Supplementary Figure 1. (A) Expression of DSB repair proteins Supplementary Figure 1. (A) Expression of DSB repair proteins. The protein expression was tested by Western blotting and the relative bands’ intensities were evaluated by UNSCAN-IT. β-actin was used as loading control. Shown are the mean+/-SEM values of at least 3 independent blots. (B) DNA-PK kinase measured by pulldown peptide assay in extracts from FaDu and SKX cells. Shown are mean +/- SEM values of at least 3 experiments.(C) Western blot analysis showing loss of p-SMC1 (S966) and p- KAP1 (S824) signal 30 min after 20Gy in SKX compared to FaDu cells. (D) Western Blot showing the cytoplasmic marker Calpain exclusively in whole cell extract (WCE) while nuclear SP1 marker in both WCE and nuclear fractions (NF) of SKX cells. Supplementary Table 1. Sequences of primers used for ATM mRNA analysis.

Supplementary Figure 1 A C D B p-SMC1 (S966) p-KAP1 (S824) β-actin IR (Gy) 20 SKX MCF7 WCE SP1 Calpain NF B

Supplementary Table 1 Primer Sequence 1F 1R 5´-ATGAGTCTAGTACTTAATG-3´ 5´-GTTGACAGCCAAAGTCTTG-3´ 2F 2R 5´-GAAGATACCAGATCCTTGGAGATTTC-3´ 5´-CTCCTGCACATTGCATTAGAGAGTTGGC-3´ 7A 7B 5´-TGCCTCCAATTCTTCACAG-3´ 5´-CCTCTCCTTTGTTAGATGCC-3´ 4F 4R 5´-AGGACACGAAGGGAGATTC-3´ 5´-CCCTGAAAAGTCACAGAG-3´ 5F 5R 5´-GAGGATTTCTATAGATCTTG-3´ 5´-CTGTGCTTCTTATAAAC-3´ 6F 6R 5´-CTTAAAATATATCACCTGTTTG-3´ 5´-TTGATGTTCTAAAAGGC-3´ 7F 7R 5´-CTACAGCCTTTTAGAACATC-3´ 5´-TCTGTCTCTTAGAGATTG-3´ 9F 9R 5´-CTTAGGGAACATAAAATTC-3´ 5´-CAAGAATTTTTCCATGC-3´ 4A 4B 5´-AAGATGTTGTTGTCCCTACTATG-3´ 5´-AAGGCTGAATGAAAGGGTAATTC-3´