Elevated miR-20b-5p expression in peripheral blood mononuclear cells: A novel, independent molecular biomarker of favorable prognosis in chronic lymphocytic leukemia

Abstract

MicroRNA-20b-5p (miR-20b-5p) is part of the miR-106a/363 cluster and a member of the cancer-related miR-17 family. miR-20b-5p regulates important transcription factors, including hypoxia-inducible factor 1 (HIF1) and signal transducer and activator of transcription 3 (STAT3). Recently, the dysregulation of miR-20b-5p expression has been observed in many B-cell lymphomas and T-cell leukemias. In this research study, we examined the putative prognostic value of miR-20b-5p in CLL. Therefore, total RNA was isolated from peripheral blood mononuclear cells (PBMCs) collected from 88 CLL patients; next, total RNA was polyadenylated and first-strand cDNA was synthesized, using an oligo-dT–adapter primer. miR-20b-5p expression was quantified using an in-house–developed real-time quantitative PCR assay. Kaplan-Meier OS analysis and bootstrap univariate Cox regression showed that high miR-20b-5p expression predicts better OS for CLL patients (p < 0.001). Interestingly, miR-20b-5p overexpression retains its favorable prognostic role in CLL patients of intermediate risk or stratified according to established prognostic factors [CD38 expression and mutational status of the immunoglobulin heavy chain variable (IGHV) region]. In conclusion, miR-20b-5p is a potential independent molecular biomarker of favorable prognosis in CLL.