Clin Chem Lab Med. 2014 Aug;52(8):1217-27. doi: 10.1515/cclm-2013-0950.
Colorectal cancer is the second most frequent cause of cancer-related death in the developed world. Recent studies have tried to associate colorectal cancer with the aberrant expression of several microRNAs. The aim of the present study was the development of a highly sensitive quantitative real-time PCR which can be used to evaluate the miR-182 expression levels in colorectal adenocarcinoma and adjacent non-cancerous tissue specimens and associate them with several clinicopathological characteristics, aiming to examine the prognostic potential of miR-182.
Total RNA was isolated from 116 malignant colorectal adenocarcinoma specimens and 60 paired non-cancerous tissues. Then, polyadenylation of 2 μg total RNA by poly(A) polymerase and reverse transcription with suitable oligo-dT-adapter followed. miR-182 levels were quantified by real-time PCR based on SYBR Green chemistry. The results were analyzed by the comparative quantification cycle method and by extensive biostatistical analysis.
miR-182 was found to be significantly upregulated in colorectal adenocarcinoma specimens compared to their non-cancerous counterparts (p<0.001). miR-182 expression increases as the histological grade increases (p=0.013). miR-182 overexpression is associated with high depth of tumor invasion, positive regional lymph node status, and advanced TNM stage of patients. Therefore, miR-182 is an unfavorable prognostic marker in colorectal adenocarcinoma, predicting poor overall survival (p=0.007). Most importantly, miR-182 expression retained its unfavorable prognostic significance among patients with well- or moderately differentiated colorectal adenocarcinoma (p=0.006) and among metastasis-free patients (p=0.025).
The increased levels of the oncogene-like miR-182 increase the risk for disease progression and predict poor overall survival for colorectal adenocarcinoma patients.
结直肠癌是发达国家癌症相关死亡的第二大主要原因。最近的研究试图将结直肠癌与几种 microRNA 的异常表达联系起来。本研究的目的是开发一种高度敏感的实时定量 PCR，用于评估结直肠腺癌和相邻非癌组织标本中的 miR-182 表达水平，并将其与几种临床病理特征相关联，旨在检验 miR-182 的预后潜能。
从 116 例恶性结直肠腺癌标本和 60 对非癌组织中分离总 RNA。然后，通过 poly(A) 聚合酶对 2μg 总 RNA 进行多聚腺苷酸化，并用合适的 oligo-dT 接头进行反转录。通过基于 SYBR Green 化学的实时 PCR 定量 miR-182 水平。结果通过比较定量周期法和广泛的生物统计学分析进行分析。
与非癌组织相比，结直肠腺癌标本中 miR-182 显著上调（p<0.001）。miR-182 的表达随着组织学分级的增加而增加（p=0.013）。miR-182 的过表达与肿瘤浸润深度高、区域淋巴结状态阳性和患者 TNM 分期晚期相关。因此，miR-182 是结直肠腺癌中不利的预后标志物，预测总体生存率差（p=0.007）。最重要的是，miR-182 表达在分化良好或中度分化的结直肠腺癌患者（p=0.006）和无转移患者（p=0.025）中保留了其不利的预后意义。
癌基因样 miR-182 的水平升高增加了疾病进展的风险，并预测结直肠腺癌患者总体生存率差。
