Nude mice

Four-week-old male nude mice were purchased from SPF Biotechnology (Beijing, China). MHCC 97H with different LDLR levels was prepared for subcutaneous injection of 5 × 10⁶/mouse to develop implanted tumors. An orthotopic transplantation model was performed following a previous report [20 (link)]. Six-week-old male nude mice (SPF Biotechnology) were randomly divided into 3 groups that contained 10 mice per group. Subcutaneous injection-derived tumors were cut into small pieces (2 × 2 × 2 mm³) in cold saline solution. Sequentially, absorbable sutures anchored the tissue pieces to the livers of the mice under anesthesia, with 10 mice for the MOCK group and 20 mice for the LDLR_KD groups. Two weeks later, simvastatin (Selleck) was administered to one of the LDLR_KD groups (50 mg/kg every 2 days). Control solvent treatment was performed in the MOCK and other LDLR_KD groups. Four weeks later, the livers of all of the mice with tumors were resected. Tissues were fixed in 4% PFA for paraffin sections.

Chlorin e6 (Ce6, purity ≥98%), triptolide (TPL, purity ≥98%), methoxy PEG, and 4-amino-1-butanol were acquired from Macklin Co., Ltd. (Shanghai, China). The CCK-8 kit was obtained from Bioground Co., Ltd. (Chongqing, China). DCFH-DA and Annexin V-FITC/PI kits were sourced from Thermo Fisher Scientific Co., Ltd. Human hepatocarcinoma cell lines (HepG2 cell) and mouse hepatocarcinoma cell lines (H22 cell) were procured from the Chinese Academy of Medical Sciences Co., Ltd. (Shanghai, China). Male ICR mice (4 weeks of age, 20–25 g) and nude mice (4 weeks of age, 18–20 g) were purchased from SPF Biotechnology Co. Ltd. (Beijing, China). All animal experiments were approved by the ethics committee of the “Experimental Animals Administrative Committee of Chengdu University of Traditional Chinese Medicine” (Chengdu, China) and were conformed to the Guidelines for the Care and Use of Laboratory Animals published by the National Institutes of Health, USA. Animal welfare was ensured in all animal experiments (permission number: SYXK2020-124). All animals were acclimated for a minimum of 7 days prior to experimentation and housed under a 12/12-h light/dark cycle, with up to five animals per cage and unlimited access to food and water.