Chemokine CXCL8 and its receptors as markers of colorectal cancer

BACKGROUND: The chemokine CXCL8 and its receptor are involved in the activation and transport of inflammatory mediators and regulate the proliferation and renewal of cancer stem cells in colon cancer. It is believed that CXC signaling may be associated with poor prognosis in colorectal cancer. AIM: To study the possibilities of using CXCL8-CXCR1/2 pathway indicators as markers in colorectal cancer. MATERIAL AND METHODS: Isolation of ribonucleic acid (RNA) from histological sections of tumors obtained intraoperatively from 59 patients diagnosed with colorectal cancer was carried out using magnetic particles, and quantitative polymerase chain reaction in real time was performed. Calculation of the normalized expression of the CXCL8 and CXCR1 genes relative to the referee gene was done using special software. Statistical data processing was performed using Statistica 3.0, BioStat v. 7.1 programs. Comparisons of characteristics were performed using the Mann–Whitney U test. Cox and Kaplan–Meier criteria were used to analyze overall and disease-free survival. RESULTS: The expression of CXCL8 in intestinal adenocarcinoma cells with low differentiation [Me (Q1–Q3) — 8.770 (1.127–1.114)] was significantly higher than in the groups of moderately and well differentiated tumors (p=0.004 and p=0.012, respectively); and in tumor tissue refractory to chemotherapy, it was significantly higher [4.374 (2.052–7.045)] compared to resistant [2.200 (1.388–5.037); p=0.008] and sensitive [1.624 (0.739–2.586); p=0.042]. The level of CXCR1 messenger RNA in tumor tissue was increased in the presence of BRAF mutation [3.645 (0.801–1.090); p=0.009] and low tumor differentiation [6.965 (3.938–12.225); p=0.002], as well as in tumor tissue refractory to FOLFOX/XELOX chemotherapy [46.224 (27.580–83.570); p=0.0009]. CONCLUSION: Expression of components of the CXCL8-CXCR1/2 signaling pathway in tumor tissue may be a marker of sensitivity to FOLFOX/XELOX chemotherapy in colorectal cancer.