Tumor Angiogenesis In Hepatocellular Carcinoma Research Articles

Novel fusion protein PK5-RL-Gal-3C inhibits hepatocellular carcinoma via anti-angiogenesis and cytotoxicity

BackgroundGalectin-3 (Gal-3), the only chimeric β-galactosides-binding lectin, consists of Gal-3N (N-terminal regulatory peptide) and Gal-3C (C-terminal carbohydrate-recognition domain). Interestingly, Gal-3C could specifically inhibit endogenous full-length Gal-3 to exhibit anti-tumor activity. Here, we aimed to further improve the anti-tumor activity of Gal-3C via developing novel fusion proteins.MethodsPK5 (the fifth kringle domain of plasminogen) was introduced to the N-terminus of Gal-3C via rigid linker (RL) to generate novel fusion protein PK5-RL-Gal-3C. Then, we investigated the anti-tumor activity of PK5-RL-Gal-3C in vivo and in vitro by using several experiments, and figured out their molecular mechanisms in anti-angiogenesis and cytotoxicity to hepatocellular carcinoma (HCC).ResultsOur results show that PK5-RL-Gal-3C can inhibit HCC both in vivo and in vitro without obvious toxicity, and also significantly prolong the survival time of tumor-bearing mice. Mechanically, we find that PK5-RL-Gal-3C inhibits angiogenesis and show cytotoxicity to HCC. In detail, HUVEC-related and matrigel plug assays indicate that PK5-RL-Gal-3C plays an important role in inhibiting angiogenesis by regulating HIF1α/VEGF and Ang-2 both in vivo and in vitro. Moreover, PK5-RL-Gal-3C induces cell cycle arrest at G1 phase and apoptosis with inhibition of Cyclin D1, Cyclin D3, CDK4, and Bcl-2, but activation of p27, p21, caspase-3, -8 and -9.ConclusionNovel fusion protein PK5-RL-Gal-3C is potent therapeutic agent by inhibiting tumor angiogenesis in HCC and potential antagonist of Gal-3, which provides new strategy for exploring novel antagonist of Gal-3 and promotes their application in clinical treatment.

MYBL1 induces transcriptional activation of ANGPT2 to promote tumor angiogenesis and confer sorafenib resistance in human hepatocellular carcinoma

Angiogenesis is considered as an important process in tumor growth, metastasis of hepatocellular carcinoma (HCC) and associated with cancer progression, suggesting that an important research and development field of clinical molecular targeted drugs for HCC. However, the molecular mechanisms underlying tumor angiogenesis in HCC remains elusive. In the current study, we demonstrate that upregulation of AMYB proto-oncogene-like 1 (MYBL1) was associated with high endothelial vessel (EV) density and contributed to poor prognosis of HCC patient. Functionally, MYBL1 overexpressing enhanced the capacity of HCC cells to induce tube formation, migration of HUVECs, neovascularization in CAMs, finally, enhanced HCC cells metastasis, while silencing MYBL1 had the converse effect. Furthermore, HCC cells with high MYBL1 expression were more resistance to sorafenib treatment. We observed that CD31 staining was significantly increased in tumors formed by MYBL1-overexpressing cells but decreased in MYBL1-silenced tumors. Mechanistically, MYBL1 binds to the ANGPT2 promoter and transcriptionally upregulate ANGPT2 mRNA expression. Strikingly, treatment with monoclonal antibody against ANGPT2 significantly inhibited the growth of MYBL1-overexpressing tumors and efficiently impaired angiogenesis. Furthermore, the histone post-translational factors: protein arginine methyltransferase 5 (PRMT5), MEP50, and WDR5 were required for MYBL1-mediated ANGPT2 upregulation. Importantly, we confirmed the correlation between MYBL1 and ANGPT2 expression in a large cohort of clinical HCC samples and several published datasets in pancreatic cancer, esophageal carcinoma, stomach adenocarcinoma, and colon cancer. Our results demonstrate that MYBL1 upregulated the ANGPT2 expression, then induced angiogenesis and confer sorafenib resistance to HCC cells, and MYBL1 may represent a novel prognostic biomarker and therapeutic target for patients with HCC.

Serum Angiopoietin 2 acts as a diagnostic and prognostic biomarker in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is typically accompanied by abundant arterial blood flow. Although angiogenic growth factors such as Angiopoietin 2 (Ang2) play a central role in tumor angiogenesis in HCC, the role of serum Ang2 as a biomarker in HCC remains unclear. In this study, we aimed to investigate the potential of Ang2 as a diagnostic and prognostic biomarker in HCC using a sandwich enzyme-linked immunosorbent assay (ELISA). The median Ang2 levels in controls (n=20), chronic liver disease patients (n=98), and HCC patients (n=275) were 1.58, 2.33, and 3.53 ng/mL, respectively. The optimal cut-off value of Ang2 was determined as 3.5 ng/mL by receiver operating curve analysis. The sensitivity, specificity, and accuracy of Ang2 for HCC detection were 50.9, 83.7, and 59.5%, respectively. Spearman's rank correlation coefficient analysis demonstrated only a weak correlation between Ang2 serum levels and alpha-fetoprotein (AFP) or des-gamma-carboxy prothrombin (DCP) serum levels. The diagnostic value of Ang2 was comparable to those of other existing markers. In addition, 24 out of 73 patients with normal AFP and DCP levels (32.9%) demonstrated abnormally high Ang2 levels (≥3.5 ng/mL). Although no significant difference in overall survival was found between Ang2high and Ang2low patients with curative ablation therapy, recurrence-free survival (RFS) in Ang2high patients was observed to be significantly shorter than those in Ang2low patients. Multivariate analysis demonstrated that high serum Ang2 levels (≥3.5 ng/mL) and the presence of multiple tumors were poor prognostic factors. In conclusion, our findings indicate that serum Ang2 is a potential novel biomarker for both diagnosis and prognosis in HCC.

YY1 Promotes Endothelial Cell-Dependent Tumor Angiogenesis in Hepatocellular Carcinoma by Transcriptionally Activating VEGFA.

Hepatocellular carcinoma (HCC) is a typical hypervascular solid tumor that requires neoangiogenesis for growth. The vascular endothelial growth factor (VEGF) is the most potent proangiogenic factor in neovascularization. The multifunctional Yin-Yang 1 (YY1) is involved in the regulation of tumor malignancy of HCC. However, the relationship between YY1 and endothelial cell-dependent tumor angiogenesis in HCC remains unclear. In this study, we observed that YY1 is positively correlated with microvessel density (MVD) and poor prognosis in HCC tissues. We further found that YY1 promotes the transcriptional activity of VEGFA by binding its promoter in HCC. The secreted VEGFA from HCC cells activates phosphorylation of VEGFR2 to promotes tube formation, cell migration, and invasion of vascular endothelial cells in vitro, and promotes tumor growth and angiogenesis in vivo. In addition, upregulation of YY1 enhanced resistance of bevacizumab in HCC cells. These results indicate that YY1 plays essential roles in HCC angiogenesis and resistance of bevacizumab by inducing VEGFA transcription and that YY1 may represent a potential molecular target for antiangiogenic therapy during HCC progression.

MiR-302 a/b/c suppresses tumor angiogenesis in hepatocellular carcinoma by targeting MACC1.

Hepatocellular carcinoma (HCC) is a hypervascularized tumor. Aberrant angiogenesis is the main cause, which results in cancer growth and progression. It has been showed that microRNA-302 cluster (miR-302) may be associated with angiogenesis. Here, we aimed to identify the role of miR-302a/b/c in the regulation of cell angiogenesis in HCC. MRNA expression of miR-302a/b/c and MACC1 was detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The protein of MACC1 was measured using Western blot. Cells proliferation, migration, and invasion abilities were investigated via Cell Counting Kit-8 (CCK-8) assay or transwell assay, respectively. Tube formatting assays were used to explore the tube formation capacity. The interaction among miR-302a/b/c was analyzed by luciferase assay. The expression of miR-302a/b/c was greatly reduced while MACC1 expression, whether mRNA or protein was conspicuously elevated in HCC tissues and cells. Then, functional experiment results showed miR-302a/b/c overexpression and MACC1 down-regulation inhibited the proliferation, migration, invasion ability, and tube formation capacity of HUVECs. In addition, we detected that miR-302a/b/c directly targeted MACC1 and suppressed MACC1 expression, and miR-302a/b/c could suppress tumor angiogenesis in HCC by targeting MACC1. MiR-302a/b/c may function as a potential suppressor of tumor angiogenesis in HCC by targeting MACC1, indicating a promising target for HCC therapy.

Effects of microRNA-126 on cell proliferation, apoptosis and tumor angiogenesis via the down-regulating ERK signaling pathway by targeting EGFL7 in hepatocellular carcinoma.

This study intends to explore the effects of microRNA-126 (miR-126) on cell proliferation, apoptosis, and tumor angiogenesis in hepatocellular carcinoma (HCC) by regulating epidermal growth factor-like domain 7 (EGFL7) through extracellular signal-regulated kinase (ERK) signaling. HCC tissues and adjacent normal tissues were obtained from 184 HCC patients. HCC cells were separately transfected with recombinant plasmids. Western blotting and qRT-PCR were applied to detect miR-126 and EGFL7, ERK, Fas/FasL, Bcl-2, Caspase mRNA and protein levels. CCK8 and TUNEL were performed to determinate cell proliferation and apoptosis. Flow cytometry was used to analyze cell cycle distribution. Rats model of HCC was constructed, and tumor weight and the number of new blood vessels were recorded after 3 weeks of tumor transplantation. Compared with the adjacent normal tissues, HCC tissues exhibited lower miR-126 expression, and higher EGFL7, and ERK mRNA and protein levels. Overexpression of miR-126 in HCC cell lines suppressed EGFL7, ERK, Bcl-2, and P-ERK, and increased apoptotic-associated proteins Fas/FasL and Caspase-3, and it inhibited cell proliferation and induced cell apoptosis. Overexpression of miR-126 in nude mice resulted in reduced tumor weight and less new blood vessels in tumors. The inhibition of miR-126 decreased cell apoptosis, and enhanced cell proliferation and tumor angiogenesis. This study demonstrates that miR-126 might decrease cell proliferation, induce apoptosis, and inhibit tumor angiogenesis in HCC by inhibiting EGFL7 via down-regulating the ERK signaling pathway.

Hsp90\u03b2 promoted endothelial cell-dependent tumor angiogenesis in hepatocellular carcinoma

BackgroundVascular endothelial growth factor receptors (VEGFRs) are the major receptors involved in endothelial cell-dependent tumor angiogenesis. There are studies account for the effects of Hsp90 on angiogenesis, but the role and mechanism of Hsp90β isoforms and NVP-BEP800, a specific inhibitor of Hsp90β, in tumor angiogenesis is rarely mentioned.MethodsImmunohistochemistry and statistical analysis was used to evaluate the correlation between Hsp90β expression, CD31 endothelial cell-dependent vessel density, and VEGFRs expression in tissue samples of 96 HCCs. Kaplan-Meier survival analysis and COX proportional hazards analysis the relation of Hsp90β and prognosis. HUVEC cells were transfected with Hsp90β or treated with NVP-BEP800, and then cell proliferation, migration, invasion and tube formation were investigated. The VEGFR1 and VEGFR2 expression was determined by Western blot and immunofluorescence. The VEGFR1 and VEGFR2 promoter activities were detected by dual luciferase report system. In vivo, the angiogenesis promotion of Hsp90β and anti-angiogenesis efficacy of NVP-BEP800 was tested in HCC xenograft models. Histological analysis was performed on tumor samples to evaluate Hsp90β, VEGFRs expression and MVD.ResultsThis study investigated the correlation between Hsp90β expression and CD31+ endothelial cell-dependent vessel density. Hsp90β promoted VEGFRs expression by increasing their promoter activities. The proliferation, migration, invasion, and tube formation activities of human endothelial cells significantly increased when Hsp90β was overexpressed. NVP-BEP800 down-regulated VEGFRs expression to significantly reduce tubular differentiation, as well as endothelial cell proliferation, migration, and invasion. Furthermore, NVP-BEP800 decreased VEGFR1 and VEGFR2 promoter activities. In vivo, Hsp90β promoted VEGFRs and CD31 expression in human hepatocellular carcinoma tumor xenografts and was associated with increased tumor microvessel density. After 18 days of treatment with 30 mg/kg/day NVP-BEP800, VEGFRs and CD31 expression significantly decreased.ConclusionHsp90β induced endothelial cell-dependent tumor angiogenesis by activating VEGFRs transcription. NVP-BEP800 has potential as a therapeutic strategy for inhibiting tumor angiogenesis by decreasing endothelial cell progression and metastasis. It can help develop a therapeutic strategy for tumor treatment through the inhibition of endothelial cell progression and metastasis.

Transcriptional Induction of Periostin by a Sulfatase 2-TGFβ1-SMAD Signaling Axis Mediates Tumor Angiogenesis in Hepatocellular Carcinoma.

Existing antiangiogenic approaches to treat metastatic hepatocellular carcinoma (HCC) are weakly effectual, prompting further study of tumor angiogenesis in this disease setting. Here, we report a novel role for sulfatase 2 (SULF2) in driving HCC angiogenesis. Sulf2-deficient mice (Sulf2 KO) exhibited resistance to diethylnitrosamine-induced HCC and did not develop metastases like wild-type mice (Sulf2 WT). The smaller and less numerous tumors formed in Sulf2 KO mice exhibited a markedly lower microvascular density. In human HCC cells, SULF2 overexpression increased endothelial proliferation, adhesion, chemotaxis, and tube formation in a paracrine fashion. Mechanistic analyses identified the extracellular matrix protein periostin (POSTN), a ligand of αvβ3/5 integrins, as an effector protein in SULF2-induced angiogenesis. POSTN silencing in HCC cells attenuated SULF2-induced angiogenesis and tumor growth in vivo The TGFβ1/SMAD pathway was identified as a critical signaling axis between SULF2 and upregulation of POSTN transcription. In clinical HCC specimens, elevated levels of SULF2 correlated with increased microvascular density, POSTN levels, and relatively poorer patient survival. Together, our findings define an important axis controlling angiogenesis in HCC and a mechanistic foundation for rational drug development. Cancer Res; 77(3); 632-45. ©2016 AACR.

Correlation between BMP-2 expression and tumor angiogenesis in hepatocellular carcinoma

Correlation between BMP-2 expression and tumor angiogenesis in hepatocellular carcinoma

MiR-451 acts as a suppressor of angiogenesis in hepatocellular carcinoma by targeting the IL-6R-STAT3 pathway.

Hepatocellular carcinoma(HCC) is a highly vascularized tumor and the third ranking contributor of tumor-associated death. Our previous study corroborated the inhibitory roles of miRNA-451(miR-451) in HCC cell growth and invasion. However, its effect on angiogenesis in HCC remains poorly elucidated. In this study, overexpression of miR-451 clearly attenuated the promoting effects of HCC cells on cell proliferation, migration and tube formation of human umbilical vein endothelial cells(HUVECs). Importantly, ectopic expression of miR‑451 also attenuated tumor growth and angiogenesis in nude mice. Invitro, the expression of IL‑6 receptor(IL‑6R) was reduced and identified as a direct target of miR‑451 by bioinformatics and a dual‑firefly luciferase reporter assay. Moreover, upregulation of IL‑6R strikingly ameliorated the inhibitory function of conditioned medium from miR‑451‑transfected HCC cells in HUVEC proliferation, migration and tube formation. Further mechanistic assay substantiated that miR‑451 restrained vascular endothelial growth factor(VEGF) production of HCC cells by targeting IL‑6R‑STAT3 signaling as evidenced that IL‑6R upregulation induced the increase in VEGF levels and interrupting signal transducer and activator of transcription3(STAT3) signaling with ectopic expression of dominant-negative STAT3(STAT3D) markedly decreased VEGF expression. Additionally, conditioned medium of miR-451-overexpressed HCC also impaired the VEGF receptor2(VEGFR2) signaling in HUVECs. Accordingly, miR-451 may function as a potential suppressor of tumor angiogenesis in HCC by targeting IL-6R-STAT3-VEGF signaling, suggesting a promising therapeutic avenue for managing HCC.

FGFR3 promotes angiogenesis-dependent metastasis of hepatocellular carcinoma via facilitating MCP-1-mediated vascular formation.

The biological role of fibroblast growth factor receptor 3 (FGFR3) in tumor angiogenesis of hepatocellular carcinoma (HCC) has not been discussed before. Our previous work had indicated FGFR3 was overexpressed in HCC, and silencing FGFR3 in Hu7 cells could regulate tumorigenesis via down-regulating the phosphorylation level of key members of classic signaling pathways including ERK and AKT. In the present work, we explored the role of FGFR3 in angiogenesis-dependent metastasis by using SMMC-7721 and QGY-7703 stable cell lines. Our results indicated FGFR3 could regulate in vitro cell migration ability and in vivo lung metastasis ability of HCC, which was in accordance with increased angiogenesis ability in vitro and in vivo. Using the supernatant from SMMC-7721/FGFR3 cells, we conducted a human angiogenesis protein microarray including 43 angiogenesis factors and found that FGFR3 modulated angiogenesis and metastasis of HCC mainly by promoting the protein level of monocyte chemotactic protein 1 (MCP-1). Silencing FGFR3 by short hairpin RNA (shRNA) could reduce MCP-1 level in lysates and supernatant of QGY-7703 cells and SMMC-7721 cells. Silencing MCP-1 in QGY-7703 or SMMC-7721 cells could induce similar phenotypes compared with silencing FGFR3. Our results suggested FGFR3 promoted metastasis potential of HCC, at least partially if not all, via facilitating MCP-1-mediated angiogenesis, in addition to previously found cell growth and metastasis. MCP-1, a key medium between HCC cells and HUVECs, might be a novel anti-vascular target in HCC.

Robo1 promotes angiogenesis in hepatocellular carcinoma through the Rho family of guanosine triphosphatases' signaling pathway.

Robo1 is a member of the Robo immunoglobulin superfamily of proteins, and it plays an important role in angiogenesis and cancer. In this study, we investigate the role of roundabout 1 (Robo1) in tumor angiogenesis in hepatocellular carcinoma (HCC). Firstly, the relationship between Robo1 expression on tumors and patient's survival and endothelial cells in tumor blood vessels and patient's survival was studied. Secondly, Robo1 was overexpressed or knocked down in human umbilical vein endothelial cells (HUVECs). Cell proliferation, motility, and tube formation were compared in HUVEC with different Robo1 expression. Also, HUVECs with different Robo1 expression were mixed with HCCLM3 and HepG2 hepatoma cells and then implanted in a nude mouse model to examine the effects of Robo1 in endothelial cells on tumor growth and angiogenesis. Cell motility-related molecules were studied to investigate the potential mechanism how Robo1 promoted tumor angiogenesis in HCC. The disease-free survival of the patients with high Robo1 expression in tumoral endothelial cells was significantly shorter than that of those with low expression (P = 0.021). Overexpression of Robo1 in HUVECs resulted in increased proliferation, motility, and tube formation in vitro. In the implanted mixture of tumor cells and HUVECs with an increased Robo1 expression, tumor growth and microvessel density were enhanced compared with controls. Robo1 promoted cell division cycle 42 (Cdc42) expression in HUVECs, and a distorted actin cytoskeleton in HUVECs was observed when Robo1 expression was suppressed. In conclusion, Robo1 promoted angiogenesis in HCC mediated by Cdc42.

Suppression of Vascular Endothelial Growth Factor via Inactivation of Eukaryotic Elongation Factor 2 by Alkaloids in Coptidis rhizome in Hepatocellular Carcinoma

To investigate the inhibitory effect of Coptidis rhizome aqueous extract (CRAE) on vascular endothelial growth factor (VEGF) expression and tumor angiogenesis in hepatocellular carcinoma (HCC). Quality control of CRAE was determined. Secretion of VEGF protein and expression of its mRNA in MHCC97L and Hep G2 cells were measured with enzyme-linked immunosorbent assay and quantitative real-time polymerase chain reaction. Synthesis of nascent protein was determined by AHA-protein-labeling technologies. The in vivo antiangiogenic effect of CRAE was evaluated with a xenograft model. Absence of organochlorine pesticides in CRAE was found, and phytochemical analysis showed that its components were in proportion of magnoflorine 2.2%, jatrorrhizine 1.68%, palmatine 4.4%, and berberine 13.8%. CRAE exhibited significant inhibition on VEGF secretion from MHCC97L and HepG2 cells at nontoxic doses. The mRNA transcripts of VEGF could not be inhibited by CRAE; however, synthesis of VEGF nascent protein was potently blocked by CRAE. CRAE intervention increased the phosphorylation of eukaryotic elongation factor 2 (eEF2) in HCC cells, which blocked eEF2 activity for proceeding nascent protein synthesis. The activity of eEF2 was restored in CRAE-treated HCC cells in the presence of A484594, leading to the recovery of VEGF expression. Berberine was found to be the major active component in CRAE; however, CRAE is more effective in inhibiting eEF2 activity compared to berberine treatment alone, suggesting the additive effect of other components present. Reduction of tumor size and neovascularization were observed in mice xenograft model. Our study postulates the antiangiogenic effect of CRAE on hepatocellular carcinoma via an eEF2-driven pathway.

Des‐γ‐carboxyl prothrombin is associated with tumor angiogenesis in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a hypervascular tumor, and angiogenesis plays an important role in its development. Previously, we demonstrated that des-γ-carboxyl prothrombin (DCP) promotes both cell proliferation and migration of human umbilical vein endothelial cells (HUVECs) by inducing the autophosphorylation of kinase insert domain receptor (KDR). In the present study, DCP-associated tumor angiogenesis was assessed by comparing hypovascular and common hypervascular HCC. The solitary HCCs of 827 patients were classified into two groups according to the tumor density at the arterial phase of a dynamic computed tomography scan; the initial clinical data of patients with the hyper- and hypovascular types were compared. The HCC tissues from 95 tumors were analyzed by immunohistochemical staining for DCP and phosphorylated KDR, and intratumoral microvessel density (MVD) was analyzed to evaluate microvessel angiogenesis. The serum DCP levels (320 ± 3532 mAU/mL) and tumor size (18.4 ± 9.0 mm) of patients with hypervascular HCC were significantly greater than those with hypovascular HCC (38.7 ± 80 mAU/mL and 14.6 ± 5.2 mm, P < 0.001). Immunohistochemical analysis revealed that the expressions of DCP and phospho-KDR were significantly greater in hypervascular HCC (71.4% and 31.0%, respectively) than in hypovascular HCC (7.6% and 5.7%, respectively). Intratumoral MVD was significantly correlated with DCP (r = 0.48, P < 0.0001). des-γ-carboxyl prothrombin production is associated with tumor angiogenesis in HCC.

Expression of membrane type-1 matrix metalioproteinase in invasive hepatocellular carcinoma

Objective To investigate effect and expression of membrane type-1 matrix metalloproteinase ( MT1 -MMP,MMP-14) in invasive hepatocellular carcinoma (HCC).Methods We selected 123 patients with HCC randomly from January 2004 to December 2006 which underwent radical hepatectomy,they were divided into the invasion group (n =74) and the non invasion group (n =49) by the standards including tumor size,number,complete capsule,portal vein thrombosis and extrahepatic metastasis.The serum vascular endothelial growth factor (VEGF) was measured with the quantitative sandwich enzymelinked immunosorbent assay (ELISA) three days before operation.With three-step immunohistochemical technique ( ABC),to determine protein expression of MT1-MMP and microvessel density (MVD) in postoperative tissue samples in the two groups,and mRNA expression of MT1-MMP was measured by quantitative real-time polymerase chain reaction (PCR).Results The preoperative serum VEGF in the invasion group (133.89 ± 68.56 ) μg/L was significantly elevated as compared to that in non invasion group ( 100.64 ± 81.37 ) μg/L ( P ＜ 0.01 ).Tissue location of MT1 -MMP was mainly at membrane and in cytoplasm of HCC cells.In invasive HCC,mRNA and protein expression of MT1-MMP were significantly increased compared to that in no invasive HCC (P ＜ 0.05 ),and MVD expression increased accordingly (P＜0.01).Conclusion In invasive HCC,expression of MT1-MMP was significantly increased,and companied with increased secretion of VEGF,also the formation of tumor angiogenesis in HCC increased.High expression of MT1-MMP in postoperative tissue samples could be used as a valuable predictor for invasive HCC,and it prompted poor clinical prognosis. Key words: Membrane-type matrix metalloprotenise-1 ; Vascular endothelial growth factor; Microvessel density; Invasion; Prognosis

Oxidative stress is closely associated with tumor angiogenesis of hepatocellular carcinoma

Oxidative stress (OS) plays an important role in the progression of chronic liver disease and hepatocarcinogenesis. However, the role of OS in the progression of hepatocellular carcinoma (HCC) is unclear. The aim of this study was to assess whether OS promotes angiogenesis in HCC. The expressions of vascular endothelial growth factor (VEGF), VEGF receptor2 (VEGFR2), and phosphorylated Akt were assessed, and microvessel density (MVD) and the cancer-associated fibroblast (CAF) population were examined by immunohistological staining in 55 HCC samples. The OS level in these tissues was assessed using 8-hydroxy-2'-deoxyguanosine (8-OHdG) and 4-hydroxy-2-nonenal (4-HNE) immunostaining, and an 8-OHdG enzyme-linked immunosorbent assay (ELISA). The expression and activation of angiogenic factors and the effect of growth stimulation of human umbilical vein endothelial cells (HUVECs) were also assessed in vitro, using HLE hepatoma-derived cells and conditioned medium with or without treatment with hydrogen peroxide (H₂O₂); a phosphoinositide 3-kinase (PI3K) inhibitor, wortmannin; and an anti-oxidative agent, N-acetyl-L-cysteine (NAC). A higher OS grade was significantly associated with higher MVD, VEGF expression, Akt activity, and OS grade of CAFs, but not with the percentage of the CAF population in HCC tissues. Additionally, cancer cells constituted a major population of OS marker-positive cells in HCC tissues. In vitro, H₂O₂ treatment induced up-regulation of VEGF at both the mRNA and protein levels, activated Akt, and resulted in the proliferation of HUVECs; the addition of wortmannin and NAC counteracted the effects of OS. OS enhances the malignant potential of HCC through the stimulation of angiogenesis by activation of the Akt-VEGF pathway.

Abstract 5647: EGCG suppresses the growth of human hepatocellular carcinoma cells by inhibiting activation of the VEGF/VEGFR axis

Abstract The receptor tyrosine kinase (RTK) vascular endothelial growth factor (VEGF) receptor (VEGFR) plays an important role in tumor angiogenesis of hepatocellular carcinoma (HCC). (−)-Epigallocatechin gallate (EGCG), the major biologically active component of green tea, inhibits growth in a variety of human cancer cells by inhibiting the activation of several types of RTKs. In this study, we examined the effects of EGCG on the activity of the VEGF/VEGFR axis in human HCC cells. The levels of total and phosphorylated (i.e. activated) form of VEGFR-2 protein (p-VEGFR-2) were observed to increase in a series of human HCC cell lines in comparison to the Hc normal human hepatocytes. EGCG preferentially inhibited the growth of HuH7 HCC cells, which express the constitutive activation of the VEGF/VEGFR axis, in comparison to Hc cells. Treatment with HuH7 cells with EGCG caused a time- and dose-dependent decrease in the expression of VEGFR-2 and p-VEGFR-2 proteins. The production of VEGF from HuH7 cells was reduced by the treatment with EGCG. Drinking of EGCG significantly inhibited the growth of HuH7 xenografts in nude mice and this was associated with the inhibition of the activation of VEGFR-2 and its related downstream signaling molecules, including ERK and Akt. EGCG drinking also decreased the expression of Bcl-xL protein and VEGF mRNA in the xenografts. These findings suggest that EGCG can exert, at least in part, its growth inhibitive effect on HCC cells by inhibiting the VEGF/VEGFR axis. EGCG might therefore be useful in the treatment of HCC. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5647.

(–)‐Epigallocatechin gallate suppresses the growth of human hepatocellular carcinoma cells by inhibiting activation of the vascular endothelial growth factor–vascular endothelial growth factor receptor axis

The receptor tyrosine kinase vascular endothelial growth factor (VEGF) receptor (VEGFR) plays an important role in tumor angiogenesis of hepatocellular carcinoma (HCC). (-)-Epigallocatechin gallate (EGCG), the major biologically active component of green tea, inhibits growth in a variety of human cancer cells by inhibiting the activation of several types of receptor tyrosine kinases. In this study, we examined the effects of EGCG on the activity of the VEGF-VEGFR axis in human HCC cells. The levels of total and phosphorylated (i.e. activated) form of VEGFR-2 protein (p-VEGFR-2) were observed to increase in a series of human HCC cell lines in comparison to the Hc normal human hepatocytes. EGCG preferentially inhibited the growth of HuH7 HCC cells, which express constitutive activation of the VEGF-VEGFR axis, in comparison to Hc cells. Treatment of HuH7 cells with EGCG caused a time- and dose-dependent decrease in the expression of VEGFR-2 and p-VEGFR-2 proteins. The production of VEGF from HuH7 cells was reduced by treatment with EGCG. Drinking of EGCG significantly inhibited the growth of HuH7 xenografts in nude mice and this was associated with inhibition of the activation of VEGFR-2 and its related downstream signaling molecules, including ERK and Akt. EGCG drinking also decreased the expression of Bcl-x(L) protein and VEGF mRNA in the xenografts. These findings suggest that EGCG can exert, at least in part, its growth-inhibitive effect on HCC cells by inhibiting the VEGF-VEGFR axis. EGCG might therefore be useful in the treatment of HCC.

Biology of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a common cancer in the world due to high prevalence of hepatitis B or C virus infection. Research in recent years has uncovered important molecular pathways involved in development and progression of HCC. Several genetic aberrations and molecular mechanisms responsible for initiation of hepatocarcinogenesis have been identified. Novel biomarkers for HCC are being developed for better detection and prognostication. Alpha-fetoprotein, the conventional marker of HCC, has limited sensitivity and specificity. Serum levels of isoforms of AFP based on differential lectin binding of the glycan moiety appear to be more sensitive and specific than total AFP level in early detection of HCC. The clinical usefulness of other HCC biomarkers such as des-gamma-carboxy prothrombin and glypican-3 are under investigation. HCC is an aggressive tumor with early vascular invasion and metastasis. Studies over the past two decades have elucidated the clinical predictors of outcome, leading to several staging systems for HCC based on clinical parameters. However, the predictive accuracy of clinical staging systems is limited. Recent studies suggested that biological factors may provide additional prognostic information. In particular, gene expression profiling appears to be a promising approach. Study of tumor angiogenesis in HCC reveals that the expression of angiogenic factors such as vascular endothelial growth factor and angiopoietins may also predict prognosis. The elucidation of tumor biology of HCC is of particular importance in the current era of rapid development of anti-cancer molecular targeting agents, which provide hope for an effective systemic therapy for HCC.

Identification of molecular markers for the oncogenic differentiation of hepatocellular carcinoma

The aim of this study was to identify molecular markers associated with oncogenic differentiation in hepatocellular carcinoma (HCC). Using an unsupervised clustering method with a cDNA microarray, HCC (T) gene expression profiles and corresponding non-tumor tissues (NT) from 40 patients were analyzed. Of total 217 genes, 72 were expressed preferentially in HCC tissues. Among 186 differentially regulated genes, there were molecular chaperone and tumor suppressor gene clusters in the Edmondson grades I and II (GI/II) subclass compared with the liver cirrhosis (LC) subclass. The Edmondson grades III and IV (GIII/IV) subclass with a poor survival (P=0.0133) contained 122 differentially regulated genes with a cluster containing various metastasis- and invasion-related genes compared with the GI/II subclass. Immunohistochemical analysis revealed that ANXA2, one of the 72 genes preferentially expressed in HCC, was over-expressed in the sinusoidal endothelium and in malignant hepatocytes in HCC. The genes identified in the HCC subclasses will be useful molecular markers for the genesis and progression of HCC. In addition, ANXA2 might be a novel marker for tumor angiogenesis in HCC.