MicroRNA-Based Classification of Hepatocellular Carcinoma and Oncogenic Role of miR-517a

Hepatocellular carcinoma (HCC) is a complex and heterogeneous tumor due to activation of multiple cellular pathways and molecular alterations. Herein, we report the first molecular classification of 89 HCC based on the expression of 358 microRNAs and integrative genomic analysis. Three main subclasses of HCC were identified : two of them were associated with beta-catenin mutations or aggressive phenotype. A subset of the subclass of aggressive tumors (8/89, 9%) showed overexpression of a cluster of microRNAs located on chr19q13.41 (C19MC locus. We showed that miR 517a, representing C19MC, promoted cell proliferation, migration and invasion in vitro and induced the development of aggressive tumors in vivo suggesting its role as a novel oncogenic driver in HCC.

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Toffanin S, Hoshida Y, Lachenmayer A, Villanueva A, Cabellos L, Minguez B, Savic R, Ward SC, Thung S, Chiang DY, Alsinet C, Tovar V, Roayaie S, Schwartz M, Bruix J, Waxman S, Friedman SL, Golub T, Mazzaferro V, Llovet JM