[Frontiers in Bioscience E4, 1937-1940, January 1, 2012]

miRNAs are stable in colorectal cancer archival tissue blocks

Liselle Bovell1, Chandrakumar Shanmugam1, Venkat R. Katkoori1, Bin Zhang2, Emily Vogtmann3, William E. Grizzle1, 4, Upender Manne1,4

1Department of Pathology, 2Depatment of Biostatistics, 3Department of Epidemiology, and 4Comprehensive Cancer Center, University of Alabama at Birmingham, 515B1-Kracke, Building 619, 19th Street South, Birmingham, AL, 35294-7331, USA

TABLE CONTENTS

1. Abstract
2. Introduction
3. Materials and methods
4. Results
5. Discussion
6. Acknowledgements
7. References

1. ABSTRACT

MicroRNAs (miRNAs) have prognostic and therapeutic value for colorectal cancers RCs). Although formalin-fixed paraffin-embedded (FFPE) tissues are available for biomarker studies, the stability of miRNAs in these tissues stored for long periods (more than 20 years) is unknown. The present effort involved analysis of 345 FFPE CRC tissues, stored for 6 to 28 years (1982-2004), for the expression of six miRNAs (miR-20a, miR-21, miR-106a, miR-181b, miR-203, and miR-324-5p) using TaqMan(r) microRNA assays and quantitative real-time PCR (qRT-PCR). Evaluation, by linear regression analysis, of miRNA expression among archived CRC tissues found similar levels of all six miRNAs in tissues stored over this period (correlation coefficients, R2, ranged from less than 0.0001-0.009; and t-test p-values were greater than or equal to 0.05). Thus, miRNAs are stable in FFPE tissues stored for long periods of time, and such samples can be used for discovery of biomarkers.