Upregulation of serum exosomal miR-21 was associated with poor prognosis of acute myeloid leukemia patients

Accumulating reports have showed that altered expression of blood-circulating (miRNAs) can serve as diagnostic biomarkers of cancer, but descriptions of serum exosomal miRNAs in AML are still lacking. The present study was designed to measure serum exosomal miR-21 levels in AML patients and explore its correlation with clinical variables and prognosis. In this study, blood samples were collected from 135 AML patients and 60 controls. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to detect serum exosomal miR-21 expression levels. The data showed that serum exosomal miR-21 levels were significantly higher in AML patients than those in healthy controls. In addition, serum exosomal miR-21 levels were significantly decreased at one month and three months after their treatment. Further receiver operating characteristic (ROC) curve analysis showed that serum exosomal miR-21 level could identify AML patients from normal controls with relative high sensitivity and specificity. Moreover, serum exosomal miR-21 upregulation was closely associated with worse clinical features and shorter survival. In multivariate Cox regression analysis, serum exosomal miR-21 expression showed a significance correlation with survival. In conclusion, serum exosomal miR-21 could be used to predict the diagnosis and prognosis of AML patients.