Gastric cancer increase the percentage of intermediate (CD14++CD16+) and nonclassical (CD14+CD16+) monocytes

Introduction: Gastric cancer is one of the most common malignancies diagnosed worldwide. Despite therapeutic options, prognosis is unfavorable, particularly when dealing with an advanced stage carcinoma. Similarly to other malignancies, the development of gastric cancer is associated with increased macrophage infiltration. Monocytes are peripheral blood precursors of tissue macrophages. In the relation to the expression of CD14 and CD16 receptors, human peripheral blood monocytes can be divided into: "clasical monocytes" CD14++CD16-, intermediate monocytes CD14++CD16+ and non-classical monocytes CD14+CD16+. However, little is known about monocytes involvement in the regulation of immune response in patients with gastric malignancies. Material and methods: In this study, the phenotype of peripheral blood monocytes was determined in patients with gastric tumors by flow cytometry. We also analyzed the level of interleukin 10 (IL-10) and tumor necrosis factor alpha (TNF-alpha) production after 24 h stimulation of peripheral blood mononuclear cells with lipopolysaccharide. The results obtained in group of gastric cancer patients were compared to those of age-matched group of healthy individuals. Results: We observed a significant decrease in percentage of monocytes in the peripheral blood of gastric cancer patients as compared to healthy donors. Moreover gastric cancer patients shows a significant decrease of CD14++CD16- monocytes subpopulation and an increase in CDI4++CD16+ and CD14+CD16+ monocytes subpopulations as compared to healthy volunteers. In stomach cancer patients we also have observed increased production of IL-10 as compared to controls. Conclusions: In summary, this study has revealed that gastric malignancies significantly modulate the phenotype of peripheral blood monocytes giving them anti-inflammatory properties. Therapeutic targeting of anti-inflammatory monocytes in the peripheral blood could modulate the complex activities of macrophages in tumor environment.