Intact tissue of gastrointestinal cancer specimen orthotopically transplanted into nude mice.

BACKGROUND/AIMS: A relevant animal model of human gastrointestinal cancer in nude mice, which can be adapted for repetitive investigations, could improve our understanding of carcinogenesis and cancer metastasis. Furthermore, it may support the development of new and effective therapeutic concepts.

METHODOLOGY

We have established an orthotopic transplantation tumor model for human tumors in nude mice with intact tissues of colorectal, pancreatic, and gastric cancer. We investigated the biological characteristics of original and corresponding transplanted tumors, including routine pathological examination (HE staining), mucin production (PAS staining), and immunostaining. In addition, the lung and liver specimens were screened for micrometastases.

RESULTS

1. Overall, 10 out of 22 surgical specimens were growing in nude mice subcutaneously and/or orthotopically (4/6 colon, 5/10 pancreatic, and 1/6 gastric cancer). In the group of fresh tumor tissues with greater than 50% tumor cell content, the take rate was 100% (3/3 pancreatic, and 3/3 colon). 2) The orthotopically transplanted tumors resemble the original tumors morphologically and biologically, including local invasion, regional and distant metastases, and CEA production. 3) The detection of dissemination of cancer cells can be achieved by immunostaining.

CONCLUSIONS

An orthotopic xenotransplantation model for human gastrointestinal carcinomas in nude mice was established. The comparative analysis by immunohistochemistry suggests that this study will be helpful for developing new diagnostic methods to monitor micrometastatic disease.