The Detection And Prognosis Significance Of Peripheral Blood Exosomal MiRNAs In Acute Myeloid Leukemia

Purpose:The aim of this study was to characterize the miRNAs profiles of serum exosomes and investigate the expression of serum exosomal microRNAs(miRNAs)represent potentially useful biomarkers for the diagnosis,and prognosis in acute myeloid leukemia(AML).Methods:In this study,we examined the prognostic significance of serum exosomal microRNAs(miRNAs)in acute myeloid leukemia(AML).A cohort of 289 cases of newly diagnosed and genetically defined AML,uniformly treated and followed,was studied from March 2014 to May 2018.Extraction of circulating exosomes from serum samples of AML patients by using exoRNeasy kit.Exosomal miRNAs expression was assessed utilizing quantitative reverse-transcription-polymerase chain reaction(qRT-PCR)for several miRNAs.We studied the relationship between miRNAs levels and patient outcomes,including event-free survival(EFS)and overall survival(OS).Results:In this study,exosomal vesicles with a particle size distribution of 50-150 nm were extracted,and the relative expression of miRNAs was determined by qRT-PCR.Through literature studied,we analyzed the relationship between the three miRNAs(let-7b,miR-532 and miR-660)of plasma endosome in AML patients.There were no significant differences in clinical features,gene mutations between the high and low expression groups of exosomal microRNAs(let-7b,miR-532,miR-660)in the serum of AML patients.Survival analysis demonstrated that let-7b low expression expresser had poorer OS and EFS than high expresser(P=0.012 and P=0.022).The expression of let-7b was as an independent prognostic factor in multivariate analysis for OS(P=0.021,HR:0.532,95%CI 0.312 0.909)and EFS(P=0.031,HR:0.473,95%CI 0.276 0.810).Patients with high expression of miR-532 had better OS and EFS than low expression(P=0.004 and 0.014),it was associated with OS(P=0.005,HR:0.471,95%CI 0.277 0.800)and EFS(P=0.020,HR:0.531,95%CI 0.312 0.903)by multivariate Cox analysis.AML patients with miR-660 up-regulated showed longer duration in OS(P=0.005)and EFS(P=0.004).But multivariate analysis of clinical features revealed that miR-660 was not an independent prognostic factor(P=0.054,HR:0.583,95%CI 0.337 1.009)。Conclusion:We successfully detected the expression of miRNAs in exosomes by fluorescence quantitative qRT-PCR.High expression levels of serum exosomal let-7b、miR-532 and miR-660 were associated with longer OS and EFS.Among them,let-7b and miR-532 were as an independent prognostic factor in multivariate analysis for OS after adjusting for age,WBC levels and genes of FLT3-ITD,NPM1,CEBPA,DNMT3A mutations.Serum exosomal miRNAs expression might serve as a reliable predictor for overall survival in AML patients.According to the expression level of exosome miRNAs and the clinical data of patients,we successfully constructed a model for predicting the survival rate of patients.The results of this study provide data support for the expression of exosomal miRNAs and these miRNAs may be potential targets for the treatment of AML.