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

Abstract

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.