Role of Deregulated microRNAs in Breast Cancer Progression Using FFPE Tissue

• Published in: PloS one Vol. 8; no. 1; p. e54213
• Main Authors: Chen, Liang, Li, Youhuai, Fu, Yebo, Peng, Jin, Mo, Meng-Hsuan, Stamatakos, Michael, Teal, Christine B., Brem, Rachel F., Stojadinovic, Alexander, Grinkemeyer, Michael, McCaffrey, Timothy A., Man, Yan-gao, Fu, Sidney W.
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 23.01.2013; Public Library of Science (PLoS)
• Subjects: Analysis; Biology; Biomarkers; Breast - metabolism; Breast - pathology; Breast cancer; Breast Neoplasms - diagnosis; Breast Neoplasms - genetics; Breast Neoplasms - metabolism; Breast Neoplasms - pathology; Cancer; Cancer research; Carcinoma, Ductal, Breast - diagnosis; Carcinoma, Ductal, Breast - genetics; Carcinoma, Ductal, Breast - metabolism; Carcinoma, Ductal, Breast - pathology; Carcinoma, Intraductal, Noninfiltrating - diagnosis; Carcinoma, Intraductal, Noninfiltrating - genetics; Carcinoma, Intraductal, Noninfiltrating - metabolism; Carcinoma, Intraductal, Noninfiltrating - pathology; Cell adhesion & migration; Cell Line, Tumor; Cell Transformation, Neoplastic - genetics; Deregulation; Development and progression; Disease Progression; Feasibility studies; Female; Formaldehyde; Gene expression; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Genes; Health sciences; Humans; Hyperplasia; Hyperplasia - diagnosis; Hyperplasia - genetics; Hyperplasia - metabolism; Hyperplasia - pathology; Immunology; Invasiveness; Medical diagnosis; Medical prognosis; Medicine; MicroRNA; MicroRNAs; MicroRNAs - genetics; MicroRNAs - metabolism; miRNA; mRNA; MSH2 protein; Neoplasm Proteins - genetics; Neoplasm Proteins - metabolism; Neoplasm Staging; Paraffin; Paraffin Embedding; Ribonucleic acid; RNA; Smad7 protein; Tissue Fixation; Tissues; Transforming growth factors; Tumorigenesis; Colombia; United States > US
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0054213

MicroRNAs (miRNAs) contribute to cancer initiation and progression by silencing the expression of their target genes, causing either mRNA molecule degradation or translational inhibition. Intraductal epithelial proliferations of the breast are histologically and clinically classified into normal, atypical ductal hyperplasia (ADH), ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC). To better understand the progression of ductal breast cancer development, we attempt to identify deregulated miRNAs in this process using Formalin-Fixed, Paraffin-Embedded (FFPE) tissues from breast cancer patients. Following tissue microdissection, we obtained 8 normal, 4 ADH, 6 DCIS and 7 IDC samples, which were subject to RNA isolation and miRNA expression profiling analysis. We found that miR-21, miR-200b/c, miR-141, and miR-183 were consistently up-regulated in ADH, DCIS and IDC compared to normal, while miR-557 was uniquely down-regulated in DCIS. Interestingly, the most significant miRNA deregulations occurred during the transition from normal to ADH. However, the data did not reveal a step-wise miRNA alteration among discrete steps along tumor progression, which is in accordance with previous reports of mRNA profiling of different stages of breast cancer. Furthermore, the expression of MSH2 and SMAD7, two important molecules involving TGF-β pathway, was restored following miR-21 knockdown in both MCF-7 and Hs578T breast cancer cells. In this study, we have not only identified a number of potential candidate miRNAs for breast cancer, but also found that deregulation of miRNA expression during breast tumorigenesis might be an early event since it occurred significantly during normal to ADH transition. Consequently, we have demonstrated the feasibility of miRNA expression profiling analysis using archived FFPE tissues, typically with rich clinical information, as a means of miRNA biomarker discovery.