Identification of lncRNA UCA1-associated microRNAs in breast cancer cell line MDA231 using miRNA-Seq

LncRNA urothelial carcinoma-associated 1 (UCA1) is an oncogene in breast cancer. Previous reports indicates that lncRNAs may function as competing endogenous RNAs (ceRNAs) to sponge miRNAs, thereby modulating the derepression of miRNA targets. To characterize microRNAs that associated with UCA1, the microRNAs associated with UCA1 were extracted from the UCA1-MS2 RNP complexes and analyzed by miRNA-seq. Cell lysates were prepared from cultured MDA231-UCA1-MS2 cells and MDA231-Con cells and then incubated with Amylose-resin-attached MBP-MCP (MS2 coat protein) at 4°C for 5 h with gentle rotation. After incubation, the supernatant was removed by a short centrifugation and the Amylose beads were washed three times in lysis buffer，Bound UCA1-MS2 RNP complexes were eluted with 100 µl lysis buffer containing 20 mM maltose. miRNAs associated with UCA1 were extracted and analyzed by miRNA-seq.