49 research outputs found
BCAR1, a human homologue of the adapter protein p130Cas, and antiestrogen resistance in breast cancer cells
BACKGROUND: Treatment of breast cancer with the antiestrogen tamoxifen is
effective in approximately one half of the patients with estrogen
receptor-positive disease, but tumors recur frequently because of the
development of metastases that are resistant to tamoxifen. We have
previously shown that mutagenesis of human estrogen-dependent ZR-75-1
breast cancer cells by insertion of a defective retrovirus genome caused
the cells to become antiestrogen resistant. In this study, we isolated and
characterized the crucial gene at the breast cancer antiestrogen
resistance 1 (BCAR1) locus. METHODS/RESULTS: Transfer of the BCAR1 locus
from retrovirus-mutated, antiestrogen-resistant cells to
estrogen-dependent ZR-75-1 cells by cell fusion conferred an
antiestrogen-resistant phenotype on the recipient cells. The complete
coding sequence of BCAR1 was isolated by use of exon-trapping and
complementary DNA (cDNA) library screening. Sequence analysis of human
BCAR1 cDNA predicted a protein of 870 amino acids that was strongly
homologous to rat p130Cas-adapter protein. Genomic analysis revealed that
BCAR1 consists of seven exons and is located at chromosome 16q23.1. BCAR1
transcripts were detected in multiple human tissues and were similar in
size to transcripts produced by retrovirus-mutated ZR-75-1 cells.
Transfection of BCAR1 cDNA into ZR-75-1 cells again resulted in sustained
cell proliferation in the presence of antiestrogens, confirming that BCAR1
was the responsible gene in the locus. CONCLUSIONS: Overexpression of the
BCAR1 gene confers antiestrogen resistance on human ZR-75-1 breast cancer
cells. Overexpression of BCAR1 in retrovirus-mutated cells appears to
result from activation of the gene's promoter. The isolation and
characterization of this gene open new avenues to elucidating mechanisms
by which the growth of human breast cancer becomes independent of
estrogen
Bcar1/p130Cas protein and primary breast cancer: prognosis and response to tamoxifen treatment
BACKGROUND: The product of the Bcar1/p130Cas (breast cancer
resistance/p130Crk-associated substrate) gene causes resistance to
antiestrogen drugs in human breast cancer cells in vitro. To investigate
its role in clinical breast cancer, we determined the levels of
Bcar1/p130Cas protein in a large series of primary breast carcinomas.
METHODS: We measured Bcar1/p130Cas protein in cytosol extracts from 937
primary breast carcinomas by western blot analysis. The levels of
Bcar1/p130Cas protein were tested for associations and trends against
clinicopathologic and patient characteristics, the lengths of relapse-free
survival and overall survival (n = 775), and the efficacy of first-line
treatment with tamoxifen for recurrent or metastatic disease (n = 268).
RESULTS: Bcar1/p130Cas levels in primary tumors were associated with
age/menopausal status and the levels of estrogen receptor and progesterone
receptor. In univariate survival analysis, higher Bcar1/p130Cas levels
were associated with poor relapse-free survival and overall survival (both
two-sided P =.04; log-rank test for trend). In multivariate analysis, a
high level of Bcar1/p130Cas was independently associated with poor
relapse-free survival and overall survival. The response to tamoxifen
therapy in patients with recurrent disease was reduced in patients with
primary tumors that expressed high levels of Bcar1/p130Cas. In
multivariate analysis for response, Bcar1/p130Cas was independent of
classical predictive factors, such as estrogen receptor status,
age/menopausal status, disease-free interval, and dominant site of
relapse. CONCLUSION: Patients with primary breast tumors expressing a high
level of Bcar1/p130Cas protein appear to experience more rapid disease
recurrence and have a greater risk of (intrinsic) resistance to tamoxifen
therapy. Thus, measurement of Bcar1/p130Cas may provide useful prognostic
information for patients with primary or metastatic breast cancer
Medication Use and Clinical Outcomes by the Dutch Institute for Clinical Auditing Medicines Program: Quantitative Analysis
BACKGROUND: The Dutch Institute for Clinical Auditing (DICA) Medicines Program was set up in September 2018 to evaluate expensive medicine use in daily practice in terms of real-world effectiveness using only existing data sources. OBJECTIVE: The aim of this study is to describe the potential of the addition of declaration data to quality registries to provide participating centers with benchmark information about the use of medicines and outcomes among patients. METHODS: A total of 3 national population-based registries were linked to clinical and financial data from the hospital pharmacy, the Dutch diagnosis treatment combinations information system including in-hospital activities, and survival data from health care insurers. The first results of the real-world data (RWD) linkage are presented using descriptive statistics to assess patient, tumor, and treatment characteristics. Time-to-next-treatment (TTNT) and overall survival (OS) were estimated using the Kaplan-Meier method. RESULTS: A total of 21 Dutch hospitals participated in the DICA Medicines Program, which included 7412 patients with colorectal cancer, 1981 patients with metastasized colon cancer, 3860 patients with lung cancer, 1253 patients with metastasized breast cancer, and 7564 patients with rheumatic disease. The data were used for hospital benchmarking to gain insights into medication use in specific patient populations, treatment information, clinical outcomes, and costs. Detailed treatment information (duration and treatment steps) led to insights into differences between hospitals in daily clinical practices. Furthermore, exploratory analyses on clinical outcomes (TTNT and OS) were possible. CONCLUSIONS: The DICA Medicines Program shows that it is possible to gather and link RWD about medicines to 4 disease-specific population-based registries. Since these RWD became available with minimal registration burden and effort for hospitals, this method can be explored in other population-based registries to evaluate real-world efficacy
Combinations of Service Use Types of People With Early Cognitive Disorders
Objectives Understanding which persons most likely use particular combinations of service types is important as this could lead to a better understanding of care pathways. The aim of this study is to identify combinations of service use within a sample of community-dwelling people with mild cognitive impairment (MCI) and dementia and identify factors related to these service use combinations. Methods A latent class analysis performed at baseline on a merged dataset (n = 530) was used to classify care recipients based on following service use types: general practitioner visits, physiotherapist visits, hospital outpatient specialist visits, emergency room visits, hospital inpatient visits with stay over, day care visits, use of domestic homecare, use of personal homecare, and informal care on (instrumental) activities of daily living. Multinomial logistic regression was performed to identify factors associated with service use combinations using clinical characteristics of the care recipient and demographic characteristics of the care recipient and caregiver. Results Three service use classes were identified; a formal homecare class (10% of participants), an informal care class (46% of participants), and a low user class (44% of participants). Factors increasing the likelihood of being in the formal homecare class compared with the low service use class included a diagnosis of MCI or dementia, activities of daily living impairment, older age of the care recipient, and care recipient not living together with the caregiver. Conclusions Besides a diagnosis of MCI or dementia, other factors (activities of daily living impairment, age, and living situation) were associated with service use. We recommend using these factors alongside the diagnostic label for care indication
Prevalence and prognosis of Alzheimer's disease at the mild cognitive impairment stage
Vos et al. compare the prevalence and prognosis of Alzheimer's disease at the mild cognitive impairment stage based on the IWG-1, IWG-2 and NIA-AA criteria. All three aid identification of early Alzheimer's disease, but combining amyloid and neuronal injury markers according to the NIA-AA criteria offers the most accurate prognosi
The Plant Pathogen Phytophthora andina Emerged via Hybridization of an Unknown Phytophthora Species and the Irish Potato Famine Pathogen, P. infestans
Emerging plant pathogens have largely been a consequence of the movement of pathogens to new geographic regions. Another documented mechanism for the emergence of plant pathogens is hybridization between individuals of different species or subspecies, which may allow rapid evolution and adaptation to new hosts or environments. Hybrid plant pathogens have traditionally been difficult to detect or confirm, but the increasing ease of cloning and sequencing PCR products now makes the identification of species that consistently have genes or alleles with phylogenetically divergent origins relatively straightforward. We investigated the genetic origin of Phytophthora andina, an increasingly common pathogen of Andean crops Solanum betaceum, S. muricatum, S. quitoense, and several wild Solanum spp. It has been hypothesized that P. andina is a hybrid between the potato late blight pathogen P. infestans and another Phytophthora species. We tested this hypothesis by cloning four nuclear loci to obtain haplotypes and using these loci to infer the phylogenetic relationships of P. andina to P. infestans and other related species. Sequencing of cloned PCR products in every case revealed two distinct haplotypes for each locus in P. andina, such that each isolate had one allele derived from a P. infestans parent and a second divergent allele derived from an unknown species that is closely related but distinct from P. infestans, P. mirabilis, and P. ipomoeae. To the best of our knowledge, the unknown parent has not yet been collected. We also observed sequence polymorphism among P. andina isolates at three of the four loci, many of which segregate between previously described P. andina clonal lineages. These results provide strong support that P. andina emerged via hybridization between P. infestans and another unknown Phytophthora species also belonging to Phytophthora clade 1c
Consensus classification of posterior cortical atrophy
INTRODUCTION: A classification framework for posterior cortical atrophy (PCA) is proposed to improve the uniformity of definition of the syndrome in a variety of research settings. METHODS: Consensus statements about PCA were developed through a detailed literature review, the formation of an international multidisciplinary working party which convened on four occasions, and a Web-based quantitative survey regarding symptom frequency and the conceptualization of PCA. RESULTS: A three-level classification framework for PCA is described comprising both syndrome- and disease-level descriptions. Classification level 1 (PCA) defines the core clinical, cognitive, and neuroimaging features and exclusion criteria of the clinico-radiological syndrome. Classification level 2 (PCA-pure, PCA-plus) establishes whether, in addition to the core PCA syndrome, the core features of any other neurodegenerative syndromes are present. Classification level 3 (PCA attributable to AD [PCA-AD], Lewy body disease [PCA-LBD], corticobasal degeneration [PCA-CBD], prion disease [PCA-prion]) provides a more formal determination of the underlying cause of the PCA syndrome, based on available pathophysiological biomarker evidence. The issue of additional syndrome-level descriptors is discussed in relation to the challenges of defining stages of syndrome severity and characterizing phenotypic heterogeneity within the PCA spectrum. DISCUSSION: There was strong agreement regarding the definition of the core clinico-radiological syndrome, meaning that the current consensus statement should be regarded as a refinement, development, and extension of previous single-center PCA criteria rather than any wholesale alteration or redescription of the syndrome. The framework and terminology may facilitate the interpretation of research data across studies, be applicable across a broad range of research scenarios (e.g., behavioral interventions, pharmacological trials), and provide a foundation for future collaborative work
New insights into the genetic etiology of Alzheimer's disease and related dementias
Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele
Common variants in Alzheimer's disease and risk stratification by polygenic risk scores.
Funder: Funder: Fundación bancaria ‘La Caixa’ Number: LCF/PR/PR16/51110003 Funder: Grifols SA Number: LCF/PR/PR16/51110003 Funder: European Union/EFPIA Innovative Medicines Initiative Joint Number: 115975 Funder: JPco-fuND FP-829-029 Number: 733051061Genetic discoveries of Alzheimer's disease are the drivers of our understanding, and together with polygenetic risk stratification can contribute towards planning of feasible and efficient preventive and curative clinical trials. We first perform a large genetic association study by merging all available case-control datasets and by-proxy study results (discovery n = 409,435 and validation size n = 58,190). Here, we add six variants associated with Alzheimer's disease risk (near APP, CHRNE, PRKD3/NDUFAF7, PLCG2 and two exonic variants in the SHARPIN gene). Assessment of the polygenic risk score and stratifying by APOE reveal a 4 to 5.5 years difference in median age at onset of Alzheimer's disease patients in APOE ɛ4 carriers. Because of this study, the underlying mechanisms of APP can be studied to refine the amyloid cascade and the polygenic risk score provides a tool to select individuals at high risk of Alzheimer's disease