Effect of ING4 expression on the in vivo sensitivity of SPC-A1/DTX cells to DTX. (A) After 28 d, SPC-A1/DTX/ING4 cells with DTX treatment produced smaller tumors than SPC-A1/DTX/control cells with DTX treatment. (B) Representative picture of tumors from SPC-A1/DTX/control or SPC-A1/DTX/ING4 group with DTX treatment. (C) The growth curve of tumor volumes. Each data point presents the mean ± SD of 6 mice. *p < 0.05 and **p < 0.01 compared with SPC-A1/shcontrol combined with DTX treatment. (D) Tumors developed from SPC-A1/DTX/ING4 cells with DTX treatment showed a lower level of PCNA antigen and increased level of apoptosis than tumors developed from SPC-A1/ DTX/control cells combined with DTX treatment. Upper: H&E staining; Intermediate: immunostaining. Lower: TUNEL staining. (E). After 28 d, Western blot analysis of ING4 protein expression in tumors formed from SPC-A1/DTX/control or SPC-A1/DTX/ING4 cells. GAPDH was used as an internal control. Results represent the average of three independent experiments (mean ± SD).