Vìsnik Dnìpropetrovsʹkogo Unìversitetu: Serìâ Bìologìâ, Medicina (Sep 2015)
White blood cells of peripheral blood with ConA-positive glycotopes in patients with chronic leukemia
Abstract
141 Tumor growth progression of blood cells occurs due to changes in their genetic apparatus, which affects not only the cells morphological characteristics, but also their functional activity which to a greater extent depends on the membrane surface structures, a significant part of which is of glycoprotein nature. Complex type N-glycans are components of surface glycoproteins in the most of leukocytes. Thus, the study of changes in carbohydrate determinants of glycoproteins on the surface of leucocytes in tumorigenesis can help to reveal the mechanisms of this process. The aim of our study was to investigate the monocytes and granulocytes cytoplasmic membrane N-glycosylation in patients with chronic leukemia. The object of the study were blood cells of patients with chronic lymphocytic leukemia (n = 12) and polycythemia vera (n = 15) aged 58–66 years. Healthy hematologic volunteers (n = 15) aged 55 to 65 years were in the control group. N-glycan exposure on monocytes and granulocytes was investigated by flow cytometer Beckman Сoulter EPICS with Canavalia ensiformis lectin – Con A conjugated with fluorescent labels. The number of dead cells was monitored by means of binding them with propidium iodide. The result has been analyzed with FC Express. According to our data, levels of ConA-positive monocytes and granulocytes were 9,9 ± 1,0% and 32,7 ± 3,2%, respectively, in peripheral blood of healthy persons. The level of ConA-positive monocytes decreased to 31,0 ± 2,3% and the number of ConA-binding granulocytes increased to 66,7 ± 3,8% in patients with chronic lymphocytic leukemia compared with the norm. The number of ConA-positive monocytes decreased 3.3 times, and the level of granulocytes interacting with Canavalia ensiformis lectin slightly increased relative to control in polycythemia vera patients. There is significant increase in Con A-positive epitopes on granulocytes in patients with chronic lymphocytic leukemia and polycythemia vera compared with the control group, and absence of any difference in Con A-positive epitopes on monocytes. 100 times increase of the number of ConA-binding glycotopes is observed on the surface of granulocytes in peripheral blood of patients with polycythemia vera, and 3,3 times increase in patients with chronic lymphocytic leukemia, which may serve as an additional marker for the diagnosing these diseases.
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