Sideroflexin1 as a novel tumor marker independently predicts survival in lung adenocarcinoma

BACKGROUND: Targeted therapy for lung cancers is based on prognostic genes and needs more investigation. No study has yet evaluated the effects of Sideroflexin1 (SFXN1) on lung cancer. METHODS: Data were analyzed from large patient cohorts in the Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO). RESULTS: The mRNA and protein expression of SFXN1 is apparently upregulated in lung adenocarcinoma (LUAD) tissues. Among LUAD patients, upregulated SFXN1 mRNA expression can independently predict unfavorable overall survival (OS, P=0.006) and recurrence-free survival (RFS; P=0.003). In addition, detection data from DNA copy number alterations (CNAs) showed that 164 (32.03%) of the 512 cases had copy number loss (−2 and −1), while 121 (23.63%) of the cases had copy number amplification (+1 and +2). We also found a weak negative correlation between the methylation status of one CpG site (chr5: 174, 944, 791–174, 944, 793) and SFXN1 expression (P<0.0001). CONCLUSIONS: Upregulated SFXN1 mRNA expression can be a prognostic biomarker of unfavorable OS and RFS in patients with LUAD.