Identification of alterations in the nucleotide sequence of the chromatin remodeling gene PBRM1 in clear cell renal cell carcinoma patients

Kidney cancer is a heterogeneous group of malignant tumors, the vast majority of which are renal cell carcinomas (RCC) of various morphological types, of which the most common is the clear cell renal cell carcinoma (ccRCC). Particular attention in the carcinogenesis of the ccRCC is given to a number of tumor suppressor genes located on the short arm of the third chromosome. One of these genes, which are inactivated in the case of ccRCC is the PBRM1 gene encoding the PBAF SWI/SNF subunit of the chromatin remodeling complex, BAF180. The PBRM1 gene is located on the short arm of the third chromosome in the 3p21 region near the von Hippel-Lindau gene (VHL), the mutation in which is the main event in the occurrence of ccRCC. The aim of our investigation is identification of changes in the nucleotide sequence of the PBRM1 tumor suppressor gene in patients with ccRCC. 210 pairs of DNA samples isolated from ccRCC tissue were studied. Analysis of changes in the nucleotide sequence of DNA was carried out by HRM analysis and direct sequencing. In the PBRM1 gene, two somatic mutations were found (c.233G>A (p.D45N) in exon 2, c.1675-1676delTC in exon 15) which were not described previously, and one known polymorphic variant rs17264436 (in exon 23). The frequency of detected mutations was 0.95 % of cases. Analysis of the allelic association for the polymorphic locus rs17264436 showed a statistically significant increase in the risk of developing advanced kidney cancer in carriers of allele rs17264436*A, which can be used in the development of prognostic marker panels. Perhaps the low frequency of mutations in the samples we studied is due to the fact that the inactivation of the PBRM1 gene takes place in other ways, and may also be due to the ethno-specificity of the studied group of patients.

[Frequency of 5382insC mutation of the BRCA1 gene]

The paper assesses c5266dupC (5382insC) mutation incidence among breast cancer patients, residents of the Republic of Bashkorstan and Tyumen Region. It appeared as high as 4%.

[Population study of the Udmurt population: analysis of ten polymorphic DNA loci of the nuclear genome]

Genetic structure of Southern and Northern ethnographic groups of the Udmurt population from six regions of the Republic of Udmurtia has been studied. All the samples were examined using ten polymorphic DNA loci: VNTR/PAH, VNTR/ApoB, VNTR/DAT1, VNTR/eNOS, ACE, CCR5delta32, KM19, IVS6a, THOI, and FABP2. Allelic and genotype frequencies were estimated for each of the six populations. The average heterozygosity for these ten polymorphic loci varied from 0.47 in Udmurts from Glazovskii region to 0.53 in Udmurts from Malopuginskii region. The level of genetic variation (F(ST)) between populations of Udmurts was 0.0048. Ethnographic subdivision of the population into Northern and Southern Udmurts is in good agreement with the values of genetic distances and phylogenetic analysis.

[Analysis of mitochondrial DNA variation in the population of Oroks]

Mitochondrial DNA (mtDNA) variation was studied in population of Oroks (n = 61), the indigenous inhabitants of Eastern Siberia. Most of the mtDNA types examined fell into five haplogroups (C, D, G, M10, and Y) typical of Eastern Eurasian populations. For three haplogroups (D, C, and M10), the founder effect was established. In one individual, a unique lineage belonging to haplogroup HV and typical of Caucasoids was detected.

[Phylogeografic analysis of mitochondrial DNA Nogays: the high level of mixture of maternal lineages from Eastern and Western Eurasia]

Analysis of markers mtDNA in a population of Nogays (n = 206), living on Nothern Caucasus and speaking on language of Turkic branch of the Altaic linguistic family, has shown, that the level of their genetic differentiation is high (H = 0.99). Among the found haplotypes there is all the basic Western Eurasian haplogroups, most often of which are clusters H (22%) and U (21%), however, the percentage of the lineages specific only for populations of East Eurasia (40%) is highest. In a population of Nogays there are also variants mtDNA, belonging to haplogroup M1, characteristic for North East Africa, and gaplogroup U2, typical for populations of India. This testifies about presence in a gene pool of Nogays people of components of a various parentage.

[Polymorphism of human mitochondrial DNA]

To date, a large data set on the mitochondrial DNA (mtDNA) sequence variation in human populations has been accumulated. The use of direct sequencing of the main noncoding region of mtDNA along with the RFLP analysis provide performance of complex analysis of mtDNA polymorphism in human populations. This approach proved to be effective for obtaining molecular genetic portraits of the world populations, as well as for the elucidation of the human evolutionary history and past migrations.

[Analysis of mitochondrial DNA haplotypes in yakut population]

To study the mitochondrial gene pool structure in Yakuts, polymorphism of mtDNA hypervariable segment I (16,024-16,390) was analyzed in 191 people sampled from the indigenous population of the Sakha Republic. In total, 67 haplotypes of 14 haplogroups were detected. Most (91.6%) haplotypes belonged to haplogroups A, B, C, D, F, G, M*, and Y, which are specific for East Eurasian ethnic groups; 8.4% haplotypes represented Caucasian haplogroups H, HV1, J, T, U, and W. A high frequency of mtDNA types belonging to Asian supercluster M was peculiar for Yakuts: mtDNA types belonging to haplogroup C, D, or G and undifferentiated mtDNA types of haplogroup M (M*) accounted for 81% of all haplotypes. The highest diversity was observed for haplogroups C and D, which comprised respectively 22 (44%) and 18 (30%) haplotypes. Yakuts showed the lowest genetic diversity (H = 0.964) among all Turkic ethnic groups. Phylogenetic analysis testified to a common genetic substrate of Yakuts, Mongols, and Central Asian (Kazakh, Kyrgyz, Uigur) populations. Yakuts proved to share 21 (55.5%) mtDNA haplogroups with the Central Asian ethnic groups and Mongols. Comparisons with modern paleo-Asian populations (Chukcha, Itelmen, Koryaks) revealed three (8.9%) haplotypes common for Yakuts and Koryaks. The results of mtDNA analysis disagree with the hypothesis of an appreciable paleo-Asian contribution to the modern Yakut gene pool.

[Polymorphism of hypervariable segment I of mitochondrial DNA in three ethnic groups of the Volga-Ural region]

A population genetic study of the polymorphism in the first hypervariable segment (HVSI) of mitochondrial DNA control region was carried out for three ethnic populations of the Volga-Ural region, Bashkirs, Russians, and Komi-Permyaks. This analysis showed that most of the mtDNA HVSI haplotypes detected in the populations of Bashkirs, Russians and Komi-Permyaks contained the combinations of nucleotide substitutions detected earlier in Asian, European, and Finno-Ugric populations. These findings are consistent with historical, anthropological, and ethnographical data suggesting the presence of European and Mongoloid components of different geographical descent in the gene pool of the contemporary population of the Volga-Ural region. The data on the genetic structure and the phylogenetic relationships between populations of the Volga-Ural region based on modern molecular genetic methods of mitochondrial genome investigation would be a substantial addition to the already existing information for some other regions of Europe and Asia. These data would provide more complete examination of the development of interethnic diversity of mitochondrial gene pools of contemporary ethnic populations with the purpose of reconstructing the genetic demographic processes that accompanied peopling of the Middle Ural and Volga region.

[Analysis of Y-chromosomal diallelic loci polymorphism in populations of the Volga-Ural region]

Three diallelic polymorphisms of human Y chromosome, DYS287 (Y Alu polymorphism, YAP), T/C transition at the RBF5 locus (Tat), and G/A transition at the LLY22 locus, were studied in eight ethnic populations of the Volga-Ural region, representing Turkic (Bashkirs, Tatars, and Chuvashes) and Finno-Ugric (Maris, Mordovians, Udmurts, Komi-Zyryans, and Komi-Permyaks) branches of the Uralic linguistic family, and in the group of Slavic migrants, belonging to the Indo-European linguistic family (Russians). Ethnic populations of the Volga-Ural region were characterized by a low frequency of the Y chromosome Alu insertion. Examination of an association between the Alu polymorphism and Tat mutation revealed absolute C/YAP linkage. Analysis of the haplotype frequency distribution patterns constructed from the data on the DYS287 and RBF5 polymorphisms revealed substantial differences between Udmurts and the other ethnic populations. The differences were also observed between Komi-Zyryans and the populations of Bashkirs, Mordovians, Komi-Permyaks, and Russians. Analysis of the degree of genetic differentiation pointed to high level of genetic differentiation of the male lineages of the Finno-Ugric ethnic groups. The data on the linkage between mutations of the RBF5 and the LLY22 loci indicated the common origin of the Tat mutation in Bashkirs, Mordovians, Udmurts, and Komi-Zyryans, and of a number of ancestral C allele-bearing chromosomes in Tatars, Maris, and Chuvashes.