Computer analysis of regulation of hepatocarcinoma marker genes hypermethylated by HCV proteins

Hepatitis C virus (HCV) is a risk factor that leads to hepatocellular carcinoma (HCC) development. Epigenetic changes are known to play an important role in the molecular genetic mechanisms of virus-induced oncogenesis. Aberrant DNA methylation is a mediator of epigenetic changes that are closely associated with the HCC pathogenesis and considered a biomarker for its early diagnosis. The ANDSystem software package was used to reconstruct and evaluate the statistical significance of the pathways HCV could potentially use to regulate 32 hypermethylated genes in HCC, including both oncosuppressor and protumorigenic ones identified by genome-wide analysis of DNA methylation. The reconstructed pathways included those affecting protein-protein interactions (PPI), gene expression, protein activity, stability, and transport regulations, the expression regulation pathways being statistically significant. It has been shown that 8 out of 10 HCV proteins were involved in these pathways, the HCV NS3 protein being implicated in the largest number of regulatory pathways. NS3 was associated with the regulation of 5 tumor-suppressor genes, which may be the evidence of its central role in HCC pathogenesis. Analysis of the reconstructed pathways has demonstrated that following the transcription factor inhibition caused by binding to viral proteins, the expression of a number of oncosuppressors (WT1, MGMT, SOCS1, P53) was suppressed, while the expression of others (RASF1, RUNX3, WIF1, DAPK1) was activated. Thus, the performed gene-network reconstruction has shown that HCV proteins can influence not only the methylation status of oncosuppressor genes, but also their transcriptional regulation. The results obtained can be used in the search for pharmacological targets to develop new drugs against HCV-induced HCC.

Phagocyte system under spaceflight conditions

The spaceflight conditions lead to disturbances in immune system and cause the changes in microbial and chemical environment that create preconditions for immunodeficiency and allergic disease development. With the spaceflights lengthening the problem of crewmembers immunodeficiency and the probability of allergic disease manifestation became actual. The higher risk of various pathological conditions noted in cosmonauts during space flight due to lowered immunological resistance and unnatural biological and chemical environment (autoimmune reactions, bacterial and viral autoinfections, possible allergic events etc.) proves the need of studying the mechanisms of these disturbances and determination the most labile links between the immune system and antigen environment. In this case phagocytes seems to be one of the most important cells that can influence both induction and effector stage of immune reactions and also take part in the regulation of the immune response. The goal of the investigation was to conduct studies of one of the of the phagocytes metabolic and migration activity that are closely connected with functional activity of the cells.