Transcriptome Profiling Of Environmental Carcinogen Aflatoxin B1-transformed Rat Hepatic Stem Cells

Environmental pollutant Aflatoxin B1(AFB1) is worldspread in nature.Long-term exposure to Aflatoxin B1(AFB1) often leads to liver cancer. There wefocused on the rat hepatic stem-like cell line WB-F344, which was transformedmalignantly by treatment with AFB1, on the basis of the cancer stem cell hypothesis.Significantly, the application of gene chip technology to profile the transcriptome intransformed cells could illuminate principle points on mechanism of drug-inducedcarcinogenesis through the perspective of perturbation the integrated pathway.The rat oval cells WB-F344were treated by AFB1and that resulted in induciblemalignant transformation. Many transforming focuses appeared. Cells had the abilityof anchorage independent growth, and the clone formation ratios were0.8%,1.3%and2%, respectively. Special genes of liver stem cells, Yp, Vimentin, AFP and CK18,were all expressed significantly.We used the Rat OneArray genome microarray to detect the gene expression ofWB-F344cells with the treatment of AFB1. There are1315differentially expressedgenes (DEGs), and down-regulated genes played a key role. Clustering analysis ofDEGs revealed that the effect on cells during the treatment of med-or high-doseAFB1was conformable. In the whole, up-or down-gene expression in all dosageswas superior in DEGs. Gene Ontology (GO) analysis showed that malignanttransformation of the liver stem cells was closely correlated to biological process,primary focusing on cell migration, cell adhesion and inflammatory response, etc.Pathway analysis showed that significant pathway mainly focused on MAPKsignaling pathway, pathways in cancer, focal adhesion, regulation of actincytoskeleton, etc. It further indicated that the capital genes in these pathways greatlycontributed to the malignant transformation. In DEG interaction network, we foundthat these genes (MET, CCL2, ITGA1, EGFR, COL1A1, ELN, etc.) were in core. Itsuggested that these genes might be pivotal during malignant transformation of theliver stem cells by AFB1.In addition, it showed that these microarrays used corresponded completely toPhalanx control standard. Correlation and principal component analysis ofexperimental groups also revealed correlation modes. Meanwhile, qRT-PCR wasapplied to validate the microarray data. These results demonstrated that these genes could effectively reflect their expression changes, and further ensured the biologicalanalysis of the study a real significance.