Repression of Dicer is associated with invasive phenotype and chemoresistance in ovarian cancer.

Dicer is a key enzyme that processes microRNA (miRNA) precursors into their mature form, enabling them to regulate gene expression. However, the effects of Dicer on the biological behavior of cancer cells remain largely unclear. In this study, it was demonstrated that Dicer down-regulation promoted cell proliferation, migration and cell cycle progression in A2780 and SKOV3 ovarian cancer cells. Furthermore, Dicer expression was significantly decreased in cisplatin-resistant A2780 cells (A2780/DDP) compared with parental A2780 cells. Knockdown of Dicer by RNA interference decreased the sensitivity of A2780 cells to cisplatin. Moreover, EZH2 depletion by short hairpin RNA (shRNA) increased the expression of Dicer . Our data suggest that Dicer is involved in numerous biological/pathological processes, including drug resistance in ovarian cancer, and that its expression may be regulated by EZH2.