SKA3 promotes lung adenocarcinoma progression via the EGFR/E2F1/SKA3/integrin β1 signaling loop

Spindle and kinetochore-associated complex subunit 3 (SKA3) contributes to tumor growth and metastasis, but its specific roles have not been clearly elucidated. In this study, we found that SKA3 contributed to lung adenocarcinoma (LUAD) progression by interacting with integrin β1. The expression characteristics of SKA3 in LUAD patients were analyzed by The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) datasets and validated in 33 paired LUAD tissues by immunohistochemistry. Our data confirmed that SKA3 was a crucial regulator of LUAD progression and was associated with worse patient survival. In vitro and in vivo studies showed that SKA3 increased cell migration and invasion. Mechanistically, it was demonstrated that SKA3 could bind to integrin β1 and promote its activation, which further promoted the activation of EGFR. As a positive feedback loop, the activation of EGFR in turn promoted the expression of SKA3 via E2F1-mediated transcriptional regulation. Inhibition of EGFR with AZD9291 blocked SKA3 signaling induced by E2F1. These results indicated that SKA3 was crucial for the activation of EGFR and its downstream signaling pathway. Our findings uncovered the oncogenic role of SKA3 in LUAD progression and elucidated a novel EGFR/E2F1/SKA3/integrin β1 signaling loop, providing a potential SKA3-directed therapeutic strategy for LUAD patients.