The Expression of Natural Killer Group 2D Molecule on Peripheral Blood T-lymphocytes in Metastatic and Non-metastatic Colorectal Cancer Patients in Comparison to Healthy Controls

Background: T-lymphocytes are considered as the most important immune cells fighting against various cancers. These cells are activated by different co-stimulatory receptors such as natural killer group 2D (NKG2D) molecules. Besides being stimulated via antigen-specific T-cell receptors, T-lymphocytes are further activated by NKG2D molecules. Up to now, the expression of NKG2D molecules has not been studied in various stages of colorectal cancer. Methods: In this study, peripheral blood samples of 18, 15, 11, and 10 individuals were obtained in control, low-grade non-metastatic, high-grade non-metastatic, and metastatic groups, respectively. The ratio of NKG2D expressing T-cells and the mean florescent intensity of NKG2D on these cells were evaluated in study groups by flow cytometry. Findings: There was no significant difference among the patients of low-grade non-metastatic, highgrade non-metastatic, and metastatic groups in comparison with the control subjects. Conclusion: Regarding the role of NKG2D molecules in T-cell activation, further studies are needed to explain our findings of not significant difference between various stages of colorectal cancer and healthy controls.