Fig. 1.

Arginine deprivation inhibited the growth of retinoblastoma cells in vitro. A Retinoblastoma cell lines (Y79, WERI-Rb-1, and Rb-YAM10) were treated with increasing concentrations of rhArg for 72 h. The data are presented as the means ± SEMs, n = 3. Differences were assessed by one-way ANOVA followed by Bonferroni’s multiple comparison test. p values are indicated as follows: *, p < 0.05; ****, p < 0.0001. B HPLC‒MS analysis of the arginine levels in the cell culture medium. n = 3. ND, not detected. C Growth pattern changes following arginine deprivation at the indicated time points. Scale bar, 100 μm. D Characterization of urea cycle enzymes in retinoblastoma. Mouse liver extract was used as the positive control