лукиан самосаткийThe search and application of genetic prognostic and predictive biomarkers in colorectal cancer (CRC) are aimed at identifying the characteristics of colorectal tumors for choosing a therapy strategy. The review is devoted to summarizing the achievements in scientific and clinical research on this topic.

Aim. Based on genetic and epigenetic changes in CRC to analyze and summarize the world practice of using them as prognostic and predictive biomarkers of CRC to assess the patient’s prognosis and response to therapy.

The analysis of modern literature data published in leading peer-reviewed journals in the Russian and international databases of scientific citation RSCI (Russian Science Citation Index), Medline and PubMed is carried out. The main phenotypes of the CRC pathogenesis are considered, as well as their possible functional intersections during the development of the disease. Both biomarkers already used in global clinical practice and potential promising biomarkers, including gene expression, are analyzed to identify subgroups of patients with high cancer risk at early stages of CRC. As a new approach from the perspective of personalized medicine, a set of tumor derivatives in biological media detected by liquid biopsy: circulating tumor cells, circulating DNA, microRNAs, and long non-coding RNAs is considered as biomarkers. It is noted that the joint use of biomarkers makes it possible to improve the prognosis and selection of therapeutic effects. A review of the literature confirms that modern methods of genetic analysis make a significant contribution to understanding the molecular mechanisms of CRC progression and resistance to antitumor therapy, thereby facilitating the selection of the most appropriate treatment strategy. To assess the potential of individual CRC biomarkers or biomarker panels, large-scale standardized studies and verification of these biomarkers in prospective international programs are necessary.

Epstein–Barr virus (EBV) is widespread among the human population and underlies development of numerous malignant neoplasms. The mechanism of EBV-associated carcinogenesis is based on the ability of viral proteins and microRNAs to cause genetic and epigenetic changes which can directly or indirectly stimulate cell growth, inhibit apoptosis, and protect tumor cells from the effects of their microenvironment and the host’s immune response. EBV can lead to development of such malignant neoplasms as Burkitt lymphoma, Hodgkin lymphoma, nasopharyngeal, gastric cancer, etc. The review discusses molecular mechanisms of EBV-associated carcinogenesis promoting the virus’s survival in the host’s cells, and regulating oncoproteins.

The results of more than 500 studies from the PubMed, Google Scholar, ResearchGate, Web of Science, RSCI (Russian Science Citation Index) and CyberLeninka databases performed primarily in the last 10 years were analyzed. Literature analysis has shown that EBV has a wide variety of mechanisms to avoid immune surveillance which ensures its lifelong persistence in the human body. Expression of latent proteins (in particular, EBNA1, LMP1, and LMP2A) which modulate the host’s signaling pathways, suppress apoptosis, and alter the immune response, plays the key role in its survival. Additionally, it was established that the type of latency maintained in the infected cells affects the probability of malignant transformation. For example, type II latency is characteristic of the majority of epithelial tumors, while type III is associated with lymphomas. Transition from latent to lytic phase is accompanied by expression of proteins promoting carcinogenesis. In the literature, special attention is paid to the roles of LMP1 and LMP2A oncoproteins which activate PI3K/AKT and JAK/STAT pathways disturbing regulation of cell proliferation and apoptosis. EBV-induced tumors are often characterized by epigenetic changes supporting persistence of the virus and tumor cell growth.

Therefore, EBV is capable of extorting multifactorial effects on the host cell which makes it an important subject of cancer virology. This confirms the necessity of further studies for refinement of molecular mechanisms of carcinogenesis and development of targeted therapeutic approaches to treatment of EBV-associated tumors.

The article presents a new classification of endometrial cancer developed by the International Federation of Gynecology and Obstetrics (FIGO): FIGO 2023. Literature search was performed in the PubMed, Medline, RSCI (Russian Science Citation Index) databases using key words “endometrial cancer”, “molecular genetic study”, “FIGO 2023”, “POLE gene mutations”, “dMMR status”, “ТР53 gene”, “NSMP”. In total, 206 articles were found (published between 1983 and 2024), the more significant articles (45) were included in this literature review. The renewed FIGO 2023 classification contains 19 endometrial cancer substages: 5 are included in stage I, 3 in stage II, 8 in stage III, 3 in stage IV. The main differences of the new classification from FIGO 2009 are the specification of tumor type (aggressive/non-aggressive), level of lymphovascular involvement, presence of macro- or micrometastases in the lymph nodes, as well as characteristics of molecular and genetic markers. According to the new FIGO 2023 classification, change of stage is recommended depending on the presence of mutations in the POLE and ТР53 genes. Thus, stage IA includes tumors with favorable prognosis and mutation in the POLE gene (stage IAmPOLEmut), stage IIC includes tumors with unfavorable prognosis and mutation in the ТР53 gene (stage IICmp53abn). According to the data of trials, the identified substages – which take into account molecular profile of the tumor – significantly differ in terms of oncological outcomes of disease progression.

Therefore, introduction of the new FIGO 2023 classification taking into account molecular biology features of the tumor will allow to adopt a more targeted approach to management of patients with endometrial cancer and to make predictions on disease progression. One of the remaining important questions is further study of long-term results of adjuvant therapy.

Cells of neuroblastoma, soft tissue sarcomas, osteosarcoma, Ewing’s sarcoma and some other tumors in children and adults are able to express disialogangliside GD2. The introduction of anti-GD2 monoclonal antibodies into neuroblastoma treatment protocols has improved outcomes. Studies of the effectiveness of using anti-GD2 monoclonal antibodies in other tumors are also underway.

In this review, we describe the main cellular and molecular processes occurring during passive anti-GD2 immunotherapy in pediatric tumors, as well as the factors that can affect them. We concluded that the leading role belongs to antibody-dependent cellular cytotoxicity realized by natural killers via the classical mechanism with the induction of caspase-dependent apoptosis, as well as macrophages, neutrophils through phagocytosis, trogocytosis and direct cytotoxicity. Efficient phagocytosis is promoted by expression of calreticulin by tumor cells and LRP1 receptor by phagocytes, while expression of CD47 by tumor cells and its interaction with SIRPα on phagocytes contribute to evasion of phagocytosis. In parallel, activation of T-cell adaptive immune response occurs. The use of granulocyte and granulocyte-macrophage colony-stimulating factors can enhance cytotoxicity. Addition of exogenous interleukin 2 does not improve the effectiveness of treatment, and the use of interleukins 15 and 21 enhances cytotoxicity in vitro, which requires clinical trials. Complement-dependent cytotoxicity probably does not affect the therapeutic efficacy of passive anti-GD2 immunotherapy. Tumor microenvironment and molecular features of immunocompetent cells can affect anti-GD2-mediated cytotoxicity, especially when used in combination with programmed cell death 1 (PD-1) inhibitors, thus, further study of this issue is especially relevant. Anti-GD2 monoclonal antibodies directly reduce the proliferative activity and induce apoptosis of tumor cells by inhibiting signaling pathways (mainly PI3K/Akt/mTOR), transcription factors, focal adhesion complexes, and integrins. Mechanisms for inducing mitochondria-dependent cell death, which has signs of apoptosis and necrosis, are also probable.

Ferroptosis (FP) is a type of non-apoptotic programmed cell death associated with iron-dependent lipid peroxidation. FP is characterized by a decrease in the activity of glutathione peroxidase 4, which is necessary for the suppression of lipid peroxidation, accumulation of redox-active iron and oxidation of cell membrane phospholipids containing polyunsaturated fatty acids. FP plays a central role in the mechanisms of human aging, regulating degeneration – the main cause of tissue damage and organ failure. FP makes a significant contribution to the development of age-related pathologies, including neurodegenerative conditions, cardiovascular diseases, and cancer. Of particular interest is the participation of FP in the pathogenesis of age-related oncological diseases, including acute myeloid leukemia (AML). Previous studies show that FP largely regulates the sensitivity of AML cells to chemotherapeutic drugs, and some of the FP-related genes play a vital role in AML oncogenesis. In addition, there is considerable interest in investigating the effect of immune infiltration on FP and the prognosis of AML. Thus, an in-depth study of the unique mechanism of FP in AML may provide new insights into the diagnosis and treatment of this disease. This review analyzes the main regulatory molecular mechanisms of FP and the relationship of FP with the occurrence and development of AML. In addition, recent advances in the study of the role of FP in the prognosis and therapy of AML are summarized.

Introduction. Metastatic melanoma of the skin (mMC) is characterized by an extremely unfavorable prognosis of survival. Significant remission of mMK is associated with the use of vemurafenib, which blocks the proliferation of cells with a mutation in the BRAF gene. However, after its cancellation, relapse develops rapidly, determining the need for continued treatment. The search for another therapeutic target in the primary mMC led to a small subpopulation of stem-like CD20 antigen-expressing cells. Pilot clinical trials of CD20-blocking rituxibam did not yield the desired result, which we interpreted as a lack of control of CD20 expression in recurrent cells, which is available only in vivo in an adequate human model of recurrent mMK / BRAF⁺ with high CD20 expression.

Aim. To create an in vivo model of recurrent human mMC / BRAF⁺ with control of the representation of a subpopulation of cells with CD20 expression.

Materials and methods. Vemurafenib (Roche, Switzerland), human melanoma cell culture MelCher5k / BRAF⁺, male Balb / c nude immunodeficient mice weighing 20–23 g breeding and maintenance at the N. N. Blokhin National Medical Research Center of Oncology were used. Mice with a transplanted tumor (n = 12) were divided into 2 groups: without the drug (control) and with the drug (vemurafenib). A comparative assessment of the growth dynamics of tumor nodes in the groups was carried out according to the volume ratio using the standard T / C (treatment / control) criterion, expressed as a percentage. The dynamics of the expression of S100, CD20, and CD45 markers was evaluated by flow cytofluorometry before the start of vemurafenib administration and at the end of follow-up.

Results. According to the data obtained, in mice with MelCher5k / BRAF⁺ treated with vemurafenib from days 7 to 21, tumor reduction was observed from day 10 with complete remission by day 20. Relapses with the development of a tumor node at the implantation site (renewed growth of melanoma cells) occurred on day 28 (a week after drug withdrawal), and then the tumor progressed rapidly over the course of 34–41 days. In mice treated with vemurafenib, the proportion of CD20⁺ cells in the new focus was 35 %, which was 1.82 times higher than the proportion of CD20⁺ cells in the tumor of mice not treated with this drug (19 %). At the same time, the cells of the newly emerged tumor expressed the melanoma marker S100⁺ and did not express CD45.

Conclusion. Thus, in vivo, using the MelCher5k / BRAF⁺ model, it was shown that in a recurrent tumor node developing after the use of vemurafenib, the proportion of stem-like cells expressing CD20 significantly increases. These data suggest that it is advisable to use the model to evaluate the clinical prospects of CD20-targeted agents capable of prolonging remission after vemurafenib withdrawal in patients with recurrent melanoma.

Introduction. One of the key components of cell membranes are membrane proteins, which provide a wide range of functions – from transport and signal transmission to coordination of intercellular interactions. Among them, of particular interest is the sodium-dependent phosphate transporter NaPi2b, which plays an important role in maintaining phosphate homeostasis and is characterized by an increased content in a number of tumor cells. The large extracellular domain (ECD) of NaPi2b contains the MX35 epitope, which is of significant interest in the context of the development of monoclonal antibodies for targeted therapy of ovarian and lung carcinoma. Recognition of the MX35 epitope depends on the conformation of the large ECD, which is influenced by disulfide bonds and glycosylation. Between cysteine residues C322 and C328, there is a proline residue P325, which we hypothesize may contribute to the conformation of the NaPi2b large ECD by forming a disulfide bond between C322 and C328, potentially affecting the interaction of monoclonal antibodies with the MX35 epitope.

Aim. To study the impact of the proline residue at position 325 in the large ECD of the transporter NaPi2b on the interaction of monoclonal antibodies L3(28/1) with the MX35 epitope.

Materials and methods. The human ovarian epithelial carcinoma cell lines OVCAR-8 and OVCAR-4 were used in the study. By site-directed mutagenesis, the proline residue P325 of NaPi2b was replaced with an alanine residue, resulting in OVCAR-8 cells stably expressing the mutant variant of NaPi2bp.P325A. The effect of the p.P325A substitution in NaPi2b on the interaction of monoclonal antibodies L3(28/1) with the MX35 epitope was analyzed using western blotting and laser confocal microscopy. To assess the impact of the p.P325A mutation on the formation of disulfide bonds in the NaPi2b large ECD, cysteine residues thiol groups were modified using maleimide-containing compounds.

Results. It was found that the substitution of p.P325A in NaPi2b did not significantly affect the recognition of the MX35 epitope by L3(28/1) antibodies, as shown by both western blot analysis and confocal microscopy. The number of disulfide bonds in the large ECD of the mutant NaPi2bp.P325A form was unchanged compared to wild-type NaPi2b.

Conclusion. Substitution p.P325A in the NaPi2b transporter does not have a significant effect on the recognition of the MX35 epitope by antibodies or the formation of disulfide bonds in the NaPi2b large ECD. Future studies could focus on a more detailed investigation of the roles of other substitutions in the NaPi2b large ECD and their influence on the epitope’s accessibility to antibodies.

Introduction. The use of hypomethylating agents in the treatment of acute myeloid leukemia has increased overall patient survival by 12 %. However, alongside their potent antitumor effect, hypomethylating agents negatively impact genome stability due to the transposition of activated LINE1 elements, which contributes to the short duration of remission. Since LINE1 retrotransposition requires the ORF2-encoded reverse transcriptase, homologous to the retroviral enzyme, we proposed combining hypomethylating agents with a non-nucleoside inhibitor of this enzyme to reduce the genotoxic effects of 5-azacytidine.

Aim. To evaluate the effect of efavirenz on 5-azacytidine in cultured acute myeloid leukemia cells regarding: сytotoxic activity, expression of long interspersed nuclear elements (LINE1), the level of genetic instability.

Materials and methods. The study was conducted on THP-1 and KG-1 acute myeloid leukemia cell lines. 5-Azacytidine (hypomethylating agents) and efavirenz (reverse transcriptase inhibitor) were used. Cytotoxicity was assessed via the resazurin assay, apoptosis and necrosis rates were measured by flow cytometry, LINE1 expression was quantified using real-time polymerase chain reaction, and DNA damage was evaluated via the comet assay.

Results. Efavirenz did not affect the cytotoxicity of 5-azacytidine. Immunofluorescence staining of LINE1-encoded ORF1 protein and flow cytometry confirmed that efavirenz did not alter LINE1 expression levels. However, comet assay data indicated that combining 5-azacytidine with efavirenz reduced its genotoxic effects.

Conclusion. Our findings demonstrate, for the first time, the potential of a novel acute myeloid leukemia treatment strategy combining hypomethylating agents with reverse transcriptase inhibitors.

Introduction. Due to the ambiguous role of neutrophils in carcinogenesis, it is relevant to study their phenotypic transformation and subpopulation composition that determines protumor (CD15⁺CD66b⁺) or antitumor (CD62L⁺CD63⁺) potential.

Aim. To assess the dynamics of CD15⁺CD66b⁺ and CD62L⁺CD6⁺ circulating neutrophil subpopulations in patients with benign neoplasms and during the progression of kidney cancer.

Materials and methods. The study focused on circulating neutrophils from patients with benign neoplasms and kidney cancer. The phenotype of monopopulations (CD15⁺, CD66b⁺, CD62L⁺, CD63⁺, CD95⁺) and subpopulations (CD15⁺CD66b⁺, CD62L⁺CD63⁺) of neutrophils was assessed using flow cytometry (BioSino, China). Statistical analysis was performed using Statistica 13 and Jamovi 2.3.28.

Results. A significant increase in the number of CD15⁺, CD62L⁺, and CD66b⁺ neutrophil monopopulations, as well as in the number of CD15⁺CD66b⁺ neutrophils, was observed in the groups of patients with benign kidney tumors and kidney cancer compared to the control group. In patients with benign renal tumors, the percentage of CD62L⁺CD63⁺  neutrophils was three times higher than in patients with stage I–II kidney cancer, and twice as high as in those with advanced kidney cancer. According to the Cox regression model, changes in the numbers of CD15⁺CD66b⁺ and CD62L⁺CD63⁺  neutrophils, alongside an increase in leukocyte count, serve as prognostic markers of kidney cancer in patients over 68 years of age.

Conclusion. The number of circulating neutrophils with a protumor phenotype (CD15⁺CD66b⁺) increases even at the stage of benign kidney neoplasms compared to controls and remains elevated throughout all stages of carcinogenesis. Meanwhile, the number of circulating neutrophils with an antitumor phenotype (CD62L⁺CD63⁺) significantly increases in benign renal neoplasms but decreases during cancer progression. Assessment of the circulating neutrophil phenotype may help predict the risk of kidney neoplasms.

Introduction. Some cytostatic drugs are based on the compounds of plant origin. Development of the new plant metabolites-derived antitumor drugs is an actual and perspective trend in oncology. Recently we isolated a compound from the rhizome of Petasites hybridus (L.) and identified it as a corynan-like indole alkaloid P1.

Aim. To identify of the possibility of the Petasites hybridus (L.)-derived alkaloid to bind with molecular targets mediating carcinogenesis and tumor growth and the assessment of its effect on tumor and normal cell cultures.

Materials and methods. The research was performed in silico by molecular docking and in vitro by cultural methods. Molecular docking of alkaloid Р1 with receptors of epidermal growth factor (EGFR), platelet growth factor (PDGFR), MET, MRP2 and NOX4 was carried out using software AutoDock Vina 4.0. The docking area grid was built in AutoDockTools 1.5.7. Cultural experiments were performed on tumor cell line highly expressing EGFR (Н1299) and normal lung fibroblasts. Cells were cultured with various concentrations of the alkaloid, their viability was assessed in ХТТ-test and by direct count of alive and dead cells.

Results. Maximal binding energy of alkaloid Р1 with molecular targets was noted for МеТ (–8,6 kcal/M), minimal – for NOX4 (–5,9 kcal/M). Binding energy of alkaloid Р1 with EGFR was –6,4; with PDGFR –7,2; with MRP2 –6,3 kcal/M. Binding of alkaloid P1 occurred with the amino acid residues of the active centers of the majority of the studied receptors. Alkaloid showed the ability to inhibit the growth of H1299 cell line (lung adenocarcinoma) in the wide range of concentrations more actively than of normal fibroblasts: half-maximal inhibitory concentration for P1 was 127,24 and 256,29 μM/l respectively. Maximal difference of the dead cells amount between H1299 line and fibroblasts was observed in alkaloid concentrations 21,7–87 μM/l, but, in spite of some signs of mitotic failure (multinucleate and giantnucleate H1299 cells) mitotic index did not change.

Conclusion. Alkaloid isolated from the rhizome of Petasites hybridus (L.) is able to bind with the targets mediating tumor growth and impairs lung adenocarcinoma Н1299 cells. Further research is necessary for detailed study of its` antitumor effect in in vitro and in vivo models.