Evaluation of microRNA Expression Features in Patients with Various Types of Arterial Damage: Thoracic Aortic Aneurysm and Coronary Atherosclerosis

Circulating serum miRNA are increasingly used as biomarkers and potential treatment targets in several clinical scenarios, including cardiovascular diseases. However, the current data on circulating miRNA in thoracic aorta aneurism (TAA) patients are inconclusive. The aim of the present study is to compare the levels of several circulating miRNA in patients with degenerative TAA, coronary artery disease (CAD), and controls for special profile identification. We have identified several candidates for the role of new biomarkers: miR-143-3p, miR-181-5p, miR-126-3p, miR-126-5p, miR-145-5p, miR-150-5p, and miR-195-5p.

MATERIALS AND METHODS

Serum samples of 100 patients were analyzed, including 388 TAA patients scheduled for elective surgery, 67 patients with stable CAD and 17 controls, were used for miRNA isolation and identification.

RESULTS

More specific for TAA with very high predictive ability in ROC analysis was an increase in the levels of miR-21-5p, miR-29b-5p, miR-126-5p/-3p, miR-181b-5p, and miR-92a-3p, with the latter microRNA being investigated as a novel potential marker of TAA for the first time.

CONCLUSION

TAA and CAD patients demonstrated a significant increase in the levels of circulating miR-126-5p/-3p, miR-181b-5p, and miR-29b-3p. More specific for TAA with very high predictive ability in ROC analysis was an increase in the levels of miR-21-5p, -29b-5p, -126-5p/-3p, 181b-5p, and -92a-3p, with the latter microRNA being investigated as a potential marker of TAA for the first time.

Diversity and Differential Expression of MicroRNAs in the Human Skeletal Muscle with Distinct Fiber Type Composition

The ratio of fast- and slow-twitch fibers in human skeletal muscle is variable and largely determined by genetic factors. In this study, we investigated the contribution of microRNA (miRNA) in skeletal muscle fiber type composition. The study involved biopsy samples of the vastus lateralis muscle from 24 male participants with distinct fiber type ratios. The miRNA study included samples from five endurance athletes and five power athletes with the predominance of slow-twitch (61.6-72.8%) and fast-twitch (69.3-80.7%) fibers, respectively. Total and small RNA were extracted from tissue samples. Total RNA sequencing (N = 24) revealed 352 differentially expressed genes between the groups with the predominance of fast- and slow-twitch muscle fibers. Small RNA sequencing showed upregulation of miR-206, miR-501-3p and miR-185-5p, and downregulation of miR-499a-5p and miR-208-5p in the group of power athletes with fast-twitch fiber predominance. Two miRtronic miRNAs, miR-208b-3p and miR-499a-5p, had strong correlations in expression with their host genes (MYH7 and MYH7B, respectively). Correlations between the expression of miRNAs and their experimentally validated messenger RNA (mRNA) targets were calculated, and 11 miRNA-mRNA interactions with strong negative correlations were identified. Two of them belonged to miR-208b-3p and miR-499a-5p, indicating their regulatory links with the expression of CDKN1A and FOXO4, respectively.

Circulating Extracellular miRNA Analysis in Patients with Stable CAD and Acute Coronary Syndromes

Extracellular circulating microRNAs (miRNAs) are currently a focus of interest as non-invasive biomarkers of cardiovascular pathologies, including coronary artery disease (CAD) and acute coronary syndromes (ACS): myocardial infarction with and without ST-segment elevation (STEMI and NSTEMI) and unstable angina (UA). However, the current data for some miRNAs are controversial and inconsistent, probably due to pre-analytical and methodological variances in different studies. In this work, we fulfilled the basic pre-analytical requirements provided for circulating miRNA studies for application to stable CAD and ACS research. We used quantitative PCR to determine the relative plasma levels of eight circulating miRNAs that are potentially associated with atherosclerosis. In a cohort of 136 adult clinic CAD patients and outpatient controls, we found that the plasma levels of miR-21-5p and miR-146a-5p were significantly elevated in ACS patients, and the level of miR-17-5p was decreased in ACS and stable CAD patients compared to both healthy controls and hypertensive patients without CAD. Within the ACS patient group, no differences were found in the plasma levels of these miRNAs between patients with positive and negative troponin, nor were any differences found between STEMI and NSTEMI. Our results indicate that increased plasma levels of miR-146a-5p and miR-21-5p can be considered general ACS circulating biomarkers and that lowered miR-17-5p can be considered a general biomarker of CAD.

[Change of transcription level of photoreceptor-specific CRX gene in the peripheral blood of the participants of an arctic world oceanic international flight]

The CRX gene encoding the cone-rod homeobox protein is a specific photoreceptor transcription factor crucial for retinal function. Persons temporarily residing in the Arctic zone during the polar summer may suffer from disturbances associated with extremely high ambient illumination. These environmental changes are mediated by retinal photoreceptors; therefore, it is important to study the expression of retinal genes in order to assess individual capacities of sensory adaptation to polar day conditions.

PURPOSE

To reveal the dynamics of CRX expression level in humans after a prolonged temporary exposure to polar day conditions.

MATERIAL AND METHODS

The study included 6 pilots (males from 39 to 69 y.o.) who participated in the Arctic World Oceanic International Flight Sever Vash (West to East, from 62°N 74°E to 72°N 114°E). Samples of peripheral blood for RNA isolation were collected at the start and at the end of the flight. The level of mRNA in the samples was evaluated based on the data of quantitative real-time PCR of the CRX gene, as well as the b2M and TBP housekeeping genes (reference).

RESULTS

Expression of the CRX gene in the studied group (p<0.01) was revealed; the total average level of mRNA was about 3 times higher prior to, and approximately 7 times higher after normalization to the b2M gene. Five pilots had increased expression of the CRX gene within the range of -1.53 to -3.07 (Z-score of <0 before the flight and >0 after the flight). In one pilot, the level of CRX expression was higher at the start, but it reduced by the end of the circumnavigation flight.

CONCLUSIONS

The results confirm the hypothesis that the CRX gene is expressed after a prolonged temporary exposure to polar day conditions. It was also revealed that during rapid adaptation, equal changes in the illumination of retinal photoreceptors lead to different individual dynamics of CRX expression.

DNA methylation across the genome in aged human skeletal muscle tissue and muscle-derived cells: the role of HOX genes and physical activity

Skeletal muscle tissue demonstrates global hypermethylation with age. However, methylome changes across the time-course of differentiation in aged human muscle derived cells, and larger coverage arrays in aged muscle tissue have not been undertaken. Using 850K DNA methylation arrays we compared the methylomes of young (27 ± 4.4 years) and aged (83 ± 4 years) human skeletal muscle and that of young/aged heterogenous muscle-derived human primary cells (HDMCs) over several time points of differentiation (0, 72 h, 7, 10 days). Aged muscle tissue was hypermethylated compared with young tissue, enriched for; pathways-in-cancer (including; focal adhesion, MAPK signaling, PI3K-Akt-mTOR signaling, p53 signaling, Jak-STAT signaling, TGF-beta and notch signaling), rap1-signaling, axon-guidance and hippo-signalling. Aged cells also demonstrated a hypermethylated profile in pathways; axon-guidance, adherens-junction and calcium-signaling, particularly at later timepoints of myotube formation, corresponding with reduced morphological differentiation and reductions in MyoD/Myogenin gene expression compared with young cells. While young cells showed little alterations in DNA methylation during differentiation, aged cells demonstrated extensive and significantly altered DNA methylation, particularly at 7 days of differentiation and most notably in focal adhesion and PI3K-AKT signalling pathways. While the methylomes were vastly different between muscle tissue and HDMCs, we identified a small number of CpG sites showing a hypermethylated state with age, in both muscle tissue and cells on genes KIF15, DYRK2, FHL2, MRPS33, ABCA17P. Most notably, differential methylation analysis of chromosomal regions identified three locations containing enrichment of 6–8 CpGs in the HOX family of genes altered with age. With HOXD10, HOXD9, HOXD8, HOXA3, HOXC9, HOXB1, HOXB3, HOXC-AS2 and HOXC10 all hypermethylated in aged tissue. In aged cells the same HOX genes (and additionally HOXC-AS3) displayed the most variable methylation at 7 days of differentiation versus young cells, with HOXD8, HOXC9, HOXB1 and HOXC-AS3 hypermethylated and HOXC10 and HOXC-AS2 hypomethylated. We also determined that there was an inverse relationship between DNA methylation and gene expression for HOXB1, HOXA3 and HOXC-AS3. Finally, increased physical activity in young adults was associated with oppositely regulating HOXB1 and HOXA3 methylation compared with age. Overall, we demonstrate that a considerable number of HOX genes are differentially epigenetically regulated in aged human skeletal muscle and HDMCs and increased physical activity may help prevent age-related epigenetic changes in these HOX genes.

Elevated Plasma Levels of Circulating Extracellular miR-320a-3p in Patients with Paroxysmal Atrial Fibrillation

The potential of extracellular circulating microRNAs (miRNAs) as non-invasive biomarkers of atrial fibrillation (AF) has been confirmed by a number of recent studies. However, the current data for some miRNAs are controversial and inconsistent, probably due to pre-analytical and methodological differences. In this work, we attempted to fulfill the basic pre-analytical requirements provided for circulating miRNA studies for application to paroxysmal atrial fibrillation (PAF) research. We used quantitative PCR (qPCR) to determine the relative plasma levels of circulating miRNAs expressed in the heart or associated with atrial remodeling or fibrillation with reported altered plasma/serum levels in AF: miR-146a-5p, miR-150-5p, miR-19a-3p, miR-21-5p, miR-29b-3p, miR-320a-3p, miR-328-3p, miR-375-3p, and miR-409-3p. First, in a cohort of 90 adult outpatient clinic patients, we found that the plasma level of miR-320a-3p was elevated in PAF patients compared to healthy controls and hypertensive patients without AF. We further analyzed the impact of medication therapies on miRNA relative levels and found elevated miR-320a-3p levels in patients receiving angiotensin-converting-enzyme inhibitors (ACEI) therapy. Additionally, we found that miR-320a-3p, miR-21-5p, and miR-146a-5p plasma levels positively correlated with the CHA₂DS₂-Vasc score and were elevated in subjects with CHA₂DS₂-Vasc ≥ 2. Our results indicate that, amongst the analyzed miRNAs, miR-320a-3p may be considered as a potential PAF circulating plasma biomarker, leading to speculation as to whether this miRNA is a marker of platelet state change due to ACEI therapy.

Data on somatic mutations obtained by whole exome sequencing of FFPE tissue samples from Russian patients with prostate cancer

Prostate cancer (PCa) is the most frequently diagnosed among men malignant disease that remains poorly characterized at the molecular level. Advanced PCa is not curable, and the current treatment methods can only increase the life expectancy by several months. Identification of the genetic aberrations in tumor cells provides clues to understanding the mechanisms of PCa pathogenesis and the basis for developing new therapeutic approaches. Here we present data on somatic mutations, namely single nucleotide variations (SNVs), small insertions and deletions, detected in prostate tumor tissue obtained from Russian patients with PCa. Moreover, we provide a raw dataset on the whole exome and targeted DNA sequencing of tumor and non-tumor prostate tissue obtained from Russian patients with PCa and benign prostatic hyperplasia (BPH). This data is available at NCBI Sequence Read Archive under Accession No. PRJNA506922.

[Targeted gene sequencing panels: applicability for neoantigen profiling of colon and rectal adenocarcinoma]

Cancer immunotherapy represents a promising and rapidly developing approach for the treatment of oncological diseases. Among the methods of personalized adjuvant immunotherapy, neoantigenic peptide-based drugs have demonstrated substantial efficiency. These drugs are designed to target mutant proteins arising from somatic alterations in the genome of tumor cells and thus stimulate immune response against tumor tissues. The methods of individual screening for potentially immunogenic mutations are mostly based on next-generation exome sequencing of tumor samples, which is a complex and costly procedure for clinical application. Targeted gene sequencing panels limited to a certain set of genes represent a reasonable alternative to WES. Targeted sequencing is also more efficient when there is a low amount of the sample DNA available. We have estimated the potential efficiency of targeted oncological panels in terms of somatic neoantigen profiling in colorectal cancer (colon and rectal adenocarcinoma). The clinical practice of identification of frequent somatic variants does not provide enough data for designing an efficient personalized drug when applied to low and medium mutated cancers such as colorectal cancer. Our analysis of 11 commercially available panels containing different number of genes has shown that neither the larger size of a panel nor its initial customization for colorectal cancer provides a significantly better estimation of an individual somatic mutation profile. The optimal approach is to use the general-purpose medium-sized cancer panels (2300-11200 amplicons and/or 150-600 genes). These panels allow to detect a sufficient number of immunogenic epitopes (>3) per patient for over 30-50% of patients.

[GSTP1, APC and RASSF1 gene methylation in prostate cancer samples: comparative analysis of MS-HRM method and Infinium HumanMethylation450 BeadChip beadchiparray diagnostic value]

There is a clear need in molecular markers for prostate cancer (PC) risk stratification. Alteration of DNA methylation is one of processes that occur during ÐÑ progression. Methylation-sensitive PCR with high resolution melting curve analysis (MS-HRM) can be used for gene methylation analysis in routine laboratory practice. This method requires very small amounts of DNA for analysis. Numerous results have been accumulated on DNA methylation in PC samples analyzed by the Infinium HumanMethylation450 BeadChip (HM450). However, the consistency of MS-HRM results with chip hybridization results has not been examined yet. The aim of this study was to assess the consistency of results of GSTP1, APC and RASSF1 gene methylation analysis in ÐÑ biopsy samples obtained by MS-HRM and chip hybridization. The methylation levels of each gene determined by MS-HRM were statistically different in the group of PC tissue samples and the samples without signs of tumor growth. Chip hybridization data analysis confirmed the results obtained with the MS-HRM. Differences in methylation levels between tumor tissue and histologically intact tissue of each sample determined by MS-HRM and chip hybridization, were consistent with each other. Thus, we showed that the assessment of GSTP1, APC and RASSF1 gene methylation analysis using MS-HRM is suitable for the design of laboratory assays that will differentiate the PC tissue from the tissue without signs of tumor growth.

[Current principles in the screening, diagnosis, and therapy of colorectal cancer]

The data available in the literature on the prevalence of colorectal cancer (CRC), its risk factors and genetic aspects are analyzed. Basic screening tests and their diagnostic value are described. The paper indicates the importance of methods (colonoscopy, occult blood feces analysis, fecal immunochemical test, determination of molecular genetic profile of fecal enterocytes) for the early primary diagnosis of colonic epithelial tumors and techniques (echography, computed tomography, magnetic resonance imaging, positron emission tomography) that are required to specify clinical TNM staging and enable one to choose an optimal treatment policy for CRC patients owing to the estimation of tumor volume and to the diagnosis of reginal and distant metastases. It also shows that new screening methods based on the detection of molecular markers for early (premorphological) tumor stages are promising. The role of primary CRC prevention aimed at molding and maintaining a healthy lifestyle in the population is demonstrated.

[THE EVOLUTION OF MARKERS OF PROSTATE CANCER]

The implementation of biochemical laboratory tests in oncology practice increased exponentially during last decades and continues to be in progress nowadays. The application of modern molecular genetic technologies permits using diagnostic systems with greater diagnostic sensitivity and specificity. The new tests are actively implemented permitting to diagnose physical presence of tumor systemic manifestations of malignant neoplasm (cachexia, pyrexia), paraneoplastic syndromes and also to detect tumor markers. The oncomarker permits to differentiate malignant from benign tumor on the basis of quantitative differences in content of corresponding antigene-tumor marker in blood serum independently of localization of tumor nidus. The prostate cancer is a medical social problem of male population. On initial stages, this disease can take its course asymptomatically or with symptomatic conditioned by such concomitant and more prevalent pathologies as chronic prostatitis and prostate benign hyperplasia. The early diagnostic ofprostate cancer permits implementing timely radical treatment frequently contributing to total recovery of patients. The article presents detailed description of evolutionary conception of markers using in diagnostic, staging and prognostication of course of prostate cancer. The acid phosphatase was applied for the first time in early diagnostic of staging of prostate cancer in 1974. Nowadays, in century of "OMX"-technologies, in common clinical practice detection of RNA in urine of patient is used for staging diagnostic and prognostication of progression of process of tissue neotransformation.

[Genome-wide analysis of DNA methylation in prostate cancer using the technology of Infinium HumanMethylation450 BeadChip (HM450)]

Using the technology of DNA chips Infinium HumanMethylation 450 BeadChip it was analyzed quantitative DNA methylation status in 12 paired samples of prostate adenocarcinoma, and morphologically altered tissues. Analysis of differentially methylated regions of the genome showed an association with abnormal status for 21610 and 3852 hypomethylated hyper-methylated CpG sites. Dominance in the cancer genome hypermethylated sites and their predominant localization in the regulatory regions of genes indicate their possible role in the implementation of mechanisms of gene suppression in the pathogenesis of prostate cancer (PCa). For 14 genes studied were characterized array maximum values hypermethylation in promoter region (> 50% CpG sites) in combination with a high level of methylation differences between treatment groups (> 40%). Role of hypermethylation in some of them: AOX1, KLF8, ZNF154, TMEM106A in the pathogenesis of prostate cancer has been showed previously. Hypermethylation of genes ACSS3, TAC1, TUBA4B, ZSCAN12 not previously been shown for prostate cancer, but is characterized by the association with other cancers. In turn, the differences in the levels of methylation in genes GPRASP1, NKX2-6, ARX, CYBA, EPSTI1, RHCG been documented as a result of a number of genome-research oncology, but has not been studied in detail. To assess the diagnostic potential of epigenetic markers of prostate cancer there was carried out unbiased selection of individual CpG sites most reliably discriminate against tumor samples from a group of no tumor samples. In selected diagnostic model based on logistic regression included 9 CpG sites. Validation of the model was carried out on an independent dataset of methylation of 40 paired samples from the prostate cancer project Atlas of Cancer Genome (TCGA) analyzed on the same version of the DNA chip. Summarized rates of diagnostic informativeness of a model (specificity 95%, sensitivity of 97%, the area under the curve of the diagnostic test (ROC) - 0,96), obtained after validation, allow us to consider these CpG Sites as potential markers for molecular diagnosis of prostate cancer.

[Molecular mechanisms of lung cancer development at its different stages in nuclear industry workers]

OBJECTIVE

to assess mutational events in exons 5, 7, and 8 of the p53 gene and to reveal mutant p53 protein in verified cases of morphologically altered (proliferative and precancerous changes, lung cancer) and histologically unaltered, lung tissues in workers exposed to occupational radiation.

MATERIAL AND METHODS

The investigation used formalin-fixed paraffin-embedded unaltered and altered lung tissue blocks (FFPBs) obtained from the human radiobiological tissue repository. The shelf-life of FFPBs was 5-31 years. An immunohistochemical technique using mouse antibodies against p53 protein (<<DAKO>>, Denmark), stained with diaminobenzidine (DAB) chromogen, was employed to determine p53 protein. DNA was isolated from lung tissue FFPBs with QIAmp DNA FFPE Tissue Kit, (<<QIAGEN>>, USA). Polymerase chain reaction (PCR) was performed to amplify the p53 gene exons 5, 7, and 8 selected for examination, by applying the sequences of genes and primers, the specificity of which was checked using the online resource (http://www.ncbi.nlm.nih.gov/blast). PCR products were detected by temporal temperature gradient gel-electrophoresis and the Sanger sequencing method. The obtained DNA fragments were analyzed on a sequencer ABI Prism 3100 Genetic Analizer (<<Applied Biosystems>>, USA). Computer-aided DNA analysis was made using the BLAST program. A package of applied Statistica 6.0 programs was employed for statistical data processing. Results. Immunohistochemical analysis showed that mutant p53 protein was absent in the cells of unaltered lung tissue and the number of cells with mutant p53 protein increased in all the patients with proliferative and precancerous changes and lung cancer, suggesting p53 protein dysfunction. The total number of p53 gene mutations in exons 5, 7, and 8, if there were proliferative and precancerous lung tissue changes and lung cancer, were 25, 20, and 40%, respectively. All the found mutations were transversions (the substitution of purine for pyrimidine or, conversely), indicating the action of exogenous mutagens.

CONCLUSION

The results of this investigation have confirmed other investigators' data showing that p53 gene mutations in lung cancer are observed in 40-70% of cases. The differences in the number of cases of altered lung tissue with mutations in the p53 gene (not more than 40%) and in those of p53 protein expression were found in 100%, suggesting the regulation of p53 gene function in the cell at multiple levels.

SOD2 gene polymorphism and muscle damage markers in elite athletes

Exercise-induced oxidative stress is a state that primarily occurs in athletes involved in high-intensity sports when pro-oxidants overwhelm the antioxidant defense system to oxidize proteins, lipids, and nucleic acids. During exercise, oxidative stress is linked to muscle metabolism and muscle damage, because exercise increases free radical production. The T allele of the Ala16Val (rs4880 C/T) polymorphism in the mitochondrial superoxide dismutase 2 (SOD2) gene has been reported to reduce SOD2 efficiency against oxidative stress. In the present study we tested the hypothesis that the SOD2 TT genotype would be underrepresented in elite athletes involved in high-intensity sports and associated with increased values of muscle and liver damage biomarkers. The study involved 2664 Caucasian (2262 Russian and 402 Polish) athletes. SOD2 genotype and allele frequencies were compared to 917 controls. Muscle and liver damage markers [creatine kinase (CK), creatinine, alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP)] were examined in serum from 1444 Russian athletes. The frequency of the SOD2 TT genotype (18.6%) was significantly lower in power/strength athletes (n = 524) compared to controls (25.0%, p = 0.0076) or athletes involved in low-intensity sports (n = 180; 33.9%, p < 0.0001). Furthermore, the SOD2 T allele was significantly associated with increased activity of CK (females: p = 0.0144) and creatinine level (females: p = 0.0276; males: p = 0.0135) in athletes. Our data show that the SOD2 TT genotype might be unfavorable for high-intensity athletic events.

[Possibility of DNA isolation from archived autopsy tissues for molecular genetic studies]

Optimal conditions were defined for DNA isolation from formalin-fixed and paraffin-embedded (FFPE) archived autopsy lung tissue slices. The quality of DNA preparations isolated from the FFPE archived slices was assessed and their suitability for further molecular genetic analysis estimated. DNA isolated from the FFPE slices stored less and more than 10 years was suitable for molecular genetic studies in 100 and 66.7% of cases, respectively.

Associations of single nucleotide polymorphisms with malignant and borderline bone tumors

Bone neoplasms - are a rare group of diseases, which ethiology and pathogenesis are not fully understood. We have studied 6 single nucleotide polymorphisms rs792/(GHI), rs7956547(IGFI), rs3761243(GNRH2), rs11737764(FGF2), rs6599400(FGFR3), and rs1690916(MDM2) associations with bone tumors. In our work we've detected significant associations with some single nucleotide polymorphisms: IGFl.rs7956547, GNRH2.rs3761243 and FGFR3.rs6599400 in patients with malignant and borderline bone tumors.

[Contemporary pharmacogenetic approaches to the treatment of age-related macular degeneration]

A study on the role of CFH, HTRA and IL-8 gene polymorphism in age-related macular degeneration (AMD) development has been conducted. At the first stage of the study genetic testing was done in 69 patients with exudative AMD and 370 random Moscow citizens without the disease. The goal of the second stage was to determine the influence of gene polymorphism on patient's response to endovitreal ranibizumab treatment. For that, visual acuity and foveal thickness were assessed before and after ranibizumab injections in 120 patients with wet AMD. All patients were genotyped for the genes of interest. The results showed that the presence of homozygous 402H polymorphism in CFH gene, as well as homozygous (-625)A mutation in HTRA1 gene, determines certain clinical presentations. Moreover, visual acuity below 0.1 and presence of 402H, (-625)A and (-251)A alleles in both copies of all three genes (CFH, HTRA and IL-8) are negative predictors of disease severity and antiangiogenic treatment response.

Association of FGFR3 and MDM2 gene nucleotide polymorphisms with bone tumors

Association study of 6 candidate single-nucleotide polymorphisms (rs7921, rs7956547, rs3761243, rs11737764, rs6599400, rs1690916) was carried out in a group of patients with bone tumors of different histological structure (n=68) and control group of normal subjects (n=96). Significant associations of rs6599400 and rs1690916 polymorphisms with disease risk were detected (odds ratio 2.15 [1.06-4.24] and 0.39 [0.19-0.78], respectively). These polymorphisms were located in untranslated genome regions: polymorphism rs6599400 in the 5' region of fibroblast growth factor-3 receptor gene (FGFR3), rs1690916 in the 3' region of mouse MDM2 p53-binding protein homolog (MDM2). These data indicated a possible role of hereditary genetic factors in the formation of predisposition to bone sarcomas and confirmed previous findings according to which these genes should be regarded among the most probable factors involved in tumor development, including tumors of the bone and cartilage tissues.

[Hypermethylation of the CDH1, SEPT9, HLTF and ALX4 genes and their diagnostic significance in colorectal cancer]

Sequential treatment of bisulfate-converted DNA was used to study methylation of promoter areas of SEPT9, HLTF, ALX4 and CDH1 genes. Methylation profiles were evaluated by comparing bioptical findings on colorectal cancer (n=55) and morphologically intact areas of the large bowel (n=71). Significant differences between groups were established for SEPT9, HLTF and ALX4 genes (p < or = 10(-9)) in evaluating medium-rate methylation of CpG. Diagnostic sensitivity (Se) peaked for SEPT9 (78 +/- 7%); specificity--(86 +/- 4%) (Sp). On site CpG (position "+14"), similar findings were reported: Se=81 +/- 6%, Sp=77 +/- 5%. Therefore, CpG(14)SEPT9 may be used as a separate marker. As a result of the use of HLTF as marker on all 23 sites, Se was 67 +/- 6% and Sp--87 +/- 3%; ALX4 diagnostic sensitivity--59 +/- 6%. Specificity level was similar to those of the other genes (88 +/- 3%). Despite the role of CDH1 gene in colorectal cancer, the group-to-group differences in methylation rates were minimal. Such values of Se and Sp as 54 +/- 6% and 67 +/- 5%, respectively, could not support methylation of the CDH1 promoter area for diagnostic purposes. Therefore, combined evaluation of SEPT9, HLTF and ALX4 genes offered more advantage as far as diagnosis is concerned. Hypermethylation in two of the three genes was assumed as a criterion for diagnosis. Under such conditions, diagnostic sensitivity was 81 +/- 7% (Sp=93 +/- 3%). With such high values, the criterion has a potential of being instrumental in working out diagnostic tests for colorectal cancer.

[Problems and prospects of non-invasive screening for colorectal cancer]

High prevalence of colorectal cancer makes it a most serious socio-medical problem. Hence, the necessity of overall screening for prodromal changes and malignant neoplasms at the early stages of the disease. Despite a variety of efficacious instrumental diagnostic tools, the development of non-invasive screening techniques based on recent progress in understanding molecular mechanisms of carcinogenesis remains a highly topical issue. A pathogenetic model of colorectal cancer and pathophysiological basis of screening for colonic neoplasms are considered with the emphasis on the detection of tumour cells in faeces and their DNA carrying mutations in suppressor genes and oncogenes. Results of the studies with the use of one or several DNA oncomarkers are analysed in the context of their value for the diagnosis of colorectal neoplasms. High sensitivity and specificity of these methods make them very promising for application to the screening for colorectal cancer.

[Familial transthyretin amyloidosis]

A case of familial transthyretin amyloidosis with TTR Cys 114 gene polymorphism is described (first in Russia and third in the world). The clinical picture of the proband was dominated by symptoms of autonomous polyneuropathy (orthostatic hypotension, erectile dysfunction, diarrhea, tachycardia, foot dyshydrosis) and of somatic nerve lesions (dumbness, impaired surface and deep sensitivity in the limbs). The patient presented with vitreous body opacity, disturbed eye movements, lateralized sensory symptoms, and difficulty of speech (baryphonia). Electromyographic quantitative autonomous testing and measurement of evoked sympathetic skin potentials confirmed affection of peripheral nerves. Heart ultrasound revealed restrictive amyloid cardiopathy. Histological analysis showed amyloid deposition in the intestines and sural nerve. The proband, his daughter, brother (monozygous twin), and brother's daughter had mutant TTR Cys 114 gene. The brother also had amyloid deposits in the absence of clinical signs of the disease. Analysis of familial medical history demonstrated autosomal dominant inheritance of this mutation in 4 generations. Its possible origin and clinical features of the disease are discussed.

Association of haplotypes of interleukin-10 gene with the risk of cancer

Polymorphisms of promotor region of IL-8, IL-10, and IL-12 genes were analyzed in cancer patients and subjects without history of cancer. The distribution of alleles of the analyzed polymorphisms in the control group coincided with that in other Caucasian populations. The incidences of three IL-10 gene polymorphisms (G-1082A, C-819T, and C-592A) significantly differed in controls and patients. Of 8 theoretically probable IL-10 gene haplotypes determined by these polymorphisms, 3 variants were revealed. Haplotype ACC was more incident in cancer patients, while ATA haplotype was rarer. The results are in line with the findings of other studies indicating the involvement of the immune system genes in the pathogenesis of cancer.

[Contribution of rennin-angiotensin-aldosterone system genes and NO synthase gene to the development of arterial hypertension]

Arterial hypertension (AH) is one of the most widespread cardiovascular disorders, 39.2% of men and 41.1% of women having elevated arterial pressure (AP). Hence, the necessity to elucidate possible causes of this abnormality. Heredity is considered to be a major factor determining AP in humans, and researchers all over the world are engaged in the search for AP markers. This paper is focused on genes controlling the renin-angiotensin-aldosterone system, viz. genes of angiotensin II, type 1 angiotensin II receptors, angiotensin-converting enzyme, and NO synthase. An overview of population studies with special reference to these genes indicates that molecular-genetic mechanisms of AH remain unclear. Joint efforts of researchers working in different centres are needed to address the problem.

[Using the mass spectrometry analysis for hepatitis C virus typing]

Determination of the hepatitis C virus (HCV) genotype has become the standard procedure in laboratory diagnostics of HCV infection. Genotype elucidation has prognostic value assignment helps in assessing disease prognosis and promotes establishing appropriate duration of treatment. Now 11 major genotypes and more than 70 subtypes of HCV have been identified using the sequence variability within 5' non-coding region (5' NCR). In Russia the most common subtypes are 1a, 1b, 2a, 3a and more rare - 4 and 5 types. While the "gold standard" for testing is nucleic acid sequencing, a variety of other assays, including the line probe assay or type-specific amplification, has been developed to provide more rapid and cheaper forms of testing. The aim of this study was to determine the type-specific single nucleotide polymorphism (SNP) in 5' NCR HCV by the classical three-step minisequencing method with followed MALDI-TOF mass spectrometry detection The fragments of 5'NCR of HCV genomes were amplified by the nested RT PCR. The removal of excess nucleotides and primers was performed. Three oligonucleotide primers were design to detect two sets of type-specific SNP in 5' NCR HCV. The primer extension reaction was performed using modified thermostable DNA polymerase and in the presence of ddNTP. The molecular weights of primers extension reaction products were analyzed using MALDI-TOF mass spectrometry. The HCV genotype was determined according the presence in analyses sample the molecules with expected molecular weights. The suggested method was used to type HCV from 69 HCV-positive sera. The 1a genotype was determine in 4.5% samples, 1b - 48%, 2a - 4.5% 3a - 29%, 4 - 1.5%. The mixes of two genotypes were found in 13% samples. All data confirmed by direct nucleic acid sequence. Thus, the new method for HCV typing has been developed using the minisequencing reaction and mass spectrometry for the determination of nucleic acid molecular weight.

[Allele Frequency Analysis of Four Single Nucleotide Polymorphisms Locating in Promoter and 5'-Untranslated Regions of ABCAI Gene in Young Men - Survivors From Myocardial Infarction]

Analysis of allele distribution of four single nucleotide polymorphisms (C-17G, C69T, G-191C and 319insG) of promoter and 5'-untranslated regions of the ABCA1 gene was carried out in a sample of 171 men, who had survived myocardial infarction before 45 years, and in controls. Two-fold increase of T69 and C-191 allele frequencies were observed in Russian population in comparison to Dutch one. While comparing allele and genotype distributions of the polymorphisms in the samples under study no statistically significant differences were found, so as no influence of different alleles on lipid spectrum data was observed. Role of polymorphisms under study appears to be insignificant in formation of genetic susceptibility to myocardial infarction in young men.

[Direct genetic analysis of the rifampicin resistance of M. tuberculosis isolates in sputum samples]

The paper shows a rapid method for diagnosing the resistance of Mycobacterium tuberculosis to rifampicin in the testing of clinical sputum samples. The sputum samples from 12 patients ineffectively treated for pulmonary tuberculosis were treated by the immunomagnetic mycobacterial separation technique; polymerase chain reaction was used to perform the amplification and direct sequencing of the gene fragment rho poB by identifying the mutations responsible for mycobacterial rifampicin resistance. Other equal parts of the same sputum samples were cultured on liquid medium for 5 days and subsequently examined in the same manner and also cultured on the Löwenstein-Jensen solid medium, followed by the determination of rifampicin sensitivity by the routine procedure. Routine examination revealed 7 cases of rifampicin resistance. Short-term (5-day) cultivation of sputum samples, followed by a molecular genetic study, also established rifampicin resistance in all the 7 cases of the 12 tested samples.

[Molecular characteristics of multiresistant clinical strains of Mycobacterium tuberculosis isolated in Russia]

The efficiency of tuberculosis control programs is largely determined by methods for rapid diagnosis of the agent. In comparison with the traditional methods, new molecular technologies for characterization of mycobacteria appear to be more promising, because the result can be obtained in almost no time. Sixty-five strains of M. tuberculosis isolated in various regions of Russia were investigated. Drug resistance and strain appurtenance of this sample were determined by classical (absolute concentrations method, IS6110-RFLP) and modern molecular genetic methods (detection of mutations in rpo B gene, DRE-PCR). The spectrum of mutations of the rpoB gene associated with rifampicin resistance was evaluated by direct sequencing. Mutations involving codons 531 (62.7%), 526 (18.6%), and 516 (10.2%) of rpoB gene predominated in the studied sample. The studied strains were discriminated into 52 individual strains by IS6110-RFLP and DRE-PCR typing. Analysis of the resultant genetic variants showed the predominance of M. tuberculosis family W. The efficiency of combined approach to screening for M. tuberculosis is discussed.

[Detection and characteristics of rpoB gene mutations in rifampicin-resistant clinical strains of M. tuberculosis]

The resistance of M. tuberculosis to rifampicin, one of the key agents used in the treatment of tuberculosis is due to point mutations in the rpoB gene encoding for the B-subunit of PNA polymerase. Based on the detection of such mutations, genotypic determinations of rifampicin resistance is a serous alternative to routine microbiological assays that take much more time. Nevertheless, the efficiency of genotypic methods largely depends how completely the resistance-associated mutations are studied and characterized. It is shown that the types and detection rates of certain rpoB mutations can greatly vary in the Mycobacterium strains spread in different geographical regions. By applying the approach based on the direct sequencing of PCR with rpoB gene fragments, the present paper analyzed 48 rifampicin-sensitive and 52 rifampicin-resistant clinical M. tuberculosis strains provided by Moscow tuberculous control facilities. Mutations responsible for rifampicin resistance were detected in 51 (98%) of the 52 resistant strains. The mutations involving codons 531 (46%), 526 (23%), and 516 (23%) of the rpoB gene were proved to be dominant. An unusual double mutation combining the replacement of F by L in codon 514 and previously uncharacterized methionine deletion in the position 515 was detected in the single investigated strain. The efficiency of the employed approach for rapid diagnosis of rifampicin-resistant M. tuberculosis strains is discussed.

Nucleotide sequence of carnation ringspot dianthovirus RNA-1

The nucleotide sequence of carnation ringspot virus (CRSV) RNA-1, the type member of the dianthovirus genus, has been determined. The 3756 nucleotide genomic RNA-1 contains three large open reading frames (ORFs), capable of encoding 27K, 54K and 38K polypeptides. In addition, a small ORF encoding a 10K polypeptide at the 3' terminus of the RNA has been identified. The gene organization of CRSV RNA-1 is similar to those of red clover necrotic mosaic (RCNMV) and sweet clover necrotic mosaic (SCNMV) dianthoviruses with the exception that CRSV RNA-1 contains the additional 3'-terminal ORF. The 27K and 54K proteins possess significant sequence similarity to corresponding polypeptides of the other dianthoviruses. The 54K protein also contains the conserved RNA-dependent RNA polymerase motif. The identification of a shifty heptanucleotide preceding the p27 ORF termination codon and a predicted secondary structure following the terminator suggest that a translational frameshifting event allows translation to continue past the p27 ORF into the p54 ORF, which is in the -1 frame, generating an 88K fusion protein. Amino acid sequence alignment of the 38K protein with the corresponding RCNMV and SCNMV polypeptides indicate that this is the viral capsid protein.