Figure 4

Cbx4 increases the sensitivity of SMMC-7721 and MHCC97L cells to doxorubicin-induced cell death. SMMC-7721 and MHCC97L cells were stably infected with empty or Flag-tagged Cbx4. (a and b) Doxorubicin was added into SMMC-7721, 2 μM (a) and MHCC97L, 3 μM (b) cells for 36 and 48 h, followed by immunoblots for the indicated proteins. (c and d) SMMC-7721 (c) and MHCC97L (d) with or without ectopic Cbx4 expression were respectively treated with and without different concentrations of doxorubicin for 36 h, and cell growth was assessed by CCK-8 assay and IC50 values of doxorubicin were calculated by GraphPad Prism 6 software. (e and f) SMMC-7721 (e) and MHCC97L (f) with or without ectopic Cbx4 expression were treated with 2 μM (e) or 3 μM (f) of doxorubicin for 36 and 48 h, and percentages of TUNEL-positive cells were calculated