[Wnt5a modulates vincristine resistance through PI3K/Akt/GSK3ß signaling pathway in human ovarian carcinoma SKOV3/VCR cells].

ABSTRACT

The aim of this study was to investigate the effect of Wnt5a on the vincristine (VCR) resistance in human ovarian carcinoma SKOV3 cells and its possible mechanism. The drug-resistant SKOV3/VCR cells were established by stepwise exposure to VCR, and then the SKOV3/VCR cells were stably transfected with specific shRNA interference plasmid vector targeting for Wnt5a. The mRNA expression level of Wnt5a was measured by RT-PCR. CCK-8 assay was used to detect the cell viability of SKOV3/VCR cells. The apoptosis was analyzed by flow cytometry. The protein expression levels of Wnt5a, MDR1, Survivin, ß-catenin, Akt, p-Akt(S473), GSK3ß and p-GSK3ß(Ser9) were detected by Western blot. The result showed that SKOV3/VCR cells had significantly higher protein expression levels of Wnt5a, MDR1, Survivin and ß-catenin, phosphorylation levels of Akt and GSK3ß, and mRNA expression level of Wnt5a, compared with SKOV3 cells (P < 0.05). WNT5A gene silencing significantly increased the sensitivity of SKOV3/VCR cells to VCR, the IC50 of VCR being decreased from 38.412 to 9.283 mg/L (P < 0.05), synergistically enhanced VCR-induced apoptosis of SKOV3/VCR cells (P < 0.05), down-regulated the protein expression levels of MDR1, ß-catenin and Survivin (P < 0.05), and inhibited phosphorylation of Akt and GSK3ß (P < 0.05). Meanwhile, LY294002 (PI3K inhibitor) decreased the protein expression levels of MDR1, ß-catenin and Survivin, as well as the phosphorylation levels of Akt and GSK3ß in SKOV3/VCR cells (P < 0.05). These results suggest that WNT5A gene silencing reverses VCR resistance in SKOV3/VCR cells possibly through blocking the PI3K/Akt/GSK3ß/ß-catenin signaling pathway, and thus down-regulating the protein expression levels of MDR1 and Survivin.