Induction of apoptosis in indole-3-carbinol-treated lung cancer H1299 cells via ROS level elevation

This study was focused on investigating the anticancer potential of indole-3-carbinol (I3C) against lung cancer H1299 cells via an increase in ROS levels. To investigate the induction of growth arrest and/or cell death in H1299 cells, a cell cycle arrest assay, terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick-end labeling (TUNEL) assay, and reactive oxygen species (ROS) detection assay were performed. Through the TUNEL assay, we detected I3C-induced DNA fragmentation. Fluorescence-activated cell sorting (FACS) analysis showed that I3C induced an increase in ROS levels and apoptotic rate in a dose- and time-dependent manner in H1299 cells. Western blotting demonstrated that activated forms of caspase-3, caspase-7, caspase-9, and poly (ADP-ribose) polymerase (PARP) were increased in I3C-treated H1299 cells following treatment with I3C. Furthermore, protein expression levels of FOXO3, bim, bax, and phosphorylated ERK and JNK were increased, while those of pAkt, Bcl-xL, and Bcl-2 were decreased by I3C treatment of H1299 cells. To confirm the relationship between cell apoptosis and ROS generation, H1299 cells were treated with I3C simultaneously with N-acetylcysteine (NAC), and it was shown that ROS levels decreased and viability increased. Moreover, in western blot analysis, expression of anti-apoptotic proteins (thioredoxin1, peroxiredoxin-1, Bcl-2, and Bcl-xL) in I3C-treated cells was evidently downregulated and pro-apoptotic proteins (active ASK1 and cleaved PARP) were upregulated compared to cells co-treated with NAC. The study showed that I3C induced downregulation of ROS regulator proteins and elevation of ROS, thus activating apoptotic signaling cascades in human lung cancer H1299 cells.

Automated summary

This study demonstrates the anticancer potential of indole-3-carbinol (I3C) against lung cancer H1299 cells by increasing ROS levels and activating apoptotic signaling cascades. I3C treatment induced growth arrest and cell death in H1299 cells through increased ROS levels, upregulation of pro-apoptotic proteins, and downregulation of anti-apoptotic proteins. This research highlights the role of ROS in regulating apoptosis and the potential therapeutic effects of targeting ROS in lung cancer treatment.