Abstract: To identify the differentially expressed miRNAs in malignantly transformed L02 cells(L02T) induced by aflatoxin B1(AFB1), we performed miRNA microarray on both control cells(L02) and L02T cells. METHODS: L02T cells were obtained after exposure to aflatoxin B1(AFB1) several times. The comparison of differential expression profiles between L02 and L02T cells was performed and analyzed. The differentially expressed miRNAs were then selected for validation by semi-quantitative real-time PCR. The targets of miRNAs were predicted by TargetScan program. RESULTS: 856 human miRNAs were analyzed by miRNA microarray. 25 differentially expressed miRNAs were found in L02T cells compared with L02 cells, with 15 upregulated and 10 downregulated. Among these miRNAs, miR-320a, miR-638 and miR-98 were validated by quantitative real-time PCR. Moreover, predicted by TargetScan program, we identified 4 genes that were potentially targeted by miR-638. These genes might be associated with hepatic cell transformation induced by AFB1. CONCLUSION: 25 differentially expressed miRNAs were identified in AFB1-transformed L02T cells. These miRNAs may play important roles in the process of malignant transformation of human cells.

Key words: aflatoxin B1, immortalized human hepatic cells, malignant cell transformation, miRNA