Xenograft Tumor Models

This animal study was approved by the Animal Ethics Committee of Cancer Hospital of China Medical University, Liaoning Cancer Hospital & Institute, and BALB/c-nude mice (female, 4–5 weeks of age) were purchased from Shanghai Experimental Animal Center (Shanghai, China). Stably transfected A2780/DDP cells (1×10⁷ cells in 0.2 mL PBS) were subcutaneously injected into the posterior flank of the nude mice, and tumors were generated after cell inoculation for 7 days. Xenografts were randomly divided into DDP-treated group and PBS-treated group (n=6). Then, cisplatin (5 mg/kg) or 0.2 mL PBS was intraperitoneally injected in nude mice every 3.5 days for another 28 days. Tumor diameter was monitored every 7 days using calipers, and tumor volume was calculated using the formula: 0.5×(length×width²). The mice were euthanized, and the tumors were dissected, weighted and photographed. The tumor tissues were collected and restored in −80°C for further RNA/protein isolation. All animal experiments were performed following the Guide for the Care and Use of Laboratory Animals (GB/T 35892–2018; Standardization Administration of the People Republic of China).