Figure 4. HepG2 cells can be sensitized to low-dose doxorubicin inducing by MSC. sFlt1. (A) Apoptosis measurement was conducted after the combination treatment. Addition of zVAD to the HepG2 cells before combination treatment can inhibite apoptosis. (B) Mixing HepG2 cells with MSC.sFlt1 (in a ratio of 10:1) plus 0.02μM doxorubicin treated for 48 h showed significantly increased apoptosis as compared with other group. Data from 3 independent experiments are shown. *p < 0.05, vs sFlt1 plus low-dose doxorubicin group.