Drug-induced liver injury (DILI) is considered to be a significant cause of drug wastage. To mitigate clinical DILI risks, assessing drugs using human liver models is crucial since animal studies may fall short due to species-specific liver pathway variations. Cell-based preclinical hepatotoxicity testing is often pertinent. In the present study, cells from a human liver cancer line (HepG2 and HepaRG) were cultured in both formats of 2D and 3D spheroids to explore their responses to drugs. Liver-specific marker expressions across cell lines and culture formats were also examined to assess disparities in DILI marker expressions. After treating each cell with the drugs, cytotoxicity and liver injury markers aspartate aminotransferase and alanine aminotransferase were increased. In addition, liver specific markers albumin and urea decreased in a drug concentration-dependent manner. These findings were consistent with drug sensitivity. Additionally, mRNA expression levels of cytochrome P450 enzymes (CYPs) involved in hepatocellular drug metabolism were compared following treatment with enzyme inducers. CYP1A2 and CYP2C9 were not epxressed in HepG2 cells. HepaRG cells exhibited significantly increased expression of CYP1A2, 2C9, and 3A4 post-treatment. Notably, enzyme expression was notably higher in 3D cultures than in 2D cultures. Collectively, these findings suggest that HepaRG cells and 3D cultures hold promise for evaluating DILI during early-stage drug development.

INTRODUCTION
MATERIALS AND METHODS
    Chemicals
    Cell culture and cytochrome P450 enzyme induction
    In vitro cell viability assay
    Lactate dehydrogenase, aspartate aminotransferase and alanine aminotransferaseassays for detecting liver injury markers
    Albumin and urea secretion
    Qauntitative real-time polymerase chain reaction analysis of cytochrome P450enzyme mRNA
    Data analysis
RESULTS
    Cytotoxicities of amiodarone HCl and acetaminophen to HepG2 and HepaRG cellsdepending on culture type
    Detection of drug-induced hepatic injury markers
    Analysis of hepatocyte specific markers albumin and urea secretion
    Compare expression levels of cytochrome P450 enzymes after inducers treatment
DISCUSSION
References

• Nam-Ju Kim(Toxicological Evaluation Laboratory, Animal and Plant Quarantine Agency, Gimcheon 39660, Korea)
• Ji-Hyun Bang(Toxicological Evaluation Laboratory, Animal and Plant Quarantine Agency, Gimcheon 39660, Korea)
• Hee Yi(Toxicological Evaluation Laboratory, Animal and Plant Quarantine Agency, Gimcheon 39660, Korea)
• Hyun-Ok Ku(Toxicological Evaluation Laboratory, Animal and Plant Quarantine Agency, Gimcheon 39660, Korea)
• Joong-Sun Kim(College of Veterinary Medicine and BK21 Plus Project Team, Chonnam National University, Gwangju 61186, Korea)
• Ji-Yeon Kim(Toxicological Evaluation Laboratory, Animal and Plant Quarantine Agency, Gimcheon 39660, Korea)
• Byung-Suk Jeon(Toxicological Evaluation Laboratory, Animal and Plant Quarantine Agency, Gimcheon 39660, Korea) Corresponding author