CircRNA Microarray Profiling Reveals hsa_circ_0058493 as a Novel Biomarker for Imatinib-Resistant CML

An-Ni Zhong,Jie Xiao,Yi Yin,Ping Xu,Lei Chen,Zhi-Ping Tan,Zhi-Ping Jiang,Bing-Jie Tang,Yan Zhu,Wen-Qun Li,Qun He,Bao Sun,Hong-Wei Shen

doi:10.3389/fphar.2021.728916

Abstract

Background: CircRNA has appeared as a critical molecular in the development of various cancers. However, the cellular function of circRNAs and exosomal circRNAs has not been well explored in Chronic myeloid leukemia (CML). Methods: Differentially expressed circRNAs were identified by a human circRNA microarray analysis. The expression of hsa_circ_0058493 in peripheral blood mononuclear cells (PBMCs) and exosomes was verified using quantitative real-time PCR. Short hairpin RNAs against hsa_circ_0058493 were constructed to silence the expression of circ_0058493. CCK8, flow cytometry and EdU assay were performed to investigate the biological functions of circ_0058493. Results: Hsa_circ_0058493 was significantly overexpressed in the PBMCs of CML patients and high level of circ_0058493 was associated with the poor clinical efficacy of imatinib. Silencing the expression of circ_0058493 significantly inhibited the development of imatinib-resistant CML cells. miR-548b-3p was overexpressed in circ_0058493-downregulated CML cells. Bioinformatic analysis revealed that circ_0058493 might exert its regulatory function acting as a “sponge” of miR-548b-3p. Moreover, hsa_circ_0058493 was significantly enriched in the exosomes derived from imatinib-resistant CML cells. Conclusion: Hsa_circ_0058493 in PBMCs could be a promising prognostic biomarker and might provide a therapeutic target for CML treatment.

Highlights

Chronic myeloid leukemia (CML) is a myeloproliferative malignancy arising from breakpoint cluster region (BCR)-ABL1 oncoprotein (Apperley, 2015)
Expressed circRNAs Are Associated With the Clinical Efficacy of CML Patients
We further analyzed the expression of top 15 statistically upregulated (Table 2) and downregulated (Table 3) circRNAs in imatinibresistant cell line K562/G01 and imatinib sensitive cell line K562 by RNA preparation and quantitative real-time PCR (RT-qPCR) and found that eight circRNAs were significantly upregulated in K562/G01 compared with K562, which were in accordance with the microarray results

Summary

Introduction

Chronic myeloid leukemia (CML) is a myeloproliferative malignancy arising from BCR-ABL1 oncoprotein (Apperley, 2015). One of the tyrosine kinase inhibitors (TKIs), was approved for the front-line treatment of CML and largely improved the prognosis of CML patients (Jabbour, 2016). The secondary mutation in BCR-ABL1 has illuminated the resistance of imatinib and can be treated with second or third-generation TKIs (Apperley, 2015). There is no mutation in BCRABL1 in 50% or more cases of treatment failure, and the underlying mechanisms of BCR-ABL1-independent resistance to imatinib remain poorly understood (Ma et al, 2014). It is essential to elucidate the molecule mechanism of imatinib resistance and explore a novel prescient biomarker or treatment target to improve the prognosis of CML patients. The cellular function of circRNAs and exosomal circRNAs has not been well explored in Chronic myeloid leukemia (CML)

Methods

Results

Discussion

Conclusion