Lee Eun Joo, Gusev Yuriy, Jiang Jinmai, Nuovo Gerard J, Lerner Megan R, Frankel Wendy L, Morgan Daniel L, Postier Russell G, Brackett Daniel J, Schmittgen Thomas D
College of Pharmacy, Ohio State University, Columbus, OH 43210, USA.
Int J Cancer. 2007 Mar 1;120(5):1046-54. doi: 10.1002/ijc.22394.
microRNAs are functional, 22 nt, noncoding RNAs that negatively regulate gene expression. Disturbance of microRNA expression may play a role in the initiation and progression of certain diseases. A microRNA expression signature has been identified that is associated with pancreatic cancer. This has been accomplished with the application of real-time PCR profiling of over 200 microRNA precursors on specimens of human pancreatic adenocarcinoma, paired benign tissue, normal pancreas, chronic pancreatitis and nine pancreatic cancer cell lines. Hierarchical clustering was able to distinguish tumor from normal pancreas, pancreatitis and cell lines. The PAM algorithm correctly classified 28 of 28 tumors, 6 of 6 normal pancreas and 11 of 15 adjacent benign tissues. One hundred microRNA precursors were aberrantly expressed in pancreatic cancer or desmoplasia (p < 0.01), including microRNAs previously reported as differentially expressed in other human cancers (miR-155, miR-21, miR-221 and miR-222) as well as those not previously reported in cancer (miR-376a and miR-301). Most of the top aberrantly expressed miRNAs displayed increased expression in the tumor. Expression of the active, mature microRNA was validated using a real-time PCR assay to quantify the mature microRNA and Northern blotting. Reverse transcription in situ PCR showed that three of the top differentially expressed miRNAs (miR-221, -376a and -301) were localized to tumor cells and not to stroma or normal acini or ducts. Aberrant microRNA expression may offer new clues to pancreatic tumorigenesis and may provide diagnostic biomarkers for pancreatic adenocarcinoma.
微小RNA是具有功能的22个核苷酸的非编码RNA，可负向调节基因表达。微小RNA表达的紊乱可能在某些疾病的发生和发展中起作用。已鉴定出一种与胰腺癌相关的微小RNA表达特征。这是通过对人胰腺腺癌标本、配对的良性组织、正常胰腺、慢性胰腺炎和9种胰腺癌细胞系中的200多种微小RNA前体进行实时PCR分析来实现的。层次聚类能够区分肿瘤与正常胰腺、胰腺炎和细胞系。PAM算法正确分类了28个肿瘤中的28个、6个正常胰腺中的6个以及15个相邻良性组织中的11个。100种微小RNA前体在胰腺癌或纤维组织形成中异常表达（p<0.01），包括先前报道在其他人类癌症中差异表达的微小RNA（miR-155、miR-21、miR-221和miR-222）以及先前未在癌症中报道的那些（miR-376a和miR-301）。大多数异常表达的顶级微小RNA在肿瘤中表达增加。使用实时PCR测定法对活性成熟微小RNA进行定量，并通过Northern印迹法验证其表达。逆转录原位PCR显示，差异表达最高的三种微小RNA（miR-221、-376a和-301）定位于肿瘤细胞，而非基质、正常腺泡或导管。异常的微小RNA表达可能为胰腺肿瘤发生提供新线索，并可能为胰腺腺癌提供诊断生物标志物。
