Qin Yu-Zhou, Xie Xue-Cheng, Liu Hai-Zhou, Lai Hao, Qiu Hai, Ge Lian-Ying
Department of Gastrointestinal Surgery, Tumor Hospital of Guangxi Medical University, Nanning, Guangxi 530021, P.R. China.
Department of Experimental Research, Tumor Hospital of Guangxi Medical University, Nanning, Guangxi 530021, P.R. China.
Oncol Rep. 2015 Jun;33(6):2728-36. doi: 10.3892/or.2015.3892. Epub 2015 Apr 1.
The overexpression of human telomerase reverse transcriptase (hTERT) has been associated with the invasion and metastasis of colorectal cancer (CRC) and has received extensive attention, although the underlying mechanism involved remains unclear. The aim of the present study was to screen and preliminarily validate new tumor‑suppressor microRNAs (miRNAs) that potentially inhibit hTERT expression and to assess its clinical significance. Screening for downregulated miRNAs in CRC tissues was performed by retrieving and analysing microRNA microarray data. miRNA candidates were then filtered by bioinformatics analysis. The expression of miRNAs candidates was verified by quantitative polymerase chain reaction in the CRC and corresponding normal tissues. Immunohistochemistry (IHC) was used for the detection of hTERT protein expression. Spearman's correlation coefficient between miRNA candidates and hTERT protein expression was calculated (r) to identify hTERT-targeting miRNAs. A survival analysis was performed to assess the prognostic significance of hTERT-targeting miRNAs in CRC. Eight miRNAs with the potential to interact with hTERT were predicted: miR‑29c-3p, miR‑124-3p, miR‑133a-3p, miR‑133b, miR-138-5p, miR-150-5p, miR-378a-3p and miR-422a, respectively. Following detection of the miRNAs using RT-qPCR, miR-29c-3p was excluded. miR-138-5p and miR-422a were observed to potentially interact with hTERT (r=-0.362, P=0.001; r=-0.306, P=0.005, respectively). The Kaplan-Meier survival curves demonstrating high- vs. low-expression group of miR‑422a showed a highly significant difference in CRC patients (P=0.024), which suggests that the downregulation of miR-422a was associated with a poorer prognosis. The results indicated that miR-138-5p and miR-422a potentially inhibited hTERT expression in CRC, and suggest a potential application of miR‑422a in prognosis prediction and CRC treatment.
人端粒酶逆转录酶（hTERT）的过表达与结直肠癌（CRC）的侵袭和转移相关，并已受到广泛关注，尽管其潜在机制仍不清楚。本研究的目的是筛选并初步验证可能抑制hTERT表达的新型肿瘤抑制性微小RNA（miRNA），并评估其临床意义。通过检索和分析微小RNA微阵列数据，对CRC组织中下调的miRNA进行筛选。然后通过生物信息学分析对miRNA候选物进行筛选。通过定量聚合酶链反应在CRC组织和相应的正常组织中验证miRNA候选物的表达。采用免疫组织化学（IHC）检测hTERT蛋白表达。计算miRNA候选物与hTERT蛋白表达之间的Spearman相关系数（r），以鉴定靶向hTERT的miRNA。进行生存分析以评估靶向hTERT的miRNA在CRC中的预后意义。预测了8种可能与hTERT相互作用的miRNA，分别为：miR-29c-3p、miR-124-3p、miR-133a-3p、miR-133b、miR-138-5p、miR-150-5p、miR-378a-3p和miR-422a。使用RT-qPCR检测这些miRNA后，排除了miR-29c-3p。观察到miR-138-5p和miR-422a可能与hTERT相互作用（r分别为-0.362，P=0.001；r=-0.306，P=0.005）。miR-422a高表达组与低表达组的Kaplan-Meier生存曲线在CRC患者中显示出高度显著差异（P=0.024），这表明miR-422a的下调与较差的预后相关。结果表明，miR-138-5p和miR-422a可能在CRC中抑制hTERT表达，并提示miR-422a在预后预测和CRC治疗中的潜在应用。
