In hepatocellular carcinoma (HCC), the presence of cancer stem cells (CSCs) have been linked to drug resistance, epithelial-mesenchymal transition (EMT), and cancer relapse. This study investigates the expression profile of ZEB1, ZEB2, ABCG2 in HCC-CSCs, and the role of EMT promoter ZEB2 in cells treated with resveratrol. The expression of ZEB1, ZEB2 and ABCG2 transcripts were analyzed in CD133^(+)/CD44^(+) cells isolated from the PLC/PRF/5 cell line. ZEB2-dependent ABCG2 gene expression and the effects of resveratrol on proliferation, cell cycle and apoptosis were explored in SNU398 cell clones. An inverse correlation between ZEB1/ZEB2 and ABCG2 levels were observed both in CSCs and in ZEB2-knock-down cells. The resveratrol treatment significantly decreased cell viability, while promoting cell cycle arrest in ZEB2-independent manner. Interestingly, resveratrol-treated cells with low levels of ZEB2 were resistant to apoptosis. The interplay of expression levels of ABCG2 and ZEB family EMT transcription factors may play a role in establishing CSC-like phenotype in HCC cells resistant to resveratrol.

Hepatocellular carcinoma (HCC) is a common malignancy worldwide with poor prognosis and high mortality. The aberrant expression or alteration of microRNAs (miRNAs) contributes to the development and progression of cancer. Studies have shown that miR-455 plays a regulatory role in the development of HCC. Therefore, in the present study, the role of miR-455 was analyzed in HepG2 cells proliferation and apoptosis using MTT and flow cytometry methods. Binding sites were predicted by bioinformatics and luciferase assay was used to verify the target relationship between miR-455 and RhoC-encoding gene RHOC. After that, the effects of miR-455 on RHOC and its product RhoC, were explored by qPCR and Western blotting. As PTEN is a key tumor suppressor gene in HCC, and Bcl-2 and Caspase 3 are important indication of apoptosis, expression levels of PTEN, Bcl2 and Caspase 3 proteins were determined in cells overexpressing RhoC. We show that miR-455 promotes HepG2 cells apoptosis and inhibits proliferation. Bioinformatics analysis and luciferase assay indicate that specific recognition sites for miR-455 are within the RhoC 3'-UTR. Luciferase activity was significantly lower in the cells co-transfected with miR-455 mimics and RhoC-WT (p < 0.01) as compared to that in control cells, pointing that RHOC gene is, indeed, targeted by miR-455. RHOC mRNA was significantly reduced after miR-455 transfection in HepG2 cells. In addition, we show that RhoC could activate the HCC cells proliferation ability and inhibit apoptosis rate (p < 0.01), and decrease expression of PTEN and Caspase 3 (p < 0.01), while upregulating levels of Bcl2. In conclusion, our study indicates that miR-455 plays a suppressive role in HCC development by targeting RhoC-encoding mRNA.

PTTG1 (vertebrate securin) is a separation inhibitor and regulates DNA repair and transcription. The protein is predominantly expressed in the second half of the S phase and at the G2 stage. With the onset of anaphase, securin is ubiquitinated by the APC/C complex and degraded rapidly. Increased expression of PTTG1 is associated with enhanced tumor cell growth and metastasis. Recently, we found a short securin isoform lacking the main APC/C recognition site (D-box) and the DNA-binding domain encoded by exons 3 and 4. The mRNA level of the short isoform in unsynchronized cells is 0.4-2% of the full-length one. We reported earlier on the ability of the short PTTG1 isoform to activate some of the genes controlled by the full-length protein. In this work, groups of genes, whose expression is altered by the action of the short and complete securin isoforms, were determined using RNA sequencing. Groups of genes whose mRNA levels are regulated by both protein isoforms and only one of the isoforms were identified. For a more detailed study of the effect of securin isoforms on the transcriptional program of cells, the NFYB gene, encoding the NF-Y transcription regulator subunit, was chosen. Our data showed that with overexpression of the short isoform, the level of NFYB mRNA decreased 2.4 ± 0.7 times, while the complete isoform did not significantly affect the expression of NFYB. 2.2-fold suppression of the short isoform of securin led to an increase in the expression of NFYB mRNA by 2.7 ± 0.3 times. Moreover, the mRNA expression of full-length securin increased by 2.7 ± 0.4 times. Since NFYB is associated with the PTTG1 promoter region, we suggest that the short isoform may be involved in regulation of the expression of the main isoform of securin by changing the level of this transcription factor. Since NFYB and PTTG1 are involved in the development of tumors and the formation of drug resistance, we assume that the short isoform of securin may play an important role in these processes. Thus, we showed the functional significance of the minor short isoform of securin.

The lack of specific symptoms for the early detection of gastric cancer leads to the fact that it is often diagnosed at a late stage, when the prognosis is unfavorable. The analysis of molecular markers in addition to standard diagnostic procedures is a promising approach for improving the preoperative diagnosis of both gastric cancer and precancerous changes in the mucosa. Therefore, the aim of our study was to analyze the diagnostic significance of using miRNA expression to diagnosis gastric cancer and precancerous conditions (dysplasia) in histological material. In this work, 122 samples of archival histological material in the form of paraffin blocks were used: 34 samples of gastric adenocarcinoma, 54 samples of gastric ulcers with dysplasia and 34 samples of normal gastric mucosa obtained from patients after bariatric surgery. The expression level of miRNA-145-5p, -150-5p, -20a-5p, -21-5p, -31-5p, -34a-5p, -375 was determined using real-time RT-PCR. Samples were stratified into different groups using the C-RT decision tree algorithm. All miRNAs, except miRNA-20a, were included in the decision tree, which allows stratification of samples for normal mucosa, dysplasia, and gastric cancer. Normal mucosa can be distinguished from gastric cancer only by miRNA-34a, -21, -375. Diagnostic characteristics for the detection of dysplasia: specificity - 97%, sensitivity - 87%; for the detection of gastric cancer: specificity - 91%, sensitivity - 93%. The sufficiently high values of the diagnostic characteristics for detecting dysplasia of the gastric mucosa and gastric cancer obtained in our study indicate the possibility of using expression data of a small amount of miRNAs for the effective separation of samples with tumor and precancerous changes in the stomach tissue.

The colorectal cancer is considered as the third most common malignant disease in the world. During last decade, the problem of colorectal cancer became especially urgent conditioned not only by increasing of number of metastatic tumors of colon and rectum, but also by implementation of high-tech methods of treatment that significantly improved the results of five-year survival period. Along with success of therapy, understanding of genomics of colorectal cancer and owing to extensive application of next generation sequencing, the opportunity of optimal choice of treatment options was offered.

Denys-Drash syndrome is characterized by a triad: nephropathy, a 46, XY disorder of sex development, and nephroblastoma with mutations in the gene WT1. A clinical case of a patient with a bilateral metachronous Wilms' tumor, a 46, XY disorder of sex development in the form of a scrotal hypospadias and bilateral abdominal cryptorchidism, without nephropathy with a mutation in 7 exon of gene WT1 is presented in the article. The child underwent left-sided nephrectomy, lower pole right partial nephrectomy, bilateral orchiopexy and two-stage correction of hypospadias. After 7 years from the start of treatment and 3 years after the last procedure, the childs condition has been assessed as satisfactory. The presented case, according to the analysis of literature, has not been previously described, therefore, it currently remains as "de novo" and requires further observation.

The development of new research methods significantly changed our views on the role that the 3D organization of the genome plays in its functional activity. It was found that the genome is subdivided into structural-functional units that restrict the area of enhancer action at the level of spatial organization. Spatial reconfiguration of an extended genomic fragment was identified as a potential mechanism that activates or represses various genes. Accordingly, a distorted spatial organization of the genome often causes various diseases, including cancer. All these observations contributed to the emergence of 3D genomics as a new avenue of research. The review summarizes the most important discoveries in the field of 3D genomics and discusses the directions of its further development.

as shown in previous studies, mutations in the BRCA1/2 and CHEK2 genes are associated with worsened long-term results of the definitive treatment for localized prostate cancer (PCa).

Studies of the last decade have demonstrated that the morphological and immunophenotypic patterns of adrenocortical carcinoma (ACC) have a high heterogeneity in both the occurrence of various tumors and the development of a solitary tumor. Carcinogenesis of ACC, like most neoplastic processes, is associated with mutations in at least 15 driver genes, with a wide range of chromosomal aberrations, epigenomic changes, and alterations of the microRNA profile. According to the literature, isolated genetic damage is also insufficient for the manifestation of the malignant phenotype of adrenocortical cells. Knudson's two-hit hypothesis is implemented in at least germline mutations: the development of ACC requires a second genetic event occurring in somatic cells, which leads to inactivation of the second allele of the gene. ACC is an extremely heterogeneous disease, which determines the complexity of differential diagnosis with benign adrenocortical tumors and that of prediction of the clinical course. Another no less important issue is the lack of valid predictors for the efficacy of mitotane, the use of which may be associated with severe adverse effects.

The paper describes 2 cases of immature ovarian teratoma with elements of nephroblastoma (ICD-0 code 9080/3) in patients aged 61 and 70 years. Microscopic examination revealed that both cases had blastemal cells with scant cytoplasm and basophil nuclei sticking together. Epidermal, glandular, rhabdomyoblastic, chondroid, bone, neuroectodermal, and histiocytic components were determined. Papillary and glomeruloid structures and primitive tubules were immured in the sarcomatous stroma. Immunohistochemical studies showed a strong reaction with Wilms tumor 1 (WT1), paired box gene (PAX-2), cytokeratin 7, desmin, smooth muscle actin, and α-1 antitrypsin. The recurrent tumors displayed a 1.8- to 6.1-fold increase in the level of p53. At the same time, the molecular genetic study revealed p53 gene mutation. In both cases, serous ovarian cystadenocarcinoma was misdiagnosed, ineffective chemotherapy was performed, and a recurrence occurred. The literature review revealed only 8 such cases.

Oral cavity squamous cell carcinoma (OC-SCC) is the most common and aggressive malignancy of the oral cavity. Recent studies have revealed infections with human papilloma virus (HPV) as an additional risk factor for oral squamous cell carcinoma development, while distinguished role of Epstein-Barr virus (EBV) remains still uncertain. However, the evidence for association between virus infection and risk of oral squamous cell carcinoma is controversially and varies significantly by geographic regions and race.

Oncogenesis can be caused by an increase in the activity of genes responsible for initiating tumor growth in stem or progenitor cells, as well as a reduction in the functioning of suppressor genes. Endogenous estrogen exposure is associated with an increased risk of breast cancer in both pre- and postmenopausal women. The most important step in the understanding of the pathogenesis of breast cancer was the development of the theory of the switching of estrogen's effect from hormonal to genotoxic, in which the main culprits of carcinogenesis are not chemical metabolites of estrogens, but their derivatives, corresponding to chemical procarcinogens according to their damaging characteristics. The origin of these substances and the formation of estrogen genotoxicity lies in the disruption of the inactivation process of catechol estrogens in methylation reactions. The main epigenetic modification of the human genome is the methylation of cell DNA molecules. DNA methylation does not alter the primary sequence of nucleotides, but is necessary for the functional suppression of certain genes. The phenomenon of hypomethylation-hypermethylation underlies the long-term silencing of various genes, including tumor suppressor genes. Nutrition and a lifestyle associated with smoking and the consumption of excessive quantities of alcohol determine estrogen metabolism and the availability of methyl groups in the body, as well as epigenetic changes in the DNA of the genome. The assessment of individual risk of breast cancer on the basis of an assay for the expression and methylation of the COMT gene responsible for estrogen metabolism seems relevant.

In most cases, oncogene amplification are prognostic and predictive markers for various tumors, therefore DNA probes are unable to reveal changes in the copy numbers should not be used to diagnose malignant tumors.

Malignant cutaneous melanoma (CM) is an extremely aggressive cancer characterized by a high level of metastatic activity and unfavorable prognosis due to a high incidence of relapses, as well as resistance to standard chemotherapy. Cutaneous melanoma accounts for 80% of deaths from malignant skin tumors. Nucleolin/C23 and nucleophosmin/B23, which constitute altogether ~70% of the nucleolus volume, are promising targets for molecular therapy of melanoma. These proteins perform many important functions in the cell, so disruption of the NCL and/or NPM gene structure and abnormal expression of the C23 and B23 proteins they encode, can lead to unlimited cell proliferation and progression of a tumor. Therefore, investigation of the structure and expression of these genes is a topical problem, which is important for understanding the mechanisms of CM carcinogenesis and for the development of new therapeutic approaches. This paper describes new NCL and NPM polymorphisms, as well as the levels of C23 and B23 expression in normal tissues, CM and mucosal melanoma.

Acral melanoma is one of the most aggressive and fast-growing forms of cutaneous melanoma and is characterized by a predominant location on the palms and feet. Primary tumors, metastases, and normal tissue samples from five acral melanoma patients were examined by massive parallel sequencing, focusing on the coding regions of 4100 genes involved in the origin and progression of hereditary and oncology diseases. Somatic mutations were found in genes related to cell division, proliferation, and apoptosis (BRAF, NRAS, VAV1, GATA1, and GCM2); cell adhesion (CTNND2 and ITGB4); angiogenesis (VEGFA); and the regulation of energy metabolism (BCS1L). Comparisons of target DNA sequences between morphologically normal and primary tumor tissues and between normal and metastatic tissues identified the candidate genes responsible for rapid metastasis in acral melanoma.

Carotid paragangliomas (CPGLs) are rare neuroendocrine tumors of the head and neck. "Germline" and somatic mutations in a number of genes were shown to be associated with the development of CPGLs; however, molecular mechanisms of the tumor pathogenesis have not been fully understood. In the work, we have used whole exome sequencing data of 52 CPGLs obtained earlier. Using MutSigCV, the search for genes with high mutation rate was performed. Thirty four genes (MADCAM1, SARM1, ZFPM1, CTDSP2, DSPP, POTED, ANP32B, FRG2B, BAGE3, CCDC89, ACOT2, KRTAP10-1, ATXN1, GXYLT1, MUC2, AQP7, TMPRSS13, KRTAP4-3, PRR21, PSPH, PLBD1, ZNF595, IGSF3, PRR16, FAM157A, KCNJ12, HYDIN, IGFBP2, KIAA1671, DISC1, MUC6, XKR3, HRNR, and MUC4) potentially associated with the CPGL initiation and progression were revealed. The involvement of these genes in the pathogenesis of CPGLs was first shown, and possible mechanisms of their participation in that were discussed.

To identify the expression of the molecular markers p53 and p16INK4A in head and neck squamous cell carcinoma (HNSCC) and to assess their impact on its clinical and morphological characteristics and overall survival (OS) rates in patients with HNSCC.

BRCA1 (breast cancer 1) protein is involved in the genome stability maintenance participating in homologous recombination-dependent DNA repair. Disruption of BRCA1 functioning is associated with breast and ovarian cancer. Despite the important role of BRCA1 in DNA repair in all cell types, the development of BRCA1-associated cancer takes place mainly in estrogen-dependent tissues such as breast and ovarian ones. Using breast cancer cell line MCF-7 it was demonstrated in in vitro experiments that the estrogen 17β-estradiol (E2), phytoestrogens (genistein and apigenin) and antiestrogens (tamoxifen and fulvestrant) inhibited estrogen receptor (ERα) expression while only genistein influenced BRCA1 increasing its expression. In hypoxia, that is an important factor of solid tumors progression, the decrease of BRCA1 and ERα expression was demonstrated in MCF-7 cells. Therefore, hypoxia influences both BRCA1-dependent DNA repair and hormonal regulation of breast cancer cell growth. Taken together, obtained results demonstrate a relationship between BRCA1 and steroid hormones signal transduction pathways in breast cancer cells and point out to the importance of complex BRCA1 and ERa expression regulation mechanisms studies including epigenetic gene expression regulation.

Placenta is a highly specialized organ that is necessary for successful gestation. Several models of the placental barrier are used to study how it functions, including the transplacental transport of xenobiotics. One of these models, human choriocarcinoma cell line BeWo is widely used in vitro. Notably, cancerous BeWo cells form multilayer structures that normally are not found in the human placenta. Here, we aim to develop techniques suitable for monitoring BeWo b30 cells in culture. To assess the state of BeWo b30 cells growing on a membrane, we use impedance spectroscopy, which allows us to estimate the number of cell layers by the change in the electrical parameters of the biological system. In mature BeWo b30 cell cultures, we also note a significant increase in the expression of genes encoding metallothioneins (particularly, MT1B, MT1F, and MT2A) and syncytins (ERVW-1 and ERVFRD-1), which can be used as biomarkers reflecting the development of mature phenotypic characteristics, namely, trophoblastic invasion and formation of the syncytium.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the only curative therapy for hematopoietic malignancies. The graft-derived donor lymphocytes are capable of eliminating the residual recipient malignant cells in the course of allogeneic immune response, thus decreasing the chances of a relapse of the disease. Foreign peptides of the recipient presented by the MHC molecules are able to elicit the immune response immunologically. These polymorphic peptides are known as minor histocompatibility antigens (MiHAs). MiHAs occur due to the nonsynonymous single nucleotide polymorphisms in human genome. Transfusion of T cells specific to MiHAs presented predominantly in the cells of hematopoietic origin will allow the targeted elimination of residual malignant clones avoiding undesirable damage to healthy tissues. To induce the immune response, the donor must be homozygous by the MiHA allele and the recipient must either be homozygous or heterozygous by the alternative MiHA allele. The therapeutic mismatch occurs in 25% of cases under the optimal frequency of allelic variants. Minor antigen ACC-1Y originates from polymorphism in the BCL-2A1 gene; its immunogenic mismatch occurrence approaches the theoretical maximum. In addition, BCL2A1 is overexpressed in cells of various lymphomas. ACC-1Y is presented on allele HLA-A*24:02, which is relatively frequent in the Russian population. Combination of these factors makes the minor antigen ACC-1Y a promising target for immunotherapy. Transfusion of donor CD8^(+) lymphocytes modified with transgenic MiHA-specific TCR is one of the promising methods of posttransplant leukemia therapy and relapse prophylaxis. We obtained a sequence of high-affinity ACC-1Y-specific TCR after the antigen-specific expansion of T cells derived from a healthy ACC-IY^(-/-) donor. We cloned this sequence into the lentiviral vector and obtained the assembled viral particles. Further, we transduced the CD8^(+) lymphocyte culture and demonstrated its antigen-specific cytotoxic activity. It is suggested that CD8^(+) lymphocytes modified by the described method could be potentially transferred to recipients as a therapy against relapse after allo-HSCT.