4.4. In Vivo Tumor Xenograft Mouse Model

All experimental procedures involving mouse models were approved by the Laboratory Animal Ethics Committee of Beijing Institute of Genomics, Chinese Academy of Sciences under the HHS Federal Wide Assurance of Compliance Number 00014534 (7 September 2016) and IRB registration number IORG0005863 (7 September 2016).

Thirty-two 5–6-week-old male BALB/c nu/nu mice weighing 18–23 g were randomly divided into four groups. Mice were raised under specific pathogen-free conditions with a 12/12-h light/dark cycle and received chow and tap water ad libitum. Tumor xenografts were established through the subcutaneous injection of 5 × 10⁶ A549 cells (in 100 µL). After a five-day cell implantation, the four groups were intraperitoneally injected with PBS, FIP-nha (20 mg/kg body weight), FIP-nha (40 mg/kg body weight), or doxorubicin (4 mg/kg body weight) every week. Body weight and tumor size were measured every three days; tumor volume (mm³) was calculated based on the formula 0.5 × larger diameter × small diameter².