Figure 5. Concurrent treatment of [Ru(dppz)2(PIP)]2+ plus the Chk1 inhibitor CHIR-124 potentiates synergistic apoptosis in cancer cells.
(a) Viability of HeLa (cervical cancer) or hSAEC1-KT (normal epithelial) cells after incubation with 1 in the absence or presence of Chk1 inhibitor CHIR-124 (500 nM) for 48 h constant exposure. (b) Morphological evidence for apoptosis (pyknosis/karyorrhexis, arrows) in HeLa cells treated with 40 μM 1 plus CHIR-124 for 48 h. Scale bars = 20 μm. (c) Quantification of apoptotic cells for experimental conditions as shown in (b). Equivalent results for 2 (40 μM, 48 h) included. Data mean of two independent experiments +/− SD. (d) Immunoblot analysis for cleaved (cl.) caspase 3 levels (19 and 17 kDa fragments indicated) in HeLa cells treated as in (b) and (c). Cisplatin incubation (20 μM, 24 h) employed as a positive control and β-actin levels were monitored as a loading control. (e) γH2AX foci (green) in HeLa cell nuclei after treatment with 40 μM 1 +/− CHIR-124 for 24 h. Nuclear staining (DAPI) included (blue). Scale bars = 10 μm. (f) Quantification of γH2AX foci from cells treated as in (e). Data mean of two independent experiments +/− SEM. Minimum of 150 cells counted per experiment. (g) Western blot analysis for γH2AX levels in HeLa cells treated as in (e,f). Cisplatin treatment (20 μM, 24 h) was included as a positive control for γH2AX induction. β-actin levels were monitored as a loading control.