mRNA/microRNA gene expression profile in microsatellite unstable colorectal cancer

• Main Authors: Calin George A, Liu Chang-gong, Pichiorri Flavia, Spizzo Riccardo, Veronese Angelo, Gafà Roberta, Ferracin Manuela, Lanza Giovanni, Croce Carlo M, Negrini Massimo
• Format: Article
• Language: English
• Published: BMC 2007-08-01
• Series: Molecular Cancer
• Online Access: http://www.molecular-cancer.com/content/6/1/54

<p>Abstract</p> <p>Background</p> <p>Colorectal cancer develops through two main genetic instability pathways characterized by distinct pathologic features and clinical outcome.</p> <p>Results</p> <p>We investigated colon cancer samples (23 characterized by microsatellite stability, MSS, and 16 by high microsatellite instability, MSI-H) for genome-wide expression of microRNA (miRNA) and mRNA. Based on combined miRNA and mRNA gene expression, a molecular signature consisting of twenty seven differentially expressed genes, inclusive of 8 miRNAs, could correctly distinguish MSI-H versus MSS colon cancer samples. Among the differentially expressed miRNAs, various members of the oncogenic miR-17-92 family were significantly up-regulated in MSS cancers. The majority of protein coding genes were also up-regulated in MSS cancers. Their functional classification revealed that they were most frequently associated with cell cycle, DNA replication, recombination, repair, gastrointestinal disease and immune response.</p> <p>Conclusion</p> <p>This is the first report that indicates the existence of differences in miRNA expression between MSS versus MSI-H colorectal cancers. In addition, the work suggests that the combination of mRNA/miRNA expression signatures may represent a general approach for improving bio-molecular classification of human cancer.</p>