EIF4A3 Acts on the PI3K–AKT–ERK1/2–P70S6K Pathway through FLOT1 to Influence the Development of Lung Adenocarcinoma

Lung adenocarcinoma (LUAD) is a major lung cancer subtype. In this study, we discovered that the eukaryotic translation initiation factor EIF4A3 expression was significantly higher in LUAD tissues and that this higher expression was closely linked to a poor prognosis for LUAD. In addition, we demonstrated that the knockdown of EIF4A3 significantly inhibited the proliferation, invasion, and migration of LUAD cells in vitro and in vivo. The findings of mass spectrometry analysis revealed that EIF4A3 could interact with Flotillin-1 in LUAD cells and that EIF4A3 could positively regulate the expression of FLOT1 at the protein level. Meanwhile, transcriptome sequencing showed that EIF4A3 could influence the development of LUAD by affecting PI3K–AKT–ERK1/2–P70S6K and PI3K class III–mediated autophagy in the Apelin pathway. In addition, we confirmed that Flotillin-1 expression was upregulated in LUAD based on the existing literature, and knockdown of FLOT1 could inhibit the proliferation and migration of LUAD cells. In addition, the knockdown of Flotillin-1 reversed the increase of cell proliferation and migration caused by EIF4A3 overexpression. Furthermore, we found that the activation of PI3K–AKT–ERK1/2–P70S6K signaling pathway and PI3K class III–mediated autophagy caused by EIF4A3 overexpression was rescued by the knockdown of FLOT1. In a word, we proved that EIF4A3 positively regulates the expression of FLOT1 and plays a procancer role in LUAD. IMPLICATIONS: Our study revealed the role of EIF4A3 in prognosis and tumor progression in LUAD, indicating that EIF4A3 could be used as the molecular diagnostic and prognostic therapeutic target.