Silencing of ABCC2 by siRNA increased the inhibitory effects of cisplatin on growth of tumors in nude mice. (A) Expression of ABCC2 in tumor tissues (Immunohistochemistry method, DAB staining, 200×). CNE2, CNE2/shABCC2-1 cells were transplanted s.c. in nude mice, with ABCC2-shRNA negative construct (ShABCC2-) as control. (B) Efficacy of cisplatin on growth of tumors transplanted s.c. in nude mice. The efficacy was evaluated by relative tumor sizes (RTS). At the time of cisplatin administration, the weight of tumors were in the range of 50–200 mg. Data were expressed as mean ± SEM value. * P < 0.05. P value were shown in Tab 1. (C) The treated: control (T: C) ratio of tumor weight for s.c. tumors in nude mice. CNE2, CNE2 treated with shABCC2 construct (shABCC2-1) were used, with shABCC2 negative construct (shABCC2-) as control.