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.