Journal: Hepatic Oncology
Article Title: RTA‑408 induces p38‑dependent apoptosis and suppresses cell viability in hepatocellular carcinoma cells
doi: 10.1080/20450923.2026.2659967
Figure Lengend Snippet: p38 inhibition attenuates RTA-408-induced p38 signaling, LC3B/p62 accumulation, and apoptotic protein activation in hepatocellular carcinoma cells. HepG2 and PP5 cells were treated for 24 h with vehicle control (Con), RTA-408 (400 nM) alone, or RTA-408 (400 nM) plus SB203580 (10 μM). Protein expression was analyzed by western blotting. Representative immunoblots show phosphorylated p38 (p-p38), total p38, NRF2, LC3B, p62, cleaved caspase-3 (c-cas3), and β-actin. Densitometric analyses of p-p38/p38, as well as NRF2, LC3B, p62, and c-cas3 normalized to β-actin, are shown in the accompanying bar graphs. In both HepG2 and PP5 cells, RTA-408 increased p38 phosphorylation, NRF2 expression, LC3B accumulation, p62 accumulation, and cleaved caspase-3 levels, whereas co-treatment with SB203580 markedly attenuated these RTA-408-induced effects without altering total p38 expression. These findings indicate that p38 activity contributes to RTA-408-induced stress signaling, LC3B/p62-associated responses, and apoptotic protein activation in hepatocellular carcinoma cells. Data are presented as mean ± SEM from three independent experiments ( n = 3). *P < 0.05 and **P < 0.01 versus control; #P < 0.05 and ##P < 0.01 versus RTA-408 alone.
Article Snippet: RTA-408 (omaveloxolone) (MCE; 1474034-05-3; USA) and the p38 MAPK inhibitor, SB203580 (MCE; 152121-47-6; USA), were dissolved in dimethyl sulfoxide (DMSO) to prepare stock solutions (10 mM for RTA-408 and 10 mM for SB203580), which were stored at − 20 °C according to the manufacturer’s instructions.
Techniques: Inhibition, Activation Assay, Control, Expressing, Western Blot, Phospho-proteomics, Activity Assay