Gene expression profiling of 91 hepatocellular carcinomas with hepatitis C virus etiology

To characterize the genetic alterations that instigate hepatitis C virus-induced hepatocellular carcinoma (HCC), we conducted an integrative genomic analysis of 103 HCCs. Most tumors harbored 1q gain, 8q gain or 8p loss, with occasional alterations in 13 additional chromosome arms. In addition to amplifications at 11q13 in 6 tumors, 4 tumors harbored focal gains at 6p21 incorporating VEGFA, which were confirmed in 4 of 113 HCC in an independent validation set. Strikingly, this locus overlapped with copy gains in 4 of 371 lung adenocarcinomas. Overexpression of VEGFA via 6p21 gain suggested a cell-nonautonomous mechanism of oncogene activation. Hierarchical clustering of gene expression among 91 tumors identified 5 classes, including ‘Wnt-CTNNB1’, ‘proliferation’ and ‘interferon-related’ gene classes. We also discovered a novel class defined by polysomy of chromosome 7, gains of which were associated with early tumor recurrence after resection. These findings reveal key alterations in HCC pathogenesis and implicate potential therapeutic targets. Keywords: disease state analysis