Significance of the microRNA‑17‑92 gene cluster expressed in B‑cell non‑Hodgkin's lymphoma.

To evaluate the prognostic value of the microRNA (miR)-17-92 gene cluster, the expression of miR-17-92 in B-cell non-Hodgkin's lymphoma (B-NHL) was examined. Patients with B-NHL, who received therapy in the Department of Hematology, Harbin Medical University Cancer Hospital between January 2012 and October 2014, were enrolled in the study. The expression of the miR-17-92 cluster in tumor tissue samples was detected by reverse transcription-quantitative polymerase chain reaction analysis. The overall survival (OS) and event-free survival (EFS) times were also investigated by the Kaplan-Meier method and comparisons between groups were estimated using a log-rank test. Three types of lymphoid cancer cells with wild-type (WT), knockout of miR-17-92 (KO), and overexpression of miR-17-92 (TG), were utilized to establish a tumor xenograft model, and a reactive hyperplasia lymph cell was used as a control. The tumor incubation times and weights were examined. A total of 71 patients with B-NHL were registered. No significant correlations were identified between the expression of miR-17-92 and clinical factors (P>0.05). Members of the miR-17-92 cluster exhibited various expression in the subtypes of B-NHL, and the difference between follicular lymphoma (FL) and germinal center B-cell like (GBC) was most marked. The overexpression of miR-18, miR-19a, and miR-92a induced a marked reduction in the OS of patients with B-NHL, and high-levels of miR-19a and miR-92a led to a decline in EFS. The overexpression of miR-17-92 shortened the duration of incubation required for visualization of the xenograft tumor, whereas knockout led to inhibition of tumor formation. The expression of miR-17-92 in FL differed significantly from that in GBC, and miR-19a may have a crucial effect on the OS and EFS of patients with B-NHL.