Fig. 1: TfR1 overexpression and hypoxia-upregulation in NPC.

a Schematic representation of CSPs upregulated in hypoxic NPC identified through DGE analysis among a total of 1442 CSPs. b Left: Venn diagram illustrating the intersection of CSPs upregulated in tumor samples of the three cohorts: GSE12452 (log₂(fold change) >1 and P < 0.01), GSE53819 (log₂(fold change) >1 and P < 0.01), and GSE61218 (log₂(fold change) >1 and P < 0.01). Right: Venn diagram illustrating the intersection of CSPs that are upregulated in tumor samples with high hypoxia scores of the GSE102349 cohort (log₂(fold change) >10 and P < 0.01). c Distribution of TfR1 mRNA abundance in tumor and normal samples from different cohorts: GSE12452 (normal, n = 10; tumor, n = 31), GSE53819 (normal, n = 18; tumor, n = 18), and GSE61218 (normal, n = 6; tumor, n = 10). d Distribution of TFRC mRNA abundance in tumor samples from the GSE102349 cohort (n = 113) with high or low hypoxia scores. e Representative images of IHC staining showing TfR1 protein expression in clinical primary NPC tissues and NNE tissues collected from multiple patients. Scale bar, 50 μm. f Distribution of TfR1 IHC staining scores in NPC (n = 174) and NNE (n = 98) tissues. g Distribution of TfR1 IHC staining scores in NPC and matched adjacent non-cancerous tissues (n = 117). h IF staining analysis in NPC tissues depicting the co-expression of HIF-1α and TfR1. Scale bar, 50 μm. i Spearman correlation between HIF-1α expression and TfR1 expression based on h (n = 40 random regions from different tissues). The box plots in c, d, and f show the median ±1 quartile, with whiskers extending to the minimum or maximum values within 1.5 times the interquartile range from the box boundaries. Mann–Whitney test in c, d, and f and Wilcoxon matched-pairs signed rank test in g were used to calculate P values. Source data are provided as a Source Data file.