Clinical significance of gene polymorphisms for hereditary predisposition to breast and ovarian cancer (review of literature).

The review presents classical and modern views on the molecular genetic causes underlying hereditary predisposition to breast and ovarian cancer. A computerized literature search was carried out in the electronic databases MEDLINE, Scopus, and Web of Science, published between January 1994 and May 2021, using the keywords: «hereditary breast and ovarian cancer¼, «BRCA¼ and «DNA repair¼. Current views on the role of germline mutations in genes for susceptibility to breast cancer (BC): BRCA1, BRCA2, PALB2, TP53, CHEK2, PTEN, ATM, and PPM1D are presented. The role of a complex of genes involved in homologous DNA repair and causing other hereditary oncological diseases is considered. The role of the loss of heterozygosity in these genes, which increases the level of chromosomal instability and leads to an increased risk of malignant transformation, is considered. Germinal mutations in the genes under consideration in 90% of clinical cases are the cause of initiation of tissue malignancy and greatly increase the risk of developing hereditary breast cancer and OC. The review emphasizes the complex nature of pathogenesis and significant polymorphism of genetic targets for hereditary breast cancer and OC. It is concluded that it is necessary to use NGS panels for complex screening of genes of hereditary susceptibility to these oncological diseases. The review provides data on the clinical significance of each group of genes of hereditary predisposition in the pathogenesis of breast cancer and OC, and also demonstrates the possible role of methylation of the promoter regions of genes and the state of mitochondrial DNA in the development of these pathologies. The purpose of this review was to broaden the horizons of specialists in the field of oncology and clinical diagnostics in the context of the rapidly expanding spectrum of molecular genetic markers of hereditary breast and ovarian cancers.

Specific Features of Transcription Activity of Cancer-Testis Antigens in Patients with Metastatic and Non-Metastatic Breast Cancer.

Cancer-testis antigens, effective markers of tissue malignant transformation, are characterized by heterogonous transcription depending on the pathological features of breast cancer. We performed screening of transcription profile of cancer-testis antigens specific for breast tumor tissues in female patients with and without regional metastasis. The relative expression of 16 genes (MAGEA1, MAGEA2, MAGEA3, MAGEA4, MAGEB1, MAGEB2, GAGE1, GAGE3, GAGE4, MAGEC1, BAGE, XAGE3, NY-ESO1, SSX2, SYCP1, and PRAME1) was analyzed by RT-qPCR method in biopsy specimens of the mammary gland tissues obtained during surgery from 25 patients. Differential transcription activity of cancer-testis antigens genes was observed in patients with metastatic (enhanced expression of MAGEA2, MAGEB1, and XAGE3 genes) and non-metastatic (enhanced expression of GAGE3 and PRAME1 genes) breast cancer.

[The activity of proapoptotic genes increases after renal ischemia/reperfusion].

According to the World Health Organization, pathologies associated with ischemia/reperfusion occupy the leading position in the structure of mortality. The efficiency of localized kidney cancer surgery is limited by the damaging effects of prolonged warm ischemia and reperfusion. Ischemia/reperfusion damage to renal tissue may be related to changes in the expression profiles of pro- and antiapoptotic genes. Here, we have presented the longitudinal expression profiles of apoptosis-related genes in tissues of left and right (intact) kidneys of male rats exposed to unilateral ischemia followed by reperfusion. The profiles have been assessed at time points of 1, 3, and 48 h after the ischemic/reperfusion exposure by RT-qPCR quantification of mRNAs encoded by 13 genes, including BAX, p53, AIFM1, APAF1, CASP8, CASP3, CASP9,CASP7, MDM2, BCL2, CIAP1, XIAP, and ICAD, after normalization with respect to a reference gene ACTB. The study revealed a shift in the expression of pro- and antiapoptotic genes toward the predominance of proapoptotic processes, as was evinced by the increase in expression detected for the BAX, p53, AIFM1, APAF1, and CASP8 genes. One hour after the reperfusion, activation of mitochondrial, or intrinsic apoptosis was detected, while р53-dependent and extrinsic, i.e., receptor-driven, apoptosis joined at later time points. Changes in the level of expression of caspase 7 (CASP7)-encoding mRNA have only been detected 48 h after the restoration of blood flow. Changes have been observed in the transcription of pro- and antiapoptotic genes in tissues of both kidneys, which suggests the involvement of the contralateral kidney in systemic pathological process that develops during unilateral ischemia/reperfusion.

[Molecular biology of colorectal cancer in clinical practice].

The review summarizes current data on the molecular genetic mechanisms underlying the pathogenesis of colorectal cancer (CRC) and addresses the connections between these mechanisms and biomarkers used for predictive diagnosis, risk stratification, prognosis, and predicting response to chemotherapy and tar-geted therapy. Evidence of microRNA involvement in the regulation of major signaling pathways affected by CRC pathogenesis is discussed, and signaling pathways that can be used as targets in the therapy of colorectal cancer are examined.

[Changes in the number of copies of genetic loci in gastric cancer].

It is assumed that changes in the number of copies that belong to the basic mechanisms that control the expression of genes are important for malignization. Therefore, the characterization of these genes and the precise assessment of the number of copies are important for understanding the molecular basis of tumor emergence and progression in the human organism, as well as for the identification of predictive markers of malignization. In the present study, the relative number of copies of 19 loci (BAX, GSTP1, CASP3, CASP8, HIF1A, OCT4, C-MYC, SOX2, BCL2, CASP8/FADD, NANOG, P53, CASP9, IL-10, NFKB1, HV2, and ACTB) in cancerous and conventionally healthy tissues from 25 residents of southern Russia with a histologically confirmed diagnosis of adenocarcinoma (stages G1-G2 and G3) or signet cell gastric cancer were determined by quantitative real-time PCR. Changes in the number of copies of the gene were shown to be specific to particular histological types of cancer, as well as to depend on the stage of tumor cell differentiation. The data suggest that the number of copies of changes in the BAX, CASP3, CASP8, OCT4, C-MYC, SOX2, BCL2, NANOG, CASP9, NFKB1, HV2, ACTB, MKI67, IL-10, GSTP1, and P53 genes play an important role in the malignization of gastric tissue.

Separation and study of the range of plasminogen isoforms in patients with prostate cancer.

Using affinity chromatography, two-dimensional electrophoresis, and MALDI-TOF mass spectrometry, plasminogen isoforms were separated and identified in blood plasma. Healthy donors and patients with prostate cancer in various stages of development were included in the studied sample. With the development of prostate cancer, four additional specific plasminogen isoforms are registered in blood plasma; they are characterized by lower molecular weights and higher pI values compared to isoforms found in the control group.

[The role of micro-RNA in the regulation of signal pathways in gliomas]. / Rol' mikro-RNK v reguliatsii signal'nykh putei pri gliomakh.

Gliomas are invasive brain tumors with high rates of recurrence and mortality. Glioblastoma multiforme (GBM) is the most deadly form of glioma with nearly 100% rate of recurrence and unfavorable prognosis in patients. Micro-RNAs (miR) are the class of wide-spread short non-coding RNAs that inhibit translation via binding to the mRNA of target genes. The aim of the present review is to analyze recent studies and experimental results concerning aberrant expression profiles of miR, which target components of the signaling pathways Hedgehog, Notch, Wnt, EGFR, TGFb, HIF1a in glioma/glioblastoma. Particularly, the interactions of miR with targets of 2-hydroxyglutarate (the product of mutant isocytrate dehydrogenase, R132H IDH1, which is specific for the glioma pathogenesis) have been considered in the present review. Detecting specific miRNAs in tissue and serum may serve as a diagnostic and prognostic tool for glioma, as well as for predicting treatment response of an individual patient, and potentially serving as a mechanism for creating personalized treatment strategies.