1. Inferred inactivation of the Cftr gene in the duodena of mice exposed to hexavalent chromium (Cr(VI)) in drinking water supports its tumor-suppressor status and implies its potential role in Cr(VI)-induced carcinogenesis of the small intestines.
- Author
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Mezencev R and Auerbach SS
- Subjects
- Administration, Oral, Animals, Cell Transformation, Neoplastic genetics, Cell Transformation, Neoplastic metabolism, Cell Transformation, Neoplastic pathology, Chromium administration & dosage, Cystic Fibrosis Transmembrane Conductance Regulator metabolism, Databases, Genetic, Drinking Water, Duodenal Neoplasms genetics, Duodenal Neoplasms metabolism, Duodenal Neoplasms pathology, Duodenum metabolism, Duodenum pathology, Gene Expression Profiling, Mice, Risk Assessment, Systems Biology, Transcriptome, Tumor Suppressor Proteins metabolism, Water Pollutants, Chemical administration & dosage, Cell Transformation, Neoplastic chemically induced, Chromium toxicity, Cystic Fibrosis Transmembrane Conductance Regulator genetics, Duodenal Neoplasms chemically induced, Duodenum drug effects, Gene Silencing drug effects, Tumor Suppressor Proteins genetics, Water Pollutants, Chemical toxicity
- Abstract
Carcinogenicity of hexavalent chromium [Cr (VI)] has been supported by a number of epidemiological and animal studies; however, its carcinogenic mode of action is still incompletely understood. To identify mechanisms involved in cancer development, we analyzed gene expression data from duodena of mice exposed to Cr(VI) in drinking water. This analysis included (i) identification of upstream regulatory molecules that are likely responsible for the observed gene expression changes, (ii) identification of annotated gene expression data from public repositories that correlate with gene expression changes in duodena of Cr(VI)-exposed mice, and (iii) identification of hallmark and oncogenic signature gene sets relevant to these data. We identified the inactivated CFTR gene among the top scoring upstream regulators, and found positive correlations between the expression data from duodena of Cr(VI)-exposed mice and other datasets in public repositories associated with the inactivation of the CFTR gene. In addition, we found enrichment of signatures for oncogenic signaling, sustained cell proliferation, impaired apoptosis and tissue remodeling. Results of our computational study support the tumor-suppressor role of the CFTR gene. Furthermore, our results support human relevance of the Cr(VI)-mediated carcinogenesis observed in the small intestines of exposed mice and suggest possible groups that may be more vulnerable to the adverse outcomes associated with the inactivation of CFTR by hexavalent chromium or other agents. Lastly, our findings predict, for the first time, the role of CFTR inactivation in chemical carcinogenesis and expand the range of plausible mechanisms that may be operative in Cr(VI)-mediated carcinogenesis of intestinal and possibly other tissues., (Published by Elsevier Inc.)
- Published
- 2021
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