circRNA_001275 upregulates Wnt7a expression by competitively sponging miR-370-3p to promote cisplatin resistance in esophageal cancer

Circular RNAs (circRNAs) are aberrantly expressed in various tumors and are associated with tumorigenesis. The present study aimed to determine the role of circRNA_001275 in cisplatin-resistant esophageal cancer. Three pairs of cisplatin-resistant tissues and corresponding adjacent tissues were collected and subjected to circRNA chip analysis. Additionally, the effect of circRNA_001275 on cisplatin-resistant cells was investigated. The relationship between circRNA_001275, microRNAs (miRs) and target genes were analyzed using luciferase assays, and validated via reverse transcription-quantitative PCR (RT-qPCR) and western blotting. The results showed that circRNA_001275 was significantly upregulated in cisplatin-resistant esophageal cancer tissues and cells (P<0.05). Overexpression of circRNA_001275 promoted the proliferation and invasion, and decreased the apoptosis of cisplatin-resistant cells. On the other hand, circRNA_001275 silencing inhibited cell proliferation and invasion, and promoted cell apoptosis (P<0.05). Dual-luciferase reporter assays revealed that circRNA_001275 directly binds to miR-370-3p, and that Wnt family member 7A (Wnt7a) is targeted by miR-370-3p. RT-qPCR and western blotting further demonstrated that circRNA_001275 serves as an miR-370-3p sponge to upregulate Wnt7a expression. In conclusion, the present study revealed that circRNA_001275 was upregulated in cisplatin-resistant esophageal cancer and promoted cisplatin resistance by sponging miR-370-3p to upregulate Wnt7a expression. Therefore circRNA_001275 may serve as a potential diagnostic biomarker and therapeutic target for patients with cisplatin-resistant esophageal cancer.