a Comparison of GC-induced transcriptional changes in RNA sequencing experiments across three cell lines (A549, H2122 and H1944) that are growth-arrested by glucocorticoids (n = 2). Adjusted P values (Padj) were determined by DESeq2 (Wald test P values corrected for multiple testing using Benjamini and Hochberg method). b Intersect of genes differentially expressed upon GC treatment with a cell cycle gene set (hsa04110). c Representative immunofluorescence images showing expression and localisation of p57 (red), with DAPI as nuclear staining (blue) (n = 3). Scale bar, 10 μm. d Western blot for p57-IP experiments in H2122 cell line treated with GCs (left). Waterfall plot depicting p57-IP enrichment over IgG control in H2122 cell line treated with GCs (right). Proteins considered to be interacting with p57 are 1.5 LFQ enriched over IgG (dotted line) and significant (−log(P value) >1.3; red) (n = 4). P values were determined by two-sided t test. e Normalised CDKN1C mRNA expression level throughout the time-course experiment with glucocorticoids in A549 cells (ENCSR897XFT). Mean values ± SEM of independent biological replicates are depicted (n = 4; for timepoints 5, 6, 7 and 8, n = 3). f Normalised mRNA expression level of cell cycle genes (hsa04110; n = 125 genes) throughout the glucocorticoid-treatment time course in A549 cells (ENCSR897XFT). Box plot depicting expression of cell cycle genes based on at least three biological replicates per timepoint is depicted. The central mark indicates the median, and the bottom and top edges of the box indicate the 25th and 75th percentiles, respectively. The maximum whisker lengths are specified as 1.5 times the interquartile range and outliers are depicted as empty circles. g Representative immunofluorescence images showing expression and localisation of GR (green), p57 (red) in p57-WT and p57-KO cell lines. DAPI is used as nuclear staining (blue) (n = 3). Scale bar, 10 μm. h Percentage of cells undergoing mitosis in a 60 h real-time imaging experiment under vehicle (Veh) and glucocorticoid (GC) treatment. Mean values ± SD of independent biological replicates is depicted (A549 n = 4, H2122 n = 3, H1944 n = 3). P values were determined by two-sided Welch’s t test. i–k GR activity signature, E2F target (M5925), and cell cycle (hsa04110) gene signature GSEA enrichment profiles for whole-transcriptome experiments of p57-WT and p57-KO H2122 cells, GC-treated (GC) compared to untreated (Veh) (n = 2). Nominal P values were determined by GSEA software.