用树鼩cDNA芯片研究树鼩肝癌中参与信号传导的部分基因变化情况

目的利用树鼩cDNA芯片研究黄曲霉毒素B1（AFBl）和（或）乙型肝炎病毒（HBV）引起的树鼩肝细胞癌（HCC）发生过程中参与信号传导的部分基因表达变化情况，从而进一步探讨HCC发生的分子机制。方法实验树鼩分3组：A组（AFB1组）、B组（AFB1＋HBV组）、C组（正常对照组）。所有动物在实验过程中定期接受剖腹手术取肝组织检查，至肝癌形成时处死动物取肝癌和癌旁组织。用树鼩cDNA芯片检测实验第30、60、90周肝活检组织、肝癌组织及其癌旁组织中各基因的表达情况，并用实时逆转录聚合酶链反应（Real time RT-PCR）法验证cDNA芯片结果。结果在A组和B组从癌前到癌变过程中胰岛素样生长因子-Ⅱ（IGF-Ⅱ）、C-rel、核因子-κB2（NF—κB2）均显示有差异表达，同时bcl-2、细胞周期素A（cyclin A）、睫状神经营养因子（CNTF）仅在B组显示有差异表达。而C组这几个基因无差异表达。实验组与对照组比较，在诱癌的早、中期（30、60周）均出现CNTF及cyclin A的差异表达。realtime RT PCR结果与cDNA芯片检测结果基本一致。A组IGF-Ⅱ、C—rel基因及B组IGF-Ⅱ基因，在肝癌组织表达水平明显低于癌旁及实验30、60周组织，而癌旁与实验30、60周相比较则无明显差异；B组CNTF基因在癌旁、肝癌及60周之间比较无明显改变，但均明显高于30周；A组CNTF基因表达水平在癌旁、肝癌组织高于癌前组织，但差异无统计学意义；C组这3个基因不同时期比较亦无明显差异。结论树目自部分信号传导通路相关cDNA芯片应用于检测树目目HCC发生过程中信号传导通路中各基因表达的变化，对进一步了解树鼠甸HCC发生的机制有重要实用价值。IGF-Ⅱ、NF-κB2、C-rel、Bcl-2、cyclin A及CNTF这几个基因与树HCC的发生发展密切相关。

A cDNA microarray study of the differential expression of genes in signal transduction pathway during hepatocarcinogenesis in tree shrews

OBJECTIVES: To study the differential expression of genes in signal transduction pathway (STP) during the hepatocarcinogenesis in tree shrews induced by AFB1 and/or HBV and to elucidate the molecular mechanism of hepatocellular carcinoma (HCC) development. METHODS: Adult tree shrews were divided into three groups: Group A was fed AFB1 only, Group B was infected firstly with HBV then fed AFB1 as in Group A, Group C served as the normal control. Liver biopsies were obtained at the 30th, 60th and 90th week of the experiment or until HCC occurred and the animals were sacrificed. Tree shrew-specific cDNA microarray was applied for detecting the differential expression of corresponding genes in each group at different time points during the experiment, and real time RT PCR was applied to verify the results of the cDNA microarray. RESULTS: Genes of IGF-II, C-rel, and NF-kappaB2 were differentially expressed between para-cancerous tissues and HCC tissues in both group A and group B, and the differential expression of bcl-2, cyclin A and CNTF was only seen in group B. Between the experimental groups A and B and the control group C, there were differential expressions of CNTF and cyclin A in the early 30th week and middle 60th week stage of hepatocarcinogenesis in tree shrews. Real time RT PCR results showed that the expression level of IGF-II and C-Rel in group A and of IGF-II in group B in HCC tissues were significantly lower than that in the adjacent non-cancerous tissues and in the biopsies taken at the 30th and 60th week of the experiment. Nevertheless, there were no significant differences between the para-cancerous tissues and the cancer tissues at the 30th and 60th week. These results were consistent with the cDNA microarray assay. The expression levels of C-Rel and CNTF in group B were not obviously altered in the para-cancerous tissues, HCC and at the 60th week, but they were significantly lower in these tissues than that in the tissues at the 30th week. In group A, the expression levels of CNTF in adjacent liver and HCC tissues were higher than that in para-cancerous lesions, but the difference did not reach a statistically significant level. In group C, the expression level of IGF-II, C-Rel and CNTF at different stages showed no significant differences, which was consistent with the cDNA microarray results. CONCLUSIONS: To apply the tree shrew-specific cDNA microarray to detect the differential expression of genes related to signal transduction pathway during tree shrew hepatocarcinogenesis could be a valuable utility for further comprehending the mechanism of HCC. IGF-II, NF-kappaB2, C-rel, Bcl-2, and cyclin A. CNTF may be involved in the occurrence and progress of HCC in tree shrews.