Linear and circular long noncoding RNAs regulate cellular reprogramming by sponging multiple miRNAs

Using a doxycycline inducible expression of Yamanaka factors (Oct4, Sox2, Klf4 and c-Myc) to generate induced pluripotent stem cells (iPSCs) from mouse embryonic fibroblasts (MEFs), we investigated the dynamic changes of miRNAs, long intergenic noncoding RNAs (lincRNAs) and noncoding circular RNAs (circRNAs) from cells collected at early reprogramming stage. We found that the pools of miRNAs highly expressed in MEFs remain unchanged from day 0 to day 6 after doxycycline induction; unexpectedly, many genes targeted by these miRNAs were actually up-regulated during reprogramming; meanwhile, lincRNAs and circRNAs which have complementary binding sites with the miRNAs were also highly expressed in the reprogramming MEFs (rMEFs). Intriguingly, we found that knockdown of lincRNAs and circRNAs sharing the miRNA binding sites with Oct4 mRNA resulted in down-regulation of Oct4 expression, and significantly decreased the colony formation during reprogramming. Our results suggest that the ceRNA network plays an important role in reprogramming somatic cells to pluripotent stem cells. Examination of dynamic changes of miRNAs, mRNAs lincRNAs and circRNAs during reprogramming.