Human Thyroid Cancer Cell Xenografts

The patient-derived PTC and ATC cells (3.5 × 10⁶ cells/mouse) were cultured in vitro and then injected subcutaneously into the upper left flank region of female BALB/c nude mice. After 11 days, tumor-bearing mice were assigned to groups randomly (n = 10/group) and administered 10 mg/kg lenvatinib (p.o.) and 40 mg/kg sorafenib (p.o.), either alone or in combination with 25 mg/kg HNHA (given i.p.) once every 2 days. Tumor size was measured every three day using calipers. Tumor volume was estimated using the following formula: L × S2/2 (L, longest diameter; S, shortest diameter). Animals were maintained under specific pathogen-free conditions. All experiments were approved by the Animal Experiment Committee of Yonsei University.