XAF1抑制肝癌细胞增殖和诱导凋亡的实验研究

目的 X-染色体相关凋亡抑制蛋白（XIAP）相关因子1（XAF1）可与XIAP直接结合并拮抗其抗凋亡作用。本研究探讨XAF1基因在裸鼠体内抑制肝癌细胞增殖和诱导其凋亡的作用。方法应用免疫组织化学、TUNEL方法检测稳定高表达质粒DNA的肝癌细胞克隆Bel7404／XAF1、Bel7404／XAF1-AS和Bel7404／vector在体内的增殖和凋亡。结果Bel7404／XAF1组裸鼠肿瘤组织生长速度明显慢于其余两组的瘤组织（P〈0．05）,组成性高表达XAF1可以抑制裸鼠移植瘤的形成;TUNEL法检测Bel7404／vector的凋亡率为2．18％,Bel7404／XAF1凋亡率为7．09％,Bel7404／XAF1-AS凋亡率为2．91％（P〈0．05）。结论XAF1能够在体内抑制肝癌细胞增殖和诱导其凋亡,XAF1有可能成为肝癌基因治疗的新靶点。     

miR-155在肝细胞癌中的表达及对肝癌细胞增殖的影响

目的:检测微小RNA-155(miR-155)在肝癌组织中的表达并分析其对肝癌细胞增殖和细胞凋亡的影响.方法:采用TagMan MGB探针法荧光定量P C R分析42例原发性肝癌及对应的癌旁组织miR-155的表达;利用miR-155反义寡核苷酸(ASO-miR-155)降低肝癌细胞HepG2和SMMC7721中miR-155的表达;利用MTT比色法检测肝癌细胞增殖的变化,并通过流式细胞技术检测肝癌细胞早期凋亡情况.结果:42例肝癌及癌旁组织标本中,miR-155在52%(22/42)肝癌组织中的表达明显高于癌旁组织(P<0.05);利用脂质体将ASO-miR-155转染肝癌细胞HepG2和SMMC7721后,miR-155的表达明显降低,肝癌细胞HepG2和SMMC7721生长受到明显抑制;并且细胞的早期凋亡明显增加.结论:miR-155在肝癌组织中过表达,降低其表达能明显抑制肝癌细胞的生长并诱导细胞早期凋亡,miR-155有可能成为肝癌治疗的新靶点.     

洛铂对肝癌HepG2细胞增殖和调亡的作用及机制

目的在体外细胞中研究洛铂对肝癌HepG2细胞在增殖、凋亡方面的作用及其机制。方法将HepG2细胞分为洛铂组(增殖实验:5、10、15μmol/L组;凋亡实验:10μmol/L;侵袭实验:4μg/ml)和对照组(不加药物)。利用CCK8法和流式细胞术分别检测2组HepG2细胞的增殖和凋亡情况。通过Western Blot初步检测2组细胞中增殖、凋亡相关蛋白NF-κB、Bcl-2、Bax、Bid、Puma、Caspase-3的表达变化。增殖实验采用双因素方差分析,凋亡实验采用χ2检验,侵袭实验采用t检验。结果在作用于细胞24、48、72 h后,对照组与实验组细胞生长增殖抑制率差异有统计学意义(F=273.5,P<0.01),同一时间不同浓度间、同一浓度不同时间差异均有统计学意义(F分别为1857、1365,P值均<0.01)。2组间细胞凋亡率比较差异有统计学意义(χ2=1821,P<0.001)。实验组HepG2细胞中穿透Transwell小室的细胞数少于对照组(21.30±2.74 vs 45.00±4.26,t=11.89,P<0.001)。洛铂组HepG2细胞Bcl-2表达水平下降,NF-κB、Bax、Puma、Caspase-3表达水平升高。结论洛铂可通过影响一系列增殖、凋亡蛋白发挥抑制肝癌细胞增殖及促进凋亡的作用,但细胞内信号通路复杂,需要进一步研究。     

细胞凋亡与细胞增殖在人肝细胞癌中的表达和意义

目的：为了解人肝细胞癌中细胞凋的形态与分布规律，探索细胞凋亡标记率和增殖标记率与肝细胞癌组织学分级的关系。方法：对21例人肝细胞癌和17例慢性肝病分别作TUNEL标记和PCNA免疫组化检测，采用图像细胞仪作阳性细胞计数。结果：(1)细胞核染色质浓缩、边聚、胞浆嗜酸性变及核周空晕与TUNEL标记有极好的相关性：(2)凋亡细胞多呈弥散分布，以癌坏死区周围多见，包膜浸润处少见；(3)增殖细胞和凋亡细胞率与肝癌组织学分级呈正相关，Ⅲ级组肝细胞癌中增殖细胞率为278±6．4高于Ⅱ级组141±35(P<0．01)，又高于Ⅰ级组7．4±0．8(P<0.001)，Ⅲ级组肝细胞癌中凋亡细胞率为21±0．97高于Ⅱ级组0.92±O.26(P<0.05)，又高于Ⅰ级组0．45±0.08(P<0．001)(4)包膜浸润和门脉癌栓组凋亡细胞率和增殖细胞率均高于无包膜浸润和门脉癌检组结论：本研究提示细胞凋亡和细胞增殖与肝细胞癌组织学分级、包膜浸润和门脉癌检密切相关。     

细胞凋亡与细胞增殖在人肝细胞癌中的表达和意义

目的了解人肝细胞癌中细胞凋亡的形态与分布规律，探索细胞凋亡标记率和增殖标记率与肝细胞癌组织学分级的关系。方法 对２１例人肝细胞癌和１７例慢性肝病分别作ＴＵＮＥＬ标记和ＰＣＮＡ免疫组化检测，采用图像细胞仪作阳性细胞计数。结果 （１）细胞核染色质浓缩，边聚，胞浆嗜酸性变及核周空晕与ＴＵＮＥＬ标记有极好的相关性；（２）凋亡细胞胞多呈弥散分布，以癌坏死区周围多见，包膜浸润处少见；（３）增殖细胞率和凋亡细胞     

丙型肝炎病毒F蛋白抑制肝癌细胞增殖功能的研究

目的 研究HCV F蛋白的生物学功能.方法 扩增目的基因片段,通过酶切连接方法将编码HCV F蛋白的基因片段克隆至载体pSEB-3Flag中,用构建好的重组质粒pSEB-3Flag-F转染Huh7、SMMC7721细胞,经Blasticidine抗性筛选,拟建立HCV F蛋白稳定表达的细胞株,用RT-PCR方法检测HCV-F基因的表达.通过MTS、细胞计数、结晶紫以及流式细胞检测实验观察F蛋白对转染细胞增殖和细胞周期的影响.计量资料分析采用t检验.结果 成功建立了HCV F基因稳定表达的细胞株Huh7-F和SMMC7721-F,MTS、细胞计数实验均证实Huh7-F和SMMC7721-F细胞较对照细胞增殖速度减慢,Huh7-F稳定细胞株结晶紫定量A值为1.072±0.070,对照组为1.387±0.005(t=-6.347,P＜0.05);SMMC7721-F稳定细胞株A值为1.594±0.007,对照组为1.921±0.090(t=-4.81,P＜0.05).流式细胞仪检测Huh7-F稳定细胞株48hS期细胞百分比分别为47.12％±0.04％,对照组S期细胞数为55.32％000±1.45％(t=-7.99,P＜0.05);SMMC7721-F稳定细胞株S期细胞百分比分别为30.75％±0.09％,对照组S期细胞数为33.23％±0.28％(t=-5.91,P＜0.05).结论 稳定转染HCV F基因可以明显抑制Huh7细胞、SMMC7721细胞的增殖.     

miR-221/222在肝癌细胞抵抗内质网应激凋亡中的作用

目的 研究内质网应激对miR-221/222的调控及其在肝癌细胞抵抗内质网应激诱导细胞凋亡中作用.方法 采用miR-221/222抑制物和miR-221/222类似物分别阻断或模拟内源性miR221/222的功能,并利用Western blot和流式细胞技术分析内质网应激条件下miR-221/222对肝癌细胞周期和凋亡的调控作用.结果 内质网应激诱导miR-221/222表达下调,miR-221/222类似物和抑制物分别抑制和促进内质网应激诱导的p27Kip1表达上调,干扰p27Kip1不仅抑制了内质网应激诱导的肝癌细胞G0/G1期阻滞,也促进了内质网应激介导的肝癌细胞凋亡.结论 内质网应激诱导miR-221/222下调能够通过促进p27Kipl表达对内质网应激条件下肝癌细胞周期和凋亡起重要调控作用.

Abstract：

Objective To investigate the role of miR-221/222 in inhibiting endoplasmic reticulum stress-induced human hepatocarcinoma cells apoptosis. Method miR-221/222 mimics and inhibitors were used to mimic or block the function of endogenous miR-221/222 respectively. Western blot and flow cytometry were used to test the effects of miR-221/222 on cell cycle and apoptosis under endoplasmic reticulum stress in human hepatocellular carcinoma cells. Results Endoplasmic reticulum stress resulted in miR-221/222down-regulation in human hepatocellular carcinoma cells. miR-221/222 mimics and inhibitors inhibited and promoted respectively endoplasmic reticulum stress-mediated p27Kip1 induction. Moreover, p27Kip1 suppression not only resulted in reduction in the fraction of G1 phase cells, but also promoted the endoplasmic reticulum stress-mediated apoptosis in human hepatocellular carcinoma cells. Conclusions miR-221/222 were downregulated by endoplasmic reticulum stress in human hepatocellular carcinoma cells, which subsequently protected human hepatocellular carcinoma cells against endoplasmic reticulum stress-induced apoptosis through p27KiP1 regulation.     

miR-409-3p在肝癌HepG2细胞中的表达及其在细胞增殖中的作用机制

目的 本研究旨在明确miR-409-3p在肝癌细胞系中的表达及其意义,并探讨可能的分子机制。方法 利用实时荧光定量PCR的方法检测miR-409-3p在正常肝细胞LO2,以及HepG2、BEL-7402、SMMC-7721、MHCC-97H四种肝癌细胞中的表达差异。阳离子脂质体法将miR-409-3p mimics及microRNA mimics control瞬时转染至肝癌细胞株HepG2中,利用CCK8法、平板克隆、流式细胞术检测miR-409-3p对体外癌细胞增殖、细胞周期及凋亡的影响。Western Blot检测过表达miR-409-3p的HepG2细胞中c-Met蛋白的表达变化,荧光素酶报告系统鉴定靶向关系。计量资料两组间比较采用成组t检验,多组间比较采用单因素方差分析,进一步两两比较采用SNK法。结果 基于TCGA肝癌microRNA表达谱数据,肝癌组织中miR-409-3p的表达水平显著低于癌旁组织(t=7.752,P<0.05)。与在LO2中的表达水平相比,miR-409-3p在HepG2、SMMC-7721、MHCC-97H、BEL-7402中的表达水平均明显降...     

环状RNA-UBXN7促进肝癌细胞增殖和迁移并抑制其凋亡

目的探讨环状RNA-UBXN7(circ_UBXN7)对肝癌细胞增殖、迁移以及凋亡的影响,并初步探讨其中的分子机制。方法采用qRT-PCR检测circ_UBXN7在肝癌组织和细胞中的表达水平,并分析circ_UBXN7与患者临床病理因素如年龄、性别、肿瘤体积、病理分型、分期、淋巴结转移之间的相关性。构建携带circ_UBXN7全长序列的慢病毒(Lenti-circ_UBXN7)和携带circ_UBXN7 shRNA的慢病毒(Lenti-circ_UBXN7-shRNA)分别转染肝癌细胞株(HepG2和HUH-7)。CCK-8实验检测circ_UBXN7表达上调或下调后对HepG2和HUH-7细胞的增殖能力的影响。Annexin V/PI实验检测circ_UBXN7表达上调或下调后HepG2和HUH-7细胞的凋亡变化。JC-1法检测circ_UBXN7表达上调或下调后HepG2和HUH-7细胞线粒体势能的变化。Transwell检测circ_UBXN7表达上调或下调后HepG2和HUH-7细胞迁移能力变化。蛋白质印迹法检测细胞上皮间质化标志蛋白TWIST、E-钙黏蛋白(E-cadherin)、N-cadherin、Vimentin的表达变化。circ_UBXN7表达水平与临床病理因素采用χ2检验,两组比较采用t检验,三组及以上比较采用单因素方差分析且组间比较采用LSD法。结果circ_UBXN7在肝癌组织中表达显著高于癌旁组织,且其表达水平与肿瘤体积、分期和淋巴结转移显著正相关(P<0.05)。Lenti-circ_UBXN7可以上调HepG2和HUH-7细胞内circ_UBXN7表达并促进细胞增殖;Lenti-circ_UBXN7-shRNA可以下调circ_UBXN7表达并诱导细胞凋亡。Lenti-circ_UBXN7-shRNA可以导致细胞线粒体膜势能降低。Lenti-circ_UBXN7可以促进细胞迁移,而Lenti-circ_UBXN7-shRNA可以抑制细胞迁移。Lenti-circ_UBXN7可以诱导Twist、N-cadherin、Vimentin蛋白表达增高,并降低E-cadherin蛋白表达;而Lenti-circ_UBXN7-shRNA对各蛋白表达水平的影响则相反。Starbase V2.0软件显示miR-203a与circ_UBXN7存在潜在结合位点,并且在HepG2和HUH-7细胞中miR-203a与circ_UBXN7表达水平呈负相关。结论circ_UBXN7在肝癌发生发展中发挥重要促癌作用,有望成为肝癌治疗的潜在靶点。     

普罗布考抑制过氧化氢刺激大鼠主动脉平滑肌细胞增殖的机制

目的研究普罗布考抑制过氧化氢促大鼠主动脉平滑肌细胞增殖的机制。方法采用MTT3、H-胸腺嘧啶核苷掺入法、流式细胞术和逆转录聚合酶链反应观察过氧化氢刺激条件下普罗布考对血管平滑肌细胞细胞周期、DNA合成、细胞增殖和凋亡的影响。结果普罗布考抑制过氧化氢刺激血管平滑肌细胞增殖和DNA合成。与过氧化氢组比较,普罗布考 过氧化氢组细胞计数、吸光度值和3H-胸腺嘧啶核苷掺入量分别下降了46.9%、45.0%和39.5%(P<0.05)。普罗布考通过使血管平滑肌细胞生长停滞在G0/G1期抑制过氧化氢刺激细胞增殖。过氧化氢使细胞外信号调节激酶1 mRNA相对表达量增加近6倍,丝裂原活化蛋白激酶磷酯酶1 mRNA相对表达量下降了82.2%。普罗布考抑制细胞外信号调节蛋白激酶1 mRNA的表达,增强丝裂原活化蛋白激酶磷酯酶1 mRNA的表达。普罗布考诱导过氧化氢刺激条件下血管平滑肌细胞凋亡。结论普罗布考通过下调细胞外信号调节蛋白激酶1 mRNA的表达抑制细胞周期运转和诱导血管平滑肌细胞凋亡两种机制抑制过氧化氢刺激血管平滑肌细胞增殖。     

Ethanol Inhibition of Insulin Signaling in Hepatocellular Carcinoma Cells

Chronic ethanol toxicity impairs liver regeneration, inhibits DNA synthesis, and mutes cellular responses to growth factor stimulation. Previous studies demonstrated that the adverse effects of ethanol are mediated by inhibition of tyrosyi phosphorylation of the insulin receptor and the insulin receptor substrate-type 1 (IRS-1). However, overexpression of IRS-1 leads to increased DNA synthesis and cellular transformation due to constitutive activation of mitogen-activated protein (MAP) kinase. The present study examines the effects of ethanol on insulin signaling through IRS-1 in FOCUS hepatocellular carcinoma cells, which overexpress IRS-1, to determine whether such ceils were resistant to the inhibitory effects of ethanol. The results demonstrated that ethanol treatment (100 mM) caused 30 to 50% reductions in the levels of insulin-stimulated tyrosyi phosphorylation of the insulin receptor β-subunit, tyrosyi phosphorylation of IRS-1, phosphorylation of Erk2, association of phosphatidylinositol-3 kinase with tyrosyl-phosphorylated IRS-1, and MAP kinase and phosphatidylinositol-3 kinase activities. In contrast, ethanol treatment had no effect on epidermal growth factor-stimulated tyrosyi phosphorylation of She. Corresponding with the pronounced inhibition of MAP kinase, ethanol treatment resulted in 30 to 50% reductions in the expression levels of two important insulin-responsive genes: glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and proliferating cell nuclear antigen (PCNA). The findings suggest that, in FOCUS hepatocellular carcinoma cells, which overexpress IRS-1, ethanol treatment substantially inhibits IRS-1 and MAP kinase signaling and growth-associated gene expression, but has no effect on She phosphorylation, which activates p21^ras through an IRS-1 independent pathway.     

Comparison of Percutaneous Acetic Acid Injection and Percutaneous Ethanol Injection for Hepatocellular Carcinoma in Cirrhotic Patients: A Prospective Study

Background: Ultrasound-guided percutaneous ethanol injection (PEI) and percutaneous acetic acid injection (PAI) are effective in the treatment of hepatocellular carcinoma (HCC). We conducted a prospective study to compare the therapeutic efficacy of both these methods. Methods: Sixty-three patients were treated by PAI using 50% acetic acid and 62 by PEI using pure ethanol. There were no significant baseline differences in age, sex, Child-Pugh class, tumour size and number, or other clinico-biochemical parameters between the two groups. Results: During a follow-up period of 24 ± 9 (range 6-38) months, 19 (30%) of the PAI group and 21 (34%) of the PEI group died ( P &#114 = &#114 0.704). The 1- and 3-year survival rates were 84% and 51% for the PAI group and 81% and 46% for the PEI group ( P &#114 = &#114 0.651). The corresponding tumour recurrence rates were 51% and 74% for the PAI group, and 54% and 64% for the PEI group ( P &#114 = &#114 0.787). The treatment sessions were 3.9 ± 1.6 and 6.2 ± 2.3 for the PAI and PEI groups, respectively, in each treatment cycle ( P &#114 = &#114 0.008). A multivariate analysis using the Cox regression model revealed that ascites (relative risk (RR) 3.1, 95% confidence interval (CI) 1.5-6.3, P &#114 = &#114 0.002), large (>3 &#114 cm) or multinodular HCCs (RR 2.4, 95% CI 1.1-5.4, P &#114 = &#114 0.04), and development of tumour recurrence (RR 7.0, 95% CI 3.1-16.0, P &#114 < &#114 0.001) were independent, poor prognostic factors in both groups. Conclusions: PAI and PEI are equally effective in the treatment of HCC. PAI has the advantage of fewer treatment sessions in each treatment course. Careful pretreatment patient selection may improve survival.     

3种选择性环氧合酶-2抑制剂对肝细胞癌生长的影响

背景肝细胞癌(HCC)中有环氧合酶(COX)-2表达,非甾体抗炎药阿司匹林可能通过抑制COX-2的表达而抑制HCC生长.目的比较3种选择性COX-2抑制剂美洛昔康、赛来昔布和罗非昔布对人肝癌细胞株SMMC-7721 生长的影响,观察高选择性COX-2抑制剂罗非昔布对裸鼠HCC原位移植瘤生长的影响.方法采用3H-胸腺嘧啶核苷(3H-TdR)掺入检测SMMC-7721细胞的DNA合成情况;采用免疫细胞化学染色检测增殖细胞核抗原(PCNA)的表达;采用DNA原位末端标记(TUNEL)染色检测细胞凋亡.给予HCC原位移植瘤裸鼠罗非昔布每日30 mg/kg 8周,测量肿瘤体积和重量.结果美洛昔康、赛来昔布和罗非昔布均能显著抑制SMMC-7721细胞的3H-TdR掺入,其抑制作用呈剂量依赖性,50%抑制浓度(IC50)分别为8.55×10-8mol/L、1.22×10-8mol/L和6.27×10-9 mol/L.3种选择性OX-2抑制剂(1×10-5 mol/L)作用24 h均可明显降低SMMC-772I细胞的PCNA表达,使细胞凋亡指数较对照组显著增高(14.6%±2.8%、21.6%±3.6%和27.1%±3.5%对1.0%±0.7%,P＜0.01),COX-2抑制剂的选择性越高,凋亡指数也越高(P＜0.01).罗非昔布组裸鼠的HCC原位移植瘤显著小于对照组,体积抑瘤率和重量抑瘤率分别为73.2%和78.1%.结论3种选择性COX-2抑制剂均能在体外有效抑制SMMC-7721细胞的生长,选择性越高,抑制作用越强.罗非昔布在体内能抑制HCC的生长,可能成为治疗HCC的有效药物.     

The Role of Fas/Fas Ligand System in the Pathogenesis of Liver Cirrhosis and Hepatocellular Carcinoma

Background

The Fas receptor/ligand system including soluble forms is the most important apoptotic initiator in the liver. Dysregulation of this pathway may contribute to abnormal cell proliferation and cell death and is regarded as one of the mechanisms preventing the immune system from rejecting the tumor cells.

Objectives

To analyze the role of Fas system Fas/ Fas ligand (Fas/ FasL) in the multi-step process of hepatic fibrosis/carcinogenesis, and to use of the serum markers as possible candidate biomarkers for early detection of hepatocellular carcinoma (HCC).

Patients and Methods

Ninety patients were enrolled: 30 cases of chronic hepatitis C (CHC) without cirrhosis, 30 cases of CHC with liver cirrhosis, and 30 cases of HCC and hepatitis V virus (HCV) infection. Ten wedge liver biopsies, taken during laparoscopic cholecystectomy, were served as normal controls. Serum soluble Fas (sFas) levels were measured using ELISA technique; Fas and FasL proteins were detected in hepatic tissue by indirect Immuno-histochemical technique (IHC); electron microscopic (EM) and immune electron microscopic examinations were performed for detection of Fas expression on lymphocytes.

Results

Hepatic expression of both Fas and FasL as well as expression of Fas on separated lymphocytes were significantly increased in the diseased groups (P < 0. 01) compared to the control specimens. The highest expression was noticed in CHC specimens, particularly with the necro-inflammatory activity and advancement of the fibrosis. The sFas in cirrhotic patients and HCC were significantly higher than that in normal controls and CHC without cirrhosis group (P < 0.01).

Conclusions

Apoptosis and the Fas system were significantly involved in the process of converting liver cirrhosis into hepatocellular carcinoma. Down-regulation of Fas expression, up regulation of FasL expression in hepatocytes, and elevation of serum sFas levels were important in tumor evasion from immune surveillance, and in hepatic carcinogenesis.     

Association of Upregulated HMGB1 and c-IAP2 Proteins With Hepatocellular Carcinoma Development and Progression

Background:

Hepatocellular carcinoma (HCC) is one of the most important health problems in China.

Objectives:

This study analyzed expression of high-mobility group protein B1 (HMGB1) and inhibitor of apoptosis protein-2 (c-IAP2) proteins in HCC compared to paired para-tumor tissue samples to assess the association with HCC pathogenesis and progression.

Materials and Methods:

Sixty-eight HCC and para-tumor tissue samples were collected for Western blot, qRT-PCR and immunohistochemical analyses of HMGB1 and c-IAP2.

Results:

HMGB1 and c-IAP2 proteins were highly expressed in HCC tissue samples [85.3% (58/68) and 82.4% (56/68), respectively] compared to para-tumor tissue samples [32.3% and 27.9%, respectively]. Furthermore, expression of HMGB1 was significantly associated with enhanced c-IAP2 expression in HCC tissue samples (r = 0.878, P < 0.01). Expression of HMGB1 was associated with tumor multiplicity and size, alpha-fetoprotein (AFP) level and advanced TNM stage, while expression of c-IAP2 was associated with tumor size, AFP level and advanced TNM stage.

Conclusions:

Expression of HMGB1 and c-IAP2 proteins was associated with HCC development and progression, and the expression of HMGB1 and c-IAP2 proteins in HCC were significantly associated with each other. Additionally, these proteins may show promise as biomarkers to predict HCC progression.     

肝细胞癌患者HCV感染及其致癌机理研究

目的：揭示肝细胞癌患者的ＨＣＶ感染情况及其致癌机理。方法：应用免疫组织化学ＳＰ法对４６例肝细胞癌癌组织及其３８例癌旁肝组织中丙型肝炎病毒核心抗原作了定位研究，并进一步检测其中癌基因ｒａｓ、ｃｍｙｃ和抑癌基因ｐ５３的蛋白表达。结果：核心抗原的检出率分别为２１７％和３６８％，４６例肝癌患者中１６例存在丙型肝炎病毒感染；ｐ２１、ｃｍｙｃ和ｐ５３蛋白在癌组织中的检出率分别为５８７％、６７４％和３０４％；丙型肝炎病毒感染的阳性与阴性组患者之间的ｐ２１、ｃｍｙｃ和ｐ５３蛋白的表达无显著性差异（Ｐ＞０．０５）；两组患者癌旁肝硬化的阳性率分别为８７５％和８６７％（Ｐ＞００５）。结论：上述结果提示丙型肝炎病毒致肝细胞癌的机理可能与ｒａｓ、ｃｍｙｃ和ｐ５３基因的激活或失活无关，其机理尚待进一步探索     

Potential Role and Clinical Value of PPP2CA in Hepatocellular Carcinoma

Background and AimsProtein phosphatase 2A (PP2A) is associated with many cancers. This study aimed to clarify whether PPP2CA, which encodes the alpha isoform of the catalytic subunit of PP2A, plays a role in hepatocellular carcinoma (HCC) and to identify the potential underlying molecular pathways.MethodsBased on bioinformatics, public databases and our in-house RNA-Seq database, we analyzed the clinical value and molecular mechanism of PPP2CA in HCC.ResultsData were analyzed from 2,545 patients with HCC and 1,993 controls without HCC indexed in The Cancer Genome Atlas database, the Gene Expression Omnibus database and our in-house RNA-Seq database. PPP2CA expression was significantly higher in HCC tissue than in non-cancerous tissues (standardized mean difference: 0.69, 95% confidence interval [CI]: 0.50–0.89). PPP2CA expression was able to differentiate HCC from non-HCC, with an area under the summary receiver operator characteristic curve of 0.79 (95% CI: 0.75–0.83). Immunohistochemistry of tissue sections confirmed that PPP2CA protein was up-regulated in HCC tissues. High PPP2CA expression in HCC patients was associated with shorter overall, progression-free and disease-free survival. Potential molecular pathways through which PPP2CA may be involved in HCC were determined using miRWalk 2.0 as well as analysis of Gene Ontology categories, Kyoto Encyclopedia of Genes and Genomes pathways, and protein-protein interaction networks.ConclusionsPPP2CA is up-regulated in HCC and higher expression correlates with worse prognosis. PPP2CA shows potential as a diagnostic marker for HCC. Future studies should examine whether PPP2CA contributes to HCC through the candidate microRNAs, pathways and hub genes identified in this study.     

氧化应激在肝细胞癌中的研究进展

肝细胞癌(HCC)是消化系统常见恶性肿瘤之一,数条涉及增殖和凋亡调节的分子通路参与了HCC的形成,但相关机制目前尚未完全明确。近年研究发现,环境或细胞线粒体功能障碍等因素造成的氧化应激参与了HCC的形成。本文就氧化应激在HCC中的研究进展作一综述。