Non-invasive prenatal testing (NIPT) is a molecular genetic method of assessing the risks of fetal chromosomal abnormalities from cell-free fetal DNA by isolating and sequencing cell-free fetal and placental DNA fragments in maternal blood (cell-free fetoplacental DNA). NIPT has been in use for the past decade, so as a consequence, there is still no consensus or solution regarding the ethical issues surrounding the testing. Gender selection, the range of risks assessed, genetic counseling, discrimination against children with chromosomal abnormalities and their parents, and the «routinization» of the method are the main ethical problems physicians of different specialties and patients face. The impact of NIPT results on the reproductive choices of couples is hard to underestimate, so the involvement of various medical and other specialists in the system of prenatal screening requires particular consultative attention and assistance. Keywords: non-invasive prenatal testing, bioethics, prenatal diagnosis, prenatal screening, chromosomal abnormality.

Clear cell renal cell carcinoma (ccRCC) is the most common and aggressive histologic subtype of renal tumors. At the time of diagnosis, one-third of patients develop distant metastases. Significant progress in the treatment of metastatic renal cancer has been made with the advent of targeted therapies based on immune checkpoint inhibitors. However, such therapy is not always effective. Therefore, it is relevant to study the molecular mechanisms underlying resistance to therapies that promote renal cancer progression. In this study, tumor samples obtained from patients with metastatic and non-metastatic ccRCC were investigated. The expression levels of eight genes, CD274, LGALS9, PVR, TDO2, IDO1, CD276, CEACAM1 and ADAM17, were analyzed in tumor tissue compared with the corresponding histological normal tissue. Gene expression was analyzed by real-time PCR. LGALS9, TDO2 and IDO1 genes were found to be most frequently upregulated in kidney cancer. Statistically significant differences in expression levels in the studied groups were shown for CD274, PVR and CD276 genes (Mann-Whitney test, p = <0.001; 0.003; 0.004, respectively). Our findings on the molecular genetic level of tumor progression may be useful for the development of new therapeutic treatment regimens.

Cystic Fibrosis (CF) is an autosomal recessive disease caused by mutations in the CFTR gene, leading to an imbalance of chloride and sodium ions in the epithelial cells of various organs. Nonsense mutations in the CFTR gene are present in 10% of CF patients, with the most common being c.3846G>A (p.Trp1282*, W1282X). Current CFTR-modulator therapy is ineffective against this class of mutations, leaving patients with nonsense mutations in the CFTR gene without effective treatment. Etiotropic therapy for CF can be developed based on the latest genome editing methods, such as base editors, which allow precise changes to nucleotides in the genome. Adenine base editors allow for targeted correction of nonsense mutations. The aim of this study was to evaluate the effectiveness of correcting the c.3846G>A mutation in induced pluripotent stem cells (iPSCs) from a CF patient using an adenine base editor. The xCas9(3.7)-ABE(7.10) editor was used in combination with a guide RNA (in a separate B52-1282 plasmid) to convert c.3846A>G. Plasmids were transfected into iPSCs with the F508del/c.3846G>A genotype in the CFTR gene using electroporation. The effectiveness of correction was evaluated 48 hours later using deep targeted sequencing. The results showed a conversion frequency of 10.9% of c.3846A>G alleles, with no increase in unwanted changes (indels) in the editing locus compared to the untransfected control. Therefore, this study demonstrates that the adenine base editor xCas9(3.7)-ABE(7.10) allows for correction of the c.3846G>A mutation in the CFTR gene in 10.9% of alleles in iPSCs from a CF patient without introducing additional mutations in the editing locus.

The tumor suppressor p53 is the central point of cellular defense against oncogenic transformation. Mutations of TP53 gene are present in approximately half of human tumors and promote not only tumor progression, but also resistance to anticancer drugs. Creation of isogenic models, differing in their TP53 status, is valuable not only for studying its role in carcinogenesis, but also for screening of anticancer drugs and their combinations. Establishment of isogenic models using the CRISPR/Cas9 system is usually done through single cell cloning, which can lead to clonal effects, because of heterogeneity of the cell cultures. In this article we present the process of creation of new knockout cell sublines of MCF7 and A549 using CRISPR/Cas9 and selection using nutlin-3, which allows selecting cell sublines without clonal selection. Phenotypically the knockout of TP53 was confirmed by total absence of p53, absence of induction of p53-dependent gene CDKN1A, and shift in sensitivity to DNA-damaging drugs.

The CRISPR/Cas technology, which is the most efficient among the existing genome editing methods, allows modifying target regions of the DNA molecule and is used in various fields of biology, genetics, agriculture, biotechnology, and medicine. Models of cell lines required for studying the role of certain genes in the development and therapy of malignant and other diseases can be created using CRISPR/Cas method. One of such genes is p21 (CDKN1A), which is regulated by the p53 tumor suppressor and negatively controls cell cycle progression. The ambiguous influence of the p21 protein on the processes of carcinogenesis and its key role in the response of cells to therapy make it a promising target for research in these areas. In our work, we obtained a subline of lung cancer cells A549, knockout for the p21 gene, using the CRISPR/Cas method. It is planned to use it in experiments to study the role of the p21 protein, as well as the mechanisms mediated by it, the influence of other genes, in the cell response to cancer therapy. in particular, the formation of the senescence phenotype after treatment with low-dose therapy and the escape of individual cells from this stage (formation of tumor recurrence), as well as determining the mechanisms for the emergence of tumor cell resistance.

Preeclampsia (PE) is a severe obstetric pathology that affects up to 8% of all pregnancies per year. By now numerous genetic studies have been conducted using both candidate and genome-wide approaches to reveal the genetic basis of PE. Therefore, a number of promising candidate genes for PE, including the STOX1 locus, were identified. In this article, the role of heritable variation of the STOX1 gene in the formation of predisposition to PE in various ethnic groups of Russia was analyzed. The associations of genotypes of the STOX1 locus with PE that we found were characterized by population specificity. Genotypes of polymorphic markers rs4746796 and rs7095976 with risk effect were identified in Russians. The protective genotype of the rs1694505 allele variant was revealed in the Yakut ethnicity.

Background. Detection of fusion genes is important in the preoperative differential diagnostics of thyroid cancer, as well as for tyrosine kinase inhibitors prescription. It is assumed that the assessment of the 5’/3’ expression imbalance, which indirectly reflects the presence of gene rearrangements, and gene expression markers, might widen the range of markers and would thereby improve the sensitivity of the malignant thyroid tumors diagnostics. High throughput RNA sequencing, which allows determining the full range of rearrangements in combination with expression markers, is supposed to be promising application and is under active implementation into clinical practice.

Aim. To assess the detection of rearrangements and expression markers by targeted high throughput RNA sequencing in thyroid cancer.

Methods. 64 samples of thyroid cancer and 16 samples of benign thyroid lesions with a cytological diagnosis of Bethesda III-V were examined. Presence of RET, ALK, NTRK1, NTRK3, PPARG, THADA, LTK, MET, BRAF, C15orf55, ERBB4, OFD1, ROS1 gene rearrangement transcripts, 5’/3’ gene expression imbalance and expression marker levels were evaluated by high throughput sequencing using AmpliSeq technology on the custom primer panel.

Results. Fusion genes were found in 12% of cancer samples. Their list includes CCDC6-RET, ETV6-NTRK3, TPM3-NTRK1, STRN-ALK, and PAX8-PPARG. The proportion of samples with identified rearrangements meets the values expected according to the literature. No rearrangements were found in the benign samples. 5’/3’ imbalance in cancer samples was detected for the RET, NTRK1, NTRK3, MET, and THADA genes, while it was absent in benign lesions. Among the studied expression markers, the KRT7, KRT20, CHGA, CITED1 genes had significant overexpression in cancer samples, with no aberrant expression in benign neoplasms.

Conclusions. Targeted high throughput RNA sequencing based on AmpliSeq technology using the developed primer panel allows to determine gene fusions, 5’/3’ expression imbalance and expression markers with high specificity regarding the malignancy of the neoplasm. Inclusion of 5’/3’ expression imbalance and gene expression markers can improve the accuracy of differential diagnostics of malignant neoplasms.

The article presents clinical, genetic and molecular characteristics of the first case of glutaric aciduria type 2 (GA2, multiple acyl-CoA dehydrogenase deficiency) in an adult patient in Russia, which was triggered by physical activity and COVID-19. A previously undescribed mutation NM_004453.4:c.886G>C (p.Gly296Arg) (CM081237) in the ETFDH gene was discovered.