Fig. 8: Synergistic effect of treatment with DDX3X inhibitor RK-33 and knockdown of FAM134B.

A MHCC97-H, HepG2, Huh7, Hep3B, LM3, PLC/PRF/5 cells were treated with RK-33 at varying concentrations for 24 hours. The cell survival rate was then determined using the CCK-8 assay. Scale bar represents SEM, n = 5. B PLC/PRF/5, MHCC97-H, Huh7 cells were treated the RK-33 at concentration of 0, 5, 10, 15 μM for 24 h. Western blot detected DDX3X protein level. The numbers indicated the relative amount of DDX3X signal compared to the first lane on the left, normalized to GAPDH. C Statistical chart of apoptotic cells from the indicated cell lines. Scale bar represents SEM, n = 3, ***P < 0.001. D−F The gross image (D), tumor volume (E), tumor weight (F) of subcutaneous tumor model from the indicated group, n = 4, scale bar represents SEM, *P < 0.5, **P < 0.01. G The Liver/body weight ratio from HTVi model, n = 5, scale bar represents SEM, *P < 0.5, **P < 0.01, ***P < 0.001. H The representative gross images of HTVi model. I Graphical summary of the study. The interaction between FAM134B and DDX3X inhibits DDX3X K48-linked polyubiquitination and promotes its K63-linked polyubiquitination, thereby stabilizing the expression of the DDX3X protein. Subsequently, DDX3X activates the AKT signaling pathway by facilitating the translation of Rac1. Additionally, DDX3X enhances the transcription of FAM134B, suggesting the existence of a positive feedback loop between these two proteins.