Vladislav V. Kononchuk

Vitamin D deficiency is associated with the risk of atopic diseases and respiratory infections. The activated vitamin D receptor (VDR) forms a dimer with the retinoid X receptor alpha (RXRA) and binds to VDR/RXRA composite elements (CEs) in enhancers of target genes. However, VDR/RXRA CEs are identified in only 11.5% of cases in ChIP-Seq peaks. Our hypothesis was that VDR could form a VDR-Partner complex with transcription factor for which CEs have not yet been identified. We utilized Web-MCOT to search for novel VDR/Partner CEs in regulatory DNA. The potential formation of the VDR-Partner protein complex was assessed using the AlphaFold machine learning model. Through real-time RT-PCR, we measured the expression of immune system genes in a culture of U937 macrophage-like cells incubated with the active metabolite of vitamin D, calcitriol. We have predicted novel VDR/NR2C2 and VDR/PPARG CEs in the regulatory regions of immune system genes. We found potential synergism of VDR/NR2C2 and VDR/RXRA CEs in relation to the IRF5 gene, as well as potential synergism of VDR/PPARG and VDR/RXRA CEs for MAPK13. Predicting new regulatory relationships through the identification of new potential VDR/Partner CEs may provide insight into the deep mechanisms of vitamin D involvement in the pathogenesis of atopic dermatitis, bronchial asthma, allergic rhinitis, and pulmonary infections.

Tyrosine protein kinase HER2 plays an important role in carcinogenesis. In breast cancer (BC), the HER2 gene is amplified in approximately 20% of cases. Trastuzumab is used to treat BC with HER2 gene amplification. Trastuzumab is not effective in treating tumors with low HER2 expression, but trastuzumab deruxtecan was recently found to significantly improve prognosis in these patients. Nonetheless, there are still difficulties with accurate diagnosis of HER2-low BC, especially at the preoperative stage. In this study, when comparing the results between core needle biopsies and resection specimens using three immunohistochemistry scores (0, 1+, and 3+) of the HER2 protein level, we observed only moderate agreement (66.2%, κ = 0.486) in patients who did not undergo neoadjuvant therapy (n = 71). Other miRNA- or protein-coding genes regulated by HER2 signaling pathways may be additional markers for the scoring of the HER2 level. We measured levels of HER2-regulated miR-378a, -205, and -21 and mRNA levels of their target genes TRPS1, ITGA2, BCL6, and PTEN in BC surgical specimens. For estrogen receptor-positive BC (n = 64), we confirmed that the expression of miR-21, miR-378a, TRPS1, PTEN, and BCL6 is associated with the HER2 protein level. Moreover, the expression profile of miR-378a, BCL6, and PTEN differed between HER2 1+ and HER2 3+ tumors. TRPS1 expression was significantly higher in HER2 3+ tumors compared with HER2 0 tumors, but there was no difference in the amount of TRPS1 mRNA between HER2 1+ and HER2 3+ tumors. Thus, an analysis of the expression of miR-21, miR-378a, TRPS1, PTEN, and BCL6 may help to distinguish between HER2-negative, HER2-positive, and HER2-low BCs.

Introduction. Despite modern advances in research into the risk of development, immunological control and treatment options for lung cancer (LC), it is the leading cause of death from cancer. Tobacco smoking remains the predominant risk factor for the development of lung cancer, especially one of its aggressive subtypes, squamous cell lung cancer (SCLC). Benzo[a]pyrene, a component of cigarette smoke, promotes the activation of the aryl-hydrocarbon receptor (AhR). AhR regulates the expression of many oncogenes, including PD-L1, the positive status of which is an indication for immunotherapy, one of the main treatment strategies for SCLC. However, to improve the effectiveness of treatment of SCLC, further search for new diagnostic, prognostic and therapeutic markers is necessary. MicroRNAs (miRs), which are highly stable and present in biological fluids, can act as such markers.Objective. Search for microRNAs that could potentially serve as diagnostic markers or therapeutic targets for SCLC. For this purpose, microRNAs were selected whose promoter regions contain AhR binding sites or whose target is PD-L1.Materials and methods. A biocollection of tumor and conditionally normal lung tissue samples (n = 40) was collected at the thoracic department of the Novosibirsk Clinical Oncology Dispensary. The relative levels of selected miRNAs were examined using real-time reverse transcription-PCR (RT-PCR) technique.Results. The levels of miR-342 and miR-181a in SCLC tissues were reduced by 3 times relative to conditionally normal tissue. The expression of miR-181a and miR-155 is associated with tumor size (lower levels in tumors larger than 3 cm) and the presence of metastases in the lymph nodes (3- and 2-fold lower levels in cases with metastases). The level of miR-146a decreased by 3 times in patients with metastatic lesions of lymph nodes. A significant relationship between the levels of miR-93, miR-181a and miR-155 and the expression status of PD-L1 was also found.Conclusions. The expression profile of miR-146a, miR-93, miR-181a and miR-155 differs in SCLC patients depending on PD-L1 status and the presence or absence of lymph node metastases.

Aim. To assess the level of microRNA (miR) -21, -22, -126, -221 in patients with coronary artery disease (CAD) with borderline coronary artery stenosis depending on comorbidities and sex.Material and methods. We examined 37 patients with class 1-3 stable CAD aged 49-59 years with borderline (40-70%) coronary artery stenosis. The relative level of miRNA was determined using real-time polymerase chain reaction. Statistical analysis was performed using the non-parametric Mann-Whitney U-test. PResults. The miR-221 level was higher in the group of patients with stable CAD with borderline coronary artery stenosis with a metabolically unhealthy obesity (MUO) phenotype, but without diabetes (p=0,042). The level of miR-22 and miR-126 was higher in the group of patients with stable CAD phenotype with borderline stenosis and diabetes (p=0,007 and p=0,034, respectively). The analysis of miR levels in stable CAD patients depending on sex, without taking into account the phenotype, found that miR-21 and miR-221 values were higher in men (p=0,021 and p=0,014, respectively). The study of the sex characteristics of miR content in relation to different phenotypes revealed an increase of miR22 levels in men with MUO and diabetes (p=0,048) and an increase of miR-126 levels in women with concomitant diabetes in the comparison both with patients without MUO and diabetes (p=0,018), as well as with MUO and without diabetes (p=0,007).Conclusion. The study of the miRNA level in patients with CAD with borderline coronary artery stenosis is of great interest and reflects a promising direction in diagnosis based on comorbid pathology.

The purpose of the study was to mine, compile and analyze the published data on breast cancer (BC) systematization, diagnosis and treatment. In the current review, modern approaches in BC subtypes diagnosis based on genomic profiling, miRNA expression pattern analysis, SNP analysis in BRCA1 and BRCA2 genes, as well as proteomic mapping as essential components of the disease peculiarities improving the prognostic outcome were compiled and analyzed. Further, tumor-initiating stem-like cells as a factor affecting both prognosis and treatment choice for BC are considered and evaluated. And finally, modern principles of enhancing tumor sensitivity to therapeutic effects of anticancer drugs, which comprise the use of cytostatics in condensed modes, combining drugs, which exert different mechanisms of cytotoxicity, as well as the introduction of new chemotherapy drugs into therapeutic practice, including those targeted against the common metabolic pathways both in stem-like and committed breast cancer cells, are compiled and discussed. The analysis indicates that the current paradigm in BC treatment is development and implementation of the newest methods for diagnosis of BC sybtypes, which, being combined with those already implemented, would allow the administration of treatment according to the individual peculiarities of a tumor.