(A) The elevation of C/EBPα by doxorubicin. 1.3.ES2 was treated with doxorubicin for 1 hour and then the culture medium was replaced with fresh culture medium for three days. Next, total RNA was harvested in order to carry out quantitative RT-PCR. (B) The elevation of C/EBPα by p21 over-expression. 1.3.ES2 cells or HepG2 cells over-expressing p21 were harvested for analysis of the expression level of C/EBPα by quantitative RT-PCR. (C) The role of p21 in doxorubicin-mediated C/EBPα elevation. 1.3.ES2 cells were infected with lentivirus expressing p21 shRNA. Twenty-four hours post-infection, cells were treated with doxorubicin for 1 hour, which was followed by replacing the culture medium with fresh culture medium. Culturing was then continued for 3 days. Next, total RNA was harvested for analysis of the expression level of C/EBPα by quantitative RT-PCR. The expression level of B2M was used as a reference control. (D) 1.3.ES2 cells were infected with lentivirus expressing C/EBPα shRNA for 24 hours, treated with doxorubicin for 1 hour, and this was followed by culturing in fresh culture medium for 3 days. The expression levels of HBV transcripts, HBcAg and C/EBPα were analyzed by Northern blot and Western blot.analysis, *, P < 0.01, 2-sided unpaired t test.