Proliferation of sphere-forming hepatocellular carcinoma cells is suppressed in a medium without glucose and arginine, but with galactose and ornithine.

Resistance to sorafenib in hepatocellular carcinoma (HCC) cells exhibiting stemness was evaluated using a sphere formation assay. A hepatocyte selection medium (HSM) deficient in glucose and arginine was used to suppress the proliferation of cell spheres composed of HLF and PLC/PRF/5 HCC cells, which were subjected to a sphere formation assay. Cell spheres were cultured with sorafenib and subjected to a cell proliferation assay and the expression levels of cytochrome P450 (CYP3A4) were analyzed in RNA extracted from sphere-forming cells using reverse transcription-quantitative polymerase chain reaction. Sphere-forming PLC/PRF/5 cells were more resistant to sorafenib, as compared with control cells, exhibiting higher expression levels of CYP3A4. When cultured in HSM, suppressed proliferation was observed in the sphere-forming PLC/PRF/5 cells and in the control cells, with no significant variation between them. The results suggest that deprivation of glucose and arginine is a potential novel treatment for HCC.