141 research outputs found
Alterations in Vitamin D signalling and metabolic pathways in breast cancer progression: a study of VDR, CYP27B1 and CYP24A1 expression in benign and malignant breast lesions Vitamin D pathways unbalanced in breast lesions
<p>Abstract</p> <p>Background</p> <p>Breast cancer is a heterogeneous disease associated with different patient prognosis and responses to therapy. Vitamin D has been emerging as a potential treatment for cancer, as it has been demonstrated that it modulates proliferation, apoptosis, invasion and metastasis, among others. It acts mostly through the Vitamin D receptor (VDR) and the synthesis and degradation of this hormone are regulated by the enzymes CYP27B1 and CYP24A1, respectively. We aimed to study the expression of these three proteins by immunohistochemistry in a series of breast lesions.</p> <p>Methods</p> <p>We have used a cohort comprising normal breast, benign mammary lesions, carcinomas <it>in situ </it>and invasive carcinomas and assessed the expression of the VDR, CYP27B1 and CYP24A1 by immunohistochemistry.</p> <p>Results</p> <p>The results that we have obtained show that all proteins are expressed in the various breast tissues, although at different amounts. The VDR was frequently expressed in benign lesions (93.5%) and its levels of expression were diminished in invasive tumours (56.2%). Additionally, the VDR was strongly associated with the oestrogen receptor positivity in breast carcinomas. CYP27B1 expression is slightly lower in invasive carcinomas (44.6%) than in benign lesions (55.8%). In contrast, CYP24A1 expression was augmented in carcinomas (56.0% in <it>in situ </it>and 53.7% in invasive carcinomas) when compared with that in benign lesions (19.0%).</p> <p>Conclusions</p> <p>From this study, we conclude that there is a deregulation of the Vitamin D signalling and metabolic pathways in breast cancer, favouring tumour progression. Thus, during mammary malignant transformation, tumour cells lose their ability to synthesize the active form of Vitamin D and respond to VDR-mediated Vitamin D effects, while increasing their ability to degrade this hormone.</p
Female reproductive tract infections: understandings and care seeking behaviour among women of reproductive age in Lagos, Nigeria
<p>Abstract</p> <p>Background</p> <p>Reproductive tract infections (RTI's) are endemic in developing countries and entail a heavy toll on women. If untreated, RTI's can lead to adverse health outcomes such as infertility, ectopic pregnancy and increased vulnerability to transmission of the human immunodeficiency virus. It is also associated with adverse pregnancy outcomes. While RTI's and its sequelae abound in Nigeria, there is paucity of publications on the subject in the country. This study assessed the understandings and care seeking behavior with regards to RTI's among women of reproductive age in Lagos, Nigeria with the aim of improving awareness on the subject.</p> <p>Methods</p> <p>A descriptive cross sectional survey of women attending the gynaecological outpatient and family planning clinics of the Lagos State University Teaching Hospital was carried out between 1<sup>st </sup>June 2008 and 31<sup>st </sup>August 2008 using a pre-tested questionnaire. Data was analysed using the Epi-Info 3.5 statistical software of the Centre for Disease Control and Prevention, Atlanta U.S.A.</p> <p>Results</p> <p>Most of the respondents (77.2%) had heard of RTI's. Toilet was the most perceived mode of contracting RTI's (44.6%), followed by sexual intercourse and poor hygiene. Vaginal discharge was the commonest symptom of RTI's named while inability to get pregnant was the commonest named complication. Majority of the respondent's demonstrated poor overall knowledge of symptoms and complications of RTI"s. 37.4% of the respondents had experienced symptoms of RTI's in the preceding six months. Vaginal discharge was the commonest symptom reported (21.8%) and the majority of those who reported symptoms sought medical treatment. Government health centres were the most visited health facilities for treatment.</p> <p>Conclusion</p> <p>Even though most of the respondents have heard of RTI's and sought treatment when symptomatic, they demonstrated poor overall understanding of the subject. There is need to educate women on preventive strategies, as RTI's are often assymptomatic.</p
Candidate genetic analysis of plasma high-density lipoprotein-cholesterol and severity of coronary atherosclerosis
<p>Abstract</p> <p>Background</p> <p>Plasma level of high-density lipoprotein-cholesterol (HDL-C), a heritable trait, is an important determinant of susceptibility to atherosclerosis. Non-synonymous and regulatory single nucleotide polymorphisms (SNPs) in genes implicated in HDL-C synthesis and metabolism are likely to influence plasma HDL-C, apolipoprotein A-I (apo A-I) levels and severity of coronary atherosclerosis.</p> <p>Methods</p> <p>We genotyped 784 unrelated Caucasian individuals from two sets of populations (Lipoprotein and Coronary Atherosclerosis Study- LCAS, N = 333 and TexGen, N = 451) for 94 SNPs in 42 candidate genes by 5' nuclease assays. We tested the distribution of the phenotypes by the Shapiro-Wilk normality test. We used Box-Cox regression to analyze associations of the non-normally distributed phenotypes (plasma HDL-C and apo A-I levels) with the genotypes. We included sex, age, body mass index (BMI), diabetes mellitus (DM), and cigarette smoking as covariates. We calculated the q values as indicators of the false positive discovery rate (FDR).</p> <p>Results</p> <p>Plasma HDL-C levels were associated with sex (higher in females), BMI (inversely), smoking (lower in smokers), DM (lower in those with DM) and SNPs in <it>APOA5, APOC2</it>, <it>CETP, LPL </it>and <it>LIPC </it>(each q ≤0.01). Likewise, plasma apo A-I levels, available in the LCAS subset, were associated with SNPs in <it>CETP</it>, <it>APOA5</it>, and <it>APOC2 </it>as well as with BMI, sex and age (all q values ≤0.03). The <it>APOA5 </it>variant S19W was also associated with minimal lumen diameter (MLD) of coronary atherosclerotic lesions, a quantitative index of severity of coronary atherosclerosis (q = 0.018); mean number of coronary artery occlusions (p = 0.034) at the baseline and progression of coronary atherosclerosis, as indicated by the loss of MLD.</p> <p>Conclusion</p> <p>Putatively functional variants of <it>APOA2</it>, <it>APOA5, APOC2</it>, <it>CETP, LPL</it>, <it>LIPC </it>and <it>SOAT2 </it>are independent genetic determinants of plasma HDL-C levels. The non-synonymous S19W SNP in <it>APOA5 </it>is also an independent determinant of plasma apo A-I level, severity of coronary atherosclerosis and its progression.</p
A Natural Combination Extract of Viscum album L. Containing Both Triterpene Acids and Lectins Is Highly Effective against AML In Vivo
Aqueous Viscum album L. extracts are widely used in complementary cancer
medicine. Hydrophobic triterpene acids also possess anti-cancer properties,
but due to their low solubility they do not occur in significant amounts in
aqueous extracts. Using cyclodextrins we solubilised mistletoe triterpenes
(mainly oleanolic acid) and investigated the effect of a mistletoe whole plant
extract on human acute myeloid leukaemia cells in vitro, ex vivo and in vivo.
Single Viscum album L. extracts containing only solubilised triterpene acids
(TT) or lectins (viscum) inhibited cell proliferation and induced apoptosis in
a dose-dependent manner in vitro and ex vivo. The combination of viscum and TT
extracts (viscumTT) enhanced the induction of apoptosis synergistically. The
experiments demonstrated that all three extracts are able to induce apoptosis
via caspase-8 and -9 dependent pathways with down-regulation of members of the
inhibitor of apoptosis and Bcl-2 families of proteins. Finally, the acute
myeloid leukaemia mouse model experiment confirmed the therapeutic
effectiveness of viscumTT-treatment resulting in significant tumour weight
reduction, comparable to the effect in cytarabine-treated mice. These results
suggest that the combination viscumTT may have a potential therapeutic value
for the treatment AML
Pretreatment Serum Concentrations of 25-Hydroxyvitamin D and Breast Cancer Prognostic Characteristics: A Case-Control and a Case-Series Study
Results from epidemiologic studies on the relationship between vitamin D and breast cancer risk are inconclusive. It is possible that vitamin D may be effective in reducing risk only of specific subtypes due to disease heterogeneity.In case-control and case-series analyses, we examined serum concentrations of 25-hydroxyvitamin D (25OHD) in relation to breast cancer prognostic characteristics, including histologic grade, estrogen receptor (ER), and molecular subtypes defined by ER, progesterone receptor (PR) and HER2, among 579 women with incident breast cancer and 574 controls matched on age and time of blood draw enrolled in the Roswell Park Cancer Institute from 2003 to 2008. We found that breast cancer cases had significantly lower 25OHD concentrations than controls (adjusted mean, 22.8 versus 26.2 ng/mL, p<0.001). Among premenopausal women, 25OHD concentrations were lower in those with high- versus low-grade tumors, and ER negative versus ER positive tumors (p≤0.03). Levels were lowest among women with triple-negative cancer (17.5 ng/mL), significantly different from those with luminal A cancer (24.5 ng/mL, p = 0.002). In case-control analyses, premenopausal women with 25OHD concentrations above the median had significantly lower odds of having triple-negative cancer (OR = 0.21, 95% CI = 0.08-0.53) than those with levels below the median; and every 10 ng/mL increase in serum 25OHD concentrations was associated with a 64% lower odds of having triple-negative cancer (OR = 0.36, 95% CI = 0.22-0.56). The differential associations by tumor subtypes among premenopausal women were confirmed in case-series analyses.In our analyses, higher serum levels of 25OHD were associated with reduced risk of breast cancer, with associations strongest for high grade, ER negative or triple negative cancers in premenopausal women. With further confirmation in large prospective studies, these findings could warrant vitamin D supplementation for reducing breast cancer risk, particularly those with poor prognostic characteristics among premenopausal women
Association of PPARγ2 polymorphisms with carcass and meat quality traits in a Pietrain x Jinhua F2 population
The PPARγ2 gene is a key regulator of both proliferation and preadipocyte differentiation in mammals. Herein its genotype and allele frequencies were analyzed using PCR-SSCP in eight pig breeds (N = 416). Two kinds of polymorphisms of the PPARγ2 gene were detected, including a previously reported shift SNP A177G (Met59Val) in exon 1 and a novel silent mutation G876A in exon 5. The results revealed that European pig breeds carry a higher allele A frequency at the A177G locus and a fixed GG genotype at the G876A locus. Allele A at the G876A locus was only found in Jinhua pigs. The association between haplotype (A177G/G876A) and carcass and meat quality traits was analyzed in a Pietrain x Jinhua F2 population (N = 248). The PPARγ2 gene was found to be significantly associated with backfat thickness at the shoulder (p < 0.05), 6–7th ribs (p < 0.01), last rib (p < 0.01), gluteus medius (p <0.05) and ham weight (p < 0.01). Significant effects of different haplotypes on ham weight and backfat thickness at the 6–7th ribs, last rib, and gluteus medius were also observed
Dietary intake of micronutrients and the risk of developing bladder cancer: results from the Belgian case–control study on bladder cancer risk
OBJECTIVE: We aimed to investigate the effect of dietary intake of micronutrients that are metabolized and excreted via the urinary tract on bladder cancer risk. METHODS: A semi-quantitative 322 item food frequency questionnaire (FFQ) was used to collect dietary data from 200 bladder cancer cases and 386 control subjects participating in the Belgian case-control study on bladder cancer risk. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using unconditional logistic regression adjusting for age, sex, smoking characteristics, occupational exposures, and energy intake. RESULTS: We observed a positive association between calcium intake and bladder cancer (OR: 1.77; 95% CI: 1.00-3.15; p-trend = 0.049) and increased odds, although not statistically significant, for highest tertile of phosphorus intake (OR: 1.82; 95% CI: 0.95-3.49; p-trend = 0.06). We identified possible modification of the effects of both calcium and phosphorus by level of magnesium intake. Increased odds of bladder cancer were also observed for participants with highest intake of phosphorus and lowest intake of vitamin D (OR: 4.25; 95% CI: 1.44-12.55) and among older participants with the highest intakes of calcium (OR: 1.90; 95% CI: 1.08-3.36) and phosphorus (OR: 2.02; 95% CI: 1.05-3.92). CONCLUSION: The positive associations we observed between bladder cancer and intake of calcium and phosphorus require confirmation by other studies. The balances between inter-related micronutrients also warrant further examination
Lipid peroxidation, detoxification capacity, and genome damage in mice after transplacental exposure to pharmaceutical drugs
The genetic susceptibility to type 2 diabetes may be modulated by obesity status: implications for association studies
<p>Abstract</p> <p>Background</p> <p>Considering that a portion of the heterogeneity amongst previous replication studies may be due to a variable proportion of obese subjects in case-control designs, we assessed the association of genetic variants with type 2 diabetes (T2D) in large groups of obese and non-obese subjects.</p> <p>Methods</p> <p>We genotyped <it>RETN</it>, <it>KCNJ11</it>, <it>HNF4A</it>, <it>HNF1A</it>, <it>GCK</it>, <it>SLC30A8</it>, <it>ENPP1</it>, <it>ADIPOQ</it>, <it>PPARG</it>, and <it>TCF7L2 </it>polymorphisms in 1,283 normoglycemic (NG) and 1,581 T2D obese individuals as well as in 3,189 NG and 1,244 T2D non-obese subjects of European descent, allowing us to examine T2D risk over a wide range of BMI.</p> <p>Results</p> <p>Amongst non-obese individuals, we observed significant T2D associations with <it>HNF1A </it>I27L [odds ratio (OR) = 1.14, <it>P </it>= 0.04], <it>GCK </it>-30G>A (OR = 1.23, <it>P </it>= 0.01), <it>SLC30A8 </it>R325W (OR = 0.87, <it>P </it>= 0.04), and <it>TCF7L2 </it>rs7903146 (OR = 1.89, <it>P </it>= 4.5 × 10<sup>-23</sup>), and non-significant associations with <it>PPARG </it>Pro12Ala (OR = 0.85, <it>P </it>= 0.14), <it>ADIPOQ </it>-11,377C>G (OR = 1.00, <it>P </it>= 0.97) and <it>ENPP1 </it>K121Q (OR = 0.99, <it>P </it>= 0.94). In obese subjects, associations with T2D were detected with <it>PPARG </it>Pro12Ala (OR = 0.73, <it>P </it>= 0.004), <it>ADIPOQ </it>-11,377C>G (OR = 1.26, <it>P </it>= 0.02), <it>ENPP1 </it>K121Q (OR = 1.30, <it>P </it>= 0.003) and <it>TCF7L2 </it>rs7903146 (OR = 1.30, <it>P </it>= 1.1 × 10<sup>-4</sup>), and non-significant associations with <it>HNF1A </it>I27L (OR = 0.96, <it>P </it>= 0.53), <it>GCK </it>-30G>A (OR = 1.15, <it>P </it>= 0.12) and <it>SLC30A8 </it>R325W (OR = 0.95, <it>P </it>= 0.44). However, a genotypic heterogeneity was only found for <it>TCF7L2 </it>rs7903146 (<it>P </it>= 3.2 × 10<sup>-5</sup>) and <it>ENPP1 </it>K121Q (<it>P </it>= 0.02). No association with T2D was found for <it>KCNJ11</it>, <it>RETN</it>, and <it>HNF4A </it>polymorphisms in non-obese or in obese individuals.</p> <p>Conclusion</p> <p>Genetic variants modulating insulin action may have an increased effect on T2D susceptibility in the presence of obesity, whereas genetic variants acting on insulin secretion may have a greater impact on T2D susceptibility in non-obese individuals.</p
Masked mRNA is stored with aggregated nuclear speckles and its asymmetric redistribution requires a homolog of mago nashi
<p>Abstract</p> <p>Background</p> <p>Many rapidly developing systems rely on the regulated translation of stored transcripts for the formation of new proteins essential for morphogenesis. The microspores of the water fern <it>Marsilea vestita </it>dehydrate as they mature. During this process both mRNA and proteins required for subsequent development are stored within the microspores as they become fully desiccated and enter into senescence. At this point microspores become transcriptionally silent and remain so upon rehydration and for the remainder of spermatogenesis. Transcriptional silencing coupled with the translation of preformed RNA makes the microspore of <it>M. vestita </it>a useful system in which to study post-transcriptional regulation of RNA.</p> <p>Results</p> <p>We have characterized the distribution of mRNA as well as several conserved markers of subnuclear bodies within the nuclei of desiccating spores. During this period, nuclear speckles containing RNA were seen to aggregate forming a single large coalescence. We found that aggregated speckles contain several masked mRNA species known to be essential for spermatogenesis. During spermatogenesis masked mRNA and associated speckle proteins were shown to fragment and asymmetrically localize to spermatogenous but not sterile cells. This asymmetric localization was disrupted by RNAi knockdown of the <it>Marsilea </it>homolog of the Exon Junction Complex core component Mago nashi.</p> <p>Conclusions</p> <p>A subset of masked mRNA is stored in association with nuclear speckles during the dormant phase of microspore development in <it>M. vestita</it>. The asymmetric distribution of specific mRNAs to spermatogenous but not sterile cells mirrors their translational activities and appears to require the EJC or EJC components. This suggests a novel role for nuclear speckles in the post-transcriptional regulation of transcripts.</p
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