Knockdown of cir_RNA PVT1 Elevates Gastric Cancer Cisplatin Sensitivity via Sponging miR-152-3p

Background: Cisplatin (DDP) resistance is a key problem for effective treatment of gastric cancer (GC). Circular RNA PVT1 (circPVT1) acts as a vital regulator in the progression and development of various cancers. However, the in-depth mechanism of circPVT1 in GC resistance to DDP is still unclear. Materials and Methods: Quantitative real-time polymerase chain reaction was executed for the detection of the expression of circPVT1, miR-152-3p, and hepatoma-derived growth factor (HDGF) mRNA in GC tissues and cells. Western blot was used to detect the levels of HDGF protein, Bax, cleaved-casp-3, Bcl-2, p-PI3K, and p-AKT in tissue samples and/or cells. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and flow cytometry assays were performed to determine the viability, proliferation, and apoptosis of DDPresistant GC cells. The relationship between miR-152-3p and circPVT1 or HDGF was confirmed by dual-luciferase reporter assay. The biological role of circPVT1 in vivo was confirmed with a xenograft tumor model. Results: CircPVT1 and HDGF mRNA were upregulated while miR-152-3p was downregulated in chemoresistance tissues and DDP-resistant GC cells. Both circPVT1 and HDGF inhibition elevated cell sensitivity to DDP, suppressed cell viability, proliferation, and induced cell apoptosis in DDP-resistant GC cells. The MiR-152-3p inhibitor reversed the influence of circPVT1 silencing on DDP sensitivity, viability, proliferation, and apoptosis of DDPresistant GC cells. Moreover, circPVT1 regulated the HDGF/PI3K/AKT pathway through sponging miR-152-3p. In addition, circPVT1 knockdown reduced the malignancy of DDPresistant GC cells in vivo. Conclusions: CircPVT1 regulated the chemoresistance and malignancy of GC through modulating HDGF expression via sponging miR-152-3p, providing a theoretical basis for the development of effective therapeutic strategies for GC. (c) 2020 Elsevier Inc. All rights reserved.

Automated summary

The study demonstrates that circPVT1 can modulate chemoresistance and malignancy of gastric cancer by regulating HDGF expression via sponging miR-152-3p.