[Expression level of microRNA-92a and its clinical significance in multiple myeloma patients].

Objective: To investigate the relationship between the expression level of microRNA 92a (miR-92a) and del(13q14) and the prognosis of MM patients, and to explore the pathway that miR-92a involved.

Methods: Bone marrow samples from 53 newly diagnosed MM patients were collected, del(13q14) was analyzed by interphase fluorescence in situ hybridization in sorted CD138 positive plasma cell. The expression of miR-92a in plasma cells was measured by quantitative real-time PCR. The expression of c-jun was detected by Western blot in miR-92a transfected MM cell lines (LP-1, U266 and JJN3).

Results: Of the 53 MM patients, del(13q14) was detected in 31 (58.4%) patients. The median levels of miR-92a in MM patients with or without del(13q14) were 27.36±2.61 and 21.87±15.98, respectively (P>0.05). With the median follow-up of 13.5 (0.5-72.5) months, the median duration of progression-free survival of patients with high expression level of miR-92a was significantly shorter than those with low expression level of miR-92a (4.5 months vs 14.0 months, P=0.006). Overexpression of miR-92a in MM cell lines induces time-dependent down-regulation of c-jun.

Conclusions: High expression of miR-92a was associated with poor prognosis in MM patients. The expression level of miR-92a was not associated with del(13q14), and the effect of miR-92a on the progress of MM might be involved in c-jun pathway.