OBJECTIVETo establish a colorectal cancer colostomy orthotopic transplantation mice model.

METHODSA colostomy was preformed in BALB/C nu-nu nude mice. After two weeks, when the stoma healed, tumor tissues developed from Lovo cells were implanted into the submucosa of the stoma. When tumor grew up to 5 mm, fluorouracil(5-FU, 20 mg/kg) was administrated by intraperitoneal injection. Tumor developed at the colostomy was observed and its biological characteristics and behaviour were evaluated.

RESULTSColostomy was performed in 10 mice and stoma healed at two weeks. Ten colostomies developed detectable tumor in two to three weeks. Three to five weeks later, the tumors grew up to 5 mm. Survival time of mice injected with 5-FU was(15.2+/-3.7) weeks (ranged:11-21 weeks), and the survival time of the no-treatment group was(12.3+/-2.8) weeks(ranged:9-19 weeks). The difference was statistically significant(P=0.001). The rate of mesenteric metastasis was 1/5 and 2/5 in the treatment and no-treatment group respectively.

CONCLUSIONColostomy orthotopic transplantation mice model is an ideal mice model with the advantages of having high success rate, visualization of implanted tumor in living animal, long survival time and significant tumor response to common chemotherapeutic agent.