甲状腺乳头状癌中NIS基因启动子区5′-CpG岛异常甲基化状况及其意义

The Status of 5'-CpG Island Promoter Methylation of Sodium Iodide Symporter Gene in Papillary Thyroid Cancer and its Significance

[目的]探讨甲状腺乳头状癌(PTC)钠/碘协同转运体(Na+/I-symporter,NIS)基因启动子区5′-CpG岛异常甲基化状态及其与临床病理参数之间的关系。[方法]应用实时荧光甲基化特异性聚合酶链反应(real-timemethylation-specificPCR,qMSP)分别检测152例PTC患者癌组织及其癌旁正常组织中NIS基因启动子区域5′-CpG岛甲基化情况,并分析其与临床病理等参数之间的关系。[结果]在152例PTC组织中,NIS基因启动子区域5′-CpG岛甲基化率为30.9%(47/152),而癌旁正常组织中甲基化率为6.58%(10/152),两组比较存在显著性差异(P<0.01)。NIS基因启动子区域5′-CpG岛甲基化与肿瘤病灶数目、淋巴结转移及临床分期有关(P<0.05),与肿瘤大小、局部侵犯、性别和年龄等无关(P>0.05)。[结论]NIS基因启动子区域5′-CpG岛的异常甲基化是PTC频发的分子事件,可能是导致甲状腺细胞摄碘率下降的重要原因之一,在PTC的发生发展过程中发挥着重要作用。

[Purpose] To investigate the status of 5＇-CpG island promoter methylation of sodium iodide symporter（NIS） gene in papillary thyroid cancer（PTC） and its relationship with clinical features.[Methods] The status of 5＇-CpG island promoter methylation of NIS gene in cancer tissues and in cancer adjacent tissues of the 152 cases with PTC was detected by real-time methylationspecific PCR（qMSP）.And the relationship between the status of NIS 5＇-CpG island methylation and clinical pathological parameters was analyzed.[Results] The methylation rate of 5＇-CpG island of NIS gene in cancer tissues and in cancer adjacent tissues of the 152 cases was 30.9%（47/152） and 6.58%（10/152） respectively,with significant difference（P 0.01）.The 5＇-CpG island promoter methylation of NIS gene in PTC was related to number of lesions,lymph node metastasis and clinical stage（P0.05）,and not related to tumor size,local invasion,gender and age（P0.05）.[Conclusion] 5＇-CpG island promoter methylation of NIS region is a common molecular event in PTC,and it may be one of the reasons of iodine uptake rate decreasing in thyroid cells,which plays an important role in carcinogenesis of PTC.