The intraperitoneal xenograft model

Female 5-week-old athymic nude mice (BALB/c Slc-nu/nu) were purchased from Japan SLC and maintained in accordance with the institutional guidelines of Osaka Medical College. All of the animal studies were carried out according to approved experimental protocols. To assess tumorigenicity, 80×10⁴ purified CD24-positive and CD24-negative cells were suspended in 1 ml PBS and were then intraperitoneally injected into each of the 10 female nude mice (5-week-old). The body weight and abdominal circumference were measured weekly. On the 50th day after the initiation of treatment, all of the mice were sacrificed, and the presence of macroscopic disease and the ascites volumes and organ weight were examined. Dissemination tumors were resected, fixed in formalin and paraffin sections were made for hematoxylin and eosin staining.