GLAD-PCR Assay of R(5mC)GY Sites in the Regulatory Region of Tumor-Suppressor Genes Associated with Gastric Cancer.

At early stages of carcinogenesis, the regulatory regions of some tumor suppressor genes become aberrantly methylated at RCGY sites, which are substrates of DNA methyltransferase Dnmt3. Identification of aberrantly methylated sites in tumor DNA is considered to be the first step in the development of epigenetic PCR test systems for early diagnosis of cancer. Recently, we have developed a GLAD-PCR assay, a method for detecting the R(5mC)GY site in the genome position of interest even at significant excess of DNA molecules with a non-methylated RCGY site in this location. The aim of the present work is to use the GLAD-PCR assay to detect the aberrantly methylated R(5mC)GY sites in the regulatory regions of tumor suppressor genes (brinp1, bves, cacna2d3, cdh11, cpeb1, epha7, fgf2, galr1, gata4, hopx, hs3st2, irx1, lrrc3b, pcdh10, rprm, runx3, sfrp2, sox17, tcf21, tfpi2, wnt5a, zfp82, and znf331) in DNA samples obtained from gastric cancer (GC) tissues. The study of the DNA samples derived from 29 tumor and 25 normal gastric tissue samples demonstrated a high diagnostic potential of the selected RCGY sites in the regulatory regions of the irx1, cacna2d3, and epha7 genes; the total indices of sensitivity and specificity for GC detection being 96.6% and 100%, respectively.

[Markers of endothelial dysfunction in patients with arterial hypertension exposed to occupational irradiation of low intensity].

Aim To study the association between concentrations of endothelial dysfunction (ED) markers and arterial hypertension (AH) in people who were exposed to long-term action of "low-dose" ionizing radiation.Material and methods The study subjects were men of middle age (45-55 years) who were workers of the Siberian Integrated Chemical Plant with the length of service on the shop floor of at least 5 years. The subjects were divided into the main group (n=96) consisting of workers with grade 1-2 AH and the control group (n=48) consisting of arbitrarily healthy workers. Both groups contained workers who had been exposed to long-term occupational low-intensity irradiation (γ-radiation) and those not exposed to this irradiation. The study evaluated risk factors for cardiovascular diseases, presence of concomitant diseases, blood biochemistry (concentrations of glucose, high-sensitivity C-reactive protein (hsCRP), total cholesterol, low-density lipoproteins, high-density lipoproteins, triglycerides, creatinine, and ED markers, including endothelin, angiotensin II, von Willebrand factor, C-type natriuretic peptide, tissue plasminogen activator, tumor necrosis factor α (TNF-α), and homocysteine, major clinical data, total dose of external irradiation, and the content of 239Pu in the body.Results AH was associated primarily with excessive body weight and severity of atherogenic dyslipidemia and homocysteinemia. Higher plasma concentrations of TNF-α and a tendency to increasing hsCRP in the AH group, as distinct from the control group of arbitrarily healthy men, indicated a proinflammatory shift. The ED markers were related with clinical data of AH patients and associated with the lipid profile and increased blood concentrations of inflammatory mediators. The radiation exposure did not change the ED marker array in AH patients, which did not allow recommendation of the studied plasma indexes for detection of vascular endothelial injury in workers with AH of the Siberian Integrated Chemical Plant.Conclusion The study results evidenced the absence of adverse effects of long-term occupational exposure to low-intensity radiation on the vascular endothelium as evaluated by ED markers. In men aged 45-55 years, AH was associated primarily with excessive body weight, homocysteinemia, and atherogenic dyslipidemia.

[Application of GLAD-PCR Assay for Study on DNA Methylation in Regulatory Regions of Some Tumor-Suppressor Genes in Lung Cancer].

Hypermethylation of the gene regulatory regions are common for many cancer diseases. In this work we applied GLAD-PCR assay for identificating of the aberrantly methylated RCGY sites in the regulatory regions of some downregulated genes in tissue samples of lung cancer (LC). This list includes EFEMP1, EPHA5, HOXA5, HOXA9, LHX1, MYF6, NID2, OTX1, PAX9, RARB, RASSF1A, RXRG, SIX6, SKOR1 and TERT genes. The results of DNA samples from 40 cancer and 25 normal lung tissues showed a good diagnostic potential of selected RCGY sites in regulatory regions of MYF6, SIX6, RXRG, LHX1, RASSF1A and TERT genes with relatively high sensitivity (80.0 %) and specificity (88.0 %) of LC detection in tumor DNA.

[Application of GLAD-PCR analysis for the methylation sites detection in the regulatory areas of tumor-suppressor genes ELMo1 and EsR1 in colorectal cancer].

Aberrant methylation of regulation regions of tumorsuppressor genes is showed for many cancer diseases. In course of this modification an enzyme DNMT3 methylates RCGY sites in CpG-islands of regulation regions producing R(5mC)GY sites. Earlier we developed GLAD-PCR assay to determine R(5mC)GY site in a definite position of human genome. In this work we have applied GLAD-PCR assay to determine R(5mC)GY sites in regulation regions of ESR1 and ELMO1 tumor-suppressor genes. We have studied a fragment of first exon of ELMO1 gene and a part of ESR1 promoter region in DNA preparations from malignant cell line SW837 and colorectal tumor samples. We have checked four sites in each region and found two highly methylated sites: GCGC in first exon of ELMO1 gene and GCGT in promoter region of ESR1 gene. Site GCGT is weakly methylated in healthy tissues and more methylated in the most of colorectal samples. Site GCGC is not methylated in healthy tissues and significantly methylated in 60% of colorectal samples. A possibility to use GLAD-PCR assay for cancer diagnostics is discussed.

[Medical and Dosimetric Register of the Siberian Group of Chemical Enterprises Personnel--the Basis for the Evaluation of Chronic, Radiation Exposure Effects].

The characteristic of medical and dosimetric register database of Siberian Group of Chemical Enterprises personnel is represented. This characteristic includes the description of the database structure, main sources of information, quantitative composition of the cohort under study, methods of evaluation of the external and internal irradiation doses, modern data on cancer incidence and reasons of death. The database is the basis for estimating the risk of the cancer and non-cancer effects after a long-term radiation exposure and dependence of "dose-response" at different levels: from population and group to cell and molecular. Now the database of register contains the information about more than 66,500 employees at the Siberian Group of Chemical Enterprises, about 22,000 of whom were exposed to external irradiation and more than 7500 employees--to internal irradiation. The register is the information resource of a large biological material bank. Using this bank, the research of chronic radiation exposure genetic effects and markers of individual radio sensitivity is performed.

[Mortality from cancer of the population living close to a large nuclear power plant].

There was analyzed cancer mortality of residents of Seversk, located close to the world's largest complex of enterprises of the nuclear industry - the Siberian Chemical Enterprise (the period from 01.01.1970 till 31.12.2005 For comparison there were used rates of cancer mortality in the nearest town (Tomsk), similar in climate-geographical, economic and social conditions. The study found that cancer mortality of Seversk residents during the period 1970-2005 increased in 3.2 times (from 70.2 to 223.5 per 100,000). Among the causes of cancer mortality in men there were prevailed tumors of the digestive system as well as blood and lymphatic tissues. In women, the leading causes of death were tumors of the digestive system, the genitals and the breast. Standardized rates of cancer mortality in the Seversk population were lower than in residents of Tomsk, except female mortality due to hematological malignancies and malignant tumors of the urinary tract and genitals.

[The frequency and spectrum of cytogenetic anomalies in employees of Siberian Group of Chemical Enterprises].

The results of the study of frequency and spectrum of cytogenetic anomalies in 657 healthy employees of the main facilities of the Siberian Group of Chemical Enterprises exposed to external, internal and combined irradiation are presented. No dependence between age and chromosome aberrations frequency was revealed. Chronic external exposure appeared to be the main factor of induction of chromosome aberrations. The frequency of aberrant cells, chromosome type aberrations, paired fragments and rings was statistically significantly higher in employees exposed to external irradiation as compared to persons exposed to combined irradiation. A nonlinear dependence the dose of irradiation and frequency of chromosome aberrations was revealed. A statistically significant decrease of prevalence of aberrant cells, aberration of chromatid and chromosome type was established in employees exposed to irradiation at a dose range of > 0-10 mSv compared to the control group. This agrees with the phenomenon of radiation hormesis. A significant increase of the frequency of chromosome aberrations was not observed at doses below > 40 mSv. In employees exposed to irradiation at a dose range > 40-100 mSv, a statistically significant increase of frequencies of aberrant metaphases, aberrations of chromatid and chromosome types was established. Same was found for dicentrics at dose range of >100-200 mSv. This supports a well known linear threshold model. Dose-effect curve has a plateau at doses ranged from 100 to 500 mSv.

[The dynamics of heath indicators of population of industrial town].

The article presents the results of analysis of dynamics of health indicators of population of industrial town (medical demographic indicators, disability, morbidity of social hygienically important diseases) during 1970-2010. The classified administrative territorial municipality of Seversk constructed near the Siberian chemical industrial center, the internationally first-rate complex of nuclear industry enterprises was used as a research base. It is demonstrated that dynamics of health indicators of studied population had such negative tendencies as rapid population ageing, population loss due to decrease of natality and increase of mortality (population of able-bodied age included), prevalence of cardio-vascular diseases, malignant neoplasms and external causes, chronization of diseases. The established tendencies are to be considered in management decision making targeted to support and promote population health in industrial towns.

[Factors determining application activity for and satisfaction with medical care among able-bodied population of closed industrial city].

According to a poll results, nearly 16.5% of questioned able-bodied inhabitants of industrial city mentioned unsatisfactory health state of self, with main reasons of negative environmental influence and low availability of quality medical care. Most respondents (81.1%) are characterized by poor medical activity. Over a quarter of the questioned (25.7%) are dissatisfied with provided medical care. The main factors determining medical activity and satisfaction with medical care are age, sex, employment place and income level.

[The estimate of association between gene polymorphisms and the frequency and spectrum of cytogenetic abnormalities in the cohort of Siberian Group of Chemical Enterprises employees exposed to professional irradiation (microarray studies)].

The results from the research into the association between polymorphisms of genes-candidates for individual radiosensitivity and the frequency and spectrum of cytogenetic abnormalities are analyzed. The study was conducted among Siberian Group of Chemical Enterprises healthy employees exposed to professional irradiation in a dose range of 100-300 mSv. Genotyping of DNA samples from 96 employees was carried out by oligonucleotide microarray: "Cancer_SNP_Panel GT-17-211" ("Illumina") containing 1, 421 SNP-markers (Single Nucleotide Polymorphisms) of 406 genes. The standard cytogenetic analysis was performed in the entire examined group. We have also analyzed the association of these SNP with the frequencies of aberrant cells and following chromosomal aberrations: single chromatid fragments, chromatid exchanges, paired fragments, dicentric, ring and frequencies, translocations. We have found that 40 SNP (rs1800389, rs1051690, rs2392221, rs1041163, rs2114443, rs6083, rs1760904, rs4986894, rs488133, rs7462102, rs11249938, rs34206126, rs33945943, rs34324628, rs5742694, rs978458, rs5742667, rs2373721, rs2162679, rs889162, rs2233679, rs2010457, rs2873950, rs1574154, rs10934500, rs4688046, rs10934503, rs4624596, rs2288729, rs4227, rs1367696, rs751087, rs1269486, rs1149901, rs1800404, rs887477, rs696405, rs751087, rs81 92284, rs312016) are associated with the frequency of different types of chromosomal abnormalities (p-value with FDR of Benjamini-Hochberg--equal less than 0.05). 24 SNP (underlined) are associated with more than one type of chromosome abnormalities. In the future, we are going to confirm the results in further studies on the cohort of more than 600 persons.

[Medical and social importance of Acute Myocardial Infarction Register for major industrial enterprises workers (exemplified by Siberian Chemical Works)].

Prevalence of acute myocardial infarction does not differ between groups that were or were not subjected to long radiation of low intensity. Creation and completing of the Acute Myocardial Infarction Register helps to objectively monitor situations, to form risk groups, to provide purposeful measures for lower mortality with and occurrence of acute myocardial infarction.

[The health status of population in the Tomsk oblast'].

The protection and promotion of population's health is a necessary condition for the provision of national security, stable economic growth and preservation of the Russian way of life. While working out the strategy of the protection and promotion of population's health, we analyzed the dynamics of the basic indicators of population's morbidity and also studied the self-estimation of health status and the personal medical activity of regional population. As a result of this, the increase in the prevalence of socially significant diseases against some reduction in the levels of primary and general morbidity was noted. The results of a sociological survey showed that personal medical activity of citizens is not high and ineffective, and factors indicated by respondents as reasons for ill health are potentially manageable. In this connection the preventive activity should be, first of all, aimed at changing the behavior of population in relation to one's own health and the minimization of the negative effect of manageable risk factors.

[Epidemiological studies as an instrument for assessment of society welfare and quality of medical service (examplified by of analysis of myocardial infarction morbidity)].

Dynamics of incidence of myocardial infarction among adult (older than 20 years) population of Seversk in 1998-2006 was studied according to WHO program "Myocardial Infarction Register" updated in concordance with criteria of Joint European Society of Cardiology/American College of Cardiology Committee for the Redefinition of Myocardial Infarction (2002). Incidence of myocardial infarction in the studied population had steady tendency to growth with equal contribution of such components as first and recurrent myocardial infarction what was related to progressive aging of population. Hospital myocardial infarction mortality showed steady tendency to decline evidencing for improvement of quality of medical service.

[The evaluation of association between polymorphisms of DNA excision repair enzyme genes and risk of malignant tumors development in Siberian Group of Chemical Enterprises workers].

There was analyzed single nucleotide polymorphisms of DNA excision repair enzyme genes hOGG, XPD, XPG, XRCC1 in 98 Siberian Group of Chemical Enterprises cancer patients and 148 healthy donors. No association was observed between the analyzed polymorphisms and malignant tumors in both control and subgroup (under study) of persons exposed to occupational ionizing radiation. Heterozygosis for the genes hOGG and XPD was found to be a protective factor to malignant tumors in exposed persons: the odds ratio = 0.42 (95% CI 0.18-0.98; p = 0.044) for the 326Ser/Cys genotype of the hOGG gene and 0.48 (95% CI 0.23-0.99; p = = 0.047) the 751Lys/Gln genotype of the XPD gene. The data obtained show a possible modifying role of the hOGG and XPD gene polymorphisms for malignant tumors risk in exposed persons.

[The risk of arterial hypertension development in Siberian Group of Chemical Enterprises personnel].

PURPOSE: to study risk factors of arterial hypertension (AH), their significance for AH pathogenesis in atomic power plants employees occupationally exposed to long-term ionizing radiation in a "low" dose range (cumulative external radiation doses in the range up 1 Sv). The case-control study was carried in the cohort of workers aged 40-50 ever employed at the Siberian Group of Chemical Enterprises (SGCE) between 2003-2005. 970 persons were examined by standardized epidemiological methods. "Case" (n = 359) was found to be a recent AH case (less than 3 years) in SGCE employees whose average length of service is 3 years. "Control" (n = 611) - healthy men of the same age, length of service and working conditions. Risk of AH development (odds ratio (OR) = 1.6 (1.1; 2.37) was found to be higher in radiation workers in comparison with non-radiation ones without any linear dependence of risk upon cumulative external gamma-radiation dose in the range under study (OR in a cumulative external radiation dose range 7.3-21.3 mSv = 1.6 (0.96; 2.51); OR in a cumulative external radiation dose range 21.4-68.5 mSv = 1.7 (1.04; 2.67); OR in a cumulative external radiation dose range 68.6-864 mSv = 1.6 (1.01; 2.57). Not only traditional risk factors such as: obesity (OR = 7.1 (5.06; 10.1), frequent alcohol usage (OR = 1.3 (1.06; 1.63)), dyslipidemia (OR = 2.1 (1.61; 2.08)); hyperhomocisteinemia (OR = 1.4 (1.09; 1.72)); psychoemotional (OR = 1.4(1.11; 1.89)), hereditary aggravation (OR = 2.2 (1.75; 2.9)) in SGCE personnel, but also technogenic explosion descriptions are related to AH development. The long-term occupational external gamma-radiation in a dose range up 1 Sv potentiates a negative influence of CVD traditional risk factors (for hypercholesterinemia OR = 1.9 (1.3; 2.9), for AH OR = 3.1 (2.2; 4.6)) that leads to increase in risk coefficients for 30-60% in persons exposed to traditional and technogenic factors impact (for hypercholesterinemia and ionizing radiation OR = 2.5 (1.7; 3.2); for AH and IR OR = 3.9 (2.8; 5.2)) in comparison with non-radiation personnel.

[Risk factors prevalence for cardiovascular diseases among atomic power industry enterprises personnel].

UNLABELLED: A selective cross-sectional study based on Regional Medico-Dosimetric Register was carried out in some Siberian Group of Chemical Enterprises (SGCE) workers (aged 40-50) with the aim of studying the most important risk factors prevalence for cardiovascular diseases development. 2010 persons examined with the use of standardized epidemiological methods made up 32.6% of total SGCE personnel aged 40-50. PURPOSE: the study of risk factors of cardiovascular diseases, their prevalence, intensity and significance in atomic power plants workers exposed to occupational long-term ionizing radiation in a "low" dose range (cumulative doses in the range up to 1 Sv). The study of prevalence of risk factors for CVDs development in men occupationally exposed to ionizing radiation revealed frequent changes in the type of work performed, higher levels of psychoemotional tension, as well as high prevalence of low levels of high-density lipoprotein cholesterol (HDL-cholesterol) and obesity. Women workers of the main production were found to have hypercholesterolaemia more often than those of the auxiliary production. Annual health checks of nuclear workers should be extended to include waist and hips measurement, body mass index (BMI) calculation, lipid factors evaluation, as well as stress tests (bicycle and/or stress echocardiography) in case there are three or more risk factors for CVDs for workers of the main production.

[Regional medico-dosimetric register (RMDR) is a model for evaluation of long-term "low" dose ionizing radiation effects on Siberian group of chemical enterprises main production personnel].

Medico-dosimetric register is an optimal model of epidemiological studies on evaluation of ionizing radiation effects. Regional medico-dosimetric register (RMDR) is a system of interrelating information blocks including data on Siberian Group of Chemical Enterprises (SGCE) personnel. At present SGCE personnel and Seversk residents RMDR database includes information on 138496 persons, 65538 of which are SGCE workers. SGCE personnel and Seversk residents RMDR is a scientific base for researches with the aim of evaluating long-term ionizing radiation effects in a "low" dose range. Information on mortality and morbidity rate as well as "thematic" registers of the main diseases potentiates in evaluating the spectrum of somatic stochastic effects and radiogenic risks in SGCE workers and Seversk residents as well as their offsprings. A practical significance of RMDR database is the formation of the main diseases "risk" groups depending on definite risk factors in certain groups that provides targeted diagnostic and preventive therapy both among high-dose establishments' workers and residents living near-by.

[Hemoblastosis and leukemia morbidity in the townsfolk of Seversk and of Siberian group of chemical enterprises personnel].

Hemoblastosis and leukemia morbidity has been analyzed in the townsfolk of Seversk (in particular, Seversk residents and Siberian Group of Chemical Enterprises (SGCE) personnel). The standardized relative risk ratios for hemoblastosis morbidity in menes and womens of Seversk were found to be significantly higher in comparison with the regional standard ratios (in 1.8 and 1.5 times correspondingly). Hemoblastosis and leukemia morbidity rate in SGCE males is significantly higher in comparison with the similar regional standard ratios. Leukemia morbidity dependence due to cumulative external gamma-radiation in a dose range up to 1 Sv has not been found in SGCE personnel, without regard to chronic lymphatic leukemia.

[Preclinical diagnosis of cardiovascular diseases in workers engaged into industries with radiation danger].

The authors presented results of single-stage cross study of randomized select from a cohort of long seniority workers of isotope separation plant in Siberian Chemical Enterprise, with studies of inflammation markers, vascular and platelet hemostasis, serum lipid parameters, calculated atherogeneity coefficient, homocysteine levels. Serum atherogeneity coefficient and inflammation markers levels (fibrinogen, C-reactive protein) could be considered as the most informative laboratory indicators of underlying cardiovascular diseases in individuals without ischemic heart disease. Among a list of standard inductors of platelet aggregation, collagen and epinephrine should be considered preferential. Increased platelet aggregation requires disaggregant therapy, especially in smokers. Increased homocysteine level is associated with high frequency of atherosclerotic plaques and smoking.