Activations of Both Extrinsic and Intrinsic Pathways in HCT 116 Human Colorectal Cancer Cells Contribute to Apoptosis through p53-Mediated ATM/Fas Signaling by Emilia sonchifolia Extract, a Folklore Medicinal Plant
Figure 5
ESE increased ROS production and contributed to p53-correlated ATM/Fas apoptotic signaling in HCT 116 cells. (a) Treatment with ESE (50 μg/mL) for the indicated times (0, 2, and 4 h) was subjected to ROS productions by flow cytometry as described in Section 2. (b) Pretreatment with NAC (10 mM, a scavenger of ROS), or caffeine (1 mM, an inhibitor of ATM) in ESE-treated HCT 116 cells restored the cell viability by MTT assay. The values presented are the mean ± S.D. (n = 3) from three independent experiments. ***P < 0.001 shows a significant different when compared to ESE treatment. (c) ESE elevated the protein levels of ATM, phosphorylated ATM (Ser1981), p53, phosphorylation, and p53 (Ser15) by Western blotting. (d) Effects of ESE on Fas mRNA level in HCT 116 cells, and the total RNA was extracted from each treatment of ESE (50 μg/mL) on HCT 116 cells for 0, 6, and 12 h. RNA samples were reverse transcribed into cDNA and quantified with real-time PCR as described in Section 2. The ratios of Fas mRNA/GAPDH are presented. The values presented are the mean ± S.D. (n = 3) from three independent experiments. ***P < 0.001 shows a significant different when compared to control (0 h) sample.
