Chemically Induced Colitis-Associated Cancer Models in Rodents for Pharmacological Modulation: A Systematic Review

Abstract

Animal models for colitis-associated colorectal cancer (CACC) represent an important tool to explore the mechanistic basis of cancer-related inflammation, providing important evidence that several inflammatory mediators play specific roles in the initiation and perpetuation of colitis and CACC. Although several original articles have been published describing the CACC model in rodents, there is no consensus about the induction method. This review aims to identify, summarize, compare, and discuss the chemical methods for the induction of CACC through the PRISMA methodology. Methods: We searched MEDLINE via the Pubmed platform for studies published through March 2021, using a highly sensitive search expression. The inclusion criteria were only original articles, articles where a chemically-induced animal model of CACC is described, preclinical studies in vivo with rodents, and articles published in English. Results: Chemically inducible models typically begin with the administration of a carcinogenic compound (as azoxymethane (AOM) or 1,2-dimethylhydrazine (DMH)), and inflammation is caused by repeated cycles of colitis-inducing agents (such as 2,4,6-trinitrobenzenesulfonic acid (TNBS) or dextran sulfate sodium (DSS)). The strains mostly used are C57BL/6 and Balb/c with 5–6 weeks. To characterize the preclinical model, the parameters more used include body weight, stool consistency and morbidity, inflammatory biomarkers such as tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-1β, angiogenesis markers such as proliferating cell nuclear antigen (PCNA), marker of proliferation Ki-67, and caspase 3, the presence of ulcers, thickness or hyperemia in the colon, and histological evaluation of inflammation. Conclusion: The AOM administration seems to be important to the CACC induction method, since the carcinogenic effect is achieved with just one administration. DSS has been the more used inflammatory agent; however, the TNBS contribution should be more studied, since it allows a reliable, robust, and a highly reproducible animal model of intestinal inflammation.

Heparanase 2 (Hpa2)- a new player essential for pancreatic acinar cell differentiation

“…7B ). This treatment regimen was reported to elicit pancreatic neoplasia [ 37 ] and is based upon the notion that combining the effect of carcinogens with chronic inflammation elicits tumor initiation and growth [ 38 ]. Given the severe morphological alterations of Hpa2-KO pancreas we, nonetheless, reduced the frequency of cerulein treatment from three consecutive days [ 37 ] to only once per week (Fig.…”

Laherradurin Inhibits Tumor Growth in an Azoxymethane/Dextran Sulfate Sodium Colorectal Cancer Model In Vivo

“…Therefore, the DAI score allowed us to evaluate the progression and severity of the disease during a 16-week trial, where our results show that the AOM/DSStreated groups presented symptoms of diarrhea and bleeding compared with the NC group. DSS in mouse models causes chronic inflammation and ulceration of the colon due to macrophage dysfunction, changes in intestinal microflora, and a toxic effect on the intestinal epithelium [49][50][51][52].…”

Global alteration of colonic microRNAome landscape associated with inflammatory bowel disease

“…MicroRNAs are considered central regulators of gene expression, and miRNA expression may be predictive of underlying molecular mechanisms in complex diseases such as IBD. Dextran sodium sulfate (DSS)- and TNBS-induced colitis are widely used as rodent IBD models ( 80 ). Inflammation in DSS seems to be caused by hyperosmotic damage and is confined to the mucosa and lamina propria, in contrast to the TNBS-model where inflammation is hapten-mediated and transmural, therefore the pathological tissue lesions are more closely reminiscent to the human conditions.…”