Tobita Hiroshi, Kajino Kazunori, Inami Kouichi, Kano Sayaka, Yasen Mahmut, Imamura Osamu, Kinoshita Yoshikazu, Hino Okio
Department of Pathology, Juntendo University School of Medicine, Hongo, Tokyo 113-8421, Japan.
Int J Oncol. 2006 Sep;29(3):673-9.
We recently reported that the expression of dbpA (DNA binding protein A) is associated with advanced stages of human hepatocellular carcinoma (HCC) and that its transcription is positively regulated by E2F1, which is also implicated in hepatocarcinogenesis. To study the in vivo effect of dbpA on hepatocarcinogenesis, we generated the dbpA-transgenic mouse that specifically expressed a transgene in hepatocytes. Here, we studied the effect of dbpA on the expression of other cellular genes by using microarray analyses. The expression profiles from livers of 31- and 32-week-old male transgenic mice [Tg(+)] that did not show any morphological changes and from livers of their male wild-type littermates [Tg(-)] were compared. Expression differences detected by microarray analyses were validated by reverse transcription-polymerase chain reaction (RT-PCR) using total RNA samples from livers of 3 pairs of Tg(+) and (-) mice. The 11 up-regulated genes included 7 carcinogenesis-related genes (Igfbp1, Tff3, Hpx, Orm2, Ctsl, Plg, Jdp1), and the 9 down-regulated genes included Car3 that is associated with the protection of cells from attack by oxygen radicals. We confirmed that the expression of Igfbp1 (insulin like growth factor binding protein 1) was reduced by siRNA targeting dbpA in the human HCC cell line. In conclusion, our present data suggested that dbpA could be positively involved in carcinogenesis by changing the expression profiles of cellular genes.
我们最近报道，dbpA（DNA结合蛋白A）的表达与人类肝细胞癌（HCC）的晚期阶段相关，并且其转录受E2F1正向调控，E2F1也与肝癌发生有关。为了研究dbpA在肝癌发生中的体内作用，我们构建了在肝细胞中特异性表达转基因的dbpA转基因小鼠。在此，我们通过微阵列分析研究了dbpA对其他细胞基因表达的影响。比较了31周龄和32周龄未表现出任何形态变化的雄性转基因小鼠[Tg(+)]肝脏与它们的雄性野生型同窝小鼠[Tg(-)]肝脏的表达谱。通过微阵列分析检测到的表达差异，使用来自3对Tg(+)和(-)小鼠肝脏的总RNA样本，通过逆转录聚合酶链反应（RT-PCR）进行验证。11个上调基因包括7个与致癌作用相关的基因（Igfbp1、Tff3、Hpx、Orm2、Ctsl、Plg、Jdp1），9个下调基因包括与保护细胞免受氧自由基攻击相关的Car3。我们证实在人肝癌细胞系中，靶向dbpA的小干扰RNA（siRNA）可降低Igfbp1（胰岛素样生长因子结合蛋白1）的表达。总之，我们目前的数据表明，dbpA可能通过改变细胞基因的表达谱而积极参与致癌作用。
