Significantly differentially expressed miRNAs were identified as absolute mean fold change of greater than 1. 5 andp-value of less than 0. 01, and located in the two upper-lateral quadrants. Seven miRNAs (miR-30c, miR-193b, miR-342, miR-199a, miR-125a, miR-99b, and miR-191) were found to be significantly up-regulated while 11 miRNAs (miR-196a, miR-106a, miR-20a, and let-7 family of miRNAs) were found to be significantly down-regulated in HBx-expressing cells compared to the controlcells .
The mechanism by which HBV regulates cellular miRNAs is largely unknown. One possible way is through HBV x protein(HBx). HBx plays a key role in regulating HBV replication and hepatocarcinogenesis. It upregulates 7(miR-30c, -99b, -125a, -191, -193b, -199a, -342) and down-regulates 11(let-7a, let-7c, let-7d, let-7e, let-7f, let-7g, let-7i, miR-20a, -98, -106a, -196a) miRNAs in the HBx-transfected HepG2 cells in a microarray assay.