Silencing the EZH2 gene by RNA interference reverses the drug resistance of human hepatic multidrug-resistant cancer cells to 5-Fu

Abstract

AimsThe EZH2 gene, which is expressed in various solid tumours, including liver cancer, can regulate gene transcription and promote the generation and progression of tumours. Our aim was to investigate the relationship between EZH2 and multidrug-resistance of human hepatic cancer cells using RNA interference. Main methodsWe detected the expression of EZH2 in the human hepatic multidrug-resistant cancer cell line Bel/Fu by RT-PCR and western blot; then knocked EZH2 gene by RNA interference to investigate the proliferation, the cell cycle and cell apoptosis by MTT and flow cytometry; finally we checked the alteration of MDR1 methylation and MDR1 expression after EZH2 silencing by MS-PCR, RT-PCR and western blot. Key findingsEZH2 is highly expressed in Bel/Fu cells. After EZH2-depleted Bel/Fu cells were treated with 5-Fu, the cell proliferation was inhibited, the cell cycle arrested at G1, which may be associated with the alteration of G1/S checkpoint regulators, meanwhile the apoptotic rate of the cells increased. Furthermore, the expression of MDR1 decreased and the corresponding methylation levels of MDR1 were significantly increased in EZH2-depleted Bel/Fu cells. SignificanceWe demonstrate the relationship between EZH2 and multidrug-resistance in hepatic cancer for the first time. EZH2 may become a new target for gene therapy to reverse multidrug-resistance in hepatic cancer.