Mariia S. Tretyakova

Background: Preventing metastasis is important for improving the survival rates of patients with non-small-cell lung cancer (NSCLC). Our previous investigation suggested that premalignant epithelial changes in small bronchi distant from the primary tumor serve as predictive markers of NSCLC metastasis. Specifically, isolated basal cell hyperplasia (iBCH) is associated with a high risk of distant metastasis, whereas basal cell hyperplasia combined with squamous metaplasia (BCH + SM) correlates with a low risk of distant metastasis. Methods: This exploratory study included patients enrolled both retrospectively and prospectively. A total of 83 NSCLC patients were stratified into two groups: iBCH (high metastatic risk, n = 59, including 37 metastatic events) and BCH + SM (low metastatic risk, n = 24, including 6 metastatic events). Paired peripheral blood and tumor samples from NSCLC patients with iBCH and BCH + SM were subjected to whole exome sequencing. Bioinformatic analysis included tumor mutation quantification, detection of regions with enriched mutations, mutational signatures profiling, and evaluation of metastasis-free survival and hazard ratio modeling. Results: Patients with iBCH were characterized by a higher prevalence of single nucleotide variants and a lower frequency of frameshift mutations. Single-nucleotide indels (mainly insertions) were more frequent in patients with BCH + SM. Additionally, ID1, ID3, ID11, and ID13 mutational signatures were significantly enriched in patients with BCH + SM. Moreover, the combination of SBS3, SBS4, DBS1, DBS2, DBS6, ID8, and ID23 signatures was linked to distant metastasis in NSCLC patients. Finally, a multivariable logistic regression model for assessing the probability of distant metastasis in NSCLC was developed based on the histological subtype, the bronchial lesion, and mutational signature. Conclusions: NSCLC with high and low risk of distant metastasis defined by bronchial lesions have specific mutational landscapes.

Introduction. In recent years, a rising incidence of oral cancer (OC) has been observed among young adults without traditional risk factors (smoking, alcohol consumption, and human papillomavirus infection). An aggressive clinical course and a high recurrence rate are observed in patients of this age group. Therefore, there is a growing need to identify novel molecular alterations that could elucidate the mechanisms driving the disease progression. Previously, we identified mutations in the EPHB6 gene associated with early-onset OC recurrence. Aim. To evaluate the effect of EPHB6 knockdown on the functional characteristics of OC cells in vitro. Materials and methods. The OC cell line Cal-27 was used in this study. Gene knockdown was induced using small interfering RNAs. Results. EPHB6 knockdown resulted in a 90 % reduction in gene expression relative to the control, which was accompanied by alterations in cellular functional properties, including inhibition of migration and invasion, as well as reduced tumorigenic capacity in three-dimensional cultures. Conclusion. These findings shed light on the potential mechanisms by which EPHB6 contributes to early-onset OC progression.

Relevance. Oral cancer is one of the most common cancers among neoplasms of the head and neck. Oral cancer is characterized by a poor prognosis, a lack of specific biomarkers and highly effective targeted treatment. Experimental model systems are needed to study oral cancer pathogenesis and develop new treatments. Understanding the molecular features of oral cancer represents one of the key steps in developing new therapeutic strategies. A wide range of biological models is currently available, but their versatility is limited. Experimental models for studying oral cancer have evolved from cell cultures to in vivo systems that mimic pathological processes and the tumor-stroma interactions. Here, we summarized the available information on the current state of experimental oral cancer systems. In vitro models include immortalized and primary cell lines, spheroids and organoids, whereas in vivo models are represented by syngeneic and xenogeneic models, immunocompromised, immunocompetent, humanized, and genetically engineered animals. In vitro models are effective in studying the biology of oral tumors and evaluating the effectiveness of therapy due to high reproducibility and speed of obtaining results. Existing cell lines are widely used for fundamental and translational research and serve as a crucial component in preclinical trials. In vivo models are used in phase II of preclinical research in drug development and thus represent a transitional stage to clinical trials. Conclusion. Despite significant progress in the development of variousexperimental models, each of them has its own advantages and limitations. There is no universal model that allows for the complete extrapolation of the obtained results to the human body. Therefore, when planning research, it is crucial to select carefully the most suitable biological models based on the objectives at hand.

Cellular plasticity, a critical feature of embryonic development, is often reactivated in cancer, enabling tumor cells to acquire stem-like properties and facilitate uncontrolled growth. This study compares cellular plasticity in cancer and early human development by integrating single-cell data from three cancers and embryoid bodies. The analysis identifies a shared, highly proliferative progenitor-like state, driven by an E2F-TFDP transcriptional axis and enriched in key cell-cycle regulators UBE2C , TOP2A , BIRC5 , and NUSAP1 . Functionally linked to cell-cycle progression and DNA repair, this state acts as a lineage hub within tumors. Spatial transcriptomics revealed that this state is enriched in lung adenocarcinoma and in lung tissue with basal cell hyperplasia, a potential precursor to squamous cell carcinoma. Validation across eight cancer types demonstrates a prevalence of this program in tumors versus normal cells. Collectively, these findings define a conserved mechanism of tumor plasticity with potential for early detection and targeted therapy. Abstract Figure:

A personalized approach is a priority in the diagnosis and treatment of cancer. Accurate diagnostic tests for assessing the tumor’s molecular characteristics and optimizing the treatment strategy are essential for effective personalized treatment. Multigene NGS panels simultaneously detect a variety of genetic disorders, including single nucleotide substitutions, insertions and deletions, DNA copy number variations, translocations, microsatellite instability, and tumor mutational burden. This is crucial for selecting targeted therapy and immunotherapy, assessing prognosis, and monitoring the progression of cancer. This review discusses the evolution of precision oncology in the 21st century, the possibilities and advantages of NGS in molecular oncology, the technical and analytical characteristics of various multigene NGS panels with both amplification-based and hybridization-based enrichment, and their clinical applications in molecular diagnostics. The review focuses specifically on existing Russian and international NGS technologies. It examines available Russian and international multigene NGS panels, including problems of their application in routine cancer care in Russia.

Diagnosis and selection of effective therapy of soft tissue sarcomas (STS) are complicated by low incidence and significant histological variability of these tumors. Development of molecular and genetic testing methods is aimed at improving differential diagnosis of different types of STS and identification of genetic abnormalities which can potentially serve as targets for therapy. Development of effective treatment methods requires adequate preclinical models capable of recreating biological features of the tumors. The article presents molecular and genetic testing methods for STS diagnosis and therapy, advances in in vitro STS models, problems with their use in preclinical studies, as well as possibilities of using primary cell cultures for personalized treatment.

The objective of the study: to identify current strategies, achievements, and challenges in developing HER2-targeted therapeutic conjugates and assess clinical outcomes of therapies based on them.Material and Methods. A total of 247 publications over the past 7 years were analyzed. Finally, 60 were selected for the review. The sources were searched in Scopus (n=35), PubMed (n=321) and WOS (n=91) databases. Electronic resources, such as PubMed Central (PMC), ScienceDirect and ResearchGate were used to obtain the full-text articles.Results. The therapeutic potential of HER2-targeted conjugates has been confirmed in clinical trials for drugs, such as trastuzumab emtansine (T-DM1, Kadcyla®) and trastuzumab deruxtecan (T-DXd, Enhertu®). The development of new HER2-targeted conjugates involves several approaches to improve drug characteristics and therapeutic efficacy: increasing binding affinity to the target, simultaneous blocking of two HER2 domains, various mechanisms of cytotoxic effects on tumor cells (inhibition of tubulin, RNA polymerase II, and DNA topoisomerase I), enhancing the ratio of cytotoxic agents per antibody molecule and improving the conjugate stability in the bloodstream. Trastuzumab duocarmazine (SYD985), disitamab vedotin (RC48, Aidixi®), zanidatamab zovodotin (ZW49), ARX788 and MRG002 are all currently being studied in clinical trials.Conclusion. Improvements in the design and understanding of drug-tumor interactions contribute to new clinical advances that may provide not only a survival advantage over traditional therapy, but also significantly improve the quality of life of patients with HER2-positive tumors.

Relevance. Non-small cell lung cancer (NSCLC) is the leading cause of cancer-­related mortality worldwide due to the high recurrence and metastasis rates. It is generally accepted that metastases and recurrences are formed by tumor cells with a highly invasive, stem and chemoresistant phenotype. Tumor hybrid cells (THCs) formed by the fusion of tumor cells with a wide range of normal cells: macrophages, fibroblasts, mesenchymal stem cells, etc. are considered to be potential metastasis and recurrence-­initiating cells. However, the phenotypic diversity of THCs, and their association with disease progression remain poorly understood. The aim of the study was to characterize the population composition of THCs in NSCLC and its association with clinicopathological characteristics, metastasis and recurrence. Materials and Methods. A total of 50 patients with NSCLC were included. Fresh frozen samples of tumor tissue obtained during resection and morphologically verified were used to analyze types and number of THCs. THCs were analyzed by flow cytometry in primary tumors using markers for tumor cells, cancer stem cells, leukocytes, macrophages and fibroblasts. Results and Discussion. THCs were detected in all NSCLC patients. Most THCs demonstrated leukocyte, macrophage and stem characteristics. The number and frequency of THCs depended on neoadjuvant chemotherapy. THCs with leukocyte and stem cell markers (pan-­CK+CD45+CD44+CD73+) were associated with locoregional recurrence, whereas THCs with macrophage and stem cell markers (EpCAM+CD45+CD44+CD73+CD163+) — with distant metastases. Conclusion. This study is the first to comprehensively describe the population composition of THCs in NSCLC, their association with clinicopathological characteristics, neoadjuvant chemotherapy and disease prognosis. Detection of prognostically relevant THCs could be an effective approach for predicting the risk of metastasis and recurrence of NSCLC and the basis for the development of therapy focused on the prevention of cancer progression.

The aim of this work was to study the immunomodulatory effects of lithium salt gamma-lactone of 2,3-dehydro-Lgulonic acid (LiAc) on healthy blood leukocytes and leukemia cells in vitro.Materials and methods. Peripheral blood lymphocytes and neutrophils obtained from healthy donors, as well as THP-1 cells (human monocytic leukemia) were used as test systems. To assess the proliferative activity, lymphocyte blast transformation was used. The antiproliferative effect was studied by the 3H-thymidine incorporation assay. Cytotoxic effects were studied using the Alamar Blue test. The effect on the phagocytic activity was studied using the method for assessing the neutrophil function during bacterial phagocytosis.Results. LiAc exerted a dose-dependent effect on target cells, including antiproliferative and cytotoxic effects on leukemia cells and a stimulating effect on neutrophils in phagocytosis.Conclusion. LiAc can be considered as a promising drug with immunomodulatory effects, including a suppressive effect on the proliferative activity of leukemia cells and a stimulating effect on immune mechanisms mediated by neutrophils and macrophages.

Soft tissue sarcomas are rare tumors (about 1 % of all malignant neoplasms) and include more than 70 histological subtypes, the pathogenetic features of which remain unclear. This is largely due to both quantity and volume of clinical material and high heterogeneity of the disease. Given the rarity and heterogeneity of each individual subtype of soft tissue sarcoma, there is an urgent need to develop universal model systems to understand the molecular changes that determine tumor biology. Such systems include CDX models (cell line-derived xenograft), created from cell lines, PDX (patient-derived xenograft), obtained from primary tumor/metastasis cells, both a whole fragment of surgical material and from a cell suspension; humanized animals containing various human immune cells, and GEM (genetically engineered mouse) models, which are created through transfection of genetic changes characteristic of different subtypes of soft tissue sarcomas. To create these systems, not only widely available mouse models are used, but also other animals, such as fish (Danio rerio) , rats, pigs, and dogs. Another important goal of using animal models is to screen the effectiveness of modern drugs. To date, treatment of various subtypes of soft tissue sarcomas is based on standard protocols of chemotherapy (doxorubicin, epirubicin, dacarbazine, ifosfamide) and surgical resection. In the case of inoperable forms or late stages of soft tissue sarcomas, animal models are a potential tool in predicting the effectiveness of therapy and personalized selection of treatment regimens. In this regard, studies of the mechanisms of targeted action on specific molecules and the use of humanized animals for the development of new approaches to immunotherapy are of particular relevance. The current review discusses animal model systems of the three most common types of soft tissue sarcomas: liposarcomas, undifferentiated pleomorphic and synovial sarcomas, as well as the use of these models to find new therapeutic solutions. Conclusion. Currently, PDX and GEM models are widely used to identify molecules and signaling pathways involved in the development of sarcomas, identify tumor-initiating cells, and assess the chemoresistance of known drugs and new drugs at the level of the entire tumor ecosystem. However, the key problems of animal models of soft tissue sarcomas remain changes in their composition and phenotype compared to the original tumor, poor survival of surgical material, and lack of cellular immunity in immunocompetent models, high cost, and the length of time it takes to create and maintain the model. A solution to one of the problems may be the use of humanized animals with PDX, which implies the presence in the model of immune, stromal and tumor components that are as close as possible to the human body.