Deficiency of Functional Iron-Sulfur Domains in ABCE1 Inhibits the Proliferation and Migration of Lung Adenocarcinomas By Regulating the Biogenesis of Beta-Actin In Vitro.

BACKGROUND/AIMS: ATP-binding cassette transporter E1 (ABCE1), a unique ABC superfamily member that bears two Fe-S clusters, is essential for metastatic progression in lung cancer. Fe-S clusters within ABCE1 are crucial for ribosome dissociation and translation reinitiation; however, whether these clusters promote tumor proliferation and migration is unclear.

METHODS: The interaction between ABCE1 and β-actin was confirmed using GST pull-down. The lung adenocarcinoma (LUAD) cell line A549 was transduced with lentiviral packaging vectors overexpressing either wild-type ABCE1 or ABCE1 with Fe-S cluster deletions (ΔABCE1). The role of Fe-S clusters in the viability and migration of cancer cells was evaluated using clonogenic, MTT, Transwell and wound healing assays. Cytoskeletal rearrangement was determined using immunofluorescent techniques.

RESULTS: Fe-S clusters were the key domains in ABCE1 involved in binding to β-actin. The proliferative and migratory capacity increased in cells overexpressing ABCE1. However, the absence of Fe-S clusters reversed these effects. A549 cells overexpressing ABCE1 exhibited irregular morphology and increased levels of cytoskeletal polymerization as indicated by the immunofluorescence images. In contrast, cells expressing the Fe-S cluster deletion mutant presented opposing effects.

CONCLUSION: These results demonstrate the indispensable role of Fe-S clusters when ABCE1 participates in the proliferation and migration of LUADs by interacting with β-actin. The Fe-S clusters of ABCE1 may be potential targets for the prevention of lung cancer metastasis.