Establishment of an alpha-fetoprotein-producing human gastric carcinoma in nude mice

An alpha-fetoprotein (AFP)-producing human gastric carcinoma was transplanted into BALB/c-nu/nu nude mice. The original tumor tissue had been obtained by gastrectomy from a 72-year-old patient with gastric carcinoma. The tumor had been transplanted serially (20 passages) in nude mice. The transplantability was 100%. The doubling time of the tumor ranged from 5.6 days to 11.2 days. AFP appeared in the serum of nude mice 3 to 4 weeks after subcutaneous (sc) transplantation and 6 weeks after intraperitoneal (ip) transplantation of the tumor cell suspension prepared from sc transplanted tumors. A positive correlation was observed between serum AFP level and tumor size. Serum AFP level of mice given ip transplantation increased as a function of time after transplantation. AFP was stained positively by an immunochemical technique in the original and transplanted tumors and was located in the cytoplasms of the tumor cells. The histology of the original tumor was retained. The malignant potential of these transplanted tumor cells was expressed as carcinomatous peritonitis and liver and/or lung metastases.