Abstract
Lung squamous cell carcinoma (LUSC) is an aggressive malignancy with a poor prognosis. Given the association between mitochondrial dysregulation and LUSC, the aim of the present study was to identify mitochondrial unfolded protein response (UPRmt)‑related candidate genes associated with LUSC and to explore their potential functional relevance. In the present study, differential expression, univariate Cox and survival analyses were combined to identify a UPRmt‑associated key gene in LUSC. Gene set enrichment analysis was then performed, and overexpression (OE) and knockdown cell lines were used to clarify its function using western blotting, Cell Counting Kit‑8, colony formation and Transwell® invasion assays. Using bioinformatics tools and a review of the literature, PTEN‑induced kinase 1 (PINK1) was singled out as a key gene in LUSC samples. Elevated PINK1 expression was associated with worse survival outcomes. A total of 117 pathways were enriched by PINK1, with the top 5 including 'focal adhesion' and 'mitogen‑activated protein kinase signaling pathway'. Using experimental analysis, it was observed that PINK1 significantly enhanced the proliferative, migratory, invasive and colony forming abilities of tumor cells, thereby exacerbating LUSC. Furthermore, these enhancements were diminished by the application of focal adhesion kinase (FAK) inhibitor. It was also noted that the expression levels of protein kinase B (AKT), p‑AKT, Ras homolog family member A (RhoA) and vinculin were all elevated in OE‑PINK1 cells. Collectively, these findings indicated that PINK1 exerted its influence on LUSC through the FAK/AKT/RhoA/vinculin pathway. The present study identified PINK1 as a key gene in LUSC, exerting its influence through the FAK/AKT/RhoA/vinculin pathway, thereby presenting a potential novel therapeutic target for the treatment of LUSC in the future.