Establishment Of A Model Of Colitis-associated Colon Carcinogenesis In Mice And The Detection Of The Expression Of β-catenin,MMP-7

ObjectiveTo investigate the mechanisms of human colitis-associated colon carcinoma through establishing a model of colitis-associated colon carcinogenesis in mice and detect the expression of β-catenin, MMP-7.MethodsIn this experiment, male Balb/c mice weighing 22-30g, 6-8weeks of age, were used.The mice were given 5 % DSS solution freely for 7 consecutive days after which intraperitoneal pretreatment with 20 mg/kg DMH was given, then NS was given instead for another 14 days, to complete one cycle of whole treatment plan that consisted of 3 such cycles. The symptoms were observed daily. At the end of the first week and every cycle respectively, the mice were killed for examining the whole colon under anatomic microscopy and the tissue were prepared for histologal observation and RT-PCR. Through those steps, a model of colitis-associated colon carcinogenesis in mice was established. RT-PCR method were used to detect the expression of β-catenin, MMP-7 in the colon of mice.ResultsAfter one week, the symptoms observed in the mice including loss of the body weight and hematochezia diarrhea were similar to those of ulcerative colitis patients and histological examination showed the acute stage changment of ulcerative colitis. At the end of three cycles, histological examination showed colon carcinoma and atypical hyperplasia. RT-PCR showed that the expression levers of β-catenin in normal tissue,ulcerative colitis tissue, colon carcinoma tissue were significantly different. The expression of MMP-7 wasn't obvious in all the three types of tissue.ConclusionsThis experiment imitated the acute phase, the chronic phase and finally the carcinogenesis in ulcerative colitis. Although the establishment of the model was quite convenient and the time cost was little,the rate of carcinogenesis was quite high.It's really the ideal model for the research on human colitis-associated colon carcinoma. The differences of the expression lever of β-catenin in normal tissue, ulcerative colitis and colitis-associated colon carcinoma suggested that they played important roles in colitis-associated colon carcinogenesis. But disagreeing with literatures, the expression of MMP-7 wasn't detected in this experiment, and it needs further research.