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.

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。