Hsa_circRNA_0001971 contributes to oral squamous cell carcinoma progression via miR‐186‐5p/Fibronectin type III domain containing 3B axis

Abstract

Background Circular RNAs (circRNAs) are closely associated with the progression of oral squamous cell carcinoma (OSCC). circRNA_0001971 has been proved to accelerate the OSCC development. Here, we aim to identify the new molecular mechanism of hsa_circRNA_0001971 (circRNA_0001971) in OSCC. Methods The levels of circRNA_0001971, miR‐186‐5p, and fibronectin type III domain containing 3B (FNDC3B) in tissues and cells were verified by qRT‐PCR or Western blotting. The interaction between circRNA_0001971, miR‐186‐5p, and FNDC3B was identified by bioinformatics analysis, luciferase assay, and RIP assay. The effect of circRNA_0001971/miR‐186‐5p/FNDC3B axis on OSCC cell proliferation, migration, and invasion by cell functional experiments including CCK8, wound healing, and transwell assays. Results Our study displayed that circRNA_0001971 and FNDC3B were elevated in OSCC, whereas miR‐186‐5p was declined in OSCC. Silencing circRNA_0001971 attenuated the malignancy of OSCC cells by suppressing proliferation, migration, and invasion. In OSCC cells, circRNA_0001971 sponged miR‐186‐5p to enhance FNDC3B. Due to the interaction between circRNA_0001971, miR‐186‐5p, and FNDC3B, FNDC3B overexpression relieved the negative function of silencing circRNA_0001971 in OSCC cells. Conclusion Overall, our study discovered that circRNA_0001971 was a tumor promoter in OSCC progression by targeting miR‐186‐5p/FNDC3B axis.

Roles of circRNAs in regulating the tumor microenvironment

“…Similarly, in nasopharyngeal carcinoma, circ_0000523 exerts its function by sequestering miRNAs to regulate the expression levels of target genes including collagen proteins like COL1A [ 43 ]. In oral squamous cell carcinoma, hsa_circRNA_0001971 facilitates disease progression by adsorbing miR-186-5p to modulate the expression of fibronectin FNDC3B [ 44 ]. Additionally, the circ-FNDC3B derived from the FNDC3B gene plays a crucial role in various tumors such as gastric cancer, esophageal cancer, and colorectal cancer [ 45 – 47 ], it promotes tumor epithelial-mesenchymal transition (EMT), invasion, and metastasis by regulating E-cadherin and CD44.…”