Fig. 6

Addition of AT-101 to gefitinib enhances antitumor activity of EGFR TKIs resistant tumor xenografts in vivo. PC-9-GR cells (1 × 106 cells·0.1 ml per mouse) were inoculated subcutaneously into the right front axilla of nude mice. Mice bearing tumors of 150 to 200 mm3 in size were then randomly divided into groups that received either vehicle control, gefitinib (50 mg/kg, 5 days a week), AT-101 (35 mg/kg, 5 days a week), or gefitinib plus AT-101. The tumor volumes were measured twice per week. Each treatment group consisted of six mice. The data shown represent mean ± SD. The tumors were resected from the sacrificed nude mice and fixed in 10% neutral buffered formalin. Immunohistochemistry assays were conducted for cleaved caspase 3 and Ki-67