Panoply™ Human PARP1 Over-expressing Stable Cell Line

The classic ferroptosis activator RSL3 targets enzymes with nucleophilic active sites, primarily acting on glutathione peroxidase 4 (GPX4) to trigger ferroptosis. Recent studies have shown that RSL3 is a potential pro-apoptotic agent. However, the mechanism by which RSL3 induces apoptosis during ferroptosis remains unclear. Poly(ADP-ribose) polymerase (PARP1) determines the cellular response to DNA damage, and its depletion or cleavage by activated caspase-3 induces apoptosis, thereby inhibiting tumor progression. Here, this study shows that RSL3 triggers two parallel apoptotic pathways by increasing reactive oxygen species (ROS) production during ferroptosis: (1) caspase-dependent PARP1 cleavage; and (2) DNA damage-dependent apoptosis due to reduced full-length PARP1. The latter is achieved by inhibiting METTL3-mediated m6A modification and subsequent inhibition of PARP1 translation. Furthermore, the researchers found that RSL3 retains its pro-apoptotic function in PARP inhibitor-resistant cells and effectively inhibits the growth of PARP inhibitor-resistant xenograft tumors in vivo.

Since PARP1 is a well-established DNA damage sensor, researchers investigated whether it is involved in RSL3-induced DNA damage and subsequent apoptosis. To this end, they constructed PARP1-overexpressing MHCC97H, SJSA-1, and LoVo cells. The results showed that PARP1 overexpression effectively counteracted RSL3-induced effects, restoring the levels of CDK2, CyclinD1, CDK4, and p-Rb/Rb, while simultaneously reducing the level of γH2AX (Figure 1F). Cell cycle and apoptosis analysis further demonstrated that RSL3-induced S-phase arrest and apoptosis were significantly attenuated in PARP1-overexpressing cells (Figure 1G, H). These findings highlight the crucial role of PARP1 in mediating RSL3-induced DNA damage-dependent apoptosis.

Figure 1. PARP1 is involved in RSL3-induced DNA damage and subsequent apoptosis. (Chen D, et al., 2025)