Aim: Human hepatoma cell line HuH-7-derived cells are currently the only cell culture system used for robust hepatitis C virus (HCV) replication. We recently found a new human hepatoma cell line, Li23, that enables robust HCV replication. Although both cell lines had similar liver-specific expression profiles, the overall profile of Li23 seemed to differ considerably from that of HuH-7. To understand this difference, the expression profile of Li23 cells was further characterized by a comparison with that of HuH-7 cells.
Methods: cDNA microarray analysis using Li23 and HuH-7 cells was performed. Li23-derived ORL8c cells and HuH-7-derived RSc cells, in which HCV could infect and efficiently replicate, were also used for the microarray analysis. For the comparative analysis by reverse transcription polymerase chain reaction (RT–PCR), human hepatoma cell lines (HuH-6, HepG2, HLE, HLF and PLC/PRF/5) and immortalized hepatocyte cell line (PH5CH8) were also used.
Results: Microarray analysis of Li23 versus HuH-7 cells selected 80 probes to represent highly expressed genes that have ratios of more than 30 (Li23/HuH-7) or 20 (HuH-7/Li23). Among them, 17 known genes were picked up for further analysis. The expression levels of most of these genes in Li23 and HuH-7 cells were retained in ORL8c and RSc cells, respectively. Comparative analysis by RT–PCR using several other hepatic cell lines resulted in the classification of 17 genes into three types, and identified three genes showing Li23-specific expression profiles.
Conclusion: Li23 is a new hepatoma cell line whose expression profile is distinct from those of frequently used hepatic cell lines.