SERPINE1 and SERPINB7 as potential biomarkers for intravenous vitamin C treatment in non-small-cell lung cancer
High dose intravenous vitamin C (IVC) has been proposed as a pro-oxidant anticancer agent. However, there lack biomarkers that are specific for this treatment. Here we explored profiles of gene expression responding to IVC treatment in non-small cell lung cancer (NSCLC) cells as an effort for potential biomarker discovery. Genome-wide RNA-seq was performed in human NSCLC cell lines treated with pharmacological concentrations of vitamin C(VitC) for differential expression of genes. The identified genes were analyzed for correlations with patient prognosis using data from the Kaplan-Meier Plotter and the Human Protein Atlas databases. Further, tumor samples from a retrospective study of 153 NSCLC patients were analyzed with immunohistochemistry for expression of targeted genes, and patient prognosis was correlated to these genes. Two genes, namely SERPINE1 and SERPINB7 were found to be downregulated in NSCLC cells following VitC treatment. Combined patient data from the cohort analysis and online databases revealed that these 2 genes presented an unfavorable prognostic prediction of overall survival (OS) in NSCLC patients receiving standard of care. However, high expression level of these 2 genes were associated with prolonged OS in NSCLC patients receiving IVC in addition to standard of care. These data revealed that SERPINE1 and SERPINB7 have the potential to serve as predictive factors indicating favorable responses to IVC treatment in patients with NSCLC. Further validations are warranted. Overall design: To investigate the differential gene expression profiles of NSCLC cells under VitC treatment. H1299 and PC9 treated or untreated with IC50 concentrations of VitC were collected at 24 hours, and then gene expression profiles were performed by RNA-seq analysis.