The Clinical Utility of Serum CXCR-2 Assessment in Colorectal Cancer (CRC) Patients

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.

Chemokines in progression, chemoresistance, diagnosis, and prognosis of colorectal cancer

Plenty of factors affect the oncogenesis and progression of colorectal cancer in the tumor microenvironment, including various immune cells, stromal cells, cytokines, and other factors. Chemokine is a member of the cytokine superfamily. It is an indispensable component in the tumor microenvironment. Chemokines play an antitumor or pro-tumor role by recruitment or polarization of recruiting immune cells. Meanwhile, chemokines, as signal molecules, participate in the formation of a cross talk among signaling pathways and non-coding RNAs, which may be involved in promoting tumor progression. In addition, they also function in immune escape. Chemokines are related to drug resistance of tumor cells and may even provide reference for the diagnosis, therapy, and prognosis of patients with colorectal cancer.

Serum CXCL8 and Its Specific Receptor (CXCR2) in Gastric Cancer

Gastric cancer (GC) is the second leading cause of cancer-related deaths worldwide. This malignancy is usually diagnosed at an advanced stage. Therefore, novel biomarkers useful in the early detection of GC are sorely needed. Some authors suggest the role of chemokines and their specific receptors in GC pathogenesis. The aim of the study was to investigate whether serum CXCL8 and its receptor (CXCR2) might be considered as potential candidates for biomarkers in the diagnosis and prognosis of GC. The study included 98 subjects: 64 GC patients and 34 healthy volunteers. CXCL8 and CXCR2 concentrations were assessed by the enzyme-linked immunosorbent assay (ELISA) method. Serum CXCL8 and CXCR2 concentrations were significantly higher in GC patients than in healthy controls, similar to the well-established tumor marker (CA19-9) and marker of inflammation (CRP). Diagnostic sensitivity of CXCL8 was the highest among all proteins tested and increased for the combined assessment with CA19-9. The area under the ROC curve for CXCL8 was higher than those for CXCR2 and classical tumor markers. Serum CXCL8 levels were indicated as a significant risk factor of GC occurrence. Our findings suggest that serum CXCL8 is a promising candidate for a biomarker in GC diagnosis and might be used as a significant predictor of GC risk.

Effect of interleukin-8 receptor B (IL8RB) rs1126579 C>T variation on the risk to cancer

Chemokines are a type of cytokine that participate in the migration of macrophages and monocytes to inflammatory cells. In particular, CXC chemokines are involved in the development of many cancers. Evidence for the association between interleukin-8 receptor B (IL8RB) rs1126579 C > T variation and cancer risk remains contradictory. Here, we utilized a comprehensive analysis containing odds ratios (ORs), regression, and in silico tools to evaluate the effect of IL8RB polymorphism on cancer risk. We further employed Gene set enrichment analysis combined with ELISA to evaluate the IL8RB expression in patients with prostate cancer (PRAD). A total of 5,187 cancer cases and 6,691 controls were included in the present analysis. Individuals with the TT genotype were associated with an increased risk of cancer compared to those with the TC+CC genotype. In a subgroup analysis by type of cancer, individuals with the TT genotype had a 39% increased risk of urinary cancer compared to those with the CC genotype. A subgroup analysis by ethnicity showed that Asians carrying the TC genotype had a 26% lower risk of cancer than those carrying the CC genotype. We found that the expression of IL8RB was down-regulated in PRAD. Compared to that in PRAD subjects carrying the CC genotype, the expression of IL8RB was decreased in patients with the TT+TC genotype. In conclusion, the IL8RB rs1126579 C > T variation may be associated with cancer risk, especially in Asian populations and patients with PRAD.

Circulating Biomarkers of Colorectal Cancer (CRC)-Their Utility in Diagnosis and Prognosis

The global burden of colorectal cancer (CRC) is expected to increase, with 2.2 million new cases and 1.1 million annual deaths by 2030. Therefore, the establishment of novel biomarkers useful in the early diagnosis of CRC is of utmost importance. A number of publications have documented the significance of the overexpression of several specific proteins, such as inflammatory mediators, in CRC progression. However, little is known about the potential utility of these proteins as circulating blood tumor biomarkers of CRC. Therefore, in the present review we report the results of our previous original studies as well as the findings of other authors who investigated whether inflammatory mediators might be used as novel biomarkers in the diagnosis and prognosis of CRC. Our study revealed that among all of the tested proteins, serum M-CSF, CXCL-8, IL-6 and TIMP-1 have the greatest value in the diagnosis and progression of CRC. Serum TIMP-1 is useful in differentiating between CRC and colorectal adenomas, whereas M-CSF and CRP are independent prognostic factors for the survival of patients with CRC. This review confirms the promising significance of these proteins as circulating biomarkers for CRC. However, due to their non-specific nature, further validation of their sensitivity and specificity is required.