Prognostic value of hypoxia-inducible factor-1 alpha and prolyl 4-hydroxylase beta polypeptide overexpression in gastric cancer

Figure 1 High prolyl 4-hydroxylase beta expression as a marker of tumor hypoxia. A: HIF-1α protein; B: ARNT protein; C: CA9 protein; D: SLC2A1 protein; E: VEGFA protein; F: LDHA protein. HIF-1α: Hypoxia-inducible factor-1α; ARNT: Hydrocarbon receptor nuclear translocator; CA9: Carbonic anhydrase 9; SLC2A1: Egl-9 aryl solute carrier family 2 member 1; VEGFA: Vascular endothelial growth factor A; LDHA: Lactate dehydrogenase A.

Figure 2 Representative images of hypoxia-inducible factor-1α and prolyl 4-hydroxylase beta staining of gastric tissue. A and E: HIF-1α was strongly expressed in GC tissue; B and F: HIF-1α was weakly expressed in GC tissue; C and G: P4HB had strong expression in GC tissue; D and H: P4HB had weak expression in GC tissue. Magnifications in all figures were 100 × and 400 ×. HIF-1α: Hypoxia-inducible factor-1α; GC: Gastric cancer; P4HB: Prolyl 4-hydroxylase beta.

Figure 3 Kaplan-Meier curves for disease-free survival and overall survival. A: Disease free survival curves stratified by HIF-1α expression (P = 0.00); B: Overall survival curves stratified by HIF-1α expression (P = 0.00); C: Disease free survival curves stratified by P4HB expression (P = 0.00); D: Overall survival curves stratified by P4HB expression (P = 0.00). Patients were divided into an over-expression group and a weak-expression group, according to expression of HIF-1α and P4HB. Log-rank test was used to evaluate significance. HIF-1α: Hypoxia-inducible factor-1α; P4HB: Prolyl 4-hydroxylase beta.