HepG2/C3A 3D spheroids exhibit stable physiological functionality for at least 24 days after recovering from trypsinisation

Primary human hepatocytes are widely used as an in vitro system for the assessment of drug metabolism and toxicity. Nevertheless a cell system with higher stability of physiological functions is required for the investigation of drugs' mode of action, pathway analyses and biomarkers evaluations. We recently discovered that the human hepatocellular carcinoma cell line, HepG2/C3A, cultured as spheroids in a 3D system can recover their main functions after trypsinisation within about 18 days. The objective of this study was to investigate whether the spheroids' metabolic functions remained stable after this recovery period. Therefore we evaluated physiological capabilities of the spheroids (cell survival, growth rate, glycogenesis, ATP, cholesterol and urea synthesis and drug metabolism) and the expression of key genes related to the main liver pathways in spheroids cultured for an additional 24 days after full recovery (day 18). Here we show that after the recovery period, the 3D spheroid culture can provide a metabolically competent homeostatic cell model which is in equilibrium with its culture environment for more than 3 weeks. Such a stable system could be used for the assessment of the drugs' mode of action, for biomarkers evaluation and for any systems biology studies which require medium-to long-term stability of metabolic functions.