MicroRNA-203 inhibits cell proliferation by repressing ΔNp63 expression in human esophageal squamous cell carcinoma

Background: This study was performed to investigate the effect of microRNA-203 (miR-203) and Delta Np63 on cell proliferation and the functional connection between miR-203 and Delta Np63 in ESCC. Methods: We employed 2 human ESCC cell lines, Eca109 and TE-1, as the model system. The effect of miR-203 and Delta Np63 on cell proliferation was determined in cells transfected with miR-203 mimic and Delta Np63 small interfering RNA (siRNA), respectively. The regulation of Delta Np63 expression in ESCC cells by miR-203 was studied by luciferase reporter assay, RT-PCR and western blot analysis in cells transfected with miR-203. The effect of Delta Np63 re-expression on miR-203 induced inhibition of cell proliferation was studied by cell proliferation assay in cells cotransfected with miR-203 and pcDNA-Delta Np63 plasmid (without the 3'-UTR of Delta Np63). Results: We found that both miR-203 and Delta Np63 siRNA signicantly inhibited cell proliferation in ESCC. MiR-203 could down-regulate endogenous Delta Np63 expression at the posttranscriptional level. Moreover, re-expression of Delta Np63 in cells transfected with miR-203 significantly attenuated the miR-203 induced inhibition of cell proliferation. Conclusions: Our data implied that miR-203 could inhibit cell proliferation in human ESCC through Delta Np63 mediated signal pathway. Therefore, we propose that miR-203 might be used as a therapeutic agent for human ESCC.