4.10. HCT116 Colorectal Xenografts

HCT116 cells (4 × 10⁶) were implanted subcutaneously into the right flank of the three-week-old BALB/c-nude mice (Vita River Laboratory Animal Technology Co.), according to published methods [32]. They were housed and treated according to the guidelines of the Institutional Animal Care and Use Committee. The mice were maintained under pathogen-free conditions. Tumor growth was monitored every other day by measuring two dimensions (L and W) with the following calculation formula: V (mm³) = (L × W²) × 0.5. When tumors reached a volume of ~90 mm³, the mice were randomized into two groups (n = 9/group) to receive treatment. One group was treated with normal saline as a control via intraperitoneal injection, while the other group underwent 5 mg/kg and 10 mg/kg of 4βHWE treatment. Tumor size and body weight were measured three times a week for a total of 14 days. The mice were euthanized, and the tumors were harvested 6 h after the final 4βHWE injection. The grafts were then weighed and stored at –80 °C for further western blotting analysis.