Search for useful biomarkers in hepatocellular carcinoma, tumor factors and background liver factors (Review).

Hepatocarcinogenesis is a complex and multistep process that involves the accumulation of genetic and epigenetic alterations in regulatory genes. To understand the development of hepatocellular carcinoma (HCC), current research has utilized improved array technologies. The identification of cancer-related molecules could lead to the development of novel molecular targets for treatment and biomarkers for predicting prognosis. However, prognostic prediction is insufficient when considering only tumor factors, since hepatocarcinogenesis is also greatly influenced by the status of the background liver. Clinical background liver factors, such as the presence of chronic active hepatitis or cirrhosis, are well known as risk factors for developing HCC. In contrast, genetic or epigenetic background liver factors remain unknown, albeit those are important to understand the developing process of HCC. Investigating background liver factors could contribute to the development of carcinogenic markers of HCC and to the prevention of the development of HCC. In the present study, we review the currently identified tumor factors and background liver factors from a molecular biological viewpoint and also introduce our combination array analysis.