Regina R. Miftakhova

Aim : to study the composition of the intestinal microbiota in patients with ulcerative colitis, focusing on its ability to produce functionally important metabolites. Materials and methods. A metagenomic analysis of stool samples from patients with ulcerative colitis (n = 18) and a control group of healthy volunteers (n = 47) has been done using 16S ribosomal RNA sequencing. Results . We observed decreased diversity in the gut microbiome of patients with ulcerative colitis; the Shannon index was lower in this group, indicating an uneven distribution of taxa compared to healthy volunteers. There were disproportions in the main phylotypes: a decrease in the proportion of Actinobacteria and Firmicutes , alongside an increase in Proteobacteria and Bacteroidota . We suppose that intensive protein and amino acid degradation could occur due to an increased proportion of proteolytic bacteria and bacteria producing indole, indole-acetic acid, phenol, bile acids, polyamines, and GABA in the intestines of patients with ulcerative colitis. Additionally, an increase in mucin-degrading bacteria was detected. On the contrary, the proportion of saccharolytic bacteria and butyrate producers decreased in patients with ulcerative colitis. Conclusions . Patients with ulcerative colitis exhibited an imbalance in their intestinal microbiota composition, with increased proportions of bacteria involved in protein and amino acid metabolism and decreased saccharolytic bacteria, including butyrate producers.

Vascular endothelial growth factor receptor 3 (VEGFR3) assumes a pivotal role in regulating the development and maintaining the structural integrity of the lymphatic system. Decreased activity of VEGFR3 can precipitate aplasia or hypoplasia of lymphatic system components, culminating in primary lymphedema. To date, numerous genetic variants have been identified within the FLT4 gene, which encodes VEGFR3; however, the majority of these remain uncharacterised and are classified as ‘variants of uncertain significance’. In preceding investigations involving FLT4 sequence analysis conducted on individuals presenting with primary lymphedema, we identified several rare genetic variants that possess the potential to modulate the functional activity of VEGFR3, including the heterozygous variant c.3175G>C (p.A1059P). Preliminary assessments encompassing clinical characteristics, family history, and predictive computational algorithms indicated that this variant was likely pathogenic. Consequently, this study presents the results of functional evaluation of the mutant VEGFR3 activity in cell models overexpressing the FLT4 variant c.3175G>C. VEGFC-dependent VEGFR3 phosphorylation and FLT4 expression were reduced in cells with c.3175G>C FLT4 variant compared to wild-type, confirming the pathogenic role of c.3175G>C in primary lymphedema.

Background: CAR-T (Chimeric Antigen Receptor T-Cell) therapy has proven to be highly ...

Isoforms of prostate transmembrane protein, androgen induced 1 (PMEPA1), are regulated either by TGF-beta or AR activation and provide negative loop-regulation of these signaling pathways. High levels of PMEPA1 protein have been observed in various tumor types, including prostate, bladder, colorectal cancers, and glioblastoma. Direct oncogenic role of PMEPA1 in hepatocellular carcinoma has been recently shown on an animal model. New studies also indicate an upregulation of PMEPA1 in tumor-associated immune and stromal cells; however, its specific role in tumor stromal cells remains largely unexplored. In our previous research, we developed a cancer-stroma sphere (CSS) model that integrates tumor cells with mesenchymal stem cells (MSCs). Evaluations of chemotherapy and CAR-T therapies on CSSs have demonstrated that this model closely mimics in vivo data regarding cytotoxicity and adverse effects of therapy. In the present study, we reveal that PMEPA1 is significantly overexpressed in MSCs within the CSS. Moreover, this overexpression has been induced under short-term co-culture conditions. Among the five isoforms of PMEPA1, PMEPA1a and PMEPA1b isoforms have been detected in MSCs. These findings underscore the potential role of PMEPA1 in the tumor microenvironment modulation by MSCs.

Radiation therapy or radiotherapy is a medical treatment that uses high doses of ionizing radiation to eliminate cancer cells and shrink tumors. It works by targeting the DNA within the tumor cells restricting their proliferation. Radiotherapy has been used for treating cancer for more than 100 years. Along with surgery and chemotherapy, it is one of the three main and most common approaches used in cancer therapy. Nowadays, radiotherapy has become a standard treatment option for a wide range of cancers around the world, including lung, breast, cervical, and colorectal cancers. Around 50% of all patients will require radiotherapy, 60% of whom are treated with curative intent. Moreover, it is commonly used for palliative treatment. Radiotherapy provides 5-year local control and overall survival benefit in 10.4% and 2.4% of all cancer patients, respectively. The highest local control benefit is reported for cervical (33%), head and neck (32%), and prostate (26%) cancers. But no benefit is observed in pancreas, ovary, liver, kidney, and colon cancers. Such relatively low efficiency is related to the development of radiation resistance, which results in cancer recurrence, metastatic dissemination, and poor prognosis. The identification of radioresistance biomarkers allows for improving the treatment outcome. These biomarkers mainly include proteins involved in metabolism and cell signaling pathways.

CAR-T therapy has revolutionized the field of oncology, offering a promising treatment option for cancer patients. However, the significant morbidity associated with therapy-related toxicity presents a major challenge to its widespread use. Despite extensive research into the underlying mechanisms of CAR-T therapy-related toxicity, there are still many unknowns. Furthermore, the lack of adequate in vitro models for assessing immunotoxicity and neurotoxicity further complicates the development of safer cellular therapies. Previously in our laboratory, we developed cancer-stroma spheres (CSS) composed of prostate adenocarcinoma PC3 cells and mesenchymal stem cells (MSC). Herein we present evidence that multicellular CSS could serve as a valuable in vitro model for toxicity studies related to CAR-T therapy. CSS containing CD19-overexpressing PC3M cells exhibited increased secretion of CAR-T cell toxicity-associated IL-8, MCP-1, and IP-10 in the presence of anti-CD19 CAR-T cells, compared to spheres derived from single cell types.

Background: Cancer stem cells (CSCs) represent a relatively small subset of cells within tumors, capable of self-renewal and associated with metastasis and cancer recurrence. While conventional chemotherapy targets actively dividing bulk tumor cells, dormant CSCs remain unaffected and survive. Hypoxia or deprivation of oxygen supply is a common feature of solid tumors, which plays a critical role in metastatic progression and CSC maintenance. However, the cellular responses to hypoxia might be influenced by many factors, including the severity, duration, and other specific characteristics of this stress. Objective: In our study, we assessed the impact of long-term hypoxia on the CSCs population in 5 cell lines representing 5 different tumor types. Methods: We assessed and characterized the effect of oxygen concentration on CSC population using the sphere formation assay. The protein levels in tumor spheres were examined by western blot analysis. Results: Long-term hypoxia inhibited sphere formation by PC-3 and MDA-MB-231 CSCs. Moreover, chronic hypoxic stress suppressed cell proliferation in tumor spheres in all 5 tested cell lines: SNB-19, HCT116, MDA-MB-231, NCI-H460 and PC-3. This effect was accompanied by PCNA downregulation in tumorspheres derived from NCI-H460 and PC-3 cells. Conclusion: The prolonged hypoxic conditions impede tumor sphere formation by PC-3 prostate CSCs, primarily through the downregulation of PCNA levels. The specific cellular response to hypoxia depends on the duration and, supposedly, other specific features of this stress.

Background: N6-methyladenosine (m⁶A) is the most common internal RNA modification and is involved in regulation of RNA and protein expression. AlkB family member 5 (ALKBH5) is a m⁶A demethylase. Given the important role of m⁶A in biological mechanisms, m⁶A and its regulators, have been implicated in many disease processes, including cancer. However, the contribution of ALKBH5 to invasive breast cancer (BC) remains poorly understood. The aim of this study was to evaluate the clinicopathological value of ALKBH5 in BC. Methods: Publicly available data were used to investigate ALKBH5 mRNA alterations, prognostic significance, and association with clinical parameters at the genomic and transcriptomic level. Differentially expressed genes (DEGs) and enriched pathways with low or high ALKBH5 expression were investigated. Immunohistochemistry (IHC) was used to assess ALKBH5 protein expression in a large well-characterised BC series (n = 1327) to determine the clinical significance and association of ALKBH5 expression. Results: Reduced ALKBH5 mRNA expression was significantly associated with poor prognosis and unfavourable clinical parameters. ALKBH5 gene harboured few mutations and/or copy number alternations, but low ALKBH5 mRNA expression was seen. Patients with low ALKBH5 mRNA expression had a number of differentially expressed genes and enriched pathways, including the cytokine-cytokine receptor interaction pathway. Low ALKBH5 protein expression was significantly associated with unfavourable clinical parameters associated with tumour progression including larger tumour size and worse Nottingham Prognostic Index group. Conclusion: This study implicates ALKBH5 in BC and highlights the need for further functional studies to decipher the role of ALKBH5 and RNA m⁶A methylation in BC progression.

Lymphedema is characterized by congestion of protein-rich fluid in interstitial tissues when lymph release rate exceeds absorption. Primary lymphedema occurs due to congenital dysplasia, hypoplasia or hyperplasia of lymphatic system caused by genetic disorders. In most cases, primary lymphedema is associated with vascular endothelial growth factor receptor 3 (VEGFR3) signaling pathway responsible for embryonic lymphangiogenesis. Pathogenic mutations in genes involved in formation of morphologically correct vascular structure can also be associated with primary lymphedema. This review is devoted to the role of CELSR1 in development, functioning and diseases of lymphatic system.