Expression of PKG2 in Ovarian Cancer and Its Effect on Epidermal Growth Factor Receptor

J BUON. Mar-Apr 2020;25(2):729-735.

Abstract

Purpose: This research tried to explore the expression level of II cGMP-dependent protein kinase (PKG2) in human ovarian tissue and to clarify the molecular mechanism of EGFR regulation and its clinical significance.

Methods: The expression levels of PKG2 and EGFR in 10 normal ovarian tissues, 14 benign ovarian tumor tissues and 39 epithelial ovarian cancer tissues preserved in the archives of the Affiliated Hospital of Xuzhou Medical University from 2016 to 2018 were detected by real-time fluorescence quantitative (RT-PCR), and the correlation between the expressions of the two genes was analyzed. The expressions of in vitro cultured ovarian cancer cell lines SKOV3, PKG2 and EGFR were detected by RT-PCR and western blot, and the over-expressed PKG2 plasmid and PKG2 small interfering RNA (siRNA) were transfected into the cells, and the protein and phosphorylation of Akt and ERK in EGFR and its downstream signaling pathway were detected by western blot.

Results: Compared with normal ovarian tissue, the mRNA and protein expression levels of PKG2 in ovarian cancer tissue and SKOV3 cell line were significantly reduced (p<0.05). However, the mRNA and protein expression levels of EGFR in ovarian cancer tissue and SKOV3 cell line were both high (p<0.05). In addition, after transient transfection of PKG2, the expression changes of PKG2 significantly affected the expression of EGFR, and PKG2 over-expression could significantly inhibit the phosphorylation of Akt and ERK in EGFR and its downstream signaling pathways, thereby affecting cell proliferation.

Conclusion: PKG2 may play a role in inhibiting EGFR expression in ovarian cancer, but the specific mechanism of its effect on tumor development still needs to be further explored.