Table 4.

IC₅₀ values of rhArg1 versus rhArg1-peg_{5,000 mw} for human hepatocellular carcinomas in vitro.

	rhArg1 (U/ml)	rhArg1-peg5,000 mw (U/ml)
HepG2	0.18 ± 0.06	0.22 ± 0.03
Hep3B	0.07 ± 0.03	0.10 ± 0.04

HepG2 and Hep3B were incubated in arginine-containing DMEM medium supplemented with 10% FBS with rhArg or rhArg1-peg_{5,000 mw} (0–100 U/ml) for 72 h at 37°C/5% CO₂. IC₅₀ values were calculated as the concentration of native rhArg1 or pegylated rhArg1 which inhibited 50% cell growth. The experiments were repeated three times.