Brain-Derived Neurotrophic Factor, Neutrophils and Cysteinyl Leukotriene Receptor 1 as Potential Prognostic Biomarkers for Patients with Colon Cancer

SIMPLE SUMMARY: Colorectal cancer (CRC) is one of the most common type of cancer and the third leading cause of cancer-related death. CRC is associated with inflammatory bowel disease. We have earlier shown that high levels of the inflammatory receptor CysLT(1) goes with poor prognosis for CRC patients. In this study, we found that high levels of neutrophils (CD66b) and brain-derived neurotropic factor (BDNF) goes with poor prognosis for colon cancer patient. We discovered a strong positive correlation between CysLT(1), CD66b and BDNF. Our data support that these three proteins can be used as a combined biomarker for CC patients. ABSTRACT: The tumor microenvironment has been recognized as a complex network in which immune cells play an important role in cancer progression. We found significantly higher CD66b neutrophil expression in tumor tissue than in matched normal mucosa in the Malmö colon cancer (CC) cohort and poorer survival of stage I-III patients with high CD66b expression. Additionally, mice lacking CysLT(1)R expression (cysltr1(−/−)) produce less brain-derived neurotrophic factor (BDNF) compared to WT mice and Montelukast (a CysLT(1)R antagonist)-treated mice also reduced BDNF expression in a mouse xenograft model with human SW480 CC cells. CD66b and BDNF expression was significantly higher in patient tumor tissues than in the matched normal mucosa. The univariate Cox PH analysis yielded CD66b and BDNF as an independent predictor of overall survival, which was also found in the public TCGA-COAD dataset. We also discovered a strong positive correlation between CD66b, BDNF and CysLT(1)R expression in the Malmö CC cohort and in the TCGA-COAD dataset. Our data suggest that CD66b/BDNF/CysLT(1)R expression as a prognostic combined biomarker signature for CC patients.