Circular RNA circ_0062389 modulates papillary thyroid carcinoma progression via the miR-1179/high mobility group box 1 axis

Circular RNAs (circRNAs) feature prominently in regulating the progression of tumors, including papillary thyroid carcinoma (PTC). This work is designated to delve into the role of circ_0062389 in PTC. Generally, quantitative real-time polymerase chain reaction (qRT-PCR) was employed to detect circ_0062389, miR-1179 and high mobility group box 1 (HMGB1) mRNA expression levels. RNase R assay was used to verify the circular characteristics of circ_0062389. After circ_0062389 was knocked down in PTC cells, CCK-8 assay was adopted to determine cell viability. Wound healing assay was leveraged to probe cell migration. Besides, Western blot assay was executed to examine the expression levels of HMGB1 and epithelial-mesenchymal transformation (EMT)-related markers (E-cadherin and N-cadherin). Dual-luciferase reporter assay was performed to authenticate the targeting relationships between miR-1179 and circ_0062389, as well as miR-1179 and HMGB1. Here, this work proved that circ_0062389 was greatly up-regulated in PTC tissues and cell lines. The high expression of circ_0062389 was related to large tumor size and positive lymphatic metastasis. Knocking down circ_0062389 could inhibit the proliferation, migration and EMT process of PTC cells. Besides, miR-1179 was a downstream molecule of circ_0062389. Furthermore, miR-1179 inhibitors could partially reverse the above effect of knocking down circ_0062389 on PTC cells. It was also confirmed that HMGB1 was a direct target of miR-1179 and mediated the effects of circ_0062389 and miR-1179 in PTC. Altogether, circ_0062389 can adsorb miR-1179, and regulate HMGB1 expression, thus playing a role in PTC.