CircCTDP1 promotes nasopharyngeal carcinoma progression via a microRNA‑320b/HOXA10/TGFβ2 pathway.

Circular RNAs have been reported to play a vital role in the development and progression of various types of cancer. However, the underlying molecular role of circular RNA CTDP1 (circCTDP1) in the tumorigenesis of nasopharyngeal carcinoma (NPC) remains unknown. In the present study, circCTDP1 expression was found to be markedly upregulated in NPC tissues and cell lines (SUNE1, SUNE2 and 6‑10B cell lines). Knockdown of circCTDP1 resulted in inhibition of proliferation, migration and invasion, and promoted apoptosis of NPC cells. Moreover, circCTDP1 directly interacted with microRNA (miR)‑320b based on bioinformatics prediction and dual luciferase assay, and transfection with an miR‑320b inhibitor reversed the effects of circCTDP1 knockdown on NPC cells. Furthermore, circCTDP1/miR‑320b promoted NPC progression by regulating the expression of homeobox A10 (HOXA10). In addition, it was demonstrated that HOXA10 may exert its oncogenic role in NPC by regulating the expression of transforming growth factor β2 (TGFβ2). Taken together, these results revealed a novel regulatory mechanism, which may provide an improved understanding of NPC tumorigenesis and be useful in the development of potential targets for NPC therapy.