Tumor xenograft studies

A mouse Miapaca-2 cells tumor xenograft model was established by injecting the right flank of 6-week old athymic BALB/c nude mice (Central Lab. Animal Inc. Seoul, Korea) with 5 × 10⁶ Miapaca-2 cells (in PBS). After tumors reached a volume of 50-100 mm³, mice were intraperitoneally administered HS-173 (10 mg/kg, 5 times/week) and then irradiated using fractionated dosing (IR1: 2 Gy, twice a week for 3 weeks) or a single dose (IR2: 8 Gy, once). Body weight and tumor dimensions were recorded twice per week. Tumor size was calculated according to the formula, 0.5 × long axis × (short axis)². Animal care and experimental procedures were conducted in accordance with the Guide for Animal Experiments, published by the Korean Academy of Medical Sciences, and the protocols used were approved by the Institutional Animal Care and Use Committee of Inha University Hospital (Approval No. 151119-388-1).