Functional activity of natural killer cells in biological fluids in patients with colorectal and ovarian cancers

Abstract

Aim of the study: To compare the functional activity of natural killer cells depending on the presence of a malignant process and its dissemination.

Material and methods: The study included 20 patients with Stage IIIB, C (FIGO, 2009) ovarian cancer, 10 patients with benign ovarian tumours (BOT), and 20 patients with colorectal cancer (T2-4N0-2M0). The control group consisted of 9 healthy donors. To evaluate the number and functional activity of NK cells, multicolour flow cytometry was performed.

Results: In cancer patients, the relative number of activated NK cells secreting granzyme B (GB) (CD56+CD107a+GB+PF-) was significantly decreased, and the proportion of degranulated NK cells (CD56+CD107a+GB-PF-) was significantly increased, compared to those observed in healthy donors. The total number of NK cells in peripheral blood was low in ovarian cancer patients (p < 0.05). The proportion of activated peripheral blood NK cells containing cytolytic granules GB and perforin (PF) in colorectal cancer patients increased with tumour growth. However, lymph node metastasis did not affect the content and activation of NK cells. Comparative analysis of NK-cell populations in patients with benign and malignant ovarian tumours revealed that the level of CD56+ cells was significantly higher in ascites than in peripheral blood. However, CD56+CD107a+ activated cells and CD56+CD107a+GB+PF+ cells were found more frequently in ascites of BOT patients than in ovarian cancer patients. The degranulated population of NK cells (CD56+CD107a+GB-PF-) was mainly observed in the peripheral blood of ovarian cancer patients.

Keywords: Colorectal cancer; ascites; functional activity; natural killer cells; ovarian cancer; peripheral blood.

Fig. 1

The flow cytometry gating for NK-cell populations from peripheral blood and ascites in patients with ovarian cancer. Figure provides a representative dot plots gating for ascitic fluid and peripheral blood. Part A presents a lymphocyte gate on a forward scatter/side scatter plot for samples from peripheral blood. Part E selects CD45+ cells as leucocytes for following gates of cells obtained from ascites. Parts B, F show the gates of CD45+CD56+ cell as NK. Part C, G select CD56+CD107a+ cells detected as activated NK. Parts D and H show the production of cytotoxic molecules perforin and granzyme B by NK from peripheral blood and ascites, respectively