Nu nu mice

Four-week-old immunodeficient nude mice (nu/nu) mice (Orient Bio Inc.) were maintained in pressurized ventilated cages. Cells transfected with siNQO1 or siControl (1 × 10⁷) were injected subcutaneously into five mice. 1 was administered by tail vein injection (2 mg kg^–1 d^–1) for once per three days for 2 weeks. HCT116 cells (1.0 × 10⁷) transfected with empty (pcDNA) or NQO1 expression plasmid were injected subcutaneously into the right flank of mice. When tumor growth reached a detectable size (approx. 20 mm³), the mice were treated with compound 1 (4 mg kg^–1) or vehicle PBS by tail vein injection once every 5 days for 20 days. Tumor growth was monitored periodically, and volume (V) was calculated by using the modified ellipsoidal formula: V = 1/2 × length × (width)². All animal studies were performed with the approval of Korea University Institutional Animal Care and Use Committee and Korea Animal Protection Law.

Either SW480/pcDNA6/V5 or SW480/pcDNA6/V5-TTP (2 × 10⁷ cells) were injected into the flanks of 6-week-old nude (nu/nu) mice (Orient Bio Inc., Seongnam, Korea). Prior to treatment with TRAIL, tumor size was measured two to three times per week until the volume reached approximately 200 mm³. Tumor volume was calculated as W² × L × 0.52, where L is the largest diameter and W is the diameter perpendicular to L. After establishing tumor xenografts, mice were randomized into four groups of five mice per group. Mice were fed ad libitum and maintained in environments with a controlled temperature of 22–24 °C and 12 h light and dark cycles. Mice in each treatment group were treated with TRAIL at a dose of 200 ng/kg by intra-tumoral injection twice per week for two weeks. All animal experimental procedures were approved by the Institutional Animal Care and Use Committee of the University of Ulsan Laboratory Animal Research Center. All animal experiments were performed in accordance with Institutional Animal Care and Use Committee (IACUC) guidelines. Ethical code number: 0118-06 (C1-0), date of approval: 6 December 2017.