Fig. 6.

Combination of LCL161 and M1 inhibits tumor progression in a mouse xenograft model and in human ex vivo tissues. (A–C) Effect of LCL161 and M1 combination on the mouse xenograft model with HCT 116 tumors (n = 5, tumor volume in each group was compared with the control group). D, day. (D) Intratumoral expression of Ki67 and cleaved caspase-3 (Cl-casp3) was detected by immunological histological chemistry in HCT 116 tumors. (Scale bars: 50 μm.) (E) Quantitation of cells positive for Ki67 and Cl-casp3 from multiple HCT 116 tumors and relative positive cells are shown (n = 5). (F and G) HCT 116 cells were implanted in nude mice when the tumor volume reached about 150 mm³. Nude mice were treated with vehicle, LCL161, M1, and LCL161 plus M1 as in A. (G) According to the Animal Ethical and Welfare Committee of Sun Yat-sen University, when the tumor volume reached 1,500 mm³, the mice were euthanatized for the survival curve drawing. (F) Tumor volume reached 1,500 mm³ first in the control group at day 17 (control, n = 12; LCL161, n = 12; M1, n = 9; LCL161 + M1, n = 9.). (H) Surgical colon cancer specimens (50–100 mg) were cut into small pieces (∼1 mm³) and cultured in DMEM with 10% FBS and 5% penicillin/streptomycin at 37 °C. Tissues were then treated with vehicle (OPTI SFM), M1 (5 × 10⁷ pfu), LCL161 (10 μM), and LCL161 (10 μM) plus M1 (5 × 10⁷ pfu) for 3 d. Activity of tissues was measured by tissue culture end-point staining computer image analysis after staining with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide. The inhibition rates of each treatment for eight patients are shown. Error bars represent mean ± SD. pt, patient. *P < 0.05; ***P < 0.001.