Irreparable levels of DNA damage induce HIST2H2BE transcription but not HOPX, ICEBERG or S100A7 ( S100A7 / S100A15 ) . NHEKs were irradiated with 10 or 20 gray of IR and allowed 5 days to recover. Whole cell lysates were then prepared and analysed by RT-qPCR and Western blotting for the indicated transcripts and proteins, respectively. (a) p21WAF transcript (graph), GAPDH, total p53 and p21WAF proteins (blot). (b) Cyclin A2 (CCNA2), cyclin D1 (CCND1) and involucrin (IVL) transcripts. (c) Total number of cells in all treated groups and p21WAF and IVL transcripts in non-irradiated controls, before (day 0) and after (day 5) the recovery period. (d) HOPX, HIST2H2BE, ICEBERG and S100A7 (S100A7/S100A15) transcripts. Data are reported as a fold change in mRNA expression levels relative to the non-irradiated control (0 gray) in (a), (b) and (d); in (c), data are reported as a relative fold change in mRNA expression levels between day 0 (immediately after irradiation) and day 5 (after the recovery period). Data are mean ± sd from three independent measurements (n = 3) in (b), (c) and (d); in (a), only two out of the three independent measurements are represented. Asterisks (p <0.05) indicate significant change in transcript levels relative to non-irradiated cells and were calculated by one-way ANOVA followed by Tukey’s post hoc test. Legend: GAPDH, loading control; (+) symbol, positive control (SVHFK cell line); and (-) symbol, negative control (BICR-6 cell line) for total p53 and p21WAF proteins.