Fig. 4. (A) Cell cycle arrest analysis indicated that Roxyl-ZR induced G₂ arrest accompanied by reduction of G_0/G₁ and the S phase, as determined by FACS. (B) Apoptosis analysis showed that Roxyl-ZR mediated an increase in apoptosis compared to other groups by AV/PI dual staining. (C) After cells were treated with Roxyl-ZR, vorinostat, abemaciclib, or vehicle, the levels of cyclin D1, p-Rb, Ki67, and Bcl-2 abundance were significantly down-regulated, while those of CDK4, ac-H3, and cleaved caspase-3 abundance were up-regulated with anti-β-actin as a loading control, as determined by western blot assay. (D) Roxyl-ZR decreased the level of p-STAT3 abundance in a dose-dependent manner with anti-β-actin as a loading control, as determined by western blot assay.