Novel circular RNA hsa_circ_0036683 suppresses proliferation and migration by mediating the miR‐4664‐3p/CDK2AP2 axis in non‐small cell lung cancer

Abstract

Abstract Background The aim of the present study was to investigate the function of novel circular RNA hsa_circ_0036683 (circ‐36683) in non‐small cell lung cancer (NSCLC). Methods RNA sequencing was used to screen out differentially expressed miRNAs. Expression levels of miR‐4664‐3p and circ‐36683 were evaluated in lung carcinoma cells and tissues by quantitative reverse transcription‐polymerase chain reaction (qRT‐PCR). The effects of miR‐4664‐3p and circ‐36683 on proliferation and migration were assessed using cell counting kit‐8 (CCK‐8), wound healing and transwell migration assays and xenograft experiments. The targeting relationship of circ‐36683/miR‐4664‐3p/CDK2AP2 was assessed by luciferase reporter assays, western blot, qRT‐PCR and argonaute2‐RNA immunoprecipitation (AGO2 RIP). Co‐immunoprecipitation (Co‐IP), 5‐ethynyl‐2′‐deoxyuridine (EdU) staining and CCK‐8 were used to validate the indispensable role of CDK2AP2 in suppressing cell proliferation as a result of CDK2AP1 overexpression. Results By RNA sequencing, miR‐4664‐3p was screened out as an abnormally elevated miRNA in NSCLC tissues. Transfection of miR‐4664‐3p could promote cell proliferation, migration and xenograft tumor growth. As a target of miR‐4664‐3p, CDK2AP2 expression was downregulated by miR‐4664‐3p transfection and CDK2AP2 overexpression could abolish the proliferation promotion resulting from miR‐4664‐3p elevation. Circ‐36683, derived from back splicing of ABHD2 pre‐mRNA, was attenuated in NSCLC tissue and identified as a sponge of miR‐4664‐3p. The functional study revealed that circ‐36683 overexpression suppressed cell proliferation, migration and resulted in G0/G1 phase arrest. More importantly, the antioncogenic function of circ‐36683 was largely dependent on the miR‐4664‐3p/CDK2AP2 axis, through which circ‐36683 could upregulate the expression of p53/p21/p27 and downregulate the expression of CDK2/cyclin E1. Conclusion The present study revealed the antioncogenic role of circ‐36683 in suppressing cell proliferation and migration and highlighted that targeting the circ‐36683/miR‐4664‐3p/CDK2AP2 axis is a promising strategy for the intervention of NSCLC.

Keywords

• CDK2AP2
• cell cycle
• hsa_circ_0036683
• miR‐4664‐3p
• NSCLC