GDF-15 Level Correlates with CMKLR1 and VEGF-A in Tumor-free Margin in Colorectal Cancer.

Colorectal cancer (CRC) is the third most frequently diagnosed cancer worldwide, responsible for over 880 000 deaths each year. Growth/differentiation factor 15 (GDF-15) is reported to be a promising diagnostic and prognostic factor in CRC. It induces pleiotropic effects in tumor cells: proliferation, stemness, invasion and metastasis. Some studies indicate that GDF-15 may stimulate angiogenesis in malignant neoplasms. However, it has not been investigated in CRC yet. The aim of our study was to determine the level of GDF-15 and the concentrations of hypoxia-inducible factor-1α (HIF-1α), VEGF-A and chemokine-like receptor 1 (CMKLR1) in tumor and margin specimens of CRC in relation to histological grade and TNM staging. The study comprised 33 samples of tumor and margin tissues obtained from CRC patients. To assess the concentration of GDF-15, HIF-1α, VEGF-A and CMKLR1, commercially available enzyme-linked immunosorbent assay (ELISA) kits were used. We found significantly increased levels of GDF-15 and CMKLR1 in tumor tissue compared to margin tissue and higher concentrations of HIF-1α and VEGF-A in margin tissue than in tumor tissue. The levels of GDF-15 and HIF-1α were significantly correlated with VEGF-A and CMKLR1 in margin tissue. In CRC, the increased level of GDF-15 might stimulate angiogenesis through upregulation of HIF-1α, VEGF A and CMKLR1 expression. Our study is the first one to reveal the correlation between the levels of GDF-15 and CMKLR1 in CRC. The elevated levels of HIF-1α and VEGF-A in tumor-free margin tissues suggest that noncancer cells in the tumor microenvironment are an important source of proangiogenic factors.

Assessment of CMKLR1 level in colorectal cancer and its correlation with angiogenic markers.

INTRODUCTION: Colorectal cancer (CRC) is the second most common malignant neoplasm in men and third in women. It is also the third leading cause of cancer-related death, killing annually >700,000 patients in the world. The global burden of CRC is expected to increase by 60% to >2.2 million new cases and 1.1 million deaths by 2030. The pathogenesis of cancer mainly depends on angiogenesis. This process plays a key role in the growth and infiltration of tumors which is essential for distant metastases. A large number of biochemical pathways is involved in the regulation of angiogenesis. As a subject of our study, we chose chemerin/chemokine-like receptor 1 (CMKLR1) pathway which is responsible for the angiogenic processes in malignant neoplasms. AIM OF THE STUDY: To assess the CMKLR1 level and the concentrations of the two markers of angiogenesis, matrix metalloproteinase (MMP)-9 and vascular cell adhesion molecule (VCAM)-1, in tumor and margin tissues of CRC in relation to histological grade and TNM classification. MATERIALS AND METHODS: The study used 47 samples of tumor and margin tissues derived from CRC patients. To determine the concentration of CMKLR1, MMP-9, and VCAM-1, we used the commercially available enzyme-linked immunosorbent assay kit. RESULTS: We found a significantly higher concentration of CMKLR1 and MMP-9 in tumor tissue compared to margin. There was no difference in VCAM-1 concentration between tumor and margin. The margin concentration of CMKLR1 was significantly correlated with that of both MMP-9 and VCAM-1. The margin concentration of VCAM-1 was correlated with that of MMP-9. Additionally, we observed that the tumor levels of CMKLR1 and MMP-9 were positively correlated with the tumor size (T parameter). CONCLUSION: CMKLR1 activity may be associated with the angiogenic process in CRC via MMP-9 activity. Further research, involving a larger sample, may verify whether chemerin/CMKLR1 axis could be considered as a suitable target in novel molecular therapies.