Evaluation of natural killer cell activity in solid and hematologic neoplasms

In recent years, the use of immunotherapeutic agents in current cancer therapies has been a promising method. Although the immune system shows its effectiveness against cancer as a whole, some immune system cells come to the forefront in the destruction of cancer cells by different mechanisms. Natural killer (NK) cells, one of these cells, have the ability to directly kill virus infected cells and tumor cells. It has been shown that changes in the functions of NK cells may be observed in cancer patients. These changes in the functions of NK cells suggest that these cells are important in the prognosis and treatment responses of different types of cancer. In this study, we aimed to investigate the relationship between NK cell activity and cancer types and stage. In our study; Three patients (lung cancer, breast cancer, hematological neoplasm) and healthy volunteers were included in the study. An average of 5 ml blood and heparin tubes were obtained from patients and healthy subjects. Immunophenotyping and NK cell activity were measured in blood samples. In immunophenotyping, monoclonal antibodies composed of CD3-FITC, CD16-PE CD56-PC5 and CD45-KO were used. Peripheral blood mononuclear cells (PBMC) were obtained from the blood samples taken for measurement of NK activity by the ficoll-hypaque method. NK cell activity was measured by two separate methods. The first method involves the killing of NK cells K562 leukemia cells (Dio-PI method), n the second method, expression of CD107a on the stimulated NK cells was measured. In our study, no statistically significant difference was found between the types of cancer and the types of cancer and NK cell activity by using two different methods. However, NK cell activity, which was evaluated by CD107a expression, was found to be quite high in lung cancer patients. NK cell activity was significantly higher in lung cancer patients. NK cell percentage was higher in patients with multiple myeloma than in the other groups, but the activities were lower than those in the other two cancer groups. There were no statistically significant differences between the groups and it was thought that the number of subjects in the groups was low and the distribution was heterogeneous. The results of our study need to be confirmed by working with larger and homogenous patient and control groups. Key Words: Cancer, Natural Killer Cell, CD107a, K562