357 research outputs found
Association between the c.*229C>T polymorphism of the topoisomerase IIb binding protein 1 (TopBP1) gene and breast cancer
Topoisomerase IIb binding protein 1 (TopBP1)
is involved in cell survival, DNA replication, DNA damage
repair and cell cycle checkpoint control. The biological
function of TopBP1 and its close relation with BRCA1
prompted us to investigate whether alterations in the
TopBP1 gene can influence the risk of breast cancer.
The aim of this study was to examine the association
between five polymorphisms (rs185903567, rs116645643,
rs115160714, rs116195487, and rs112843513) located in
the 30UTR region of the TopBP1 gene and breast cancer
risk as well as allele-specific gene expression. Five hundred
thirty-four breast cancer patients and 556 population controls
were genotyped for these SNPs. Allele-specific Top-
BP1 mRNA and protein expressions were determined by
using real time PCR and western blotting methods,
respectively. Only one SNP (rs115160714) showed an
association with breast cancer. Compared to homozygous
common allele carriers, heterozygous and homozygous for
the T variant had significantly increased risk of breast
cancer (adjusted odds ratio = 3.81, 95 % confidence
interval: 1.63–8.34, p = 0.001). Mean TopBP1 mRNA and
protein expression were higher in the individuals with the
CT or TT genotype. There was a significant association
between the rs115160714 and tumor grade and stage. Most
carriers of minor allele had a high grade (G3) tumors
classified as T2-T4N1M0. Our study raises a possibility
that a genetic variation of TopBP1 may be implicated in
the etiology of breast cancer
Immunohistochemical evaluation of human epidermal growth factor receptor 2 and estrogen and progesterone receptors in breast carcinoma in Jordan
INTRODUCTION: Although breast carcinoma (BC) is the most common malignancy affecting Jordanian females and the affected population in Jordan is younger than that in the West, no information is available on its biological characteristics. Our aims in this study are to evaluate the expression of estrogen receptor (ER) and progesterone receptor (PR) and Her-2/neu overexpression in BC in Jordan, and to compare the expression of these with other prognostic parameters for BC such as histological type, histological grade, tumor size, patients' age, and number of lymph node metastases. METHOD: This is a retrospective study conducted in the Department of Pathology at Jordan University of Science and Technology. A confirmed 91 cases of BC diagnosed in the period 1995 to 1998 were reviewed and graded. We used immunohistochemistry to evaluate the expression of ER, PR, and Her-2. Immunohistochemical findings were correlated with age, tumor size, grade and axillary lymph node status. RESULTS: Her-2 was overexpressed in 24% of the cases. The mean age of Her-2 positive cases was 42 years as opposed to 53 years among Her-2 negative cases (p = 0.0001). Her-2 expression was inversely related to ER and PR expression. Her-2 positive tumors tended to be larger than Her-2 negative tumors with 35% overexpression among T3 tumors as opposed to 22% among T2 tumors (p = 0.13). Her-2 positive cases tended to have higher rates of axillary metastases, but this did not reach statistical significance. ER and PR positive cases were seen in older patients with smaller tumor sizes. CONCLUSION: Her-2 overexpression was seen in 24% of BC affecting Jordanian females. Her-2 overexpression was associated with young age at presentation, larger tumor size, and was inversely related to ER and PR expression. One-fifth of the carcinomas were Her-2 positive and ER negative. This group appears to represent an aggressive form of BC presenting at a young age with large primary tumors and a high rate of four or more axillary lymph node metastases
Long-term efficacy of botulinum toxin A for treatment of blepharospasm,hemifacial spasm, and spastic entropion: a multicentre study using two drug-dose escalation indexes
PURPOSE: To investigate the long-term effectiveness and safety of botulinum
neurotoxin A (BoNT-A) treatment in patients with blepharospasm (BEB), hemifacial
spasm (HFS), and entropion (EN) and to use for the first time two modified indexes, 'botulin toxin escalation index-U' (BEI-U) and 'botulin toxin escalation
index percentage' (BEI-%), in the dose-escalation evaluation. METHODS: All
patients in this multicentre study were followed for at least 10 years and main
outcomes were clinical efficacy, duration of relief, BEI-U and BEI-%, and
frequency of adverse events. RESULTS: BEB, HFS, and EN patients received a mean
BoNT-A dose with a significant inter-group difference (P<0.0005, respectively).
The mean (+/-SD) effect duration was statistically different (P=0.009) among
three patient groups. Regarding the BoNT-A escalation indexes, the mean (+/-SD)
values of BEI-U and BEI-% were statistically different (P=0.035 and 0.047,
respectively) among the three groups. In BEB patients, the BEI-% was
significantly increased in younger compared with older patients (P=0.008). The
most frequent adverse events were upper lid ptosis, diplopia, ecchymosis, and
localized bruising. CONCLUSIONS: This long-term multicentre study supports a high
efficacy and good safety profile of BoNT-A for treatment of BEB, HFS, and EN. The
BEI indexes indicate a significantly greater BoNT-A-dose escalation for BEB
patients compared with HFS or EN patients and a significantly greater BEI-% in
younger vsolder BEB patients. These results confirm a greater efficacy in the
elderly and provide a framework for long-term studies with a more flexible and
reliable evaluation of drug-dose escalation
Neonicotinoid Insecticides and Their Impacts on Bees: A Systematic Review of Research Approaches and Identification of Knowledge Gaps
It has been suggested that the widespread use of neonicotinoid insecticides threatens bees, but research on this topic has been surrounded by controversy. In order to synthesize which research approaches have been used to examine the effect of neonicotinoids on bees and to identify knowledge gaps, we systematically reviewed research on this subject that was available on the Web of Science and PubMed in June 2015. Most of the 216 primary research studies were conducted in Europe or North America (82%), involved the neonicotinoid imidacloprid (78%), and concerned the western honey bee Apis mellifera (75%). Thus, little seems to be known about neonicotinoids and bees in areas outside Europe and North America. Furthermore, because there is considerable variation in ecological traits among bee taxa, studies on honey bees are not likely to fully predict impacts of neonicotinoids on other species. Studies on crops were dominated by seed-treated maize, oilseed rape (canola) and sunflower, whereas less is known about potential side effects on bees from the use of other application methods on insect pollinated fruit and vegetable crops, or on lawns and ornamental plants. Laboratory approaches were most common, and we suggest that their capability to infer real-world consequences are improved when combined with information from field studies about realistic exposures to neonicotinoids. Studies using field approaches often examined only bee exposure to neonicotinoids and more field studies are needed that measure impacts of exposure. Most studies measured effects on individual bees. We suggest that effects on the individual bee should be linked to both mechanisms at the sub-individual level and also to the consequences for the colony and wider bee populations. As bees are increasingly facing multiple interacting pressures future research needs to clarify the role of neonicotinoids in relative to other drivers of bee declines
Deep Convolutional Neural Networks for Breast Cancer Histology Image Analysis
Breast cancer is one of the main causes of cancer death worldwide. Early
diagnostics significantly increases the chances of correct treatment and
survival, but this process is tedious and often leads to a disagreement between
pathologists. Computer-aided diagnosis systems showed potential for improving
the diagnostic accuracy. In this work, we develop the computational approach
based on deep convolution neural networks for breast cancer histology image
classification. Hematoxylin and eosin stained breast histology microscopy image
dataset is provided as a part of the ICIAR 2018 Grand Challenge on Breast
Cancer Histology Images. Our approach utilizes several deep neural network
architectures and gradient boosted trees classifier. For 4-class classification
task, we report 87.2% accuracy. For 2-class classification task to detect
carcinomas we report 93.8% accuracy, AUC 97.3%, and sensitivity/specificity
96.5/88.0% at the high-sensitivity operating point. To our knowledge, this
approach outperforms other common methods in automated histopathological image
classification. The source code for our approach is made publicly available at
https://github.com/alexander-rakhlin/ICIAR2018Comment: 8 pages, 4 figure
The multifunctional solute carrier 3A2 (SLC3A2) confers a poor prognosis in the highly proliferative breast cancer subtypes
Background: Breast cancer (BC) is a heterogeneous disease characterised by variant biology, metabolic activity and patient outcome. This study aimed to evaluate the biological and prognostic value of the membrane solute carrier, SLC3A2 in BC with emphasis on the intrinsic molecular subtypes.
Methods: SLC3A2 was assessed at the genomic level, using METABRIC data (n=1,980), and proteomic level, using immunohistochemistry on TMA sections constructed from a large well-characterised primary BC cohort (n=2,500). SLC3A2 expression was correlated with clinicopathological parameters, molecular subtypes, and patient outcome.
Results: SLC3A2 mRNA and protein expression were strongly correlated with higher tumour grade and poor Nottingham prognostic index (NPI). High expression of SLC3A2 was observed in triple negative (TN), HER2+, and ER+ high proliferation subtypes. SLC3A2 mRNA and protein expression were significantly associated with the expression of c-MYC in all BC subtypes (p<0.001). High expression of SLC3A2 protein was associated with poor patient outcome (p<0.001)), but only in the ER+ high proliferation (p=0.01) and triple negative (p=0.04) subtypes. In multivariate analysis SLC3A2 protein was an independent risk factor for shorter breast cancer specific survival (p<0.001).
Conclusions: SLC3A2 appears to play a role in the aggressive BC subtypes driven by MYC and could act as a potential prognostic marker. Functional assessment is necessary to reveal its potential therapeutic value in the different BC subtypes
Recurrent hotspot mutations in HRAS Q61 and PI3K-AKT pathway genes as drivers of breast adenomyoepitheliomas
Adenomyoepithelioma of the breast is a rare tumor characterized by epithelial-myoepithelial differentiation, of which a subset will progress to invasive or metastatic cancer. We sought to define the genomic landscape of adenomyoepitheliomas. Massively parallel sequencing revealed highly recurrent somatic mutations in HRAS and PI3K-AKT pathway-related genes. Strikingly, HRAS mutations were restricted to estrogen receptor (ER)-negative tumors, all affected codon 61, and all but one co-occurred with PIK3CA or PIK3R1 mutations. To interrogate the functional significance of HRAS Q61 mutations in adenomyoepithelial differentiation, we expressed HRASQ61R alone or in combination with PIK3CAH1047R in non-transformed ER-negative breast epithelial cells. HRASQ61R induced characteristic phenotypes of adenomyoepitheliomas such as the expression of myoepithelial markers and loss of e-cadherin, hyperactivation of AKT signaling, and transformative properties that were arrested by combination therapy with AKT and MEK inhibitors. Our results indicate that breast adenomyoepitheliomas often manifest a unique transformation program featuring HRAS activation
The Cluster Variation Method for Efficient Linkage Analysis on Extended Pedigrees
BACKGROUND: Computing exact multipoint LOD scores for extended pedigrees rapidly becomes infeasible as the number of markers and untyped individuals increase. When markers are excluded from the computation, significant power may be lost. Therefore accurate approximate methods which take into account all markers are desirable. METHODS: We present a novel method for efficient estimation of LOD scores on extended pedigrees. Our approach is based on the Cluster Variation Method, which deterministically estimates likelihoods by performing exact computations on tractable subsets of variables (clusters) of a Bayesian network. First a distribution over inheritances on the marker loci is approximated with the Cluster Variation Method. Then this distribution is used to estimate the LOD score for each location of the trait locus. RESULTS: First we demonstrate that significant power may be lost if markers are ignored in the multi-point analysis. On a set of pedigrees where exact computation is possible we compare the estimates of the LOD scores obtained with our method to the exact LOD scores. Secondly, we compare our method to a state of the art MCMC sampler. When both methods are given equal computation time, our method is more efficient. Finally, we show that CVM scales to large problem instances. CONCLUSION: We conclude that the Cluster Variation Method is as accurate as MCMC and generally is more efficient. Our method is a promising alternative to approaches based on MCMC sampling
Chromogenic in situ hybridization (CISH): a novel alternative in screening archival breast cancer tissue samples for HER-2/neu status
BACKGROUND: Chromogenic in situ hybridization (CISH) is emerging as a practical, cost-effective, and valid alternative to fluorescent in situ hybridization in testing for gene alteration, especially in centers primarily working with immunohistochemistry (IHC). METHODS: We assessed Her-2/neu alteration using CISH on formalin-fixed paraffin-embedded primary invasive ductal carcinoma tumors in which IHC (CB11 antibody) had previously been performed, and we compared the results with IHC. The 160 selected cases were equally stratified randomly into the four IHC categories (scores of 0, 1+, 2+, and 3+). We also compared age at diagnosis and tumor histologic grade with IHC and CISH Her-2/neu. RESULTS: We were able to perform and evaluate CISH successfully on all cases. The agreement between 3+ IHC and CISH-amplified cases as well as between all IHC and CISH Her-2/neu negative cases was 100%, and the concordance on all positive cases was 72.50%, with an overall agreement of 86.25%. All the discordant cases had 2+ IHC scores. Although we noted Her-2/neu positivity more in premenopausal women, the age at diagnosis was not significantly associated with IHC or CISH results. Similarly, although the small group of well-differentiated tumors was apparently Her-2/neu negative in both tests, no significant association was noted between any tumor histologic grade and either IHC or CISH results. CONCLUSIONS: CISH is easily integrated into routine testing in our laboratory. It is a necessary adjunct in determining the subset of non-amplified IHC-positive invasive tumors that will not benefit from trastuzumab therapy. Those cases with 2+ IHC results will be triaged and subjected to CISH. Her-2/neu testing should be done on all breast cancer cases regardless of age at presentation and tumor histologic grade
Partitioning of copy-number genotypes in pedigrees
<p>Abstract</p> <p>Background</p> <p>Copy number variations (CNVs) and polymorphisms (CNPs) have only recently gained the genetic community's attention. Conservative estimates have shown that CNVs and CNPs might affect more than 10% of the genome and that they may be at least as important as single nucleotide polymorphisms in assessing human variability. Widely used tools for CNP analysis have been implemented in <it>Birdsuite </it>and <it>PLINK </it>for the purpose of conducting genetic association studies based on the unpartitioned total number of CNP copies provided by the intensities from Affymetrix's Genome-Wide Human SNP Array. Here, we are interested in partitioning copy number variations and polymorphisms in extended pedigrees for the purpose of linkage analysis on familial data.</p> <p>Results</p> <p>We have developed <it>CNGen</it>, a new software for the partitioning of copy number polymorphism using the integrated genotypes from <it>Birdsuite </it>with the Affymetrix platform. The algorithm applied to familial trios or extended pedigrees can produce partitioned copy number genotypes with distinct parental alleles. We have validated the algorithm using simulations on a complex pedigree structure using frequencies calculated from a real dataset of 300 genotyped samples from 42 pedigrees segregating a congenital heart defect phenotype.</p> <p>Conclusions</p> <p><it>CNGen </it>is the first published software for the partitioning of copy number genotypes in pedigrees, making possible the use CNPs and CNVs for linkage analysis. It was implemented with the <it>Python </it>interpreter version 2.5.2. It was successfully tested on current Linux, Windows and Mac OS workstations.</p
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