To investigate the effect of paeonol (PAE) on epithelial-mesenchymal transition (EMT) and endoplasmic reticulum stress-induced apoptosis in ovarian cancer cells by regulating the microRNA-128-3p (miR-128-3p)/ never in mitosis gene A-related kinase 2 (NEK2) signaling axis.

SKOV3 cells were divided into the following groups: SKOV3 group (normal culture), PAE group (4 mmol·L^-1 PAE treatment), inhibitor-NC group (transfected with miR-128-3p inhibitor negative control), miR-128-3p inhibitor group (transfected with miR-128-3p inhibitor), si-NC group (transfected with si-NEK2 negative control), si-NEK2 group (transfected with si-NEK2), PAE+inhibitor-NC group (based on the PAE group, transfected with miR-128-3p inhibitor negative control), PAE+miR-128-3p inhibitor group (based on the PAE group, transfected with miR-128-3p inhibitor), PAE+miR-128-3p inhibitor+si-NC group (based on the PAE group, co-transfected with miR-128-3p inhibitor and si-NEK2 negative control) and PAE+miR-128-3p inhibitor+si-NEK2 group (based on the PAE group, co-transfected with miR-128-3p inhibitor and si-NEK2). Quantitative real-time polymerase chain reaction (PCR) was used to detect the relative expression levels of mRNA; immunofluorescence was used to detect the positive expression of NEK2 protein; Western blot was used to detect the relative expression levels of related proteins.

The relative expression levels of miR-128-3p in SKOV3 group, PAE group, PAE+inhibitor-NC group and PAE+miR-128-3p inhibitor group were 1.00±0.12, 2.34±0.27, 2.30±0.29 and 1.19±0.21, respectively; the relative expression levels of NEK2 mRNA were 1.00±0.13, 0.58±0.09, 0.61±0.12 and 0.93±0.18, respectively; the positive expression of NEK2 was 1.00±0.11, 0.29±0.05, 0.31±0.06 and 0.94±0.17, respectively; the relative expression levels of E-cadherin mRNA in SKOV3 group, PAE group, PAE+inhibitor-NC group, PAE+miR-128-3p inhibitor group, PAE+miR-128-3p inhibitor+si-NC group and PAE+miR-128-3p inhibitor+si-NEK2 group were 1.00±0.12, 2.25±0.29, 2.27±0.34, 1.30±0.21, 1.32±0.20 and 2.03±0.35, respectively; the relative expression levels of N-cadherin mRNA were 1.00±0.14, 0.60±0.09, 0.63±0.12, 0.92±0.17, 0.94±0.18 and 0.67±0.13, respectively; the relative expression levels of Vimentin mRNA were 1.00±0.13, 0.62±0.09, 0.66±0.11, 0.90±0.17, 0.92±0.18 and 0.71±0.13, respectively; the relative expression levels of activating transcription factor 4 (ATF4) protein were 1.00±0.11, 3.22±0.57, 3.31±0.60, 1.51±0.24, 1.49±0.21 and 2.97±0.44, respectively; the relative expression levels of CCAAT/ enhancer binding protein (C/EBP) homologous protein (CHOP) were 1.00±0.14, 3.85±0.47, 3.62±0.41, 1.31±0.17, 1.28±0.17 and 3.26±0.57, respectively; the relative expression levels of cleaved-caspase-3 were 1.00±0.13, 4.52±0.67, 4.61±0.71, 1.67±0.26, 1.69±0.31 and 4.11±0.76, respectively. The differences in the above indicators were statistically significant when comparing PAE group with SKOV3 group, PAE+miR-128-3p inhibitor group with PAE+inhibitor-NC group and PAE+miR-128-3p inhibitor+si-NEK2 group with PAE+miR-128-3p inhibitor+si-NC group (all P<0.05).

PAE suppresses EMT and promotes endoplasmic reticulum stress-induced apoptosis in ovarian cancer cells, potentially by upregulating miR-128-3p to inhibit NEK2 expression.