Downregulation of circ_0012152 inhibits proliferation and induces apoptosis in acute myeloid leukemia cells through the miR‐625‐5p/SOX12 axis

Abstract
Acute myeloid leukemia (AML) is a highly heterogeneous disease featured by a clonal proliferation derived from primitive hematopoietic stem/progenitor cells. Circular RNAs (circRNAs) have been identified as crucial regulators in the progression of various cancers, including AML. However, the molecular mechanism of AML is still not definite. This study aimed to explore the influences of circ_0012152 on cell development in AML cells and the underlying regulatory mechanism. The expression of circ_0012152, microRNA‐625‐5p (miR‐625‐5p) and sex‐determining region Y‐related high mobility group box 12 (SOX12) was detected by quantitative real‐time polymerase chain reaction. The proliferation of AML cells was evaluated by 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assay for cell viability, 5‐ethynyl‐2′‐deoxyuridine incorporation assay for DNA biosynthesis and flow cytometry for cell cycle distribution, respectively. The death of AML cells was detected by flow cytometry. The protein expression was assessed by Western blot assay. Dual‐luciferase reporter and RNA immunoprecipitation assays were carried out to examine the relationships among circ_0012152, miR‐625‐5p and SOX12. The expression of circ_0012152 was increased in AML tissues and cells and circ_0012152 knockdown suppressed proliferation and promoted death in AML cells. Further exploration revealed that circ_0012152 inhibited miR‐625‐5p expression and downregulation of miR‐625‐5p overturned the effects of circ_0012152 knockdown on proliferation and death in AML cells. Moreover, miR‐625‐5p targeted SOX12 and circ_0012152 facilitated the expression of SOX12 by relieving miR‐625‐5p‐mediated inhibitory effect on SOX12 in AML cells. Circ_0012152 knockdown suppressed cell proliferation and promoted death by targeting SOX12 mediated by miR‐625‐5p in AML cells.