

Open-label, phase III trial evaluating whether sunitinib was superior or equivalent to sorafenib in hepatocellular cancer.

PATIENTS AND METHODS

Patients were stratified and randomly assigned to receive sunitinib 37.5 mg once per day or sorafenib 400 mg twice per day. Primary end point was overall survival (OS).

RESULTS

Early trial termination occurred for futility and safety reasons. A total of 1,074 patients were randomly assigned to the study (sunitinib arm, n = 530; sorafenib arm, n = 544). For sunitinib and sorafenib, respectively, median OS was 7.9 versus 10.2 months (hazard ratio [HR], 1.30; one-sided P = .9990; two-sided P = .0014); median progression-free survival (PFS; 3.6 v 3.0 months; HR, 1.13; one-sided P = .8785; two-sided P = .2286) and time to progression (TTP; 4.1 v 3.8 months; HR, 1.13; one-sided P = .8312; two-sided P = .3082) were comparable. Median OS was similar among Asian (7.7 v 8.8 months; HR, 1.21; one-sided P = .9829) and hepatitis B-infected patients (7.6 v 8.0 months; HR, 1.10; one-sided P = .8286), but was shorter with sunitinib in hepatitis C-infected patients (9.2 v 17.6 months; HR, 1.52; one-sided P = .9835). Sunitinib was associated with more frequent and severe adverse events (AEs) than sorafenib. Common grade 3/4 AEs were thrombocytopenia (29.7%) and neutropenia (25.7%) for sunitinib; hand-foot syndrome (21.2%) for sorafenib. Discontinuations owing to AEs were similar (sunitinib, 13.3%; sorafenib, 12.7%).

CONCLUSION

OS with sunitinib was not superior or equivalent but was significantly inferior to sorafenib. OS was comparable in Asian and hepatitis B-infected patients. OS was superior in hepatitis C-infected patients who received sorafenib. Sunitinib-treated patients reported more frequent and severe toxicity.

Blood-brain barrier destruction determines Fisher/Bickerstaff clinical phenotypes: an in vitro study

OBJECTIVE

To ascertain the hypothesis that the phenotypic differences between Bickerstaff's brainstem encephalitis (BBE) and Miller Fisher syndrome (MFS) are derived from the differences in the effects of sera on blood-brain barrier (BBB) and blood-nerve barrier.

BACKGROUND

Antibodies against GQ1b are frequently detected in BBE and MFS, and these two disorders may share the same pathogenesis, but the clinical phenotypes of BBE and MFS are substantially different.

METHODS

The effects of sera obtained from BBE patients, MFS patients and control subjects were evaluated with regard to the expression of tight junction proteins and transendothelial electrical resistance in human brain microvascular endothelial cells (BMECs) and human peripheral nerve microvascular endothelial cells.

RESULTS

The sera obtained from BBE patients decreased the transendothelial electrical resistance values and claudin-5 protein expression in BMECs, although the sera obtained from MFS patients had no effect on BMECs or peripheral nerve microvascular endothelial cells. This effect was reversed after the application of matrix metalloproteinase (MMP) inhibitor, GM6001. The presence or absence of anti-GQ1b antibodies did not significantly influence the results. MMP-9 secreted by BMECs was significantly increased after exposure to the sera obtained from BBE patients, whereas it was not changed after exposure to the sera obtained from MFS patients.

CONCLUSIONS

Only the sera obtained from BBE patients destroyed BBB and it might explain the phenotypical differences between BBE and MFS. BBE sera disrupted BBB, possibly via the autocrine secretion of MMP-9 from BBB-composing endothelial cells.

Serum angiopoietin-2 level as a predictor of tumor invasiveness in patients with hepatocellular carcinoma

BACKGROUND

Because hepatocellular carcinoma (HCC) has important angiogenic activity, the expression of angiopoietin-2 (Ang-2) may have a pathogenic role. The information about the influence of serum Ang-2 (sAng-2) in patients with HCC is scarce.

AIMS

The aim was to assess the association between sAng-2 levels and characteristics of tumor and liver disease in patients with HCC.

METHODS

sAng-2 concentrations in peripheral (sAng-2-P) and hepatic (sAng-2-H) veins were analyzed by ELISA in 33 patients with chronic liver disease who underwent a splanchnic hemodynamic study. Thirty-two patients received treatment for HCC.

RESULTS

The median age was 61 years and 79% were male. Hepatitis C infection (70%) was the main etiology. Most patients were Child-Pugh grade A (72.7%). sAng-2-P and sAng-2-H were well correlated (r = 0.95; p < 0.0001). A significant association was found between sAng-2-H and lobar tumor extension, vascular thrombosis, BCLC staging, infiltrating pattern, abnormal alpha-fetoprotein level, fulfillment of the Milan criteria, and performance of nonsystemic treatment. sAng-2-H also showed a significant correlation with the MELD score (r = 0.49; p = 0.007), albumin (r = -0.63; p < 0.001), and HVPG (r = 0.44; p = 0.02). Eleven patients received treatment with radiofrequency ablation and eight with transarterial chemoembolization. HCC treatment did not influence the sAng-2 concentration while the necrosis response to treatment was not influenced by previous sAng-2 levels.

CONCLUSIONS

Ang-2 seems to play an important role in the angiogenic processes of HCC and its serum levels are associated with tumor characteristics and invasive behavior. Our results suggest that Ang-2 is not related with treatment response and its level is not modified by treatment.

Novel antiangiogenic therapies against advanced hepatocellular carcinoma (HCC)

Angiogenesis is a cornerstone in the process of hepatocarcinogenesis. In the sorafenib era, other antiangiogenic targeted drugs, such as monoclonal antibodies and a new generation of tyrosine kinase inhibitors, have been shown in phase II trials to be safe and effective in the treatment of advanced hepatocellular carcinoma. Several currently active phase III trials are testing these drugs, both in first- and second-line settings. Strategies to overcome primary and acquired resistance to antiangiogenic therapy are urgently needed. Novel biomarkers may help in improving the efficacy of drugs targeting angiogenesis.

Predicting the treatment effect of sorafenib using serum angiogenesis markers in patients with hepatocellular carcinoma

BACKGROUND AND AIM

Sorafenib, the first agent demonstrated to have efficacy to improve the survival of patients with advanced hepatocellular carcinoma (HCC), is an active multikinase inhibitor affecting angiogenesis and tumor proliferation. We analyzed cytokines related to angiogenesis or cell proliferation, and tried to determine their utility as biomarkers of sorafenib treatment effect for HCC.

METHODS

Nine serum cytokines (angiopoietin-2 [Ang-2], follistatin, granulocyte colony-stimulating factor [G-CSF], hepatocyte growth factor [HGF], interleukin-8 [IL-8], leptin, platelet-derived growth factor-BB, platelet endothelial cell adhesion molecule-1, and vascular endothelial growth factor) were measured in 30 HCC patients treated with sorafenib, and the effects of treatment were compared using modified Response Evaluation Criteria in Solid Tumors.

RESULTS

All but IL-8 were significantly higher at baseline in patients with progressive disease. Progression-free survival was significantly shorter in patients with high levels of Ang-2, G-CSF, HGF, and leptin, and the hazard ratios were 2.51, 6.89, 2.55, and 4.14, respectively. As the number of cytokines at a high level increased, the treatment response deteriorated. Disease progression was seen in three of 12 (25.0%) patients with zero to two high biomarkers, two of six (33.3%) patients with 3-5 high biomarkers, and 10 of 12 (83.3%) patients with six to eight high biomarkers (P=0.008). The prognosis of all patients with eight high biomarkers was progressive disease.

CONCLUSION

High levels of serum cytokines at baseline were correlated with poor effects of sorafenib treatment in patients with HCC.

Pericyte-derived glial cell line-derived neurotrophic factor increase the expression of claudin-5 in the blood-brain barrier and the blood-nerve barrier

The destruction of blood-brain barrier (BBB) and blood-nerve barrier (BNB) has been considered to be a key step in the disease process of a number of neurological disorders including cerebral ischemia, Alzheimer's disease, multiple sclerosis, and diabetic neuropathy. Although glial cell line-derived neurotrophic factor (GDNF) and brain-derived neurotrophic factor (BDNF) facilitate neuronal or axonal regeneration in the brain or peripheral nerves, their action in the BBB and BNB remains unclear. The purpose of the present study was to elucidate whether these neurotrophic factors secreted from the brain or peripheral nerve pericytes increase the barrier function of the BBB or BNB, using our newly established human brain microvascular endothelial cell (BMEC) line or peripheral nerve microvascular endothelial cell (PnMEC) line. GDNF increased the expression of claudin-5 and the transendothelial electrical resistance (TEER) of BMECs and PnMECs, whereas BDNF did not have this effect. Furthermore, we herein demonstrate that the GDNF secreted from the brain and peripheral nerve pericytes was one of the key molecules responsible for the up-regulation of claudin-5 expression and the TEER value in the BBB and BNB. These results indicate that the regulation of GDNF secreted from pericytes may therefore be a novel therapeutic strategy to modify the BBB or BNB functions and promote brain or peripheral nerve regeneration.

5'-(N-ethylcarboxamido) adenosine improves angiogenesis in transplanted human ovarian tissue

To investigate the effect of 5'-(N-ethylcarboxamido) adenosine (NECA), an adenosine agonist, on triggering angiogenesis in transplanted human ovarian tissue, the expression of angiopoietin-1 (Ang1), Ang2, vascular endothelial growth factor 121 (VEGF-121) and VEGF-189 at both gene and protein levels as well as the density of vasculature were studied in tissue fragments grafted to NECA-treated and control groups of nude mice. The results showed that NECA treatment triggered down-regulation of Ang1, induced VEGF-189 expression, and stimulated neovascularization, highlighting the beneficial effect of NECA on the process of angiogenesis.

Mechanism-related circulating proteins as biomarkers for clinical outcome in patients with unresectable hepatocellular carcinoma receiving sunitinib

Background

Several proteins that promote angiogenesis are overexpressed in hepatocellular carcinoma (HCC) and have been implicated in disease pathogenesis. Sunitinib has antiangiogenic activity and is an oral multitargeted inhibitor of vascular endothelial growth factor receptors (VEGFRs)-1, -2, and -3, platelet-derived growth factor receptors (PDGFRs)-α and -β, stem-cell factor receptor (KIT), and other tyrosine kinases. In a phase II study of sunitinib in advanced HCC, we evaluated the plasma pharmacodynamics of five proteins related to the mechanism of action of sunitinib and explored potential correlations with clinical outcome.

Methods

Patients with advanced HCC received a starting dose of sunitinib 50 mg/day administered orally for 4 weeks on treatment, followed by 2 weeks off treatment. Plasma samples from 37 patients were obtained at baseline and during treatment and were analyzed for vascular endothelial growth factor (VEGF)-A, VEGF-C, soluble VEGFR-2 (sVEGFR-2), soluble VEGFR-3 (sVEGFR-3), and soluble KIT (sKIT).

Results

At the end of the first sunitinib treatment cycle, plasma VEGF-A levels were significantly increased relative to baseline, while levels of plasma VEGF-C, sVEGFR-2, sVEGFR-3, and sKIT were significantly decreased. Changes from baseline in VEGF-A, sVEGFR-2, and sVEGFR-3, but not VEGF-C or sKIT, were partially or completely reversed during the first 2-week off-treatment period. High levels of VEGF-C at baseline were significantly associated with Response Evaluation Criteria in Solid Tumors (RECIST)-defined disease control, prolonged time to tumor progression (TTP), and prolonged overall survival (OS). Baseline VEGF-C levels were an independent predictor of TTP by multivariate analysis. Changes from baseline in VEGF-A and sKIT at cycle 1 day 14 or cycle 2 day 28, and change in VEGF-C at the end of the first off-treatment period, were significantly associated with both TTP and OS, while change in sVEGFR-2 at cycle 1 day 28 was an independent predictor of OS.

Conclusions

Baseline plasma VEGF-C levels predicted disease control (based on RECIST) and were positively associated with both TTP and OS in this exploratory analysis, suggesting that this VEGF family member may have utility in predicting clinical outcome in patients with HCC who receive sunitinib.

Trial registration

ClinicalTrials.gov: NCT00247676

Corticosteroids modulate angiogenic soluble factors in ulcerative colitis patients

AIMS

The aim of this study was to compare angiogenic factors in serum levels of active ulcerative colitis (UC) patients and in healthy controls, and to analyze these angiogenic levels depending on the achievement of remission after oral corticosteroid treatment throughout treatment, and according to the Truelove-Witts activity index.

METHODS

Blood samples were collected from 13 patients receiving oral corticosteroids for treatment of UC flares at three different intervals--baseline, during, and after treatment--and from 26 healthy controls. Vascular endothelial growth factor (VEGF), placental growth factor (PlGF), VEGF receptor 1 (VEGFR1), angiopoietins (Ang) 1 and 2, and its receptor Tie2 were assayed by ELISA.

RESULTS

While VEGF and Ang2 levels in UC patients were higher than in healthy controls (P < 0.05), UC patients showed lower levels of Ang1 than healthy individuals (P < 0.05). In UC patients who achieved clinical remission after corticosteroid treatment, a statistically significant higher baseline serum level of PlGF was observed (22 ± 5 vs. 18 ± 2; P < 0.05). Angiogenic factor levels varied during treatment; however, they did not show a statistically significant correlation to the activity of the disease.

CONCLUSIONS

VEGF, Ang1, and Ang2 levels showed statistically significant differences between UC patients and healthy controls. Although determination of PlGF serum levels before corticosteroid treatment might be helpful to anticipate the response by UC patients, no angiogenic pattern that could accurately predict "a priori" this response to corticosteroid treatment was observed. Corticosteroids altered temporarily circulating levels of VEGF, angiopoietins and Tie2. No correlation was found between systemic levels of angiogenic factors and the clinical activity of UC.

Phase 1-2 trial of PTK787/ZK222584 combined with intravenous doxorubicin for treatment of patients with advanced hepatocellular carcinoma: implication for antiangiogenic approach to hepatocellular carcinoma

BACKGROUND

This phase 1-2 trial assessed the efficacy and tolerability of an oral angiogenesis inhibitor-PTK787/ZK222584 (PTK)-in combination with intravenous doxorubicin for the treatment of advanced hepatocellular carcinoma (HCC) patients.

METHODS

In phase 1, advanced HCC patients received PTK at escalating doses together with doxorubicin 60 mg/m2 given as an intravenous bolus every 3 weeks to establish the maximum tolerated dose (MTD). Subsequently, in phase 2, all patients received the same regimen with oral PTK at the MTD dose every 3 weeks for a maximum of 6 cycles.

RESULTS

Nine patients were recruited in phase 1, with the MTD established as 750 mg daily. Overall, 27 patients received the regimen with PTK at 750 mg daily. The median age was 52 years (range, 23-73 years), and 63 percent of patients were chronic hepatitis B carriers. Notably, the majority of patients had Child-Pugh B cirrhosis. The overall response rate was 26.0%, with all the responding patients having partial response. Another 20% of patients achieved stable disease for at least 12 weeks. The median progression-free survival was 5.4 months (range, 0.27-23.6 months), and overall survival was 7.3 months (range, 0.8-23.6 months). The commonest grade 3 or 4 nonhematological toxicities were mucositis (11%) and alopecia (7%), respectively. Grade 3 or 4 neutropenia was observed in 7 (26%) patients; 2 had neutropenic sepsis.

CONCLUSIONS

The combination of PTK with intravenous doxorubicin shows encouraging activity in treating advanced HCC patients.

Peripheral nerve pericytes modify the blood-nerve barrier function and tight junctional molecules through the secretion of various soluble factors

The objectives of this study were to establish pure blood-nerve barrier (BNB) and blood-brain barrier (BBB)-derived pericyte cell lines of human origin and to investigate their unique properties as barrier-forming cells. Brain and peripheral nerve pericyte cell lines were established via transfection with retrovirus vectors incorporating human temperature-sensitive SV40 T antigen (tsA58) and telomerase. These cell lines expressed several pericyte markers such as α-smooth muscle actin, NG2, platelet-derived growth factor receptor β, whereas they did not express endothelial cell markers such as vWF and PECAM. In addition, the inulin clearance was significantly lowered in peripheral nerve microvascular endothelial cells (PnMECs) through the up-regulation of claudin-5 by soluble factors released from brain or peripheral nerve pericytes. In particular, bFGF secreted from peripheral nerve pericytes strengthened the barrier function of the BNB by increasing the expression of claudin-5. Peripheral nerve pericytes may regulate the barrier function of the BNB, because the BNB does not contain cells equivalent to astrocytes which regulate the BBB function. Furthermore, these cell lines expressed several neurotrophic factors such as NGF, BDNF, and GDNF. The secretion of these growth factors from peripheral nerve pericytes might facilitate axonal regeneration in peripheral neuropathy. Investigation of the characteristics of peripheral nerve pericytes may provide novel strategies for modifying BNB functions and promoting peripheral nerve regeneration.

Angiogenesis: multiple masks in hepatocellular carcinoma and liver regeneration

Hepatocellular carcinoma (HCC) is naturally resistant to radiotherapy and cytotoxic chemotherapy, leaving surgery as the mainstream therapeutic approach. However, the 5-year recurrence rate after curative resection is as high as 61.5%. The background hepatitis B- or C-induced cirrhosis and the presence of micrometastases at the time of surgery have been regarded as two main causes of recurrence. Recently, accumulating evidence suggests that growth factors and cytokines released during the physiological process of post-surgical liver regeneration could induce the activation of dormant micrometastatic lesions. The establishment of neovasculature to support either liver regeneration or HCC growth involves multiple cell types including liver sinusoidal endothelial cells, Kupffer cells, hepatic stellate cells, and circulating endothelial progenitors. The crosstalks among these cells are driven by multiple molecules and signaling pathways, including vascular endothelial growth factors and their receptors, platelet-derived growth factor, the angiopoietin/Tie family, hepatocyte growth factor/c-Met signaling, and others. Anti-angiogenic agent targeting liver cancer vasculature has been reported to be able to generate limited survival benefit of the patients. In this review, discussions are focused on various angiogenic mechanisms of HCC and liver regeneration, as well as the prevailing anti-angiogenic strategies.

Over-expression of the Endocan gene in endothelial cells from hepatocellular carcinoma is associated with angiogenesis and tumour invasion

Endocan plays a role in tumour angiogenesis and tumour growth. The aim of this study was to detect the expression of endocan in hepatocellular carcinoma (HCC) tumour-associated endothelial cells and to correlate endocan expression with clinicopathological parameters and tumour angiogenesis. Tumour tissues and surrounding non-cancerous hepatic parenchyma from 42 primary HCC patients were studied. Endothelial cells were isolated using magnetic microbeads conjugated with anti-CD31 and endocan expression was evaluated by real-time reverse transcription-polymerase chain reaction, Western blotting and immunohistochemistry. Endocan was significantly over-expressed in endothelial cells isolated from HCC tumours compared with corresponding non-cancerous liver tissues. In addition, the endocan mRNA level was significantly correlated with the serum alpha-fetoprotein level, intra-tumoural microvessel density, vascular endothelial growth factor mRNA, and vascular and venous invasion. The over-expression of endocan in tumour endothelial cells was closely related to the process of angiogenesis and pathogenesis in HCC, and suggests that endocan might be a useful marker for HCC progression.

Angiogenesis: from chronic liver inflammation to hepatocellular carcinoma

Recently, new information relating to the potential relevance of chronic hepatic inflammation to the development and progression of hepatocellular carcinoma (HCC) has been generated. Persistent hepatocellular injury alters the homeostatic balance within the liver; deregulation of the expression of factors involved in wound healing may lead to the evolution of dysplastic lesions into transformed nodules. Progression of such nodules depends directly on the development and organization of a vascular network, which provides the nutritional and oxygen requirements to an expanding nodular mass. Angiogenic stimulation promotes intense structural and functional changes in liver architecture and physiology, in particular, it facilitates transformation of dysplasia to nodular lesions with carcinogenic potential. HCC depends on the growth and spreading of vessels throughout the tumor. Because these vascular phenomena correlate with disease progression and prognosis, therapeutic strategies are being developed that focus on precluding vascular expansion in these tumors. Accordingly, an in-depth study of factors that promote and support pathological angiogenesis in chronic hepatic diseases may provide insights into methods of preventing the development of HCC and/or stimulating the regression of established HCC.

Serum levels of angiopoietin-1, angiopoietin-2, and their receptor tie-2 in patients with nonsmall cell lung cancer during chemotherapy

This pilot study was conducted to investigate the prognostic role and the effects of chemotherapy on serum angiogenic factors enzyme-linked immunosorbent assay consisting of Angiopoietin-1 and 2 (Ang-1, Ang-2) and their receptor Tie-2 in patients with advanced stage nonsmall cell lung cancer (NSCLC). Concentration of Ang-2 was higher in NSCLC (n= 40) than in healthy people (n= 15), whereas Ang-1 and Tie-2 were comparable. In our opinion determination of Ang-1, Ang-2, and Tie-2 concentrations have no clinical significance in the prognosis of the survival time in lung cancer and can not be used as a predictor of response to the chemotherapy.

Safety and efficacy of sunitinib in patients with advanced hepatocellular carcinoma: an open-label, multicentre, phase II study

BACKGROUND

Hepatocellular carcinoma (HCC) tumour spread is partly dependent on neoangiogenesis. In this open-label, multicentre, phase II trial done in Europe and Asia, sunitinib, a multitargeted tyrosine-kinase inhibitor with anti-angiogenic properties, was assessed in patients with advanced unresectable HCC.

METHODS

Between February and July, 2006, eligible patients were enrolled and treated with repeated cycles of oral sunitinib (50 mg/day for 4 weeks, followed by 2 weeks off treatment). The primary endpoint of this Simon two-stage phase II trial was objective response rate according to Response Evaluation Criteria in Solid Tumours (RECIST) criteria, with an expected response rate of 15%. This trial is registered with ClinicalTrials.gov, number NCT00247676.

FINDINGS

Of 37 patients enrolled, one (2.7%) patient experienced a confirmed partial response, giving an overall objective response rate of 2.7% (95% CI 0.1-14.2); on the basis of this, the trial did not proceed to the second stage. 13 (35%) of 37 patients achieved stable disease for over 3 months. Commonly observed grade 3 and 4 adverse events included thrombocytopenia (14 of 37; 37.8%), neutropenia (nine of 37; 24.3%), asthenia (five of 37; 13.5%), hand-foot syndrome (four of 37; 10.8%), and anaemia (four of 37; 10.8%). There were four deaths among the 37 patients (10.8%) that were possibly related to treatment.

INTERPRETATION

Sunitinib showed pronounced toxicities at a dose of 50 mg/day in patients with unresectable HCC. The response rate was low, and the study did not meet the primary endpoint based on RECIST criteria.

FUNDING

Pfizer Oncology.

Early development of sunitinib in hepatocellular carcinoma

Sunitinib malate is an oral, multitargeted receptor tyrosine kinase inhibitor of VEGF receptors 1, 2 and 3; PDGF receptors alpha and beta, and other receptor tyrosine kinases implicated in tumor growth, angiogenesis and metastasis. Hepatocellular carcinoma (HCC) is a highly vascular tumor that overexpresses several angiogenic factors; VEGF and PDGF signaling pathways play a key role in HCC. Until recently, treatment options for advanced HCC were limited and conventional therapies have met with poor response rates. Sorafenib provided proof-of-concept for molecularly targeted therapy in advanced HCC and has recently been approved for treatment. However, not all patients can tolerate sorafenib and patients may experience tumor progression; therefore, additional treatment options are warranted. Sunitinib has shown early evidence of anti-tumor activity in Phase II trials in US, European and Asian patients with locally advanced, unresectable and metastatic HCC. A Phase III trial of sunitinib in HCC is ongoing.

An intravital microscopic study of the hepatic microcirculation in cirrhotic mice models: relationship between fibrosis and angiogenesis

This intravital fluorescence microscopy (IVFM) study validates cirrhotic mice models and describes the different intrahepatic alterations and the role of angiogenesis in the liver during genesis of cirrhosis. Cirrhosis was induced by subcutaneous injection of carbon tetrachloride (CCl(4)) and by common bile duct ligation (CBDL) in mice. Diameters of sinusoids, portal venules (PV), central venules (CV) and shunts were measured at different time points by IVFM. Thereafter, liver samples were taken for sirius red, CD31, Ki67, vascular endothelial growth factor (VEGF) and alpha-smooth muscle actin (alpha-SMA) evaluation by immunohistochemistry (IHC). In parallel with fibrogenesis, hepatic microcirculation was markedly disturbed in CCl(4) and CBDL mice with a significant decrease in sinusoidal diameter compared to control mice. In CCl(4) mice, CV were enlarged, with marked sinusoidal-free spaces around CV. In contrast, PV were enlarged in CBDL mice and bile lakes were observed. In both mice models, intrahepatic shunts developed gradually after induction. During genesis of cirrhosis using CD31 IHC we observed a progressive increase in the number of blood vessels within the fibrotic septa area and a progressively increase in staining by Ki67, VEGF and alpha-SMA of endothelial cells, hepatocytes and hepatic stellate cells respectively. In vivo study of the hepatic microcirculation demonstrated a totally disturbed intrahepatic architecture, with narrowing of sinusoids in both cirrhotic mice models. The diameters of CV and PV increased and large shunts, bypassing the sinusoids, were seen after both CCl(4) and CBDL induction. Thus present study shows that there is angiogenesis in the liver during cirrhogenesis, and this is probably due partially to an increased production of VEGF.

Management of advanced hepatocellular carcinoma in the era of targeted therapy

Systemic chemotherapy has had a disappointing track record in the management of advanced hepatocellular carcinoma (HCC). Single-agent doxorubicin produces a response rate of 10-15%, but without any survival benefit, and combination chemotherapy has also yielded unimpressive results. With recent advances in the knowledge of hepato-carcinogenesis, there has been encouraging development in the systemic therapy of advanced HCC patients, and particularly in the targeted therapy of advanced HCC. Among the newly identified targets, exciting results have been shown in targeting the anti-angiogenic pathway and the Raf/mitogen-activated protein kinase pathways. Bevacizumab, both as a single agent and in combination with other agents, has shown initial encouraging activity in treating advanced HCC. More recently, single-agent sorafenib, a putative multitargeted kinase inhibitor, has shown to prolong the overall survival of patients with advanced HCC in the pivotal phase III Sorafenib HCC Assessment Randomized Protocol (SHARP) and Oriental study. Currently, sorafenib is the only approved targeted therapy for patients with advanced HCC. In addition, however, promising early results have been reported for other molecular-targeted drugs including erlotinib and sunitinib. Future progress seems likely to depend on using controlled clinical trials to optimize synergistic combination treatments.

[Expression of vascular endothelial growth factor (VEGF) family members and prognosis after hepatic resection in HBV-related hepatocellular carcinoma]

BACKGROUND/AIMS

Human hepatocellular carcinoma (HCC) is a hypervascular tumor, and vascular endothelial growth factor (VEGF) plays a key role in the regulation of tumor-associated angiogenesis. In this study, we analyzed the significance of the expression of VEGF family members on the prognosis and clinicopathologic progress of HCC.

METHODS

Surgically resected specimens of HCC and noncancerous liver tissue were obtained from 323 patients with HCC, and VEGF mRNA was examined by quantitative reverse transcriptase-polymerase chain reactions (RT-PCRs). Patients who were seropositive for hepatitis B surface antigen were selected for the analysis (n=208). The VEGF(tumor)/GAPDH (glyceraldehyde-3-phosphate dehydrogenase)(tumor)/VEGF(nontumor)/GAPDH(nontumor) ratio was calculated using a quantitative RT-PCR assay, and the relationships between the expressions of VEGF family members and clinicopathologic parameters were analyzed to evaluate their significance in the prognosis of HCC.

RESULTS

The disease-free survival was significantly worse in the high-VEGF-A group than in the low-VEGF-A group (P=0.035), whereas VEGF-A expression was not significantly related to overall survival (P=0.172). The factors significantly related to poor prognosis in univariate analysis were tumor size, portal vein invasion, microvascular thrombi, intrahepatic metastasis, tumor capsule invasion, liver capsule invasion, preoperative serum albumin level, and VEGF-A ratio. Multivariate analysis showed that a poor prognosis in HCC patients was significantly related to portal vein invasion (hazard ratio=3.381, P<0.001), intrahepatic metastasis (hazard ratio=2.379, P<0.001), tumor size (hazard ratio=1.834, P=0.003), and preoperative serum albumin level (hazard ratio=2.050, P=0.006).

CONCLUSIONS

Our study showed that the expression of VEGF-A is positively correlated with the recurrence rate of HCC after curative resection. Therefore, a high expression of VEGF-A might be predictive of HCC recurrence after curative resection.

Review article: pharmacological therapy for hepatocellular carcinoma with sorafenib and other oral agents

BACKGROUND

Hepatocellular carcinoma (HCC) is the fifth most common malignancy worldwide. Unresectable disease patients have median survival of few months. There is a substantial need for novel treatments for patients with advanced HCC.

AIM

To provide an update review of mechanism of hepatocarcinigenesis and systemic therapies for HCC and the relevant role of Sorafenib in patients with advanced disease.

METHODS

A Medline search was performed to identify pertinent original research and review articles. Selected references in these articles were also evaluated.

RESULTS

Systemic chemotherapy for HCC has been quite ineffective. Preclinical studies demonstrated that Raf/MAPK-ERK kinase (MEK)/Extracellular signal regulated kinase (ERK) pathway has a role in HCC. HCC tumours are highly vascularized and vascular endothelial growth factor (VEGF) augments HCC development and metastasis. Sorafenib blocks tumour cell proliferation by targeting Raf/MEK/ERK signalling and exerts an antiangiogenic effect by targeting VEGF receptors-2/3 and platelet derived growth factor receptor beta tyrosine kinases.

CONCLUSIONS

Currently available therapies are not effective for patients with advanced HCC. Sorafenib has demonstrated for the first time to prolong survival in patients with advanced HCC, and it is the new reference standard for systemic treatment in these patients.

The angiogenic makeup of human hepatocellular carcinoma does not favor vascular endothelial growth factor/angiopoietin-driven sprouting neovascularization

Quantitative data on the expression of multiple factors that control angiogenesis in hepatocellular carcinoma (HCC) are limited. A better understanding of the mechanisms underlying angiogenesis in HCC will improve the rational choice of anti-angiogenic treatment. We quantified gene and protein expression of members of the vascular endothelial growth factor (VEGF) and angiopoietin systems and studied localization of VEGF, its receptors VEGFR-1 and VEGFR-2, Angiopoietin (Ang)-1 and Ang-2, and their receptor, in HCC in noncirrhotic and cirrhotic livers. We employed real-time reverse transcription polymerase chain reaction (RT-PCR), western blot, and immunohistology, and compared the outcome with highly angiogenic human renal cell carcinoma (RCC). HCC in noncirrhotic and cirrhotic livers expressed VEGF and its receptors to a similar extent as normal liver, although in cirrhotic background, VEGFR-2 levels in both tumor and adjacent tissue were decreased. Ang-1 expression was slightly increased compared with normal liver, whereas Tie-2 was strongly down-regulated in the tumor vasculature. Ang-2 messenger RNA (mRNA) levels were also low in HCCs of both noncirrhotic and cirrhotic livers, implying that VEGF-driven angiogenic sprouting accompanied by angiopoietin-driven vascular destabilization is not pronounced. In RCC, VEGF-A levels were one order of magnitude higher. At the same time, endothelially expressed Ang-2 was over 30-fold increased compared with expression in normal kidney, whereas Ang-1 expression was decreased.

CONCLUSION

In hepatocellular carcinoma, tumor vascularization is not per se VEGF/angiopoietin driven. However, increased CD31 expression and morphological changes representative of sinusoidal capillarization in tumor vasculature indicate that vascular remodeling is taking place. This portends that therapeutic intervention of HCC at the level of the vasculature is optional, and that further studies into the molecular control thereof are warranted.