Selective miRNA Expression Profile in Chronic Myeloid Leukemia K562 Cell-derived Exosomes

Background: Chronic myeloid leukemia (CML) is a myeloproliferative disorder of hematopoietic stem cellscarrying the Philadelphia (Ph) chromosome and an oncogenic BCR-ABL1 fusion gene. The tyrosine kinaseinhibitor (TKI) of BCR-ABL1 kinase is a treatment of choice for control of CML.
Objective: Recent studies havedemonstrated that miRNAs within exosomes from cancer cells play crucial roles in initiation and progression.This study was performed to assess miRNAs within exosomes of K562 cells.
Methods: miRNA microarray analysisof K562 cells and K562 cell-derived exosomes was conducted with the 6th generation miRCURYTM LNA Array(v.16.0). Gene ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were also carriedout. GO terms and signaling pathways were categorized into 66 classes (including homophilic cell adhesion,negative regulation of apoptotic process, cell adhesion) and 26 signaling pathways (such as Wnt).
Results: Inexosomes, 49 miRNAs were up regulated as compared to K562 cells, and two of them were further confirmedby quantitative real-time PCR. There are differentially expressed miRNAs between K562 cell derived-exosomesand K562 cells.
Conclusion: Selectively expressed miRNAs in exosomes may promote the development of CMLvia effects on interactions (e.g. adhesion) of CML cells with their microenvironment.