Tumor growth inhibition in xenograft model

Female nude mice (7–8 weeks old) were obtained from SIPPR-BK Labs (Shanghai). Animals were maintained under standard cleanroom conditions. The 786-0 cells (1 × 10⁷ cells) were resuspended in a serum-free medium and then implanted subcutaneously into the left armpit of the nude mice (n = 6). Treatments were initiated when tumors reached a mean volume of around 120 mm³. SN202 was formulated in 0.5% carboxymethyl cellulose (w/v) and administered orally at 5 and 20 mg/kg once per day for 21 days. Mice in the control group were dosed with an equivalent volume of the vehicle. Tumor volume and animal weight were measured every 3–4 days. At the end of the experiment, the tumors were excised and then weighed. Tumor volume (TV) was calculated by the formula: TV = Length × Width²/2. The tumor growth inhibition rate (IR) on the basis of tumor weight was calculated from IRtw = (1 -TWt/TWc) × 100%, where TWt represents the mean tumor weight of a treated group and TWc indicates that of the control group. Data are presented as mean ± SEM. Student's t test was used to determine the P value for the comparisons between the treatment and vehicle groups.