Fig. 1. Preferential radiosensitization of TNBC cells by Chk1 inhibition.
A, Meta-analysis across 15 published clinical data bases to illustrate expression patterns of triple-negative breast cancer (TNBC) and non-TNBC cell lines for a panel of genes associated with Chk1.
B, Comparison of short-term radiosensitization factors (SRF2Gy) for selective inhibitors of Chk1 (LY2603618, 100 nM), ATR-(VE-821, 2.5 μM), and ATM-(KU-55933, 2.5 μM) in TNBC and non-TNBC cell lines. Each data point represents averages of at least 3 biological repeats and horizontal lines indicate the mean. Statistical comparisons were performed with the unpaired T-test (two-tailed).
C, Clonogenic survival of non-triple-negative (MCF-7, T-47D) and triple-negative cell lines (MDA-MB-231, MDA-MB-468, BT-549) after single dose irradiation with or without LY2603618 (100 nM) treatment initiated 1 hour before irradiation. Statistical comparisons were based on 3 independent repeat experiments and carried out using the F-test (GraphPad Prism 6). * p≤0.05, ** p ≤0.01, *** p ≤0.001