KLF5-mediated aquaporin 3 activated autophagy to facilitate cisplatin resistance of gastric cancer

Abstract

Background Resistance to chemotherapeutic drugs limits the control of gastric cancer (GC) development. The study intended to probe into the mechanism of aquaporin 3 (AQP3) on the chemoresistance of GC. Methods Cisplatin (CDDP)-resistant cells were constructed. Parental AGS and HGC-27 cells and their respective CDDP-resistant cells were transfected with AQP3 overexpression plasmid, AQP3 short hairpin RNA (sh-AQP3) and sh-Kruppel-like factor 5 (shKLF5). The expressions of AQP3 and factors related to autophagy (LC3 I, LC3 II, Atg5, Beclin-1, p62)/epithelial-mesenchymal transition (EMT; E-cadherin and snail) were assessed by Western blot and qRT-PCR. Cell counting kit-8 assay was adopted to test cell viability and half maximal inhibitory concentration (IC 50) was determined. Transwell assay was used for the examination of cell migration and invasion. The regulatory relationship of AQP3 and KLF5 was tested by chromatin immunoprecipitation (ChIP) and dual luciferase reporter assays. Results AQP3 was highly-expressed in GC cells and its level was even higher in CDDP-resistant GC cells. AQP3 silencing inhibited viability, autophagy and EMT in CDDP-resistant GC cells, while AQP3 overexpression had the opposite effect. KLF5 positively modulated AQP3 in GC cells resistant to CDDP. KLF5 knockdown reversed AQP3-induced autophagy, viability, migration, invasion and EMT in CDDP-resistant GC cells. Conclusion KLF5-modulated AQP3 activated autophagy to facilitate the resistance of GC to CDDP.