Transcriptomic analysis of aflatoxin B1-regulated genes in rat hepatic epithelial cells

Abstract

Aflatoxins are the most popular hepatotoxicants. Chronic exposure to aflatoxins leads to a wide variety of liver diseases, such as hepatocellular carcinoma. In this study, we analyzed the genome wide expression profiles of aflatoxin B1-induced rat hepatic epithelial cells. The expression of 325, 184 and 199 special genes was altered when exposed to 0.03, 0.1 and 0.2 μmol/L aflatoxin B1 respectively, and 239 genes were commonly expressed. After the functional analysis on these dose-special genes, we determined several key pathways related to hepatotoxicity, such as TGF-beta signaling pathway, tight junction, adherens junction, the regulation of actin cytoskeleton, ErbB signaling pathway, p53 signaling pathway, pathways in cancer and axon guidance. Common genes were mainly associated with focal adhesion, ECM-receptor interaction, and cell adhesion molecules. Gene ontology annotations showed a good concordance with these pathways. The quantitative real-time polymerase chain reaction(PCR) analysis of selected genes showed similar patterns in microarrays. The toxicogenomic study provides a better understanding of molecular mechanisms of aflatoxins.

Keywords

aflatoxin / microarray / gene ontology / Kyoto encyclopedia of genes and genomes(KEGG) pathway / hepatotoxicity

References

[1] Williams J H, Phillips T D, Jolly P E, et al. Human aflatoxicosis in developing countries: A review of toxicology, exposure, potential health consequences, and interventions[J]. The American Journal of Clinical Nutrition, 2004, 80(5): 1106-1122.

[2] Wild C P, Gong Y Y. Mycotoxins and human disease: A largely ignored global health issue[J]. Carcinogenesis, 2010, 31(1): 71-82.

[3] Wogan G N, Kensler T W, Groopman J D. Present and future directions of translational research on aflatoxin and hepatocellular carcinoma[J]. Food Additives & Contaminants: Part A, 2012, 29(2): 249-257.

[4] IARC. Some naturally occurring substances: Food items and constituents, heterocyclic aromatic amines and mycotoxins[ C]. IARC Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Humans. Lyon, France, 1993 397-444.

[5] Jennen D G J, Magkoufopoulou C, Ketelslegers H B, et al. Comparison of HepG2 and HepaRG by whole-genome gene expression analysis for the purpose of chemical hazard identification[J]. Toxicological Sciences, 2010, 115(1): 66-79.

[6] Doktorova T Y, Ellinger-Ziegelbauer H, Vinken M, et al. Comparison of hepatocarcinogen-induced gene expression profiles in conventional primary rat hepatocytes with in vivo rat liver[J]. Archives of Toxicology, 2012, 86(9): 1399-1411.

[7] Song M K, Kim Y J, Song M, et al. Dose-response functional gene analysis by exposure to 3 different polycyclic aromatic hydrocarbons in human hepatocytes [J]. Molecular & Cellular Toxicology, 2011, 7(3): 221-232.

[8] Yam J W, Tse E Y, Ng I O. Role and significance of focal adhesion proteins in hepatocellular carcinoma[J]. Journal of Gastroenterology and Hepatology, 2009, 24(4): 520-530.

[9] Lambrechts A, Van Troys M, Ampe C. The actin cytoskeleton in normal and pathological cell motility[J]. International Journal of Biochemistry & Cell Biology, 2004, 36(10): 1890-1909.

[10] Elliott R L, Blobe G C. Role of transforming growth factor Beta in human cancer[J]. Journal of Clinical Oncology, 2005, 23(9): 2078-2093.

[11] Volkmorov V, Grigoryeva E, Krasnov G, et al. Search for potential gastric cancer markers using miRNA databases and gene expression analysis[J]. Experimental Oncology, 2013, 35(1): 2-7.

[12] Krajewska M, Krajewski S, Zapata J M, et al. TRAF-4 expression in epithelial progenitor cells: Analysis in normal adult, fetal, and tumor tissues[J]. The American Journal of Pathology, 1998, 152(6): 1549-1561.

[13] Asiljevic A, Champier J, Figarella-Branger D, et al. Molecular characterization of central neurocytomas: Potential markers for tumor typing and progression[J]. Neuropathology, 2013, 33(2): 149-161.

[14] Davidson B, Stavnes H T, Holth A, et al. Gene expression signatures differentiate ovarian/peritoneal serous carninoma from breast carcinoma in effusions[J]. Journal of Cellular and Molecular Medicine, 2011, 15(3): 535-544.

[15] Sun Q, Zhang Y A, Liu F, et al. Identification of candidate biomarkers for hepatocellular carcinoma through precancerous expression analysis in an HBx transgenic mouse [J]. Cancer Biology & Therapy, 2007, 6(10): 1532-1538.

[16] Bai Y Q, Yamamoto H, Akiyama Y, et al. Ectopic expression of homeodomain protein CDX2 in intestinal metaplasia and carcinomas of the stomach[J]. Cancer Letters, 2002, 176(1): 47-55.

[17] Dang L H, Chen F, Ying C, et al. CDX2 tumorigenic potential in the human colon cancer lines lovo and sw48[J]. Oneogene, 2006, 25, 2264-2272.

[18] Xu L, Begum S, Hearn J D, et al. GPR56, an atypical G protein-coupled receptor, binds tissue transglutaminase, TG2, and inhibits melanoma tumor growth and metastasis[J]. Proceedings of the National Academy of Sciences of the United States of America, 2006, 103(24): 9023-9028.

[19] Huang Y, Fan J, Yang J, et al. Characterization of GPR56 protein and its suppressed expression in human pancreatic cancer cells[J]. Molecular and Cellular Biochemistry, 2008, 308(1/2): 133-139.

[20] Li D Q, Wang L, Fei F, et al. Identification of breast cancer metastasis-associated proteins in an isogenic tumor metastasis model using two-dimensional gel electrophoresis and liquid chromatography-ion trap-mass spectrometry[J]. Proteomics, 2006, 6(11): 3352-3368.

[21] Bao H M, Song P M, Liu Q P, et al. Quantitative proteomic analysis of a paired human liver healthy versus carcinoma cell lines with the same genetic background to identify potential hepatocellular carcinoma markers[J]. Proteomics-Clinical Applications, 2009, 3(6): 705-719.

[22] Pwalak G, McGarvey T W, Nguyen T B, et al. Alterations in troponmyosin isoform expression in human transitional cell carcinoma of the urinary bladder[J]. International Journal of Cancer, 2004, 110(3): 368-373.