OBJECTIVETo study the expression of miR-223 in diffuse large B cell lymphoma (DLBCL) with correlation of histoloigcal subtypes and clinical prognosis.

METHODSA total of 45 cases of DLBCL were investigated by immunohistochemistry (EnVision method) for CD20, CD3, CD10, bcl-6 and MUM-1. The cases were classified into germinal center B cell-like (GCB) and non-germinal center B cell-like (non-GCB) subtypes according to Hans' algorithm. Agilent Human miRNA Microarray 16.0 was used to detect the expression of micro-RNAs in paraffin-embedded tissue of 24 cases of DLBCL that had available clinical follow-up. The expression levels of miR-223 were examined by TaqMan real-time reverse transcription polymerase chain reaction (real-time RT-PCR). Fourteen cases of reactive lymph node were selected as control.

RESULTSAmong 45 cases of DLBCL, 16 cases (35.6%) were GCB and 29 cases (64.4%) were non-GCB subtypes. The expression levels of miR-223 measured by real-time RT-PCR were 19.8 and 15.8 in GCB and non-GCB subgroups, respectively (P = 0.236). The expression of miR-223 was up-regulated in DLBCL with 17.2 folds of increase over that of the reactive lymph nodes (P = 0.014). The overexpression of miR-223 was significantly correlated with a longer overall survival (P = 0.011). Multivariate Cox proportional hazard regression analysis identified the following independent poor prognostic factors: low expression of miR-223 (RR = 5.445, 95%CI, 1.555 - 19.068, P = 0.008), abnormal level of LDH (RR = 3.974, 95%CI, 1.191 - 13.266, P = 0.025) and IPI ≥ 3 (RR = 4.044, 95%CI, 1.233 - 13.264, P = 0.021).

CONCLUSIONSThe expression of miR-223 has no relationship with the immunophenotypes of DLBCL. As a potential prognostic biomarker, overexpression of miR-223 correlates with a longer OS of patients with DLBCL.