PUM1 enhances PAK6 mRNA stability and contributes to growth and ferroptosis resistance in lung adenocarcinoma cells.

BACKGROUND

Lung adenocarcinoma (LUAD) is the most common subtype of lung cancer and a major contributor to cancer-related mortality. This study investigates the role of p21 (RAC1)-activated kinase 6 (PAK6) in LUAD progression, with a focus on its involvement in modulating resistance to ferroptosis.

METHODS

GEO datasets were analyzed to identify genes with altered expression in LUAD. Loss-of-function assays were conducted in human LUAD cell lines to assess the effects of PAK6 depletion on cell viability, proliferation, and cell death. Ferroptosis sensitivity was evaluated by measuring levels of ferrous iron (Fe) and malondialdehyde (MDA). The interaction between PAK6 and pumilio RNA-binding family member 1 (PUM1) was assessed using RNA immunoprecipitation and luciferase assays. For in vivo verification, mouse LA795 LUAD cells were implanted into nude mice.

RESULTS

Bioinformatics analysis revealed that PAK6 is upregulated in LUAD. Increased immunofluorescence staining and mRNA expression of PAK6 were confirmed in human LUAD cell lines. Loss of PAK6 inhibited the proliferation and migration of LUAD cells in vitro while promoting cell death. However, ferroptosis inhibition reduced cell death. Furthermore, PAK6 silencing elevated Fe and MDA levels, and enhanced the anti-tumor effects of the ferroptosis inducer Erastin. PUM1, which is upregulated in LUAD, binds to PAK6 and stabilizes its RNA. Silencing PUM1 promoted ferroptosis both in vitro and in animal models, an effect that was reversed by artificial restoration of PAK6.

CONCLUSION

This study demonstrates that PUM1 enhances the RNA stability of PAK6, thereby contributing to ferroptosis resistance in LUAD cells.