DPP7 as a Potential Therapeutic Marker for Colorectal Cancer.

Background: Dipeptidyl peptidase 7 (DPP7) is overexpressed in various tumors, but its role in colorectal cancer (CRC) remains unclear. Study the Impact of DPP7 on malignant progression and tumor immunity in CRC. Methods: We utilized Tumor Immune Estimation Resource 2.0 (TIMER2.0) and The Cancer Genome Atlas (TCGA) analyses to assess the expression of DPP7 in tumors and validated it through immunohistochemistry and immunoblotting. Additionally, we investigated the relationship between DPP7 and immune cell infiltration using single-sample Gene Set Enrichment Analysis (ssGSEA) analysis. Finally, the impact of DPP7 on cell proliferation, invasion, migration, and immune cell function in the tumor microenvironment was confirmed through cell experiments and animal studies. Results: DPP7 is highly expressed in CRC, and high expression of DPP7 is associated with poor prognosis. Cell experiments demonstrate that overexpression of DPP7 enhances the proliferation, migration, and invasion capabilities of colorectal cancer cells both in vitro and in vivo. Immune infiltration analysis and co-culture results indicate that overexpression of DPP7 suppresses the immune cell's cytotoxic function against tumors in the tumor microenvironment. Conclusions: DPP7 promotes the malignant potential of colorectal cancer cells and inhibits tumor immune function, thereby promoting the progression of colorectal cancer.