P7TP3 inhibits tumor development,migration, invasion and adhesion of liver cancer through the Wnt/β‐catenin signaling pathway

The effect of hepatitis C virus p7 trans‐regulated protein 3 (P7TP3) in the development of hepatocellular carcinoma (HCC) is still unknown. The present study aimed to investigate the role and mechanism of P7TP3 in HCC. P7TP3 was significantly decreased in HCC tissues when compared with corresponding liver tissues immediately around the tumor (LAT) from seven HCC patients. Fewer and smaller colonies originated from HepG2‐P7TP3 cells when compared to HepG2‐NC cells. Overexpression of P7TP3 in HepG2 cells significantly repressed the growth of HCC xenografts in nude mice. Furthermore, wound‐healing tests, Transwell assays, Matrigel Transwell assays, adhesion assays, CCK‐8 assays, flow cytometry and western blotting analysis showed that P7TP3 protein expression inhibited migration, invasion, adhesion, proliferation and cell cycle progression in HCC cell lines. Moreover, P7TP3 suppressed the activity of the Wnt/β‐catenin signaling pathway, and was restored by Wnt3a, which is an activator of the Wnt/β‐catenin signaling pathway. Consistently, β‐catenin was highly expressed by P7TP3 silencing, and restored by XAV939, an inhibitor of the Wnt/β‐catenin signaling pathway. Finally, microRNA (miR)‐182‐5p suppressed the expression of target gene P7TP3 by directly interacting with the 3′‐UTR region. Taken together, P7TP3, the direct target gene of miR‐182‐5p, inhibited HCC by regulating migration, invasion, adhesion, proliferation and cell cycle progression of liver cancer cell through the Wnt/β‐catenin signaling pathway. These findings provide strong evidence that P7TP3 functions as a new promising tumor suppressor in HCC.     

肝癌细胞系中Oct4与Wnt/β-catenin 和TGF-β信号通路的相互影响

 目的 探讨干细胞相关基因Oct4与Wnt/β-catenin 及TGF-β信号通路在肝癌细胞系中的相互作用。方法 应用RT PCR法检测Oct4、Wnt/β-catenin及TGF-β信号通路相关基因β-catenin、Wnt10b、TCF3及 ELF、Smad3和 Smad4在肝癌组织及细胞系中的表达;使用siRNA 沉默人肝癌HepG2细胞Oct4和TCF3的表达,实时荧光定量RT PCR法检测Wnt10b、β-catenin、 TCF3及 ELF、Smad3和 Smad4等基因的表达变化。结果 Oct4和β catenin、Wnt10b、TCF3及 ELF、Smad3和 Smad4在肝癌组织及细胞系中同时表达; siRNA-Oct4 沉默人肝癌HepG2细胞Oct4后,Oct4表达明显下调,β-catenin、Wnt10b随之下调达40%~50%左右,而TCF3表达升高到3倍左右;同时ELF、Smad3和 Smad4均下降到原来的1%以下;而siRNA-TCF3 沉默TCF3后,Oct4的表达也升高2~3倍;ELF升高亦达2~3倍,Smad3和 Smad4也略有升高。结论 Oct4和β-catenin、Wnt10b、TCF3及 ELF、Smad3和 Smad4在肝癌组织及细胞系中同时表达提示彼此之间有相互作用。RNAi实验证明Oct4对Wnt/β-catenin及TGF-β信号通路的成员有调控作用;Oct4 与TCF3之间的负反馈作用值得深入研究。     

CSIG promotes hepatocellular carcinoma proliferation by activating c-MYC expression

Cellular senescence-inhibited gene (CSIG) protein significantly prolongs the progression of replicative senescence, but its role in tumorigenesis is unclear. To reveal the role of CSIG in HCC, we determined its expression in HCC tissues and surrounding tissues and its functions in tumor cell proliferation in vitro and in vivo. CSIG protein was overexpressed in 86.4% of the human HCC cancerous tissues as compared with matched surrounding tissues, and its protein expression was greater in HCC cells than the non-transformed hepatic cell line L02. Furthermore, upregulation of CSIG significantly increased the colony formation of SMMC7721 and HepG2 cells, and silencing CSIG could induce cell cycle arrest and cell apoptosis. The tumorigenic ability of CSIG was confirmed in vivo in a mouse xenograft model. Our results showed that CSIG promoted the proliferation of HepG2 and SMMC7721 cells in vivo. Finally, CSIG protein directly interacted with c-MYC protein and increased c-MYC protein levels; the ubiquitination and degradation of c-MYC protein was increased with knockdown of CSIG. CSIG could also increase the expression of c-MYC protein in SMMC7721 cells in vivo, and it was noted that the level of c-MYC protein was also elevated in most human cancerous tissues with high level of CSIG.     

SFRP1 suppressed hepatoma cells growth through Wnt canonical signaling pathway

Oncogenic activation of the Wnt/beta-catenin signaling pathway is common in hepatocellular carcinoma (HCC). The secreted frizzled-related proteins (SFRPs) function as negative regulators of Wnt signaling and have important implications for carcinogenesis. Promoter hypermethylation of SFRP genes is common in human cancers. However, the role of SFRPs in HCC is not clear. Recently, we have shown that SFRP1 is frequently downregulated through promoter hypermethylation. To confirm and extend these findings, the methylation status of the other SFRP members, including SFRP2, SFRP4 and SFRP5, was examined by methylation-specific polymerase chain reaction (MS-PCR). Hypermethylation of SFRP genes, except for SFRP4, is frequent in HCCs and the levels found here were significantly higher than those seen in cirrhotic livers, chronic hepatitis livers and normal controls (p < 0.0001 for SFRP1 and SFRP2, p < 0.05 for SFRP5). To investigate the role of SFRP1 in HCCs, we used re-expression of SFRP1 in beta-catenin-dependent HCC cell lines: Huh6 and HepG2. Restoration of SFRP1 attenuated Wnt signaling in those Huh6 hepatoma cells with a beta-catenin gene point mutation, decreased abnormal accumulation of beta-catenin in the nucleus and suppressed cell growth. Conversely, restoration of SFRP1 in HepG2 hepatoma cells with truncated beta-catenin could not block the Wnt signaling pathway. Furthermore, knocking down SFRP1 by RNA interference in beta-catenin-deficient cell lines (SK-Hep1) stimulated Wnt signaling and promoted cell growth. Our data suggested that SFRP1 suppressed liver cancer cells growth through Wnt canonical signaling. Moreover, beta-catenin-independent noncanonical pathway might be involved in Wnt signaling activation through unknown molecules in HCC.     

siRNA-Mediated β-Catenin Knockdown in Human Hepatoma Cells Results in Decreased Growth and Survival

β-Catenin, the chief oncogenic component of the canonical Wnt pathway, is known to be involved in a variety of cancers, including hepatocellular carcinoma (HCC). Although the mechanism of β-catenin activation in HCC is multifactorial, it is indisputably implicated at various stages of hepatocarcinogenesis, making it an attractive therapeutic target. Here we investigate the effect of small interfering RNA-mediated β-catenin knockdown on the growth and survival of human hepatoma cell lines with (HepG2) and without (Hep3B) β-catenin mutations. Transfection of HepG2 and Hep3B cells with human β-catenin (CTNNB1) small interfering RNA resulted in a significant β-catenin decrease, as confirmed by Western blot analyses and immunofluorescence, also leading to decreased expression of known target genes such as cyclin D1 and glutamine synthetase. The decrease in β-catenin activity was confirmed by TOPflash reporter luciferase assay. The functional impact of diminished β-catenin was exhibited as temporal decrease in tumor cell viability by the MTT assay. A concomitant decrease in tumor cell proliferation was also evident with [³H]thymidine incorporation and verified with soft agar assays. Thus, β-catenin is essential for the survival and growth of hepatoma cells independent of mutations in the β-catenin gene and provide a proof of principle for the significance of the therapeutic inhibition of β-catenin in HCC.     

Human homolog of NOTUM, overexpressed in hepatocellular carcinoma, is regulated transcriptionally by beta-catenin/TCF

The Drosophila Notum gene, which is regulated by the Wingless pathway, encodes a secreted hydrolase that modifies heparan sulfate proteoglycans. In comparative analysis of the gene expression profiles in primary human hepatocellular carcinomas (HCC) and normal organs, we observed that the human ortholog of Drosophila Notum was overexpressed markedly in a subset of HCC, but expressed rarely in adult normal tissues. Immunoblotting confirmed the overexpression of NOTUM protein in 12 of 40 primary HCC cases (30%). High levels of NOTUM protein were significantly associated with intracellular (nuclear or cytoplasmic) accumulation of β-catenin protein: all 10 HCC with high intracellular β-catenin also had high NOTUM expression, whereas only 2 of 30 cases (6.7%) without intracellular β-catenin had high NOTUM expression ( P <  0.00001). NOTUM expression in HepG2 cells was downregulated significantly by induction of a dominant-negative mutant of TCF4, a β-catenin partner. In vivo binding of the β-catenin/TCF complex to the NOTUM promoter was demonstrated by chromatin immunoprecipitation in HepG2 and SW480 cells, where canonical Wnt signaling is activated constitutively. These findings provide evidence that NOTUM is a novel target of β-catenin/TCF4 and is upregulated in Wnt/β-catenin signaling-activated HCC. ( Cancer Sci 2008; 99: 1139–1146)     

沉默B7-H3基因表达对人肝癌细胞侵袭能力的影响

目的 研究靶向沉默B7-H3基因表达对HepG2细胞侵袭能力的影响及可能机制。方法 设计针对B7-H3基因的shRNA沉默质粒,转染HepG2细胞,下调B7-H3的表达。划痕修复实验检测转染前后HepG2细胞移行能力的变化,Transwell实验检测基因沉默对细胞侵袭能力的影响,MST-1法和ELISA凋亡试剂盒分别检测细胞增殖和凋亡水平变化。通过Western blot实验和明胶酶谱实验检测侵袭相关分子MMP-2、MMP-9的表达和活性变化。结果 成功构建B7-H3 shRNA沉默质粒并转染HepG2细胞。与对照质粒转染组和未转染组比较,沉默B7-H3基因表达后,B7-H3 shRNA转染组HepG2细胞的移行（24 h: P=0.001; 48 h: P<0.001; 72 h: P<0.001）和侵袭（P<0.001）能力受到显著抑制,细胞的增殖和凋亡水平没有明显变化（P>0.05）。MMP-2、MMP-9的蛋白表达（MMP-2: P<0.001; MMP-9: P=0.007）和活性（MMP-2: P<0.001; MMP-9: P<0.001）均显著下降。结论 通过B7-H3 shRNA沉默质粒靶向沉默B7-H3的基因表达能抑制HepG2细胞的侵袭能力,其机制可能与抑制MMP-2、MMP-9的表达和活性有关。     

Epigenetic silencing of <Emphasis Type="Italic">sFRP1</Emphasis> activates the canonical Wnt pathway and contributes to increased cell growth and proliferation in hepatocellular carcinoma

The Wnt pathway is a key regulator of embryonic development and stem cells, and its aberrant activation is associated with human malignancies, most notably hepatocellular carcinoma (HCC). Epigenetic deregulation of the genes encoding the secreted frizzled-related proteins (sFRPs), the Wnt signalling antagonists, has been linked with aberrant hyperactivation of the Wnt signalling in HCC cells; however, the precise underlying mechanism remains elusive. We investigated the methylation profiles of Wnt antagonists in liver samples of different stages of HCC development and liver cancer cell lines and studied the functional impact of aberrant epigenetic silencing of sFRPs on the canonical Wnt pathway and cell viability. We found that the sFRP1 gene encoding the subunit is a frequent target of aberrant DNA hypermethylation and silencing in HCC tumours, whereas other extracellular Wnt antagonists, WIF1 and Dkk3, exhibited no methylation in tumour cells, consistent with the notion that aberrant methylation events in cancer cells are non-randomly distributed among the genes and that there is a strong preference for hypermethylation of specific genes in HCC. In addition, by comparing sFRP1 methylation status in HCC tumours with normal, cirrhotic and chronic hepatitis liver tissues, we identified sFRP1 gene as a potential early marker of HCC. The restoration of sFRP1 expression in cancer cells by ectopic expression inhibited Wnt activity accompanied with destabilization of β-catenin and downregulation of c-Myc and cyclin D1, the known downstream targets of Wnt pathway. Importantly, restoring sFRP1 levels in cancer cells inhibited cell growth and induced apoptotic cell death. This study supports the critical role for sFRP1 silencing in hepatocellular carcinoma and reinforces the importance of the Wnt antagonists in preventing oncogenic stabilization of β-catenin and chronic activation of the canonical Wnt pathway, suggesting that sFRP1 may be an attractive target for early cancer detection and therapeutic intervention.     

Sox2在肝癌中的表达及其对细胞生长增殖的作用

[目的]明确Sox2蛋白在肝癌组织及肝癌细胞系中的表达,探讨Sox2分子对肝癌细胞生长增殖的作用及机制。[方法]选取临床肝癌组织标本、正常肝细胞系和多种肝癌细胞系为实验对象,从蛋白水平比较Sox2的表达水平;选取高表达Sox2的肝癌细胞系,利用RNA干涉技术降低Sox2表达,运用BrdU掺入实验、MTT实验等技术检测Sox2分子对肝癌细胞生长、增殖的影响,并检测肿瘤相关分子Wnt/β-catenin的表达水平。[结果]Sox2在肝癌组织及几种肝癌细胞中表达明显升高,以HepG2细胞系最多;MTT实验显示,与正常对照组和阴性对照组比较,从第3天开始Sox2干涉组A。值明显降低（P〈0．05）;BrdU掺人实验显示,Sox2干涉组细胞BrdU掺入率明显减少（P〈0．05）;降低Sox2表达后,Wnt/β-catenin水平明显降低。[结论]Sox2在肝癌组织及肝癌细胞中表达升高,并通过Wnt/β-catenin促进肝癌细胞生长及增殖。     

HECA通过Wnt通路抑制肝癌细胞增殖、迁移和侵袭

目的:拟在通过影响肝细胞癌HepG2细胞株中HECA基因表达变化,观察与HECA基因相关联的Wnt通路上重要调节分子的变化,讨论此通路影响肝癌细胞增殖能力状况及其相关作用机理。方法:HECA慢病毒感染肝癌细胞株HepG2,细胞株中稳定上调HECA,用HECA siRNA转染HepG2细胞株下调HECA,在HECA表达上调的细胞株中用qPCR检测Wnt通路中β-catenin、TCF4、CDK2、CDK9、Cyclin A和Cyclin K的mRNA表达水平的变化,用Western blot检测qPCR结果中差异明显的β-catenin、TCF4蛋白表达水平的变化,应用FH535抑制剂处理HECA过表达的HepG2细胞,进一步验证HECA基因与Wnt通路的关系,利用Western blot检测HECA的表达水平,用MTT、划痕、克隆形成以及Transwell实验检测对肝癌细胞侵袭、迁移、增殖能力的影响。结果:qPCR法以及Western blot法对其相关基因表达水平进行测定,结果显示在HepG2细胞株内HECA过表达后,与HECA相关联的Wnt通路重要调节分子中β-catenin、TCF4的表达水平显著降低;FH535抑制剂处理HECA过表达的HepG2细胞,Western blot实验结果显示FH535处理过的过表达组HECA水平更高,细胞功能实验也表明FH535处理过的过表达HECA组,其细胞增殖及侵袭能力下降最明显。结论:HECA基因抑制肝细胞癌增殖及侵袭的分子机制可能为:HECA通过Wnt/β-catenin这一经典通路内β-catenin与TCF4的结合活性降低而发挥作用。     

RNA干扰SMYD3基因表达对诱导肝癌细胞凋亡的影响

背景与目的:SMYD3(SETandMYNDdomain-containingprotein3)基因的表达蛋白是一种组蛋白甲基转移酶,参与肿瘤细胞增殖与凋亡的调控。本研究旨在探讨利用RNA干扰(RNAinterference,RNAi)抑制SMYD3基因表达对肝癌细胞增殖与凋亡的影响。方法:RT-PCR、免疫组织化学法分别检测SMYD3在肝癌细胞和肝癌组织中的表达。构建小发夹状RNA(smallhairpinRNA,shRNA)干扰质粒Pgenesil-1-s1、Pgenesil-1-s2及无干扰效应质粒Pgenesil-1-hk并转染入肝癌细胞HepG2,阻抑其表达SMYD3,以空质粒Pgenesil-1转染组为对照。Westernblot检测阻抑效应;MTT检测细胞增殖抑制率,流式细胞术及TUNEL检测细胞凋亡。结果:SMYD3在肝癌组织和多种肝癌细胞中表达明显增强。shRNA转染HepG2细胞后:SMYD3蛋白表达下调75%～85%;细胞增殖明显受抑制,抑制率高达60.95%～72.14%;流式细胞术结果显示Pgenesil-1-s1组HepG2细胞凋亡率(17.68±2.36)%、Pgenesil-1-s2组(19.07±1.78)%,均显著高于Pgenesil-1-hk组[(1.44±0.28)%]及Pgenesil-1组[(0.47±0.12)%](P<0.01);TUNEL检测的凋亡指数结果与流式细胞术检测结果类似。结论:SMYD3高表达于多种肝癌细胞及肝癌组织;RNAi能特异性下调SMYD3的表达,抑制肝癌细胞增殖并促进细胞凋亡,提示其可能为治疗肝癌提供新的途径。     

ADAM10 overexpression confers resistance to doxorubicin-induced apoptosis in hepatocellular carcinoma

Chemoresistance represents a major obstacle to successful treatment of hepatocellular carcinoma (HCC). A disintegrin and metalloproteinase 10 (ADAM10) is known to be frequently upregulated in many cancers. We aimed to determine the biological function of ADAM10 in the chemoresistance of HCC cells. Overexpression of ADAM10 in three HCC cell lines (HepG2, Hep3B, and Huh7) conferred protection against doxorubicin-induced apoptosis, as determined by Annexin V staining. Western blot analysis revealed that ADAM10-overexpressing cells had a significantly lower amount of cleaved caspase-3 and an elevated expression of myeloid cell leukemia-1 (Mcl-1), a prosurvival member of the Bcl-2 family. Conversely, RNA interference-mediated silencing of endogenous ADAM10 potentiated doxorubicin-induced apoptosis in HepG2 and Hep3B cells, which was coupled with increased cleavage of caspase-3 and decreased expression of Mcl-1. Ectopic expression of ADAM10 resulted in a marked increase in the phosphorylation of phosphatidylinositol 3-kinase (PI3-K) and Akt. Most interestingly, the pretreatment with the PI3-K inhibitor LY294002 significantly enhanced doxorubicin-induced apoptosis and diminished the Mcl-1 expression in ADAM10-overexpressing Huh7 cells. Our data provide evidence that ADAM10 plays an important role in modulating the chemosensitivity of HCC cells, which, at least partially, involves the activation of the PI3-K/Akt pathway. ADAM10 may be a promising target for the improvement of chemotherapeutic efficacy in HCC.     

Overexpression of HOXA1 correlates with poor prognosis in patients with hepatocellular carcinoma

HOXA1 overexpression is sufficient for malignant transformation of nontumorigenic epithelial cells. It is known that HOXA1, which was upregulated in squamous cell carcinomas, affects both cell growth and death. The forced expression of HOXA1 in human breast cancer cells results in increased cell growth activity. However, it has not been reported in hepatocellular carcinoma (HCC). In this study, we used immunohistochemistry to compare HOXA1 protein expression in HCC and normal liver tissues and further analyzed HOXA1 protein expression in 156 clinicopathologically characterized HCC cases. We stably knocked down the endogenous expression level of HOXA1 in HepG2 cells with specific shRNA-expressing lentiviral vector. Following the successful establishment of stable cells, we examined in vitro cell growth by the MTT assay, anchorage-independent growth through a soft agar colony formation assay and cell migration/invasion by transwell and Boyden chamber assay. In addition, we also investigated in vivo tumor growth by xenograft transplantation of HepG2 cells into nude mice. Our results showed that the protein expression level of HOXA1 was markedly higher in HCC tissues than that in normal liver tissue (P?=?0.019). In addition, a high expression level of HOXA1 protein was positively correlated with the T classification (P?<?0.001), the N classification (P?<?0.001), distant metastasis (P?=?0.004), and the clinical stage (P?<?0.001) of HCC patients. Patients with higher HOXA1 expression showed a significantly shorter overall survival time compared with patients with low HOXA1 expression. Multivariate analysis suggested that HOXA1 expression might be an independent prognostic indicator (P?<?0.001) for the survival of patients with HCC. HOXA1-specific shRNA (shHOXA1) successfully knocked down HOXA1 endogenous expression in HepG2 cells. Compared to the parental and control shRNA-transfected (shCtrl) HepG2 cells, the shHOXA1 cells exhibited significantly reduced in vitro cell growth, anchorage-independent growth, and cell migration and invasion (P?<?0.05). In vivo, the xenograft transplants from shHOXA1 cells gave rise to much smaller tumors compared with those from shCtrl cells. Collectively, high HOXA1 expression is associated with poor overall survival in patients with HCC. The downregulation of HOXA1 inhibits growth, anchorage-independent growth, and migration and invasion of HepG2 cells.     

The major vault protein mediates resistance to epidermal growth factor receptor inhibition in human hepatoma cells

To better understand the response of HCC to EGFR inhibition, we analyzed factors connected to the resistance of HCC cells against gefitinib. Sensitive HCC3 cells co-expressed EGFR and ErbB3 but lacked kinase-domain mutations in EGFR. Interestingly, expression of MVP was restricted to resistant cell lines, whereas ABCB1 and ABCC1 showed no association with gefitinib resistance. Moreover, ectopic MVP expression in HCC3 cells decreased gefitinib sensitivity, increased AKT phosphorylation and reduced the expression of inflammatory pathway-associated genes, whereas silencing of MVP in Hep3B and HepG2 cells increased sensitivity. These findings suggest MVP as a novel player in resistance against EGFR inhibition.     

Soluble glypican 3 inhibits the growth of hepatocellular carcinoma in vitro and in vivo

The heterogeneity of the molecular pathology of HCC poses a formidable obstacle to the development of non‐cytotoxic therapies. Several pro‐tumorigenic signaling pathways can be aberrantly activated in HCC, including those triggered by Wnts. Glypican‐3 (GPC3), a membrane‐bound heparan sulfate proteoglycan that is overexpressed in most HCCs, promotes the growth of these tumors by stimulating Wnt signaling. Because GPC3 binds with high affinity to Wnts, and its growth‐promoting activity requires attachment to the cell membrane, we have hypothesized that a mutated GPC3 lacking the GPI anchoring domain (sGPC3) will block Wnt signaling and inhibit the growth of Wnt‐dependent tumors. In addition, because sGPC3 displays heparan sulfate chains, this secreted glypican could also inhibit HCC growth by blocking the activity of other heparin‐binding growth factors. To test this hypothesis, HCC cell lines were infected with an sGPC3‐expressing lentivirus or virus control, and the effect of sGPC3 on the in vitro and in vivo growth was investigated. In addition, the signaling pathways targeted by sGPC3 were identified. We observed that sGPC3‐expressing cells had lower proliferation rate. In addition, sGPC3 significantly inhibited the in vivo growth of the Huh6, HepG2 and Huh7 HCC cell lines. sGPC3 blocked Wnt signaling in Huh6‐ and Huh7‐derived tumors and Erk1/2 and Akt phosphorylation in tumors generated by Huh7 and HepG2 cells, respectively. An anti‐angiogenic effect in Huh7 and HepG2‐derived tumors was also observed. We conclude that sGPC3 can inhibit HCC tumorigenicity by blocking the activity of several pro‐tumorigenic growth factors.     

High ADAM8 Expression is Associated with Poor Prognosis in Patients with Hepatocellular Carcinoma

In this study,we investigated the ADAM8 expression in hepatocellular carcinoma (HCC) and its correlation with clinicopathologic features,including the survival of patients with HCC. Furthermore,we examined the biological processes regulated by ADAM8 during the development of using HepG2 cell line as a model system. We used immunohistochemistry to compare ADAM8 protein expression in HCC and normal liver tissues and further analyze the ADAM8 protein expression in clinicopathologically characterized 105 HCC cases.We stably knocked down the endogenous expression level of ADAM8 in HepG2 cells with specific shRNA-expressing lentiviral vector. Following the successful establishment of stable cells,we examined in vitro cell growth by MTT assay,anchorage-independent growth by soft-agar colony formation assay and cell migration/invasion by transwell and boyden chamber assay. And in addition,we also investigated the in vivo tumor growth by xenograft transplantation of HepG2 cells into nude mice. Protein expression level of ADAM8 was markedly higher in HCC tissues than that in the normal liver tissues (P?=?0.0058).In addition,high expression of ADAM8 protein was positively correlated with serum AFP elevation,tumor size,histological differentiation,tumor recurrence,tumor metastasis,and tumor stage. Patients with higher ADAM8 expression showed a significantly shorter overall survival time than patients with low ADAM8 expression. Multivariate analysis suggested that ADAM8 expression might be an independent prognostic indicator (p?=?0.016) for the survival of patients with HCC. ADAM8-specific shRNA (shADAM8) successfully knocked down its endogenous expression in HepG2 cells. Compared to the parental and control shRNA-transfected (shCtrl) HepG2 cells,the shADAM8 cells exhibited significantly reduced in vitro cell growth,anchorage-independent growth,cell migration and invasion (p?<?0.05).In vivo,the xenograft transplants from shADAM8 cells gave rise to much smaller tumors as compared to those from shCtrl cells. High ADAM8 expression is associated with poor overall survival in patients with HCC. Down-regulation of ADAM8 inhibits the growth,anchorage-independent growth,migration and invasion of HepG2 cells. ADAM8 may be a potential target of antiangiogenic therapy for HCC.