Frequent loss of RUNX3 gene expression in human bile duct and pancreatic cancer cell lines
Frequent loss of RUNX3 gene expression in human bile duct and pancreatic cancer cell lines
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DOI：
10.1038/sj.onc.1207395
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发表时间：
2004-03-25
期刊：
影响因子：
8
通讯作者：
Chiba, T
中科院分区：
文献类型：
--
作者：
Wada, M;Yazumi, S;Chiba, T
RUNX3是一种参与转化生长因子-β信号转导的Runt域转录因子，是一种候选的肿瘤抑制基因，定位于1p36，该区域在多种人类肿瘤中普遍缺失，包括胃、胆管和胰腺肿瘤。最近，在人类胃癌中发现了频繁的RUNX3失活。为了探讨RUNX3基因异常在胆管和胰腺癌发生发展中的作用，我们研究了RUNX3基因在10个人胆管和12个胰腺癌细胞系中的表达及其甲基化状态。Northern印迹分析和逆转录聚合酶链式反应均显示7例(70%)胆管和9例(75%)胰腺癌细胞株无RUNX3表达。RUNX3基因启动子CpG岛甲基化的16株未表达RUNX3的细胞株，而表达RUNX3的6株细胞株RUNX3启动子区域未发生甲基化或仅部分甲基化。此外，甲基化抑制剂5‘-氮杂-2’-脱氧胞苷的治疗激活了所有16个原本缺乏RUNX3表达的癌细胞株中RUNX3的mRNA表达。最后，通过荧光原位杂交检测，在16个缺乏RUNX3表达的癌细胞株中，有15个发现了RUNX3的半合子缺失。这些数据表明，RUNX3的失活在胆管和胰腺癌的发生中起着重要作用，甲基化是该基因失活的常见机制。
RUNX3, a Runt domain transcription factor involved in TGF-beta signaling, is a candidate tumor-suppressor gene localized in 1p36, a region commonly deleted in a wide variety of human tumors, including those of the stomach, bile duct, and pancreas. Recently, frequent inactivation of RUNX3 has been demonstrated in human gastric carcinomas. In this study, to examine the involvement of RUNX3 abnormalities in tumorigenesis of bile duct as well as pancreatic cancers, we investigated not only the expression but also methylation status of RUNX3 in 10 human bile duct and 12 pancreatic cancer cell lines. Seven (70%) of the bile duct and nine (75%) of the pancreatic cancer cell lines exhibited no expression of RUNX3 by both Northern blot analysis and the reverse transcriptase polymerase chain reaction. All of the 16 cell lines that did not express RUNX3 also showed methylation of the promoter CpG island of the gene, whereas the six cell lines that showed RUNX3 expression were not methylated or only partially methylated in the RUNX3 promoter region. Moreover, treatment with the methylation inhibitor 5'-aza-2'-deoxycitidine activated RUNX3 mRNA expression in all of 16 cancer cell lines that originally lacked RUNX3 expression. Finally, hemizygous deletion of RUNX3, as detected by fluorescence in situ hybridization, was found in 15 of the 16 cancer cell lines that lacked RUNX3 expression. These data suggest that the inactivation of RUNX3 plays an important role in bile duct and pancreatic carcinogenesis, and that methylation is a common mechanism by which the gene is inactivated.