Genomic profiling reveals unique molecular alterations in hepatoblastomas and adjacent hepatocellular carcinomas in B3C3F1 mice

The cell of origin of hepatoblastoma in humans and mice (HB) is unknown; it has been hypothesized to be a transformed hepatocyte, an oval cell, or a multipotent hepatic progenitor cell. In mice, the current dogma is that HBs arise within hepatocellular neoplasms as a result of further transformation from a neoplastic hepatocyte. However, there is little evidence in the literature to support a direct relationship between these two cell types. Furthermore, due to differences in etiology and development of hepatoblastoma between mice and humans, many have questioned the relevance of these tumors in hazard identification and risk assessment. In order to better understand the relationship between hepatocellular carcinoma and hepatoblastoma, as well as better determine the molecular similarities between mouse and human hepatoblastoma, global gene expression analysis and targeted Hras and Ctnnb1 mutation analysis were performed using concurrent hepatoblastoma, hepatocellular carcinoma, and associated normal adjacent liver (in the context of vehicle control liver) samples from a recent National Toxicology Program chronic bioassay. The data from this study provides a better understanding of the origins of hepatoblastoma in the B6C3F1 mice and the relevance of mouse hepatoblastoma to humans when considering chemical exposures of potential human cancer risk.

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