Fig. 3: RRM2, not RRM2B, supports HB cell growth in vitro and in vivo.

a Quantitative RT-PCR and immunoblotting of RRM2 and RRM2B in the indicated HepG2 cells overexpressing a tdT control vector, RRM2, or RRM2B. b Growth curves of tdT, RRM2^OE, and RRM2B^OE HepG2 cells (n = 3 for each group). c RRM2 and RRM2B immunoblotting showing a dose-dependent knockdown of RRM2 in HepG2 cells expressing a doxycycline (dox)-inducible RRM2 shRNA. GAPDH shRNA was used as a control. d Growth curves of the indicated HepG2 cells treated with 500 ng dox (n = 3 for each group). e RRM2 and RRM2B immunoblotting in RRM2B^KO and RRM2B^KO/Res HepG2 cells. f Growth curves of the indicated RRM2B-manipulated HepG2 cells (n = 3 for each group). g Survival curves of the NSG mice orthotopically transplanted with the indicated RRM2- and RRM2B-manipulated HepG2 cells (n = 7 for the tdT group; n = 5 for each of the other groups). No significant statistical differences were observed between any groups. h Representative Ki67 IHC images of the tdT and RRM2^OE HepG2 allograft tumors. Both images share the same 100 μm scale bar. i Quantification of the percentage of Ki67⁺ cells in the most proliferative regions in the tdT and RRM2^OE HepG2 allograft tumors. Ki67⁺ cells in four tumors from each group were counted. Student t test: P values: ** <0.01.