[The Minor T Allele of the Single Nucleotide Polymorphism rs 13360222 Decreases the Activity of the HAVCR2 Gene Enhancer in a Cell Model of Human Macrophages].

The TIM-3 receptor, encoded by the Hepatitis A Virus Cellular Receptor 2 (HAVCR2) gene, is an immune checkpoint and plays an important role in preventing the development of autoimmune reactions. This receptor is expressed on the surface of various immunocytes and its functions in myeloid cells remain poorly understood, compared to the role of T cell specific TIM-3 that is actively studied in the context of the search for promising therapeutic targets in cancer immunotherapy. During this study, we performed deletion analysis of the promoter region of the HAVCR2 gene, as well as functional characterization of its enhancer, and studied the effect of a number of single nucleotide polymorphisms (SNPs) on the activity of these regulatory elements in the relevant model of human macrophage-like cells-U937 activated monocytes. We have shown that the SNPs rs10515746(A) and rs4704853(A) located in the HAVCR2 gene promoter and associated with the development of a number of pathologies, do not affect the activity of the promoter in activated monocytes. However, a minor T variant of SNP rs13360222 located in the enhancer in the third intron of the gene, significantly reduces the ability of the enhancer to activate the HAVCR2 promoter, presumably due to weakening of the binding of nuclear receptor ESR2 to the respective region.

[Serum of Mice Immunized with Mt1-MMP Metalloproteinase Reduces Migration Potential of Pancreatic Cancer Cells].

Expression levels of matrix metalloproteinases, in particular MT1-MMP, are elevated in pancreatic cancer (PC) cells, and this is associated with increased tumor proliferation, invasion, and migration. MT1-MMP is considered a promising target for drug therapy of PC, but the use of inhibitors and therapeutic antibodies to MT1-MMP is limited because maximal efficiency is only observed in a narrow time interval, at the early asymptomatic stages of the disease. This problem could be solved by immunization to MPs at the moment of detection of the primary tumor. This therapeutic effect could be provided by specific antibodies that can be re-produced in case of relapses. Here, we selected the optimal mode for immunization of mice with MT1-MMP fragments that allows us to obtain a high titer of specific antibodies in the blood serum. The obtained antiserums effectively inhibited MT1-MMP enzymatic activity, migration of PANC-02 PC cells through the collagen matrix, and activation of the main inducers of epithelial -mesenchymal transition, TGF-ß and MMP-2. These results maybe useful in the development of drugs for PC treatment, and the approach we propose might form the basis for design of antitumor drugs with prolonged action.

[Regulation of IL33 Gene Expression by SP1 and Foxa1 in Breast and Lung Cancer Cells].

Interleukin-33 (IL-33) is a member of the IL-1 cytokine family, primarily known as a mediator of the humoral immune response. It provides protection of barrier tissues and participates in the development of a range of diseases. This cytokine promotes carcinogenesis by induction of proliferation and survival of cancer cells, remodeling of the tumor microenvironment, and promoting immunosuppressive conditions. Elevated levels of IL-33 were observed in many types of cancers. This elevation correlates with a poor prognosis, making IL33 a promising target for cancer immunotherapy. The mechanisms of IL-33 expression regulation in human tumor cells are not well understood. Here, we show that that expression of IL-33 in breast and lung cancer cell lines depends, at least in part, on the activity of the SP1 and FOXA1 transcription factors. Increases in the activity of these transcription factors may be responsible for elevated levels of IL-33 and subsequent tumor progression.

[Interleukin-33: Friend or Enemy in the Fight against Tumors?]

Interleukin-33 (IL-33) belongs to the IL-1 cytokine family and acts as a danger signal. IL-33 is released from stressed or necrotic cells. Initially, IL-33 was described as an inducer of the humoral immune response, which activated Th2 cells and mast cells involved in modulating inflammation and allergic reactions. In addition, IL-33 acts as a stimulator of the Th1, NK, and CD8T cells, which induce a cytotoxic immune response against intracellular pathogens. It was recently discovered that this cytokine is involved in the development of cancer by performing both pro- and antitumor functions. IL-33 can directly affect tumor cells and provokes their proliferation, survival, and metastasis. Moreover, IL-33 stimulates carcinogenesis by remodeling the tumor microenvironment and inducing angiogenesis, thus contributing to the generation of immunosuppressive conditions. At the same time, IL-33 causes tumor infiltration with cytotoxic CD8 T lymphocytes and natural killers, which leads to cytolysis-mediated cancer cell death. This review describes the versatile role of the IL-33/ST2 cascade in the development of experimental and clinical tumors. In addition, we discuss the prospects for the application of IL-33 and ST2 as diagnostic biomarkers and targets for cancer immunotherapy.

[Relative Efficiency of Transcription Factor Binding to Allelic Variants of Regulatory Regions of Human Genes in Immunoprecipitation and Real-Time PCR].

The efficiency at which specific transcription factors interact with DNA may vary in the presence of single nucleotide polymorphisms (SNPs), and the variation provides an important mechanism that regulates expression of human genes and contributes to the individual susceptibility to various diseases. Ample genetic and epigenetic data make it possible to predict both functional polymorphic variants and the transcription factors whose binding they affect. However, predictions of the kind require experimental verification. An original method developed for the purpose includes immunoprecipitation of DNA-protein complexes, followed by quantification of the bound DNA by real-time PCR. The method does not require chemical modification of the DNA probes and yield reproducible results with total nuclear extracts from cultured human cells.

[The Novel Short Isoform of Securin Stimulates the Expression of Cyclin D3 and Angiogenesis Factors VEGFA and FGF2, but Does Not Affect the Expression of MYC Transcription Factor].

Pituitary tumor-transforming gene-1 (PTTG1) encodes securin, a multifunctional protein involved in development of various types of cancer. Securin participates in the regulation of sister chromatids separation and the expression of multiple genes involved in the control of the cell cycle, metabolism, and angiogenesis. In several human cell lines, we have found a novel short isoform of securin mRNA, which does not contain exons 3 and 4. After the translation of this new mRNA, a shortened protein is produced that, like the full-size form, is able to activate the transcription of cyclin D3 gene (CCND3), which controls the G1/S transition and angiogenesis factors VEGFA (vascular endothelial growth factor), and FGF2 (fibroblast growth factor 2) in HEK293 cells. However, unlike the full-size protein, the short isoform of PTTG1 does not affect the MYC gene expression because it lacks the DNA-binding domain, which is needed for its interactions with the MYC promoter. Furthermore, the short form of securin does not influence the expression of MYC transcriptional targets, such as TP53 and IL-8. Thus, we found a novel isoform of securin which is able to activate a more restricted repertoire of genes compared to the full-size protein.