circRNA_001275 upregulates Wnt7a expression by competitively sponging miR3703p 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 cisplatinresistant esophageal cancer. Three pairs of cisplatinresistant tissues and corresponding adjacent tissues were collected and subjected to circRNA chip analysis. Additionally, the effect of circRNA_001275 on cisplatinresistant cells was investigated. The relationship between circRNA_001275, microRNAs (miRs) and target genes were analyzed using luciferase assays, and validated via reverse transcriptionquantitative PCR (RTqPCR) and western blotting. The results showed that circRNA_001275 was significantly upregulated in cisplatinresistant esophageal cancer tissues and cells (P<0.05). Overexpression of circRNA_001275 promoted the proliferation and invasion, and decreased the apoptosis of cisplatinresistant cells. On the other hand, circRNA_001275 silencing inhibited cell proliferation and invasion, and promoted cell apoptosis (P<0.05). Dualluciferase reporter assays revealed that circRNA_001275 directly binds to miR3703p, and that Wnt family member 7A (Wnt7a) is targeted by miR3703p. RTqPCR and western blotting further demonstrated that circRNA_001275 serves as an miR3703p sponge to upregulate Wnt7a expression. In conclusion, the present study revealed that circRNA_001275 was upregulated in cisplatinresistant esophageal cancer and promoted cisplatin resistance by sponging miR3703p to upregulate Wnt7a expression. Therefore, circRNA_001275 may serve as a potential diagnostic biomarker and therapeutic target for patients with cisplatinresistant esophageal cancer.