Circ_0009910 promotes imatinib resistance through ULK1-induced autophagy by sponging miR-34a-5p in chronic myeloid leukemia

• Published in: Life sciences (1973) Vol. 243; p. 117255
• Main Authors: Cao, Hai-xia, Miao, Chao-feng, Sang, Li-na, Huang, Yu-min, Zhang, Ran, Sun, Ling, Jiang, Zhong-xing
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Inc 15.02.2020; Elsevier BV
• Subjects: Actinomycin; Antineoplastic Agents - therapeutic use; Apoptosis; Assaying; Autophagy; Autophagy - physiology; Autophagy-Related Protein-1 Homolog - physiology; Bioinformatics; Cell proliferation; Cell viability; Chronic myeloid leukemia; Circ_0009910; CML; Cytoplasm; Drug resistance; Drug Resistance, Neoplasm; Flow cytometry; Gene expression; Humans; Imatinib; Imatinib Mesylate - therapeutic use; Immunoprecipitation; Intracellular Signaling Peptides and Proteins - physiology; K562 Cells; Leukemia; Leukemia, Myelogenous, Chronic, BCR-ABL Positive - drug therapy; Leukemia, Myelogenous, Chronic, BCR-ABL Positive - genetics; Leukemia, Myelogenous, Chronic, BCR-ABL Positive - pathology; MicroRNAs - genetics; MiR-34a-5p; Myeloid leukemia; Phagocytosis; Polymerase chain reaction; Ribonucleic acid; RNA; ULK1; ULK1; CML; MiR-34a-5p; Autophagy; Circ_0009910
• ISSN: 0024-3205; 1879-0631
• DOI: 10.1016/j.lfs.2020.117255

The occurrence in drug resistance of chronic myeloid leukemia (CML) was accompanied by autophagy activation. Abnormal circular RNAs (circRNAs) participated in this progression. This study attempted to investigate the potential role of circ_0009910 in imatinib resistance of CML cells. The expression of circ_0009910 and miR-34a-5p was measured by quantitative real-time polymerase chain reaction (qRT-PCR). The characterization of circ_0009910 was investigated using oligo (dT)18 primers, Actinomycin D and RNase R. Cell viability (IC50 value) and apoptosis were assessed by Cell Counting Kit-8 (CCK8) assay and flow cytometry assay, respectively. The relative protein expression was quantified by western blot. The relationship among miR-34a-5p, circ_0009910 and ULK1 was predicted by online bioinformatics tool, and verified by dual-luciferase reporter assay and RNA immunoprecipitation (RIP). The expression of circ_0009910 was up-regulated in the serum of imatinib-resistance CML patients and K562/R cells, and associated with unfavorable clinicopathologic features. Circ_0009910 in K562 and K562/R cells was mainly localized in the cytoplasm. Circ_0009910 knockdown inhibited cell proliferation and autophagy, but induced apoptosis in K562/R cells. Circ_0009910 targeted miR-34a-5p to regulate ULK1. MiR-34a-5p depression rescued the effects of circ_0009910 knockdown on apoptosis and autophagy in K562/R cells. Circ_0009910 accelerated imatinib-resistance in CML cells by modulating ULK1-induced autophagy via targeting miR-34a-5p, providing a potential target in imatinib resistance of CML. •Circ_0009910 was highly expressed in imatinib-resistance K562 cells.•Circ_0009910 knockdown inhibited cell proliferation and autophagy, but induced apoptosis in K562/R cells.•MiR-34a-5p was a target of circ_0009910, and ULK1 was a target of miR-34a-5p.•Circ_0009910 exerted a promotion role in the resistance of CML by activating ULK1-induced autophagy via targeting miR-34a-5p.