Diagnostic and prognostic values of C-X-C motif chemokine ligand 3 in patients with colon cancer

The diagnostic and prognostic mechanisms of C-X-C motif chemokine ligand 3 (CXCL3) in colon cancer (CC) have not yet been reported. Therefore, the objective of the present study was to use cohorts of patients from Guangxi Medical University and the Gene Expression Omnibus (GEO) database to investigate and validate CXCL3 for the diagnosis and prognosis of CC, and to explore its prospective molecular mechanism. Reverse transcription-quantitative PCR (RT-qPCR) analysis of 38 paired tumor and non-tumor tissues, and immunohistochemistry (IHC) of 212 tumor and 46 non-tumor tissues was conducted to explore the expression of CXCL3 and its diagnostic and prognostic significance in the Guangxi Medical University CC cohort. A GEO dataset, GSE40967, was used to validate the prognostic significance of CXCL3. Gene set enrichment analysis (GSEA) was also conducted to explore the potential molecular mechanisms underlying the effects of CXCL3 in CC. The RT-qPCR results indicated that CXCL3 expression was significantly higher in cancer tissues compared with adjacent normal tissues, suggesting that it may have high diagnostic value for CC. Multivariate Cox analysis based on the IHC results suggested that there was no appreciable association between CXCL3 positivity and the overall survival (OS) time of CC. However, a stratified analysis revealed that high expression of CXCL3 was associated with considerably increased mortality in the subgroup of CC patients with tumor size <5 cm (adjusted P=0.042, adjusted HR=2.298, 95% CI=1.030-5.126) and with tumor thrombus (adjusted P=0.019, adjusted HR=5.096, 95% CI=1.306-19.886). In the GSE40967 dataset, high expression of CXCL3 was closely associated with poor OS in CC (adjusted P=0.049, adjusted HR=1.416, 95% CI=1.002-2.003). Furthermore, GSEA indicated that the high expression of CXCL3 was closely associated with DNA repair, cell cycle process, cell apoptosis process and the P53 regulation pathway. In summary, these result suggest that CXCL3 might serve as a novel biomarker in the diagnosis and prognosis of CC.