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.

Low plasma levels of the vitamin D metabolite 25-hydroxyvitamin D [25(OH)D] and the vitamin D receptor (VDR) gene single nucleotide polymorphisms (SNPs) have been associated with the body’s susceptibility to infectious diseases, including COVID-19. In this pilot retrospective study, representatives of the Kazakh population (central Kazakhstan) were divided into groups based on the test for IgM and IgG for coronavirus infection. We compared the 25(OH)D plasma levels and concluded that the COVID-19-positive group values (25.17 ng/mL ± 16.65) were statistically lower (p = 0.0114) compared to the COVID-19-negative ones (35.58 ng/mL ± 20.67). There was no association between age, gender and 25(OH)D concentration within the groups (p > 0.05). The genotyping of rs2228570 was performed using a TaqMan Real-Time PCR assay. Allele C predominated among the COVID-19-negative participants and significantly reduced the likelihood of coronavirus infection (p < 0.0001; OR = 0.0804; 95% CI 0.02357–0.2798). There were no statistically significant differences in the frequencies of the A, G and T alleles in the studied groups (p > 0.05). The GG genotype of rs2228570 was associated with a 4.131-fold increased likelihood of COVID-19 infection (p = 0.0288; χ2 = 5.364; OR = 4.131; 95% CI 1.223–13.71). Comprehensive studies are required to determine whether low 25(OH)D plasma concentrations and genetic background represent a risk factor for COVID-19 infection.

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.

Genetic condition of human papillomavirus high carcinogenic risk The authors consider the basic concepts of HPV-induced carcinogenesis and the molecular differences found among types of HPV and intra-type variants, and give their clinical and functional consequences. Human papillomavirus (HPV) is a diverse group of small DNA viruses, some of which have been extensively studied over the past three decades due to their carcinogenic potential. The persistence of viral infections and the uncontrolled expression of the E6 and E7 viral oncogenes are critical events in the transformation process. It is important to note that viral types are specific for each type of cell and usually cause various types of lesions, benign or malignant. Recognizing the critical role that certain specific types of HPV play in the development of cervical cancer is very important for their prevention and public health strategies for cervical cancer, which are still the leading cause of death among cancer patients in many countries.