RNA干扰肝细胞肝癌中PECAM-1的表达对肿瘤细胞侵袭及增殖的影响

目的:探讨PECAM-1在肝细胞肝癌(Hepatocellular carcinoma,HCC)组织中的表达及意义。方法:选择2013年5月-2015年6月在我院接受治疗的HCC患者100例,收集肝癌患者HCC组织及癌旁组织,另选取100例正常肝脏组织作为对照组。应用免疫组织化学法检测PECAM-1在肝癌组织、癌旁组织以及正常肝脏组织中的阳性表达。利用小分子干扰RNA技术(si RNA)构建低表达的PECAM-1,并转染至肝癌细胞中抑制PECAM-1的表达。应用Transwell小室法检测肝癌细胞的侵袭能力,CCK-8法检测肝癌细胞的增殖能力。结果:PECAM-1在肝癌组织、癌旁组织及正常肝脏组织中呈不同程度阳性表达(P0.05);PECAM-1在肝癌组织及癌旁组织中的表达显著高于正常肝脏组织,差异具有统计学意义(P0.05);PECAM-1在肝癌组织中的表达显著高于癌旁组织,差异具有统计学意义(P0.05);转染si RNA PECAM-1后,肝癌细胞中PECAM-1 m RNA的表达水平明显下降,PECAM-1蛋白表达也明显降低,差异具有统计学意义(P0.05);转染si RNA PECAM-1后,肝癌细胞侵袭及增殖能力明显降低,差异具有统计学意义(P0.001)。结论:PECAM-1在肝癌患者血清中高表达,PECAM-1 si RNA能够抑制肝癌细胞的侵袭及增殖能力,提示PECAM-1可作为预测肝癌发生及发展的临床指标。     

Breast Cancer Metastasis Suppressor 1 Regulates Hepatocellular Carcinoma Cell Apoptosis via Suppressing Osteopontin Expression

Breast cancer metastasis suppressor 1 (BRMS1) was originally identified as an active metastasis suppressor in human breast cancer. Loss of BRMS1 expression correlates with tumor progression, and BRMS1 suppresses several steps required for tumor metastasis. However, the role of BRMS1 in hepatocellular carcinoma (HCC) remains elusive. In this study, we found that the expression level of BRMS1 was significantly down-regulated in HCC tissues. Expression of BRMS1 in SK-Hep1 cells did not affect cell growth under normal culture conditions, but sensitized cells to apoptosis induced by serum deprivation or anoikis. Consistently, knockdown of endogenous BRMS1 expression in Hep3B cells suppressed cell apoptosis. We identified that BRMS1 suppresses osteopontin (OPN) expression in HCC cells and that there is a negative correlation between BRMS1 and OPN mRNA expression in HCC tissues. Moreover, knockdown of endogenous OPN expression reversed the anti-apoptosis effect achieved by knockdown of BRMS1. Taken together, our results show that BRMS1 sensitizes HCC cells to apoptosis through suppressing OPN expression, suggesting a potential role of BRMS1 in regulating HCC apoptosis and metastasis.     

盐霉素抑制人肝细胞癌转移与侵袭的体外与体内实验研究

目的：肝癌的转移与复发是肝癌治疗的一大难题,盐霉素是近年来新发现的具有抗肿瘤作用的抗生素,本文研究了盐霉素在体外及体内对人肝细胞癌转移与侵袭能力的作用及机制。方法：在体外对肝癌细胞株HepG2,SMMC-7721,BEL-7402给予盐霉素处理,体内建立裸鼠肝脏原位肿瘤模型,并给予腹腔注射盐霉素治疗。观察肿瘤细胞的转移侵袭能力以及肝内肿瘤转移灶的情况,进一步测定E．cadherin,Vimentin的表达,来研究盐霉素对肝癌转移及侵袭能力的影响及机制。结果：经盐霉素处理后,肝癌细胞株HepG2,SMMC．7721,BEL．7402的转移及侵袭能力明显下降,肝内转移灶的数目也减少。分子机制检测发现盐霉素处理后E．cadherin表达增高,Vimentin表达下降。结论：盐霉素在体内与体外都抑制了肝癌的转移与侵袭,其机制可能抑制了肿瘤细胞的上皮间质化（EMT）过程。这为控制肝癌的转移和复发提供了新的治疗思路。     

Osteopontin-Enhanced Hepatic Metastasis of Colorectal Cancer Cells

Liver metastasis is a major cause of mortality from colorectal cancer (CRC). However, mechanisms underlying this process are largely unknown. Osteopontin (OPN) is a secreted phosphorylated glycoprotein that is involved in tumor migration and metastasis. The role of OPN in cancer is currently unclear. In this study, OPN mRNA was examined in tissues from CRC, adjacent normal mucosa, and liver metastatic lesions using quantitative real-time PCR analysis. The protein expression of OPN and its receptors (integrin αv and CD44 v6) was detected by using an immunohistochemical (IHC) method. The role of OPN in liver metastasis was studied in established colon cancer Colo-205 and SW-480 cell lines transfected with sense- or antisense-OPN eukaryotic expression plasmids by flow cytometry and cell adhesion assay. Florescence redistribution after photobleaching (FRAP) was used to study gap functional intercellular communication (GJIC) among OPN-transfected cells. It was found that OPN was highly expressed in metastatic hepatic lesions from CRC compared to primary CRC tissue and adjacent normal mucosa. The expression of OPN mRNA in tumor tissues was significantly related with the CRC stages. OPN expression was also detected in normal hepatocytes surrounding CRC metastatic lesions. Two known receptors of OPN, integrin αv and CD44v6 proteins, were strongly expressed in hepatocytes from normal liver. CRC cells with forced OPN expression exhibited increased heterotypic adhesion with endothelial cells and weakened intercellular communication. OPN plays a significant role in CRC metastasis to liver through interaction with its receptors in hepatocytes, decreased homotypic adhesion, and enhanced heterotypic adhesion.     

T细胞分化蛋白2在肝细胞癌中的表达及其临床意义

目的:观察T细胞分化蛋白2(Mal2)在肝细胞癌(HCC)中的表达并探讨其临床意义。方法:采用免疫组织化学染色方法检测226例HCC患者的肿瘤组织和86例正常肝组织中Mal2蛋白的表达情况,并分析其与HCC临床病理指标的关系。通过生存分析比较不同Mal2表达水平患者的生存情况,并分析影响HCC患者生存情况的危险因素。结果:Mal2蛋白在HCC肿瘤组织中的表达水平显著高于正常肝组织(P0.05)。Mal2蛋白表达水平增高与HCC患者血管侵犯、淋巴结转移和较高的TNM分期相关。生存分析表明Mal2蛋白高表达组患者术后生存率显著低于低表达组患者(P0.05)。Mal2阳性表达、血管癌栓形成、淋巴结转移及较高的TNM分期是影响HCC患者术后生存时间的独立危险因素。结论:Mal2蛋白在HCC组织中呈过表达趋势,且与肿瘤转移密切相关,可能在HCC的诊断与预后判断中有一定的应用价值。     

Mechanism of Hepatitis C Virus (HCV)-induced Osteopontin and Its Role in Epithelial to Mesenchymal Transition of Hepatocytes

Osteopontin (OPN) is a secreted phosphoprotein, originally characterized in malignant-transformed epithelial cells. OPN is associated with tumor metastasis of several tumors and is overexpressed in hepatocellular carcinoma (HCC) tissue involving HCC invasion and metastasis. Importantly, OPN is significantly up-regulated in liver injury, inflammation, and hepatitis C virus (HCV)-associated HCC. However, the underlying mechanisms of OPN activation and its role in HCV-mediated liver disease pathogenesis are not known. In this study, we investigated the mechanism of OPN activation in HCV-infected cells. We demonstrate that HCV-mediated Ca²⁺ signaling, elevation of reactive oxygen species, and activation of cellular kinases such as p38 MAPK, JNK, PI3K, and MEK1/2 are involved in OPN activation. Incubation of HCV-infected cells with the inhibitors of AP-1 and Sp1 and site-directed mutagenesis of AP-1- and Sp1-binding sites on the OPN promoter suggest the critical role of AP-1 and Sp1 in OPN promoter activation. In addition, we show the in vivo interactions of AP-1 and Sp1 with the OPN promoter using chromatin immunoprecipitation assay. We also show the calpain-mediated processing of precursor OPN (∼75 kDa) into ∼55-, ∼42-, and ∼36-kDa forms of OPN in HCV-infected cells. Furthermore, we demonstrate the critical role of HCV-induced OPN in increased phosphorylation of Akt and GSK-3β followed by the activation of β-catenin, which can lead to EMT of hepatocytes. Taken together, these studies provide an insight into the mechanisms of OPN activation that is relevant to the metastasis of HCV-associated HCC.     

泛素相关蛋白样因子2在肝癌中的表达及意义

目的:探讨肝癌中泛素相关蛋白样因子2(UBAP2L)的表达水平与预后的关系及其对肝癌细胞侵袭、转移能力的影响。方法:挖掘oncomine数据库,提取UBAP2L在肝癌与正常组织转录水平的变化及相关临床资料,采用Kaplan-Meier法分析UBAP2L表达水平与肝癌患者预后的关系。采用实时定量PCR、Western blot检测HCCLM3、MHCC97H、Hep3B、Huh7肝癌细胞株及正常肝细胞LO2中UBAP2L mRNA及蛋白水平,免疫组织化学染色法检测本院80例肝癌组织与癌旁组织中UBAP2L的表达水平加以验证。通过慢病毒载体使UBAP2L高表达的肝癌细胞株HCCLM3表达下调,采用克隆形成和划痕实验检测UBAP2L对肝癌细胞增殖能力和侵袭、转移的影响。结果:UBAP2L在oncomine数据库大多数队列呈高表达。UBAP2L在肝癌细胞株中的mRNA和蛋白的表达水平显著高于正常肝细胞(P0.05)。肝癌组织中UBAP2L阳性、强阳性表达率高于癌旁组织(P0.05),下调UBAP2L表达可明显抑制HCCLM3肝癌细胞的克隆形成能力和运动能力(P0.05)。UBAP2L高表达组的中位生存时间与UBAP2L低表达组比较差异无统计学意义(P0.05)。结论:UBAP2L在肝癌组织中呈高表达,下调UBAP2L表达可抑制肿瘤增殖和侵袭、转移表型,其可能成为肝癌早期诊断的生物标志物和治疗的潜在靶点。     

Expression of Asialoglycoprotein Receptor 1 in Human Hepatocellular Carcinoma

Human hepatocellular carcinoma (HCC) is the fifth most common cancer in the world. Currently, surgical resection is the only effective treatment for HCC if the tumor is resectable. Small molecule, biologics and siRNA anti-cancer drugs have been explored for the treatment of HCC. Selective targeting to tumor tissue rather than normal liver in HCC patients is still a challenge. Galactosamine-mediated targeting delivery of anti-cancer drugs in the liver has been tested because its receptor, asialoglycoprotein receptor 1 (ASGPR1), is expressed in the liver and not in other human tissues. We examined ASGPR1 expression levels by immunohistochemistry in HCC with different grades. Guidance for a targeting delivery strategy for anti-cancer drugs to HCC is suggested in this report.     

Expression of<Emphasis Type="Italic"> HIWI</Emphasis> in Human Hepatocellular Carcinoma

In this study, the investigation of the expression of HIWI and its protein in hepatocellular carcinoma (HCC) was performed, and the relationships between HIWI expression and the location of HCC metastases were analyzed. Sets of fresh HCC and matched adjacent normal hepatic tissue and paraffin-embedded tissue slides were provided by the hospital hepatology and pathology departments. RT-PCR, Western blot, and immunohistochemistry were performed to detect HIWI mRNA and protein. Correlations between HIWI expression and patient’s age, sex, type of tumor, and metastasis location were recorded. HIWI mRNA and protein levels were significantly higher in HCC tissues than in adjacent normal hepatic tissue (P < 0.05). Immunohistochemistry showed positive staining for HIWI in cell cytoplasm; however, the number of HIWI-positive cells in HCC tissue (65.2%; 60/92) was significantly higher than in adjacent normal hepatic tissue (27.2%; 25/92) (P < 0.05). HIWI expression was not correlated with patients’ age, gender, tumors’ size, and location but correlated with metastasis involving lymph nodes and other remote organs (P < 0.05). HIWI expression is significantly higher in HCC tissue than in adjacent normal hepatic tissue. The results of this study suggest that HIWI may have a crucial role in HCC carcinogenesis and could serve as a potential biomarker or treatment target for HCC.     

Glypican-3, a novel prognostic marker of hepatocellular cancer, is related with postoperative metastasis and recurrence in hepatocellular cancer patients

Metastasis/recurrence has been the most fundamental characteristic of hepatocellular cancer (HCC) and the ultimate cause of most HCC-related deaths. However, there are still a limited number of reliable tumor markers that can be used to predict the possibility of metastasis/recurrence in an HCC patient after operation. Recently, much evidence has shown that glypican-3 (GPC3) can be a useful tool to identify the early development of HCC, but little research has been done to test its usefulness as a prognostic marker related to post-operative metastasis/recurrence in HCC patients. In this study, the expression of GPC3 and its relationship with clinicopathological factors were determined by immunohistochemical analysis in 61 primary HCC patients. The potential prognostic value of GPC3 was investigated by comparing the survival time between HCC patients with high and low GPC3 expression. The results demonstrated that GPC3 expression was closely related with metastasis/recurrence in an HCC patient who can receive the operation. The risk of metastasis/recurrence after surgery in an HCC patient with high GPC3 expression was increased to 3.214 as compared to that of an HCC patient with low GPC3 expression. Survival analysis showed that HCC patients with high GPC3 expression had a significantly shorter overall survival time than HCC patients with low GPC3 expression (P = 0.003). Further, multivariate analysis showed that GPC3 expression was a significant, independent prognostic parameter (P = 0.030) for HCC patients. Overall, the study indicates that GPC3 might be a valuable marker closely related with prognosis and post-operative metastasis/recurrence in HCC patients.     

MicroRNA-500 as a potential diagnostic marker for hepatocellular carcinoma

We identified that microRNA expression changed dynamically during liver development and found that miR-500 is an oncofetal miRNA in liver cancer. miR-500 was abundantly expressed in several human liver cancer cell lines and 45% of human hepatocellular carcinoma (HCC) tissue. Most importantly, an increased amount of miR-500 was found in the sera of the HCC patients. In fact, miR-500 levels in sera of the HCC patients returned to normal after the surgical treatment in three HCC patients. Our findings reveal that diverse changes of miRNAs occur during liver development and, one of these, miR-500 is an oncofetal miRNA relevant to the diagnosis of human HCC.     

HIF-lα的表达在肝移植后肝癌复发与转移中的意义

目的：探讨肝癌组织中低氧诱导因子-lα（HIF-lα）表达与肝癌行肝移植治疗后肿瘤复发与转移之间的关系。方法：选择肝癌行全肝移植患者45例,应用免疫组化方法检测其切除的肝癌组织、癌旁组织中HIF-lα的表达,分析其表达与移植后肝癌复发与转移之间的关系和意义。结果：肝癌组织中HIF-1α阳性表达率明显高于癌旁组织（X2=6.39,P〈0.01）。HIF-1α在肝癌组织中的表达与肿瘤直径、TNM分期、有无淋巴结转移、有无门静脉癌栓及肿瘤播散灶密切相关（P〈0.01）。复发转移组和未复发转移组HIF-1α阳性表达率比较,差异存在显著性（X2=8.46,P〈0.01）。Cox回归多因素分析表明HIF-1α高表达是影响肝癌患者肝移植后肿瘤复发和转移的独立预后因素（P〈0.01）。结论：HIF-1α蛋白有望成为一个预测肝癌患者肝移植后复发和转移的重要指标。     

GATA5 inhibits hepatocellular carcinoma cells malignant behaviours by blocking expression of reprogramming genes

Evidence indicated that GATA5 may suppress hepatocellular carcinoma (HCC) cell malignant transformation, but the mechanism of how GATA5 affects cancer cell reprogramming to inhibit HCC malignant behaviour is still unclear. In this study, we report that the expression of β‐catenin and reprogramming genes p‐Oct4, Nanog, Klf4, c‐myc and EpCAM was significantly higher in HCC tissues compared to normal liver tissues. In contrast, the expression of GATA5 was significantly lower in HCC tissues compared to normal liver tissues. Transfection of CDH‐GATA5 vectors into HCC cells (HLE, Bel 7402 and PLC/PRF/5 cells) increased the GATA5 expression and decreased the expression of β‐catenin and reprogramming genes p‐Oct4, Nanog, Klf4, c‐myc and EpCAM. Increased GATA5 expression by transfection with its expression vectors was also able to inhibit the cell growth, colony formation and capability of migration, invasion, while promoting apoptosis in HCC cells. Results revealed that GATA5 co‐localization with β‐catenin in the cytoplasm, preventing β‐catenin from entering the nucleus. Treatment with the specific Wnt/β‐catenin pathway inhibitor salinomycin was able to reduce the expression of β‐catenin and reprogramming genes. Salinomycin exerted a similar influence as GATA5, and siRNA‐GATA5 restored β‐catenin and reprogramming gene expression. This study demonstrates that an increase in the expression of GATA5 inhibits the expression of β‐catenin and reprogramming genes and suppresses tumour growth, colony formation, metastasis and invasion, while promoting apoptosis in HCC cells. The mechanism of GATA5 inhibiting the malignant behaviours of HCC cells may involve in the disruption of the Wnt/β‐catenin pathway and the reduction of reprogramming gene expression.     

DNA methylation-dependent regulation of TrkA, TrkB, and TrkC genes in human hepatocellular carcinoma

The tropomyosin-related kinase (Trk) family of neurotrophin receptors, TrkA, TrkB and TrkC, has been implicated in the growth and survival of human cancers. Here we report that Trks are frequently overexpressed in hepatocellular carcinoma (HCC) from patients and human liver cancer cell lines. To unravel the underlying molecular mechanism(s) for this phenomenon, DNA methylation patterns of CpG islands in TrkA, TrkB, and TrkC genes were examined in normal and cancer cell lines derived from liver. A good correlation was observed between promoter hypermethylation and lower expression of TrkA, TrkB, and TrkC genes, which was supported by the data that inhibiting DNA methylation with 5-azacytidine restored expression of those genes in normal liver cell lines. Furthermore, Trks promoted the proliferation of HepG2 and induced expression of the metastatic regulator, Twist. These results suggest that Trks may contribute to growth and metastasis of liver cancer.     

c-Src kinase impairs the expression of mitochondrial OXPHOS complexes in liver cancer

Src family kinases (SFKs) play a crucial role in the regulation of multiple cellular pathways, including mitochondrial oxidative phosphorylation (OXPHOS). Aberrant activities of one of the most predominant SFKs, c-Src, was identified as a fundamental cause for dysfunctional cell signaling and implicated in cancer development and metastasis, especially in human hepatocellular carcinoma (HCC). Recent work in our laboratory revealed that c-Src is implicated in the regulation of mitochondrial energy metabolism in cancer. In this study, we investigated the effect of c-Src expression on mitochondrial energy metabolism by examining changes in the expression and activities of OXPHOS complexes in liver cancer biopsies and cell lines. An increased expression of c-Src was correlated with an impaired expression of nuclear- and mitochondrial-encoded subunits of OXPHOS complexes I and IV, respectively, in metastatic biopsies and cell lines. Additionally, we observed a similar association between high c-Src and reduced OXPHOS complex expression and activity in mouse embryonic fibroblast (MEF) cell lines. Interestingly, the inhibition of c-Src kinase activity with the SFK inhibitor PP2 and c-Src siRNA stimulated the expression of complex I and IV subunits and increased their enzymatic activities in both cancer and normal cells. Evidence provided in this study reveals that c-Src impairs the expression and function of mitochondrial OXPHOS complexes, resulting in a significant defect in mitochondrial energy metabolism, which can be a contributing factor to the development and progression of liver cancer. Furthermore, our findings strongly suggest that SFK inhibitors should be used in the treatment of HCC and other cancers with aberrant c-Src kinase activity to improve mitochondrial energy metabolism.     

骨桥蛋白通过调控MMP-2和VEGF参与肝癌细胞侵袭的机制研究

目的：骨桥蛋白（Osteopontin,OPN）在肝癌细胞侵袭中的作用机制。方法：采用siRNA干涉的方法处理人肝癌细胞,用PCR和Western-blot法检测OPN的表达;用transwell小室检测不同处理后的HepG2和MHCC97H细胞的侵袭能力;采用Western．b1．ot和ELISA方法检测基质金属蛋白酶-2（matrixmetalloproteinase-2,MMP-2）和血管内皮生长因子（vascularendothelialgrowthfactor,VEGF）蛋白表达和活力的变化情况。结果：在不同肝癌细胞系中,随着肝癌细胞系侵袭能力的增强,OPN的表达逐渐增高。siRNA可以降低HepG2和MHCC97H细胞中OPN的表达,并且能够降低HepG2和MHCC97H细胞的侵袭能力;抑制OPN的表达能够降低MMP-2和VEGF蛋白表达和蛋白活性。结论：OPN在肝癌侵袭过程中起着重要作用,其作用机制可能是通过调控MMP-2和VEGF蛋白表达和活性来参与肝癌的侵袭,OPN可作为肝癌侵袭转移治疗的新靶点。     

TCTP在肝癌细胞增殖过程中的作用及机制研究

目的:研究翻译控制肿瘤蛋白(TCTP)在肝癌细胞增殖过程中的作用及相关机制。方法:通过western blot技术检测14对肝癌与癌旁组织中TCTP的蛋白表达水平。通过siRNA(small interference RNA)技术在肝癌细胞系SMMC-7721和BEL-7404中下调TCTP的表达,然后通过CCK-8实验、克隆形成实验和EdU实验观察下调TCTP对肝癌细胞增殖的影响。通过western blot技术分析TCTP促进肝癌发生这一过程中可能涉及的分子通路。结果:相比于对应的癌旁组织,TCTP在肝癌组织中显著高表达。用siRNA技术下调TCTP水平后能够明显抑制肝癌细胞的增殖能力。下调TCTP的表达之后,AKT和ERK蛋白的磷酸化水平也随之降低。结论:TCTP在肝癌组织中显著高表达,并且在肝癌细胞的增殖过程中发挥着极其重要作用,其作用机制可能与AKT和ERK通路的磷酸化激活有关。     

DLC-1与肝癌关系研究

DLC-1基因是一种肿瘤抑制基因,位于人类染色体8p21．3-22。它是RhoA特异性GTP酶的激动蛋白,与调控细胞增殖和粘附的信号传导通路关系密切,在人类多种肿瘤中呈低表达或表达缺失。研究发现DLC-1基因在原发性肝癌(HCC)及肝癌细胞系中表达缺失,提示该基因在原发性肝癌中抑制了肝癌细胞的增殖。DLC-1表达的恢复引起了caspase-3介导的细胞凋亡,抑制肝癌细胞的生长和癌细胞的浸润,从而在肝细胞癌的转移、侵袭及肿瘤细胞的生物特性方面发挥作用。因其与肝癌发生,转移乃至复发关系密切,使其在肝癌早期发现,早期预测肝癌的转移复发及肝癌的预后方面发挥重要角色。     

Role of Hepatitis C Virus Induced Osteopontin in Epithelial to Mesenchymal Transition,Migration and Invasion of Hepatocytes

Osteopontin (OPN) is a secreted phosphoprotein which has been linked to tumor progression and metastasis in a variety of cancers including hepatocellular carcinoma (HCC). Previous studies have shown that OPN is upregulated during liver injury and inflammation. However, the role of OPN in hepatitis C virus (HCV)-induced liver disease pathogenesis is not known. In this study, we determined the induction of OPN, and then investigated the effect of secreted forms of OPN in epithelial to mesenchymal transition (EMT), migration and invasion of hepatocytes. We show the induction of OPN mRNA and protein expression by HCV-infection. Our results also demonstrate the processing of precursor OPN (75 kDa) into 55 kDa, 42 kDa and 36 kDa forms of OPN in HCV-infected cells. Furthermore, we show the binding of secreted OPN to integrin αVβ3 and CD44 at the cell surface, leading to the activation of downstream cellular kinases such as focal adhesion kinase (FAK), Src, and Akt. Importantly, our results show the reduced expression of epithelial marker (E-cadherin) and induction of mesenchymal marker (N-cadherin) in HCV-infected cells. We also show the migration and invasion of HCV-infected cells using wound healing assay and matrigel coated Boyden chamber. In addition, we demonstrate the activation of above EMT markers, and the critical players involved in OPN-mediated cell signaling cascade using primary human hepatocytes infected with Japanese fulminant hepatitis (JFH)-1 HCV. Taken together, these studies suggest a potential role of OPN in inducing chronic liver disease and HCC associated with chronic HCV infection.