Fig 2: HAMP upregulation is associated with a poor survival outcome in ccRCC patients. (A) Patient survival outcomes of overall survival, disease-specific survival, and progression-free intervals were analyzed based on HAMP expression levels using the minimum p-value approach, as described (Menyhart et al., 2018). The 95% confidence interval of the H.R. value was listed within the parentheses. (B–E) Overall survival outcomes were compared between different groups using the minimum p-value approach described (Menyhart et al., 2018).

Fig 3: HAMP expression is associated with immune checkpoint receptors in ccRCC tissues. (A) Spearman correlation was analyzed between HAMP expression and immune checkpoint genes, and a strong correlation (Spearman r > 0.35) was noticed between HAMP and PDCD1, LAG3, TIGIT, and CTLA4. (B–C) The expression of the immune checkpoint genes was analyzed using the TCGA-KIRC dataset in a case-matched pairwise comparison (panel B) or group cohort (panel C) The p-values were derived from a paired t-test or Wilcoxon rank-sum test. (D–G) Patient survival outcomes of disease-specific and progression-free intervals were analyzed based on individual genes using the Kaplan-Meier curve, as described (Liu et al., 2018). The 95% confidence interval of the H.R. value was listed between the parentheses. The p-values were derived from the Log-rank test.

Fig 4: HAMP expression is upregulated in kidney cancers. (A) Gene expression was compared using the case-matched normal kidney and ccRCC tissues (TCGA -KIRC) from 72 cases. The p-values were derived from a paired t-test. (B) A Receiver Operating Characteristic (ROC) curve analysis for the diagnostic performance of iron-modulating gene expression in ccRCC tissues. AUC: Area under the ROC curve. (C,D) HAMP expression was compared using the case-matched normal kidney and ccRCC tissues (TCGA -KIRC) from 72 cases. The p-values were derived from a paired t-test. (E–G) HAMP expression levels were assessed using the cDNA microarray dataset as reported (Yusenko et al., 2009). The p-value was from a Student t-test. The asterisks indicate a significant difference between the two groups. **p < 0.01; *** p < 0.001; ns, no significance.

Fig 5: HAMP upregulation is correlated with HAMP gene hypomethylation in ccRCC tissues. (A,B) Spearman correlation coefficient was analyzed between HAMP gene promoter methylation and HAMP expression [RNA-seq V2 RSEM, log2 (value +1)] using the TCGA PanCancer RNA-seq dataset derived from Illumina Infinium Human Methylation BeadChips HM27 (217 ccRCC cases) and HM450 (319 ccRCC cases) platforms. (C) Spearman correlation coefficient was analyzed between HAMP gene methylation and HAMP expression. The probe cg02131995 covers the region of TSS+1297. TSS, transcription start site. (D,E) HAMP promoter methylation levels were compared quantitatively between normal kidney and ccRCC tumor tissues (D) and lymph node invasion status (E). The asterisks indicate a statistical significance (Student t-test, * p < 0.05, ** p < 0.01).