The Impact of Serum MicroRNA-21 on Outcome of Diffuse Large B-Cell Lymphoma Patients

Abstract
Background: The emerging role of circulating microRNAs (miRNAs) as diagnostic and predictive tools has become fundamental and promising scope of cancer research. The link between the aberrant expressions of various miRNAs and the pathogenesis of Diffuse Large B-Cell Lymphoma (DLBCL) has been revealed by numerous studies.
Aim of Study: This study was planned to analyze the relative expression levels of serum miRNA-21 and to elucidate its potential prognostic significance in DLBCL patients who had received cyclophosphamide, doxorubicin, vincristine, prednisone plus rituximab (R-CHOP) regimen.
Patients and Methods: Serum miRNA-21 relative expres-sion levels were analyzed by Polymerase Chain Reaction (PCR) based technique in 65 DLBCL patients prior to immu-nochemotherapy in comparison with 35 healthy individuals. Receiver operating characteristic curve analysis was used to determine the ideal miRNA-21 cutoff and Kaplan-Meier method was used to calculate the overall survival of DLBCL patients.
Results: MiRNA-21 expression levels were significantly up-regulated in DLBCL patients compared to healthy controls (p<0.001). MiRNA-21 expression levels were closely associ-ated disease stage, response to therapy, (32 microglobulin, Lactate Dehydrogenase (LDH) and C-Reactive Protein (CRP) (p<0.001; p=0.042; p<0.001; p=0.003; p=0.02 respectively). However, there was no relationship with other characteristics such as age, gender, extranodal site involvement, B symptoms, and International Prognostic Index (IPI) (all ps>0.05). Overall survival was significantly worse in patients with high miRNA-21 expression levels compared to those with low expression levels (p=0.01).
Conclusion: Serum miRNA-21 may be employed as valuable non-invasive prognostic marker in DLBCL patients treated with R-CHOP regimen.