目的 探讨Fas抗原和Caspase-8在化疗诱导人肝癌细胞凋亡中的调控作用。方法 用1×10-2mol/L浓度的氟尿嘧啶处理HepG2细胞，分别作用4、8、16、24 h。免疫细胞化学法检测Fas抗原的表达。用荧光试剂盒检测Caspase-8的活性。流式细胞仪检测氟尿嘧啶或抗-Fas-抗体诱导的肝癌细胞凋亡百分率，以及加入Caspase-8活性抑制剂IETD-FMK后凋亡百分率的变化。结果 氟尿嘧啶诱导HepG2细胞凋亡后，与对照组比较，Fas抗原表达强度增加（P<0.01），Caspase-8活性升高（P<0.01）。Fas抗原表达和Caspase-8活性随着氟尿嘧啶作用时间的延长而逐步升高,至16h后达到高峰，然后下降,但仍显著高于对照组（P<0.01）。Fas抗原的表达与Caspase-8活性变化呈显著正相关（r=0.969，P<0.01）。表达增强的Fas抗原具有转导凋亡信号的功能，借此抗-Fas-抗体增强了氟尿嘧啶诱导的HepG2细胞凋亡。Caspase-8活性抑制剂IETD-FMK能阻断Caspase-8活化而抑制氟尿嘧啶或抗-Fas-抗体诱导的HepG2细胞凋亡，实验组和抑制剂组比较，细胞凋亡百分率有显著性差异（P<0.01）。结论 氟尿嘧啶诱导HepG2细胞经Fas依赖途径凋亡。Caspase-8活性上调在该凋亡过程中发挥重要作用。

目的 研究孤立性原发性大肝癌的分子病理特征。方法 比较20例孤立性大肝癌与13例小肝癌、10例结节性肝癌的病理特征，并且采用免疫组织化学方法检测三组肝癌组织中与恶性肿瘤侵袭转移有关分子标志物的表达情况，包括PTEN蛋白、Survivin 蛋白、整合素αv 亚基、基质金属蛋白酶2（MMP2）以及微血管密度（MVD）。结果 孤立性大肝癌大多有包膜且呈膨胀性生长，肝硬化少，癌细胞分化较结节性肝癌好（P<0.05）。孤立性大肝癌的Survivin蛋白、整合素αv亚基、MMP2的表达及MVD均低于结节性肝癌，而PTEN蛋白明显高于结节性肝癌（P<0.05)，上述指标在孤立性大肝癌组与小肝癌组比较均无统计学差异（P>0.05）。结论 孤立性大肝癌具有特殊的临床和分子病理特征及相对好的肿瘤生物学行为。

目的 研究单结节原发性大肝癌的病理特征及与侵袭转移相关的分子标志物表达情况，以探讨其生物学特征。方法 比较20例单结节大肝癌与13例小肝癌、10例多结节肝癌的病理特征，用免疫组化方法检测并比较这三组肝癌中整合素αv亚基、基质金属蛋白酶2（matrix metalloproteinase22, MMP-2）的表达及肿瘤微血管密度（microvessel density, MVD）。结果 单结节大肝癌的肝硬化、细胞分化程度明显较多结节肝癌轻和好（P<0105），而癌组织坏死较小肝癌明显（P<0105）。整合素αv亚基、MMP-2的表达及MVD值在单结节肝癌中比在多结节肝癌中弱或低（P<0105） 。结论 单结节大肝癌比多结节者有相对良好的生物学行为特征，而与小肝癌相近。

AIM: To study the difference in gene expression between solitary large hepatocellular carcinoma (SLHCC) and nodular hepatocellular carcinoma (NHCC). METHODS: Polymerase chain reaction (PCR) products of 8464 human genes were spotted on a chip in array. DNAswere then fixed on a glass plate. Total RNA was isolated from freshly excised human SLHCC (n=7) and NHCC (n=15) tissues, and was reversely transcribed to cDNAs with the incorporation of fluorescent dUTP for preparation of hybridization probes. The mixed probes were then hybridizedto the cDNA microarray. After highly stringent washing, cDNA microarray was scanned for the fluorescent signalsto display the difference between the two kinds of HCC. In addition, the expression of RhoC and protocadherin LKC was also detected with the reverse transcriptase polymerase chain reaction (RT-PCR) method. RESULTS: Among the 8464 human genes, 668 (7.89%)genes were expressed differentially at the mRNA levels between SLHCC and NHCC. Three hundred and fifty five (4.19%) genes, including protocadherin LKC, were upregulated,whereas 313 (3.70%) genes, including RhoC, were down-regulated. The mRNA expression levels of RhoC and protocadherin LKC were confirmed by RT-PCR. Analysis of differentially expressedgenes confirmed that our molecular data obtained by cDNA microarray were consistent with the published biochemical and clinical observations ofSLHCC and NHCC. CONCLUSION: cDNA microarray is an effective technique in screening the difference in gene expression between SLHCC and NHCC. Many of these differentially expressed genes are involved in the invasion and metastasis of HCC.Further analysis of these genes will help to understand thedifferent molecular mechanisms of SLHCC and NHCC.

AIM: To study the relationship between hypoxia or epidermal growth factor (EGF) and the overexpression of vascular endothelial growth factor (VEGF) in hepatocellular carcinoma (HCC) and the signal transduction pathway of the transcription of VEGF in hepatoma cells. METHODS: Cobalt chloride and recombinant human EGF were used to stimulate the hepatoma cell lines HepG2. VEGF mRNA was detected by using of semi-quantitative polymerase chain reaction (RT-PCR). Specific inhibitors of phosphatidylinositol 3-kinase (PI3K) and p42/p44 mitogen activated protein kinase (MAPK) were used to observe the effects of the two kinases on the regulation of the transcription of VEGF in hepatoma cells. RESULTS: The expression of VEGF mRNA in HepG2 cells cultured in serum-free mediumwas 0.117. However, 100 nmol/L cobalt chloride for 24 h increased the expression of VEGF mRNA and VEGF mRNA increased gradually with the increase of the concentration and duration of cobalt chloride. Also, 25ng/mL recombinant human EGF stimulated the expression of VEGF in HepG2 cells and the expression increased with the increase of EGF concentration. 5nmol/L LY294002 inhibited the expression of VEGF stimulated by cobalt chloride or recombinant human EGF and the inhibition decreased step by step with increase of the concentration of LY294002. But even 20 mol/L LY294002 could not completely block theexpression of VEGF. In contrast, PD98059 had no inhibitory effects on the transcription of VEGF stimulated by cobalt chloride or recombinant human EGF. CONCLUSION: The overexpression of VEGF in HCC could be promoted by hypoxia and EGF expression in HCC. The signal transduction pathway of VEGF transcription in HepG2 cells may be through PI3K pathway, but not through p42/p44 MAPK pathway.