Slc11a1 gene polymorphism influences dextran sulfate sodium (DSS)-induced colitis in a murine model of acute inflammation

Ulcerative Colitis (UC) is an inflammatory disease characterized by colonic mucosal lesions associated with an increased risk of carcinogenesis. UC pathogenesis involves environmental and genetic factors. Genetic studies have indicated the association of gene variants coding for the divalent metal ion transporter SLC11A1 protein (formerly NRAMP1) with UC susceptibility in several animal species. Two mouse lines were genetically selected for high (AIRmax) or low (AIRmin) acute inflammatory responses (AIR). AIRmax is susceptible, and AIRmin is resistant to DSS-induced colitis and colon carcinogenesis. Furthermore, AIRmin mice present polymorphism of the Slc11a1 gene. Here we investigated the possible modulating effect of the Slc11a1 R and S variants in DSS-induced colitis by using AIRmin mice homozygous for Slc11a1 R (AIRmin^RR) or S (AIRmin^SS) alleles. We evaluated UC by the disease activity index (DAI), considering weight loss, diarrhea, blood in the anus or feces, cytokines, histopathology, and cell populations in the distal colon epithelium. AIRmin^SS mice have become susceptible to DSS effects, with higher DAI, IL6, G-CSF, and MCP-1 production and morphological and colon histopathological alterations than AIRmin^RR mice. The results point to a role of the Slc11a1 S allele in DSS colitis induction in the genetic background of AIRmin mice.

The Controversial Role of Autophagy in Tumor Development: A Systematic Review

Autophagy is a natural regulatory mechanism of the cell that eliminates unnecessary and dysfunctional cellular components to maintain homeostasis. Several authors have demonstrated that this mechanism can be induced by pathological conditions as cancer. However, their role in tumor development is still a controversial issue in cancer research. Here, we discussed the most relevant findings concerning autophagy in tumor development. In this critical review performed with studies published between 2002 and 2018, we found that the main pathway involved in the autophagy process is the PI3K/AKT/mTOR intracellular signaling pathway. Regarding their role in cancer development, breast cancer is the main study target, followed by lung, prostate and colon cancer. In these issues, 46% of the works consulted suggesting that autophagy inhibits tumor progression by favor a better antitumor response, 4% suggest that favors growth and tumor progression and, 50% of the authors failed to establish whether autophagy inhibits or favors tumor development. Herein, we concluded that depending on the study model, autophagy may favor or inhibits growth and cancer progression.