Establishment of Xenograft Tumor Model in Mice

Twelve Male nude mice (BALB/c, 4 weeks old) were obtained from Shanghai experimental animal center, Chinese academy of sciences (Shanghai, China). Mice were randomly divided into three groups: Mock, si-NC and si-HCG18 group (n = 4 each group). AGS cells were subcutaneously injected into the left axilla (1 × 10⁷ cells/mice, 0.2mL/mice). The longest diameter (L) and the shortest diameter (W) of the tumor xenograft were measured with a vernier caliper every 7 days after injection. The tumor volume was calculated using the following formula: V = L ×W²/2. At the end of the 4th-week post-injection, mice were anesthetized with pentobarbital sodium (60 mg/kg), and killed by cervical dislocation. The tumor xenografts were dissected completely and then weighed. Animal experiments were performed in accordance with the “Guidelines for the Care and Use of Laboratory Animals” published by the National Institutes of Health and were approved by Linyi Cancer Hospital’s ethics committee.