Reduction of TIP30 in esophageal squamous cell carcinoma cells involves promoter methylation and microRNA-10b
Reduction of TIP30 in esophageal squamous cell carcinoma cells involves promoter methylation and microRNA-10b
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DOI：
10.1016/j.bbrc.2014.10.016
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发表时间：
2014-10-31
影响因子：
3.1
通讯作者：
Cheng, Shidan
中科院分区：
文献类型：
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作者：
Dong, Wenjie;Shen, Ruizhe;Cheng, Shidan
TIP 30是一种公认的肿瘤抑制因子，可以促进细胞凋亡和抑制血管生成。然而，TIP 30在食管鳞状细胞癌（ESCC）生物学中的作用尚未研究。应用免疫组织化学方法检测70例食管鳞癌组织中TIP 30的表达。采用甲基化特异性PCR（MSP）方法检测食管鳞癌（肿瘤组织和配对的癌旁非肿瘤组织）中TIP 30的甲基化水平。70例食管鳞癌中有50例（71.4%）TIP 30表达缺失。61.4%（43/70）的原发性肿瘤显示TIP 30高甲基化，表明这种异常特征在ESCC中很常见。此外，TIP 30甲基化状态与肿瘤组织中TIP 30蛋白的表达之间存在统计学显著的负相关性（p = 0.001）。我们还发现microRNA-10 b（miR-10 b）靶向TIP 30基因3 '非翻译区的同源DNA区域，并在转录水平上抑制其表达。用克隆在荧光素酶基因下游的TIP 30的3 'UTR进行的报告基因测定显示，在miR-10 b存在下荧光素酶活性降低，这为miR-10 b是TIP 30的直接调节剂提供了强有力的证据。提示TIP 30的表达受启动子甲基化和miR-10 b的调控。(C)2014爱思唯尔公司All rights reserved.
TIP30 is a putative tumor suppressor that can promote apoptosis and inhibit angiogenesis. However, the role of TIP30 in esophageal squamous cell carcinoma (ESCC) biology has not been investigated. Immunohistochemistry was used to investigate the expression of TIP30 in 70 ESCC. Hypermethylation of TIP30 was evaluated by the methylation specific PCR (MSP) method in ESCC (tumor and paired adjacent non-tumor tissues). Lost expression of TIP30 was observed in 50 of 70 (71.4%) ESCC. 61.4% (43 of 70) of primary tumors analyzed displayed TIP30 hypermethylation, indicating that this aberrant characteristic is common in ESCC. Moreover, a statistically significant inverse association was found between TIP30 methylation status and expression of the TIP30 protein in tumor tissues (p = 0.001). We also found that microRNA-10b (miR-10b) targets a homologous DNA region in the 3'untranslated region of the TIP30 gene and represses its expression at the transcriptional level. Reporter assay with 3'UTR of TIP30 cloned downstream of the luciferase gene showed reduced luciferase activity in the presence of miR-10b, providing strong evidence that miR-10b is a direct regulator of TIP30. These results suggest that TIP30 expression is regulated by promoter methylation and miR-10b in ESCC. (C) 2014 Elsevier Inc. All rights reserved.