DNMT1 and hepatocellular carcinoma: Finally, to better understanding the molecular mechanisms of synergistic effect of sorafenib and AuNPs-anti-miR221 in HCC cells, we incubated two HCC cell lines with AuNPs-anti-miR221 (5 nmol/L) or sorafenib (5 μmol/L) alone or combination for 24 h, and the levels of p27 and DNMT1, downstream targets of miR221, were detected by western blot.