Expression data in non-tumor liver tissues from Peruvian patients with hepatocellular carcinoma.

Most hepatocellular carcinomas in younger patients from Peru arise from non-cirrhotic livers. Histological examination of the non-tumor liver tissues highlights the presence of clear cell foci in a significant fraction of Peruvian patients with hepatocellular carcinoma. We used microarrays to compare gene expression between non-tumor liver tissues with and without clear cell foci and identified ontologies that are distinctively differentially expressed between subsets. Non-tumor liver tissues were obtained from tumour-free margins of resected surgical pieces. Total RNA was isolated from flash-frozen samples for hybridization on Affymetrix microarrays. We selected non-tumour liver tissues according to the presence or the absence of clear cell foci in non-tumor liver parenchyma in formalin-fixed, paraffin-embedded counterpart samples under haematoxylin–eosin staining.