动物造模,结肠癌 zi-bio 2024-04-28 1418

　　Objective: To optimize the method of modeling colitis associated colon cancer using oxidized azomethane combined with sodium gluconate sulfate and explore the pathogenesis of gut microbiota in CAC.

　　Method: A (AOM1 injection) and B (AOM2 injection) model groups were established by combining different injection times of AOM with free drinking DSS. The normal group was treated with intraperitoneal injection of physiological saline combined with drinking purified water, with 10 mice in each group. After the completion of modeling, the optimal modeling plan is selected through comprehensive evaluation of indicators such as DAI score, colon length, tumor formation rate, and mortality rate. Then, the B model group mice were subjected to experiments, and serum was collected for ELISA detection of interleukin-6 (IL-6) and tumor necrosis factor α α (TNF ⁃) α） And the content of tumor markers CA199, CEA, and CA724; Simultaneously perform HE staining to observe colon lesions; And high-throughput 16S rDNA gene sequencing was performed on mouse feces to explore the changes in the gut microbiota of CAC mice.

　　Both single and enhanced AOM injection combined with DSS can induce CAC mouse models. But compared with the A model group, the B model group mice had a larger increase in colonic growth, closely arranged and consistent in shape and size, with a tumor formation rate of 100%. Compared with the normal group, the B model group showed a significant increase in IL-6 (P<0.05) and="" tnf="" the="" content="" increased="" p="">0.05); Except for CA724, the levels of CA199 and CEA in tumor markers were significantly increased (P<0.05); HE pathology shows infiltration of inflammatory cells in the colon, accompanied by high-grade intraepithelial tumor like changes on the luminal surface. The microbial community results showed that compared with the normal group, the species diversity and abundance of intestinal microbiota in CAC mice decreased, while the phyla Verrucomycota and Actinobacteria increased (P<0.05), and the phyla Bacteroidetes and Campylobacter decreased (P<0.05). Ackermann bacteria, Prevotella, Ruminococcus, Bifidobacterium, etc. significantly increased (P<0.05); There was a significant decrease in the genera of Rochella, Muribaculaceae, Phyllostachys, and Anaeroplasma (P<0.05).

　　Conclusion: The combination of AOM2 injection and free drinking of 1.5% (1.5g/100mL) DSS induces a high colon tumor formation rate, uniform tumor morphology and size, and low mortality rate in CAC model mice, which can be used as the optimal modeling scheme for pharmacological experimental evaluation. The disruption or dysfunction of various gut microbiota can lead to increased permeability, disruption of intestinal mucosal barrier function, and ultimately induce the release of enterogenous endotoxins, leading to sustained inflammatory reactions or indirect or direct causes of CAC.