Long noncoding RNA lnc-RI is a new regulator of mitosis via targeting miRNA-210-3p to release PLK1 mRNA activity

Increasing evidence indicates that lncRNAs play critical roles in various biological processes, but many have not been functionally characterized. Here, we report a novel radiation-inducible lncRNA, namely lnc-RI which is essential for cell survival and appropriate mitotic progression. Our data indicated that knockdown of lnc-RI resulted in spindle abnormalities and mitotic arrest simultaneously with sharply decreased mRNA and protein expression of PLK1, a key regulator of mitosis. Our data demonstrated that PLK1 is a key downstream mediator of lnc-RI in regulating mitosis, whereby lnc-RI competitively bound to the negative PLK1 regulating miRNA, miRNA-210-p3. Taken together, we have identified lnc-RI as a new regulator of mitosis which acts by releasing PLK1 mRNA activity via competition for binding to miRNA-210-3p.