Figure 2.

Combination treatment of DT-13 and NVB-induced caspase-dependent apoptosis in NSCLC cells. NCI-H460 and A549 cells were treated with 10 μM DT-13 and 0.01 μM NVB for 48 h. Annexin V/PI analysis for NCI-H460 (a) and A549 (b) cells were performed by flow cytometry to detect the percentage of apoptotic cells, and the frequency of apoptotic cells (including early and late apoptotic cells) was shown in the histograms. The activation of apoptosis-related proteins for NCI-H460 (c) and A549 (d) cells at 48 h was observed by the detection of active cleavage fragments of PARP, caspase-8, caspase-9 and caspase-3, β-actin was served as the loading control. NCI-H460 (e) and A549 (f) cells were pretreated with 10 μM zVAD.fmk for 2 h, and then cells were exposed with 10 μM DT-13 and 0.01 μM NVB for another 48 h. Annexin V/PI analysis was performed to detect the percentage of apoptotic cells, and the frequency of apoptotic cells (including early and late apoptotic cells) was shown in the histograms. The data were expressed as mean±S.D. in triplicate using Student’s t-test (two-tailed). *P<0.05, **P<0.01 and ***P<0.001