Fig. 5

SKP2 and PDCD4 expression in human tissues and clinical correlation. a Human breast cancer and corresponding non-cancerous tissues were used for SKP2 and PDCD4 expression by western blot. b Human breast cancer and corresponding non-cancerous tissues were used for SKP2 and PDCD4 staining by IHC and quantitated (Scale bars, 50 um, Scale bars inside the box, 20 um). Chi-square test was used to analyze the correlation between SKP2 and PDCD4. P < 0.05 was considered as significant. c SKP2 overexpression was significantly associated with poor prognosis in human breast cancer patients (P < 0.001). Gene expression data, relapse free and overall survival information were downloaded from GEO (Affymetrix microarrays only), EGA and TCGA. The database was handled by a PostgreSQL server, which integrates gene expression and clinical data simultaneously. To analyze the prognostic value of a particular gene, the patient samples were split into two groups according to various quantile expressions of the proposed biomarker. Cut-off value for survival was determined with ROC curve. The two patient cohorts were compared by a Kaplan-Meier survival plot, and the hazard ratio with 95% confidence intervals and logrank P value were calculated. d PDCD4 overexpression were significantly associated with favourable prognosis in human breast cancer patients (P < 0.001). e, f Mutation detection of SKP2 and PDCD4 in human breast cancer patients were perform in the breast cancer patients database of cBioPortal for cancer Genomics. g The working model of SKP2 via PDCD4 in tumorigenesis and DNA-damage response