Increased GOLM1 Expression Independently Predicts Unfavorable Overall Survival and Recurrence-Free Survival in Lung Adenocarcinoma

Abstract

Golgi membrane protein 1 (GOLM1) is a transmembrane glycoprotein of the Golgi cisternae, which is implicated in carcinogenesis of multiple types of cancer. In this study, using data from the Gene Expression Omnibus and The Cancer Genome Atlas, we compared the expression of GOLM1 in lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC) and studied its prognostic value in terms of overall survival (OS) and recurrence-free survival (RFS) in these 2 subtypes of non-small cell lung cancer (NSCLC). Results showed that GOLM1 was significantly upregulated in both LUAD and LUSC tissues compared to the normal controls. However, GOLM1 expression was higher in LUAD tissues than in LUSC tissues. More importantly, using over 10 years’ survival data from 502 patients with LUAD and 494 patients with LUSC, we found that high GOLM1 expression was associated with unfavorable OS and RFS in patients with LUAD, but not in patients with LUSC. The following univariate and multivariate analyses confirmed that increased GOLM1 expression was an independent prognostic indicator of poor OS (hazard ratio [HR]: 1.30, 95% confidence interval [CI]: 1.11-1.54, P = .002) and RFS (HR: 1.37, 95% CI: 1.14-1.64, P = .001) in patients with LUAD. Of 511 cases with LUAD, 248 (48.5%) had heterozygous loss (−1), while 28 (5.5%) of 511 cases with LUAD had low-level copy gain (+1). In addition, we also found that the methylation status of 1 CpG site (chr9: 88,694,942-88,694,944) showed a weak negative correlation with GOLM1 expression (Pearson r = −0.25). Based on these findings, we infer that GOLM1 might serve as a valuable prognostic biomarker in LUAD, but not in LUSC. In addition, DNA copy number alterations and methylation might be 2 important mechanisms of dysregulated GOLM1 in LUAD.