Abstract:

Objective To explore the effect of hsa_circ_0023642 on the malignant biological behavior of thyroid cancer cells and its molecular mechanism. Methods The cancer tissues and adjacent tissues of 25 patients with thyroid cancer in our hospital were selected，and the expression level of hsa_circ_0023642 and miR⁃653 were detected by real⁃time fluorescent quantitative PCR（RT⁃qPCR）；thyroid cancer cells SW579 were divided into si⁃NC group，si⁃Hsa_circ_0023642 group，miR⁃NC group，miR⁃653 group，si⁃Hsa_circ_0023642+anti⁃miR⁃NC group，and si ⁃Hsa_circ_0023642+anti ⁃miR ⁃653 group. Tetramethylazolium salt colorimetric method（MTT）was used to detect cell viability；clone formation test to detect the number of colonies formed；flow cytometry to detect cell apoptosis rate；western blot to detect protein expression；cell scratch test to detect scratch healing rate； Transwell to detect the number of cell invasion；and dual luciferase reporter experiment to detect the targeting relationship between Hsa_circ_0023642 and miR ⁃653. Results The expression of Hsa_circ_0023642 in thyroid cancer tissue was increased，and the expression of miR ⁃ 653 was decreased（P < 0.05）. After interference with hsa_circ_0023642 or with over⁃expression of miR⁃653，cell viability was decreased；the number of colonies formed was decreased；apoptosis rate was increased；Bcl⁃2 related X（Bax）expression was increased. Meanwhile，B⁃cell lymphoma/leukemia⁃2（Bcl⁃2）expression，and cell scratch healing rate were decreased，and the number of inva⁃ sive cells all showed a downward trend（P < 0.05）. Hsa_circ_0023642 targeted and regulated miR⁃653；inhibiting miR ⁃653 can reverse the effect of hsa_circ_0023642 on the proliferation，apoptosis，migration and invasion of thyroid cancer cells. Conclusion Interference with hsa_circ_0023642 can inhibit the proliferation，migration and invasion of thyroid cancer cells by regulating miR⁃653，and promote cell apoptosis. 

Key words: Hsa_circ_0023642,  , miR?653,  , thyroid cancer,  , proliferation,  , apoptosis,  , migration,  , invasion