Figure 4. XIST interacts with SMAD2 and inhibits its translocation to the cell nucleus. (A) RNA pulldown, SDS gel silver staining, and mass spectrometry identified SMAD2 as a binding partner of XIST. (B) RNA pulldown and (C) RIP assay results demonstrating the XIST/SMAD2 interaction. (D, E) Cytoplasmic and nuclear expression of XIST detected by qPCR in A549 and H1299 cells. (G) Western blot analysis of XIST and SMAD2 expression in cytoplasmic and nuclear cell fractions. (F) The score indicating the possibility of the combination between XIST and SMAD2. (H) Immunofluorescence assay showing the sub-cellular localization of XIST and SMAD2. (I) ONCOMINE analysis of the expression of SMAD2 in clinical NSCLC samples and adjacent normal tissues. XIST expression detected by qPCR in (J) NSCLC samples and matched normal tissues and (K) NSCLC cells. (L) KM plotter survival analysis showing the relationship between SMAD2 expression and NSCLC prognosis. * < 0.05 vs IgG, normal or NHBE group.