Inhibition of enhancer of zeste homolog 2 increases the expression of p16 and suppresses the proliferation and migration of ovarian carcinoma cells in vitro and in vivo.

Enhancer of zeste homolog 2 (EZH2) is a histone methyltransferase, which targets histone H3 lysine 27. Studies have reported that EZH2 is involved in the development of several types of tumor, including ovarian cancer. p16, a well-known cell cycle regulator, has been demonstrated to be a tumor suppressor gene in a variety of malignant cells. However, the regulatory association between EZH2 and p16 in ovarian cancer remains to be fully elucidated. The present study aimed to determine whether EZH2 is involved in the development of ovarian cancer by regulating the expression of p16. An EZH2 short hairpin RNA (shRNA) lentiviral vector was constructed and used for transducing A2780 and SKOV3 ovarian cancer cell lines. The expression levels of EZH2 and p16 in the ovarian cancer cells were detected using a reverse transcription-quantitative polymerase chain reaction and western blot analyses, respectively. The function of the inhibition of EZH2 in cell proliferation and migration were determined using a CCK-8 assay and Transwell assay. In addition, a nude mouse xenograft model was used to determine the function of EZH2 and p16 in the formation of ovarian cancer in vivo. The results revealed that the inhibition of EZH2 increased the expression of p16, and suppressed the proliferation and migration capabilities of ovarian cancer in vitro. The downregulated expression of EZH2 suppressed ovarian tumor formation in vivo. The results of the study revealed that p16 was negatively regulated by EZH2 in ovarian cancer, and that p16 and EZH2 are important in the tumorigenesis of ovarian cancer. EZH2 and p16 represent potential biomarkers for the diagnosis of ovarian cancer and as targets for ovarian cancer gene therapy.