Fig. 1.

Differential expression of selected microarray-identified long non-coding RNAs (lncRNAs) and their binding to insulin-like growth factor 2 messenger RNA binding protein (IMP1). a Total RNA was extracted from MDA231 cells expressing green fluorescent protein (GFP) or Flag-tagged IMP1-GFP. RT-qPCR was used to analyze the levels of six microarray-identified lncRNAs. Relative levels of the lncRNAs were nomalized to glyceraldehyde-3-phosphate dehydrogenase (GAPDH) messenger RNA (mRNA) and statistically analyzed. The data are presented as means ± SD from three independent experiments: *P < 0.05, **P < 0.01 as determined by Student’s t test. b RNA immunoprecipitation (RIP) was performed to analyze IMP1 interaction with selected lncRNAs. Following IMP1 immunoprecipitation (IP), RNA was extracted and the levels of lncRNAs were measured by RT-qPCR and normalized to GAPDH mRNA levels. Aliquots of the precipitates were used for western blots (inset) to show precipitated IMP1-GFP: **P < 0.01. c Selective lncRNAs in the precipitates of individual immunoprecipitates (IPs) were analyzed by RT-PCR followed by agarose gel electrophoresis (left). β-actin mRNA and GAPDH mRNA were used as positive and negative controls for IMP1 RIP (right). I, MDA231/IMP1-GFP cells; G, MDA231/GFP cells