SPC25 upregulation increases cancer stem cell properties in non-small cell lung adenocarcinoma cells and independently predicts poor survival.

In this study, we investigated the functional role and prognostic value of spindle pole body component 25 (SPC25) in non-small cell lung cancer (NSCLC). SPC25 expression profile in lung adenocarcinoma (LUAD), lung squamous cell carcinoma (LUSC) and normal lung tissues was examined by using data from the Cancer Genome Atlas (TCGA) and the Human Protein Atlas (HPA). LUAD A549 cells and LUSC H520 cells were used to investigate the influence of SPC25 on cancer stem cell (CSC) properties in terms of the proportion of CD133+ cells, tumorsphere formation and CSC markers, including CD133, ALDH1 and Sox2. Data mining was also performed in the Kaplan-Meier plotter and TCGA-NSCLC to assess the independent prognostic value of SPC25. Results showed SPC25 was significantly upregulated in LUAD and LUSC tissues compared with normal lung tissues. SPC25 overexpression significantly increased the CSC properties and invasion of A549 cells, but not H520 cells. In comparison, SPC25 knockdown impaired the CSC properties and invasion of A549 cells, but not H520 cells. Univariate and multivariate analysis confirmed that high SPC25 expression was an independent prognostic factor for poor overall survival (OS) (HR: 1.622, 95%CI: 1.207-2.178, p = .001) and recurrence-free survival (RFS) (HR: 1.726, 95%CI: 1.242-2.399, p = .001) in LUAD patients. However, no independent prognostic value of SPC25 was observed in LUSC patients even under the best cut-off model. Based on these findings, we infer that SPC25 upregulation can increase CSC properties in LUAD and independently predict poor survival in this histological subtype.