Association of SULT1A1 and UGT1A1 polymorphisms with breast cancer risk and phenotypes in Russian women

Estrogens are critical for breast cancer initiation and development. Sulfotransferase 1A1 (SULT1A1) and UDP-glucuronosyltransferase 1A1 (UGT1A1) conjugate and inactivate both estrogens and their metabolites, thus preventing estrogen-mediated mitosis and mutagenesis. SULT1A1 and UGT1A1 are both polymorphic, and different alleles encode functionally different allozymes. We hypothesize that low-activity alleles SULT1A1*2 and UGT1A1*28 are associated with higher risk for breast cancer and more severe breast tumor phenotypes. We performed a case-control study, which included 119 women of Russian ancestry with breast cancer and 121 age-matched Russian female controls. We used PCR followed by pyrosequencing to determine the SULT1A1 and UGT1A1 genotypes. Allele UGT1A1*28 was present at a higher frequency than the wild-type UGT1A1*1 allele in breast cancer patients as compared to controls (P = 0.002, OR = 1.79, CI 1.23–2.63). Consistently, the frequency of genotypes that contain allele UGT1A1*28 in the homozygous or the heterozygous state was greater in breast cancer patients as compared with the frequency of the wild-type UGT1A1*1/*1 genotype (P = 0.003, OR = 4.00, CI 1.49–11.11 and P = 0.014, OR = 2.04, CI 1.14–3.57, respectively). Individuals carrying allele UGT1A1*28 in the homo-or heterozygous state had larger breast tumors (>2 cm) as compared to the group with high-activity genotypes (P = 0.011, IR = 3.44, CI 1.42–8.36). No association was observed between any of the SULT1A1 genotypes and breast cancer risk or phenotypes. Our data suggest that UGT1A1, but not SULT1A1, genotypes are important for breast cancer risk and phenotype in Russian women. Published in Russian in Molekulyarnaya Biologiya, 2006, Vol. 40, No. 2, pp. 263–270. The article was translated by the authors.     

Origin of defects in assembled supramolecular structures of sweet potato starches with different amylopectin chain-length distribution

A combined approach of fluorophore-assisted capillary electrophoresis (FACEL), high-sensitivity differential scanning calorimetry (DSC), wide-angle X-ray scattering (WAXS), small-angle X-ray scattering (SAXS), and light (LM) and scanning electron microscopy (SEM) was applied to study the effects of changes in amylopectin chain-length distribution on the assembly structures of sweet potato starches with similar amylose levels. It was shown that unlike ordinary sweet potato starch, starch extracted from Quick Sweet cultivar of sweet potato had anomalous high level of amylopectin chains with a degree of polymerization (DP) 6–12. Joint analysis of the obtained data revealed that amylopectin chains with DP 10–24 are, apparently, the dominant material for the formation of supramolecular structures in starch granules. In contrast, amylopectin chains with DP < 10 facilitated the formation of defects within crystalline lamellae. An increase in relative content of amylopectin chains with DP < 10 is accompanied by the correlated structural alterations manifested at all levels of starch granule organization (crystalline lamellae, amylopectin clusters, semi-crystalline growth rings, and granule morphology). Thus, the short amylopectin chains with DP < 10 were considered as an origin of the defectiveness in starch supramolecular structures.     

The reciprocal effect of the causative agents in a mixed infection in burn injury

In vitro experiments on the joint cultivation of Pseudomonas aeruginosa, Escherichia coli, staphylococci and in vivo experiments carried out on mice with the experimental mixed infection of a burn injury revealed the pronounced antagonistic action of P. aeruginosa with respect to staphylococci and E. coli. Under the same conditions, in the joint cultivation of P. aeruginosa and fungi of the genus Candida and in the mixed infection of a burn wound caused by the same microorganisms the mutual stimulation of multiplication and a considerable aggravation of the clinical course of a burn wound were observed. The mutual influence of associates in the mixed infection of a burn injury is manifested by an increase in the number of an antibiotic-resistance microorganisms in their populations and, so far as the macroorganism is concerned, in the aggravation of the course of the infectious process and the formation of the pronounced state of immunodeficiency.     

Association of polymorphisms in SULT1A1 and UGT1A1 Genes with breast cancer risk and phenotypes in Russian women

Estrogens are critical for breast cancer initiation and development. Sulfotransferase 1A1 (SULT1A1) and UDP-glucuronosyltransferase 1A1 (UGT1A1) conjugate and inactivate both estrogens and their metabolites, thus preventing estrogen-mediated mitosis and mutagenesis. SULT1A1 and UGT1A1 genes are both polymorphic, and different alleles encode functionally different allozymes. We hypothesize that low activity alleles SULT1A1*2 and UGT1A1*28 are associated with the higher risk for breast cancer and more severe breast tumor phenotypes. We performed a case-control study, which included 119 women of Russian ancestry with breast cancer and 121 age-matched Russian female controls. We used PCR, followed by pyrosequencing to determine SULT1A1 and UGT1A1 genotypes. Our data showed that UGT1A1*28 allele was presented at a higher frequency than the wild type UGT1A1*1 allele in breast cancer patients as compared to controls (p = 0.002, OR = 1.79, CI 1.23-2.63). Consistently, the frequency of genotypes that contain the UGT1A1*28 allele in the homozygous or heterozygous state was greater than the frequency of the wild type UGT1A1*1/*1 genotype in breast cancer patients as compared to controls (p = 0.003, OR = 4.00, CI 1.49-11.11 and p = 0.014, OR = 2.04, CI 1.14-3.57, respectively). The group of individuals, carrying the UGT1A1*28 allele in the homo- or heterozygous state also presented larger breast tumors (>2 cm) as compared to the group with high enzymatic activity genotypes p = 0.011, OR = 3.44, CI 1.42-8.36). No association was observed between any of the SULT1A1 genotypes and breast cancer risk or phenotypes. Our data suggest that UGT1A1 but not SULT1A1 genotype might be important for breast cancer risk and phenotype in Russian women.     

Larvae of related Diptera species from thermally contrasting habitats exhibit continuous up-regulation of heat shock proteins and high thermotolerance

A population of Stratiomys japonica, a species belonging to the family Stratiomyidae (Diptera), common name ‘soldier flies’, occurs in a hot volcanic spring, which is apparently among the most inhospitable environments for animals because of chemical and thermal conditions. Larvae of this species, which naturally often experience temperatures more than 40 °C, have constitutively high concentrations of the normally inducible heat-shock protein Hsp70, but very low level of corresponding mRNA. Larvae of three other species of the same family, Stratiomys singularior, Nemotelus bipunctatus and Oxycera pardalina, are confined to different type semi-aquatic habitats with contrasting thermal regime. However, all of them shared the same pattern of Hsp70 expression. Interestingly, heat-shock treatment of S. japonica larvae activates heat-shock factor and significantly induces Hsp70 synthesis, whereas larvae of O. pardalina, a species from constant cold environment, produce significantly less Hsp70 in response to heat shock. Adults of the four species also exhibit lower, but detectable levels of Hsp70 without heat shock. Larvae of all species studied have very high tolerance to temperature stress in comparison with other Diptera species investigated, probably representing an inherent adaptive feature of all Stratiomyidae enabling successful colonization of highly variable and extreme habitats.