Enzymatic activity of blood serum, abzyme activity of IgG and IgA, free serum DNA and the formation of extracellular traps by neutrophils in patients with breast neoplasms

Abstract

The objective of this study included a comprehensive comparative assessment of the proteolytic, nuclease and oxidoreductase activity of serum and immunoglobulins of G and A classes, as well as the serum DNA content in patients with mammary neoplasms and the ability of their leukocytes to form neutrophil extracellular traps (NETs). To aim this, the following methods have been developed: a combined method for isolating IgG and IgA from a single serum sample, the method for fluorescent determination of serum DNA, the method of staining NETs in the culture of neutrophils with methyl green, and the method of double staining of NETs in tumor smear-imprints. Based on the results of the study it was shown that the abzymes isolated from blood serum possess proteolytic, DNase and oxidoreductase activity, which varies depending on the patient and the conditions of the reaction. Certain types of catalytic activity of serum and antibodies are different in patients with malignant and benign breast tumors, as well as in healthy individuals. Catalytic activity of serum and abzymes depends on the tumor grade as well as on histological and immunohistochemical characteristics of the tumor. Concentration of DNA in serum of breast cancer patients is reduced in comparison with healthy individuals; a negative correlation was established between the DNA content and DNase activity of sera and abzymes. The ability to form traps by neutrophils in breast cancer is significantly higher in comparison with the examined control groups (patients with benign breast tumors and healthy individuals). This finding may be used as an additional laboratory marker of the development of the tumor process in the mammary gland in women.