Expression Of β-catenin, Cox-2 And PGE₂ In Colorectal Tumor Of Rats And Its Significance Expression Of CD133 And Lgr5 In Colorectal Tumor And Its Significance

Objective:①To observe the function and significance of (3-catenin, COX-2 and PGE2 in the colorectal tumor of rats induced by 1,2-dimethylhydrazine (DMH).②To explore the expression of CD133 and Lgr5 in colorectal tumor of human. Methods:①Useing Real-time PCR and Western-blot to detect the expressions ofβ-catenin and COX-2 respectively in DMH-induced rats colon carcinogenesis models. The content of PGE2 in the colorectal tissue was detected by ELISA.②To select 26 samples of colorectal cancer,21 samples of colorectal adenomas and 21 samples of normal colorectal mucosal tissues which were confirmed pathologically.To mesure The expressions of CD 133 and Lgr5 with immunohistochemical method of SP. Results:①The model of colorectal cancer was successfully induced by DMH. There was no tumor in normal group,51 (72.86%) rats were induced to develop tumors, including 35 adenocarcinomas and 16 adenomas.The mRNA and the protein ofβ-catenin in the colorectal cancer and the adenoma tissues were all higher than normal mucosa (P<0.05), And the colorectal cancer tissue were higher than the adenomas (P <0.05); The expressions of COX-2 mRNA and protein in the colorectal cancer tissues were higher than that in the adenomas and normal mucosa tissues (P<0.05), but there were no significant association between adenomas and normal mucosa tissues (P> 0.05). In normal mucosa, colorectal adenoma and cancer tissues, the contents of PGE2 is increasing gradually, there were statistical differences among them (P<0.05).②In normal colorectal mucosa, colorectal adenomas and colorectal cancer, the positive rates of CD133 expression were 14.3%,42.9% and 73.1% respectively, colorectal cancer and adenoma groups were significantly higher than the normal colorectal mucosal tissues (P<0.05). In addition, the group of colorectal cancer were higher than the adenomas (P<0.05). The positive expression rate of Lgr5 on identical samples were respectively 0,23.8% and 65.4%, there were statistical differences among the three groups(P<0.05).Conclusions:①The increase of PGE2 in the tissue induced by high COX-2 as well as the increase ofβ-catenin may play important roles in the carcinogenesis and development of colorectal cancer;②The expresssion of CD133 and Lgr5 were higher in colorectal cancer, they may play the roles as molecular markers of stem cells in colorectal cancer.