The Significance of CXCL1 and CXCR1 as Potential Biomarkers of Colorectal Cancer

The CXCL1/CXCR2 and CXCL8-CXCR1/CXCR2 axes are under intensive investigation as they appear to regulate the progression and invasion of colorectal cancer (CRC). Growing evidence demonstrates the elevated expression of these proteins in CRC. However, a majority of relevant studies have been performed on CRC tissues using immunohistochemical techniques. Our study is the first to evaluate the diagnostic significance of serum CXCL1 and CXCR1 levels in CRC patients in comparison to well-established tumor markers, such as the carcinoembryonic antigen (CEA), and markers of inflammation, such as C-reactive protein (CRP). Thus, the aim of our study was to assess whether circulating serum levels of CXCL1 and CXCR1 might be candidates for novel biomarkers in the diagnosis and progression of CRC. The study was performed on 76 subjects, including patients with CRC and healthy volunteers as a control group. Serum concentrations of CXCL1, CXCR1, and the classical tumor marker (CEA) were measured using immunoenzyme assays, while CRP levels were assessed with the immunoturbidimetric method. Serum CXCL1 levels were statistically significantly increased in CRC patients when compared to healthy subjects, and similar results were found for CEA and CRP levels. The percentage of elevated concentrations of CXCL1 and CXCR1 was higher than that of the classical tumor biomarker and increased in the combined measurement of these proteins with CEA. In addition, among all proteins tested, serum CXCL1 seems to be the best indicator in the differentiation between CRC patients with nodal involvement and patients without the presence of lymph node metastasis. Our preliminary results indicate the role of serum CXCL1 and CXCR1 in the diagnosis of CRC, particularly in the combined measurement with CEA.