Abstract
Comprehensive protein profiling in intestinal tissues provides detailed information about the pathogenesis of colorectal cancer (CRC). This study quantified the expression levels of 92 oncology-related proteins in tumors, paired para-carcinoma tissues, and remote normal tissues from a cohort of 52 CRC patients utilizing the Olink technology. The proteomic profile of normal tissues closely resembled that of para-carcinoma tissues while distinctly differing from that of tumors. Among the 68 differentially expressed proteins (DEPs) identified between the tumor and normal tissues, WISP-1, ESM-1, and TFPI-2 showed the most pronounced alterations and exhibited relatively strong correlations. These markers also presented the highest AUC values for distinguishing between tissue types. Bioinformatic analysis of the DEPs revealed that the plasma membrane and the PI3K-AKT signaling pathway were among the most enriched GO terms and KEGG pathways. Furthermore, although TFPI-2 is typically recognized as a tumor suppressor, both Olink and enzyme linked immunosorbent assay (ELISA) analyses have demonstrated that its expression is significantly elevated in tumors compared with paired normal tissues. To the best of our knowledge, this is the first study to profile the proteome of intestinal tissue using the Olink technology. This work offers valuable insights into potential biomarkers and therapeutic targets for CRC, complementing the Olink profiling of circulating proteins.