PSMA1, a Poor Prognostic Factor, Promotes Tumor Growth in Lung Squamous Cell Carcinoma

Lung squamous cell carcinoma (LUSC) has a poor clinical prognosis and lacks effective targeted therapy. This study is aimed at investigating the role of PSMA1 (proteasome subunit alpha type-1) in LUSC. The differential expression genes (DEGs) in LUSC were retrieved from The Cancer Genome Atlas (TCGA) by "edgR" algorithm and by "limma" R package. Then, the relationship between genes and overall survival (OS) was explored by the least absolute shrinkage and selection operator (LASSO) and multivariate Cox (multi-Cox) regression. Next, the PSMA1 expression in tissues of LUSC was detected by IHC, qRT-PCR, and western blot (WB). Moreover, the effects of PSMA1 on the proliferation and viability of LUSC cell were explored by cell counting kit 8 (CCK-8) assays, colony formation assays, and flow cytometry (FCM) analysis. All 4421 DEGs were screened by TCGA database, and 26 genes associated with OS were selected by multi-Cox. Based on TCGA database, PSMA1 was highly expressed in tissues of LUSC patients, and OS and FP of patients with PSMA1 overexpression were significantly lower than those of patients with low PSMA1 expression. Furthermore, PSMA1 knockdown significantly decreased the proliferation of LUSC cells and promoted the apoptosis of LUSC cells, and these effects were reversed by PSMA1 overexpression. The results of this project supported that PSMA1 might be a critical gene regulating the development of LUSC and has the potential to be explored as a prognostic biomarker of LUSC.