No abstract

Low blood levels of the vitamin D metabolite 25-hydroxyvitamin D [25(OH)D] have been associated with an increased risk and poorer outcomes of various cancers, including hematological malignancies. The Central Kazakhstan area has a relatively high incidence rate of leukemia. However, the relationship between vitamin D status and leukemia or other types of cancer in Kazakhstan has not yet been addressed. Therefore, in this first pilot single-center study conducted in Central Kazakhstan, we compared plasma levels of 25(OH)D and the vitamin D receptor (VDR) gene expression levels in peripheral blood mononuclear cells of patients with leukemia and demographically matching healthy volunteers. The levels of 25(OH)D in patients were found to be significantly lower (10.8 ± 7.0 ng/mL; n = 31) than in healthy subjects (21.6 ± 7.8 ng/mL; n = 34; p < 0.0001). A similar difference was observed in both younger (<60 years old) and older (>60 years old) participants, though there was no association between 25(OH)D concentration and age within the patient group. In female patients, 25(OH)D levels were significantly lower than in male patients (p = 0.04). No significant seasonal variations of 25(OH)D were observed in either the patient or the control group. VDR gene expression levels appeared to be similar in leukemia patients and healthy subjects, and no correlation between the cellular VDR expression and plasma 25(OH)D concentrations was observed in either group of participants. We did not observe a significant association of 25(OH)D or VDR levels and overall survival of leukemia patients. This observational study conducted for the first time in Kazakhstan supports previous findings demonstrating reduced blood 25(OH)D levels in cancer (leukemia) patients. Larger studies are required to determine whether low 25(OH)D plasma concentrations represent a risk factor for leukemia development and/or progression.

The article presents the characteristics of the main vitamin D receptor (VDR) gene polymorphisms: rs2228570 (FokI), rs731236 (TaqI), rs1544410 (BsmI) and rs7975232 (ApaI). The role of the vitamin D hormonally active form (1,25(OH)2D3, calcitriol) as a transcription factor regulating gene expression in target cells by binding to the vitamin D receptor protein is described. The immunomodulatory and mediating effect of VDRs on the biological functions of the human body has been noted. A description of the vitamin D receptor gene and its polymorphic character have been provided. The analysis of the four most significant single nucleotide polymorphisms (SNPs) of the VDR gene was carried out. A detailed description of each polymorphism, its genomic position, the nature of interaction with other polymorphisms of the vitamin D receptor gene, as well as its effect on the structure and activity of the VDR protein were given. The analysis of the indicated single-nucleotide polymorphisms allelic composition was conducted according to the literature and specialized SNP databases. The frequency of each polymorphism individual alleles occurrence, as well as their influence on the predisposition and course of various diseases, were studied. The need for further studies of VDR gene polymorphisms, their allelic composition and prevalence was designated. It is also necessary to study the possibilities of their potential use as genetic markers for such relevant but little-studied pathologies as COVID-19.

Stable HAT-RAPD (high annealing temperature) profiles were obtained for 7 micromycetes isolated from the central Kazakhstan soils with single non-specific primers. An arbitrary primer (decamer AP3), a primer derived from the intergenic spacer regions (T3B) and microsatellite primer (GTG)5 were applied in PCR. Precise and reproducible profiles of the amplification prod-ucts were obtained for all seven hyphomycetes isolates in spite of increased annealing temperature application. The number and size of amplicons reflect a species specificity. In some cases intraspecific variability was observed. Cluster analysis of the profiles demonstrated the phylogenetic relationships between isolates that are consistent with those of ITS-region genotyping. Obtained results completely justify the application of the HAT-RAPD in mark-ing and rapid identification of soil hyphomycetes.

Host genes act as a factor related to susceptibility and resistance to viral infections. The article provides a description of modern scientific studies devoted to the study of the role of the ACE2, TMPRSS2 genes, and their single-nucleotide polymorphisms in infection with the SARS-CoV-2 virus. SNPs of the ACE2 gene, TMPRSS2 can affect the penetration of SARS-CoV-2 into the cell. In addition, the study of these polymorphisms will determine the predisposition of an individual to the disease COVID–19, or the nature of its course. Based on the literature sources, the role of angiotensin-converting enzyme 2 and transmembrane proteases in the participation of the SARS-CoV-2 virus penetration process with the body cells is noted. Other functions that ACE2 and TMPRSS2 receptors perform in the human body are also described. The characteristics of two genes and their fairly well-known polymorphisms are given. The tissues and organs in which genes are expressed are marked. Information on the frequency of alleles of genetic variants of genes in different populations is shown. In addition to describing the relationship of gene polymorphisms with the disease caused by SARSCoV-2, information is provided on the association of these genetic variations with diseases of the blood vascular system and oncological diseases.