Figure 1.

integrated screen identifies APOL3 as significant modulator for ferroptosis and antitumor immunity in CRC. (A) to (C): to identify novel ferroptosis and antitumor immunity modulators in CRC, we performed a three-stage screen analysis (A) first, we performed COX analysis to screen prognosis-related genes in CRC patients, 2832 genes were screened; (B) second, we performed WGCNA analysis to demonstrate 9 modules correlated with tumor related CD8+ T cells infiltration; (C) 9 modules were separately blanked with different color marks; (D) validation of the Pink gene list on tumor immunity by GO analysis; (E) third, differential protein expression analysis from CPTAC database, based on overlapping gene list, APOl3 was selected; (F) SsGSEA analysis demonstrated the immune-activation role of APOL3 in CRC samples; (G) mRNA expression relation between APOL3 and ferroptosis-related markers was shown, a linear regression relationship was demonstrated between APOL3 and ACSL4 (P<0.05). (H) IHC assay was performed on TMA from Zhongshan Hospital colorectal cancer center and representative images were shown, low expression of APOL3 indicates a poor prognosis in CRC patients from Zhongshan Hospital cohort; (I) IHC assay demonstrated the positive correlation between APOL3 and FACL4. Abbreviations: CRC, colorectal cancer; WGCNA, weighted gene co-expression network analysis; IHC, immunohistochemistry; CPTAC, Clinical Proteomic Tumor Analysis Consortium; TMA, tissue microarray; SsGSEA, single sample gene set enrichment analysis.