Liver And Blood Mirna Alterations As Putative Biomarkers Of Hepatotoxic Response To Short-Term Furan Exposure In Mice

Proceedings: AACR Annual Meeting 2014; April 5-9, 2014; San Diego, CA Epigenetic miRNA-based changes measured in accessible matrices may serve as useful biomarkers of environmental exposures and human health effects. We investigated miRNA profiles following short-term exposure to a known cytotoxic hepatocarcinogen, furan. We measured global liver and blood miRNA changes in female B3C6F1 mice exposed to furan for 3 weeks p.o. at daily doses of 0, 1, 2, 4, and 8 mg/kg. Small RNA was extracted from frozen samples using Exiqon miRCURY RNA Isolation kit and quantified by Qubit. RNA quality was checked by Nanodrop and Bioanalyzer, and liver miRNA were measured by miRNA-seq on the Illumina HiScanSQ platform. Blood miRNA were measured from pooled RNA samples by Affymetrix GeneChip v3 microarrays. In the liver, the 1, 2, 4, and 8 mg/kg doses resulted in 0, 10, 17 and 14 differentially altered miRNAs, respectively (>1.5-fold; B-H corrected p-value<0.05). The majority of miRNA changes in the low-dose exposure group (2mg/kg) were not seen with other treatments (7 of 10 miRNA). Conversely, most altered miRNA observed with high-dose (4 or 8 mg/kg) exposures were shared (10 miRNA), indicating different miRNA-mediated pathways for non-carcinogenic and carcinogenic furan exposures. Using Ingenuity Pathway Analysis (IPA), liver miRNAs altered by the carcinogenic doses of furan (4 and 8 mg/kg) significantly enriched (B-H corrected p-value<0.05) functions related to cellular development, growth and proliferation, movement, cell cycle, death and survival; other categories identified by IPA were related to hepatotoxicity, liver inflammation, and cancer. Using predicted miRNA-mRNA interactions, 68 mRNAs were expressed in a contrasting pattern to miRNA expression (upregulated miRNA/downregulated mRNAs and vice versa). Associated mRNAs showed enrichment of pathways similar to miRNAs. Measurements in whole blood samples indicated that 6 out of the 21 miRNAs altered by the carcinogenic doses of furan were also altered in the blood (4 in the same direction). Blood miRNAs included mmu-miR-34a, -146b, -183, -5099 (upregulated), and -10a, -99b (downregulated). Results demonstrate distinctive miRNA profiles in rodent liver for carcinogenic doses of furan with corresponding changes for a subset of liver miRNAs in blood. Our findings support ongoing efforts to identify novel miRNA biomarkers in accessible matrices related to environmental health effects. This abstract does not necessarily reflect the policy of the US EPA. Citation Format: Brian Norris Chorley, Gail Nelson, Gleta Carswell, Holly Mortensen, James Crooks, William Ward, Charles Wood, Anna F. Jackson, Carole Yauk, Les Recio, Susan Hester. Liver and blood miRNA alterations as putative biomarkers of hepatotoxic response to short-term furan exposure in mice. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5226. doi:10.1158/1538-7445.AM2014-5226