Fig. 1.

High SOD1 expression is associated with poor prognosis in NPC. a and b SOD1 is overexpressed in head and neck cancer (microarray data sets available from Oncomine (https://www.oncomine.com//)), and NPC tissues from the hospital (SYSUCC) were analysed by qPCR assays. c Immunoblotting analysis of SOD1 in ten NETs and NPC tissues (T). d Representative staining showing a relatively high expression of SOD1 in human NPC tissues compared with that in NET tissues, as analysed by IHC staining. e and f qPCR and immunoblotting analysis of SOD1 expression in nasopharynx epithelial cells and NPC cell lines; data are presented as the means ±SD (n = 3) *p < 0.05 for the indicated comparison (t-test). g SOD1 enzymatic activity in 5-8F and CNE2 cells was measured using an SOD Assay Kit-WST. h and i The overall survival and progression-free survival curves of patients with low and high SOD1 expression were generated using the Kaplan-Meier method and log-rank test