首都医科大学学报 ›› 2010, Vol. 31 ›› Issue (3): 324-328.

• 食管鳞癌的预防及早期诊断和干预 • 上一篇    下一篇

环氧合酶-2启动子甲基化在食管鳞癌中的作用

王青釭, 朱圣韬, 张澍田*   

  1. 首都医科大学附属北京友谊医院消化内科, 北京市消化疾病中心
  • 收稿日期:1900-01-01 修回日期:1900-01-01 出版日期:2010-06-21 发布日期:2010-06-21
  • 通讯作者: 张澍田

Effects of Promoter Methylation of Cyclooxygenase-2 on Lower Expressed Esophageal Squamous Cell Line

WANG Qing-gang, ZHU Sheng-tao, ZHANG Shu-tian*   

  1. Department of Gastroenterology, Beijing Friendship Hospital, Capital Medical University, Beijing Digestive Disease Center
  • Received:1900-01-01 Revised:1900-01-01 Online:2010-06-21 Published:2010-06-21
  • Contact: ZHANG Shu-tian

摘要: 目的 明确在低表达环氧合酶-2(cyclooxygenase-2,COX-2)的食管鳞癌细胞中COX-2表达与其启动子甲基化状态之间的关系。探讨对于低表达环氧合酶2的食管鳞癌给予去甲基化联合COX-2选择性抑制剂治疗的意义。方法 选择低表达COX-2的食管鳞癌TE-1细胞, RT-PCR法检测mRNA表达,DNA测序的方法检测COX-2启动子的甲基化状态。用5-氮杂脱氧胞苷和尼美舒利干预细胞株,比较干预前后细胞的COX-2启动子甲基化状态的变化及COX-2mRNA表达。用MTT法检测不同干预因素对细胞增生抑制作用的差异。ELISA检测前列腺素E2(prostaglandin E2,PGE2)浓度。结果 食管鳞癌TE-1细胞的COX-2核酸呈低表达,而其启动子呈高甲基化状态,甲基化率为58.3%。用去甲基化制剂5-氮杂脱氧胞苷干预后,该细胞的COX-2启动子甲基化率降低为30%,同时核酸表达增加,差异有统计学意义。单独用尼美舒利干预细胞的抑制率为16.2%,而联合5-氮杂脱氧胞苷和COX-2选择性抑制剂尼美舒利干预后细胞的增生抑制明显,抑制率升高为48.63%,差异具有统计学意义。去甲基化干预后PGE2浓度从553.96 pg/mL升高到647.54 pg/mL。结论 对于低表达环氧合酶2的食管鳞癌细胞其启动子高甲基化可能是影响其核酸表达的原因,给予去甲基化干预可使环氧合酶2的核酸表达增加,再联合环氧合酶2选择性抑制剂能够抑制食管鳞癌细胞的增生,是一种可能的治疗选择。

关键词: 食管鳞癌, 环氧合酶, 甲基化, 尼美舒利

Abstract: Objective To determine the relationship between cyclooxygenase-2(COX-2) expression and its promoter methylation status in lower expressed COX-2 esophageal squamous cell carcinoma(ESCC), as well as to investigate the significance of combining demethylating agent with selective COX-2 inhibitor in depression of ESCC. Methods ESCC cell line TE-1 was used in this study, and 5-aza-deoxycytidine(50-aza-DC) and nimesulide were added into the cultured TE-1 cell line. Promoter methylation status of cyclooxygenase-2 was examined by bisulfate sequencing analysis. RT-PCR was used to determine the expression of COX-2 mRNA. Cells proliferation of ESCC was tested with MTT reduction assay. Prostaglandin E2(PGE2 ) value was examined by ELISA.
Results Lower expression of COX-2 mRNA was found in TE-1 cells, while its promoter methylation status was high(58.3%). After treatment with 10 μmol/L 5-Aza-DC, the methylation status was decreased to 30%, on the other hand the mRNA level was increased. Single treatment with nimesulide showed lower suppressing effect compared to combined interference, the reduction value was 16.2% vs 48.63%, respectively(P<0.05). The concentration of PGE2 was raised after 5-Aza-DC treatment from 553.96 pg/mL to 647.54 pg/mL.
Conclusion For lower expression of COX-2 ESCC, promoter hypermethylation may be a mechanism to control gene expression. Demethylating could increase COX-2 mRNA expression. Combined treatment of ESCC with 5-Aza-DC and selective COX-2 inhibitor may be an alternative choice for depressing ESCC.

Key words: esophageal squamous cell carcinoma(ESCC), cyclooxygenase2(COX2), methylation, nimesulide

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