The review is devoted to the analysis of the mechanism of NETosis and the formation of extracellular traps by neutrophils. Neutrophil traps are DNA strands, histones and proteins that are involved in autoimmune diseases, COVID-19, as well as in the pathogenesis of other non-communicable diseases. Based on the literature data, the role of NETosis in the development oncological diseases is analyzed. Two types of neutrophils have been characterized: low-density neutrophils and high-density neutrophils. In particular, the significance of this phenomenon in the progression and metastasis of the cancer. A detailed study of this issue will be useful both from a fundamental standpoint regarding the disclosure of the mechanisms of the metastatic cascade, and from a practical point of view for the development of new immunotherapeutic approaches in the treatment of metastatic tumors.

Oncological diseases are one of the most significant medical and social diseases in most countries of the world. Over the past decades, the search and development of new drugs, treatment regimens and methods of molecular diagnostics of malignant neoplasms remains relevant. In turn, an important goal of molecular genetic research is to suppress the expression of genes responsible for the development of tumors. The key targets taken into account in the development of antitumor drugs are proteins involved in carcinogenic changes in the cell. One of the promising molecular targets for the development of medicinal compounds in targeted therapy of tumor diseases is poly(ADP-ribose)polymerase 1 (PARP1). A potential way to inhibit PARP1 even at the stage of protein translation is RNA interference due to small interfering RNAs (siRNAs). For the penetration of siRNAs into the target cell, it is necessary to develop a method of their transportation controlled in space and time. An actual direction for solving this problem is the use of highly stable porous silicon-based nanoparticles. In the current study, in order to increase the functionality of nanoparticles, their surface was modified with various agents (functionalization), providing increased efficiency of drug loading and more uniform release.

Despite their B cell origin, Reed-Berezovsky-Sternberg tumor cells (RBS) in classic Hodgkin's lymphoma (cHL) demonstrate an absolutely unique phenotype. Immunohistochemistry of RBS cells is positive for CD15 antigen in most of cases, CD30, PAX-5; they do not express the T cell antigen CD3, В cell CD19, and in most cases are negative for the B cell antigen CD20, as well as for common leukocyte antigen CD45. Taking into account such unequivocal immunophenotype, RBS cells can be identified by multiparameter flow cytometry. Thus, J.R. Fromm et al. (2006, 2014) have convincingly shown the possibility to identify RBS cells in a puncture and/or biopsy sample of lymphatic nodes in cHL and were of the fair opinion that such rather simple and reproducible technique as flow cytometry could be an additional diagnostic instrument in cHL. We have tested the technique proposed by J.R. Fromm et al. for the assessment of lymphatic node involvement in cHL and used 8 to 10-parameter flow cytometry for detection RBS cells in cHL in 8 biopsy samples of a lymphatic node, and confirmed the feasibility to identify RBS cells by high performance flow cytometry. We also performed morphological and immunohistochemical assessment of the biopsy samples of lymphatic nodes from patients with suspected cHL. The study included clinical cases with immunohistochemically confirmed cHL (n = 8), and the control samples were from those with other diagnoses than Hodgkin's lymphoma. In all cases of cHL we found RBS cells. In future we plan to analyze larger case samples by flow cytometry.