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result(s) for
"Nichols, Nicholas G."
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Treatment intensification strategies for men undergoing definitive radiotherapy for high-risk prostate cancer
by
Brisbane, Wayne
,
Chang, Albert
,
Valle, Luca
in
Acetic acid
,
Androgen Antagonists - therapeutic use
,
Androgens
2024
Purpose
Treatment intensification of external beam radiotherapy (EBRT) plays a crucial role in the treatment of high-risk prostate cancer.
Methods
We performed a critical narrative review of the relevant literature and present new developments in evidence-based treatment intensification strategies.
Results
For men with high-risk prostate cancer, there is strong evidence to support prolonging androgen deprivation therapy (ADT) to 18–36 months and escalating the dose to the prostate using a brachytherapy boost. A potentially less toxic alternative to a brachytherapy boost is delivering a focal boost to dominant intraprostatic lesions using EBRT. In patients who meet STAMPEDE high-risk criteria, there is evidence to support adding a second-generation anti-androgen agent, such as abiraterone acetate, to long-term ADT. Elective pelvic lymph node irradiation may be beneficial in select patients, though more prospective data is needed to elucidate the group of patients who may benefit the most. Tumor genomic classifier (GC) testing and advanced molecular imaging will likely play a role in improving patient selection for treatment intensification as well as contribute to the evolution of treatment intensification strategies for future patients.
Conclusion
Treatment intensification using a combination of EBRT, advanced hormonal therapies, and brachytherapy may improve patient outcomes and survival in men with high-risk prostate cancer. Shared decision-making between patients and multidisciplinary teams of radiation oncologists, urologists, and medical oncologists is essential for personalizing care in this setting and deciding which strategies make sense for individual patients.
Journal Article
A hybrid open-top light-sheet microscope for versatile multi-scale imaging of cleared tissues
2022
Light-sheet microscopy has emerged as the preferred means for high-throughput volumetric imaging of cleared tissues. However, there is a need for a flexible system that can address imaging applications with varied requirements in terms of resolution, sample size, tissue-clearing protocol, and transparent sample-holder material. Here, we present a ‘hybrid’ system that combines a unique non-orthogonal dual-objective and conventional (orthogonal) open-top light-sheet (OTLS) architecture for versatile multi-scale volumetric imaging. We demonstrate efficient screening and targeted sub-micrometer imaging of sparse axons within an intact, cleared mouse brain. The same system enables high-throughput automated imaging of multiple specimens, as spotlighted by a quantitative multi-scale analysis of brain metastases. Compared with existing academic and commercial light-sheet microscopy systems, our hybrid OTLS system provides a unique combination of versatility and performance necessary to satisfy the diverse requirements of a growing number of cleared-tissue imaging applications.
A ‘hybrid’ open-top light-sheet microscope is described, which can be used for broad multi-scale volumetric imaging of one or more large tissues, cleared with diverse protocols, and conveniently mounted on an array of sample holders.
Journal Article
Exploring the genetic architecture of inflammatory bowel disease by whole-genome sequencing identifies association at ADCY7
by
McCarthy, Shane
,
Prescott, Natalie J
,
Lees, Charlie W
in
631/208/205
,
631/208/514/1948
,
692/699/1503/257
2017
Carl Anderson, Jeffrey Barrett and colleagues use whole-genome sequencing and imputation to explore the genetic architecture of inflammatory bowel disease. They identify a low-frequency missense variant in
ADCY7
that doubles risk of ulcerative colitis and detect a burden of very rare, damaging missense variants in known Crohn's disease risk genes.
To further resolve the genetic architecture of the inflammatory bowel diseases ulcerative colitis and Crohn's disease, we sequenced the whole genomes of 4,280 patients at low coverage and compared them to 3,652 previously sequenced population controls across 73.5 million variants. We then imputed from these sequences into new and existing genome-wide association study cohorts and tested for association at ∼12 million variants in a total of 16,432 cases and 18,843 controls. We discovered a 0.6% frequency missense variant in
ADCY7
that doubles the risk of ulcerative colitis. Despite good statistical power, we did not identify any other new low-frequency risk variants and found that such variants explained little heritability. We detected a burden of very rare, damaging missense variants in known Crohn's disease risk genes, suggesting that more comprehensive sequencing studies will continue to improve understanding of the biology of complex diseases.
Journal Article
Multi-site genetic analysis of diffusion images and voxelwise heritability analysis: A pilot project of the ENIGMA–DTI working group
2013
The ENIGMA (Enhancing NeuroImaging Genetics through Meta-Analysis) Consortium was set up to analyze brain measures and genotypes from multiple sites across the world to improve the power to detect genetic variants that influence the brain. Diffusion tensor imaging (DTI) yields quantitative measures sensitive to brain development and degeneration, and some common genetic variants may be associated with white matter integrity or connectivity. DTI measures, such as the fractional anisotropy (FA) of water diffusion, may be useful for identifying genetic variants that influence brain microstructure. However, genome-wide association studies (GWAS) require large populations to obtain sufficient power to detect and replicate significant effects, motivating a multi-site consortium effort. As part of an ENIGMA–DTI working group, we analyzed high-resolution FA images from multiple imaging sites across North America, Australia, and Europe, to address the challenge of harmonizing imaging data collected at multiple sites. Four hundred images of healthy adults aged 18–85 from four sites were used to create a template and corresponding skeletonized FA image as a common reference space. Using twin and pedigree samples of different ethnicities, we used our common template to evaluate the heritability of tract-derived FA measures. We show that our template is reliable for integrating multiple datasets by combining results through meta-analysis and unifying the data through exploratory mega-analyses. Our results may help prioritize regions of the FA map that are consistently influenced by additive genetic factors for future genetic discovery studies. Protocols and templates are publicly available at (http://enigma.loni.ucla.edu/ongoing/dti-working-group/).
•We harmonize a DTI protocol for genetic studies of FA; protocols are made public.•Template created from 400 adults (18–85) from 4 sites with different DTI parameters•Meta-analysis of heritability from 2 sites performed voxelwise and in ROIs.•Reliable pooled heritability estimates found for most regions of the brain.•Results will help guide future studies to harmonize and combine DTI data.
Journal Article
SDPR induces membrane curvature and functions in the formation of caveolae
by
Hansen, Carsten G.
,
Howard, Gillian
,
Bright, Nicholas A.
in
Animals
,
Binding proteins
,
Biomedical and Life Sciences
2009
Caveolae are plasma membrane invaginations implicated in endocytosis. SDPR is a new component of caveolae that facilitates membrane curvature, caveolae formation and tubulation induced by extracellular ligands such as Shiga toxin B.
Caveolae are plasma membrane invaginations with a characteristic flask-shaped morphology. They function in diverse cellular processes, including endocytosis. The mechanism by which caveolae are generated is not fully understood, but both caveolin proteins and PTRF (polymerase I and transcript release factor, also known as cavin) are important. Here we show that loss of SDPR (serum deprivation protein response) causes loss of caveolae. SDPR binds directly to PTRF and recruits PTRF to caveolar membranes. Overexpression of SDPR, unlike PTRF, induces deformation of caveolae and extensive tubulation of the plasma membrane. The B-subunit of Shiga toxin (STB) also induces membrane tubulation and these membrane tubes also originate from caveolae. STB colocalizes extensively with both SDPR and caveolin 1. Loss of caveolae reduces the propensity of STB to induce membrane tubulation. We conclude that SDPR is a membrane-curvature-inducing component of caveolae, and that STB-induced membrane tubulation is facilitated by caveolae.
Journal Article
Hotspot activating PRKD1 somatic mutations in polymorphous low-grade adenocarcinomas of the salivary glands
2014
Jorge Reis-Filho and colleagues identify recurrent mutations in
PRKD1
in 73% of polymorphous low-grade adenocarcinoma, a malignant tumor of the minor salivary glands. The mutations cause activation of the PRKD1 serine-threonine kinase.
Polymorphous low-grade adenocarcinoma (PLGA) is the second most frequent type of malignant tumor of the minor salivary glands. We identified
PRKD1
hotspot mutations encoding p.Glu710Asp in 72.9% of PLGAs but not in other salivary gland tumors. Functional studies demonstrated that this kinase-activating alteration likely constitutes a driver of PLGA.
Journal Article
Heritability of fractional anisotropy in human white matter: A comparison of Human Connectome Project and ENIGMA-DTI data
by
Sprooten, Emma
,
Glahn, David C.
,
Winkler, Anderson
in
Adult
,
Alzheimer's disease
,
Anatomie (cytologie, histologie, embryologie...) & physiologie
2015
The degree to which genetic factors influence brain connectivity is beginning to be understood. Large-scale efforts are underway to map the profile of genetic effects in various brain regions. The NIH-funded Human Connectome Project (HCP) is providing data valuable for analyzing the degree of genetic influence underlying brain connectivity revealed by state-of-the-art neuroimaging methods. We calculated the heritability of the fractional anisotropy (FA) measure derived from diffusion tensor imaging (DTI) reconstruction in 481 HCP subjects (194/287 M/F) consisting of 57/60 pairs of mono- and dizygotic twins, and 246 siblings. FA measurements were derived using (Enhancing NeuroImaging Genetics through Meta-Analysis) ENIGMA DTI protocols and heritability estimates were calculated using the SOLAR-Eclipse imaging genetic analysis package. We compared heritability estimates derived from HCP data to those publicly available through the ENIGMA-DTI consortium, which were pooled together from five-family based studies across the US, Europe, and Australia. FA measurements from the HCP cohort for eleven major white matter tracts were highly heritable (h2=0.53–0.90, p<10−5), and were significantly correlated with the joint-analytical estimates from the ENIGMA cohort on the tract and voxel-wise levels. The similarity in regional heritability suggests that the additive genetic contribution to white matter microstructure is consistent across populations and imaging acquisition parameters. It also suggests that the overarching genetic influence provides an opportunity to define a common genetic search space for future gene-discovery studies. Uniquely, the measurements of additive genetic contribution performed in this study can be repeated using online genetic analysis tools provided by the HCP ConnectomeDB web application.
•Data from 488 HCP subjects were processed using ENIGMA-DTI protocols.•Heritability in HCP sample was compared to ENIGMA-DTI joint-analytical estimates.•Estimates from HCP and ENIGMA-DTI were highly correlated.•Genetic contribution to white matter integrity is consistent across populations.•Defines common genetic search space for future gene-discovery studies
Journal Article
Retinoic acid induces human gastruloids with posterior embryo-like structures
by
Bradley, Nicholas
,
Shendure, Jay
,
Nichols, Eva K.
in
631/532/1360
,
631/61/2320
,
Animal models
2024
Gastruloids are a powerful in vitro model of early human development. However, although elongated and composed of all three germ layers, human gastruloids do not morphologically resemble post-implantation human embryos. Here we show that an early pulse of retinoic acid (RA), together with later Matrigel, robustly induces human gastruloids with posterior embryo-like morphological structures, including a neural tube flanked by segmented somites and diverse cell types, including neural crest, neural progenitors, renal progenitors and myocytes. Through in silico staging based on single-cell RNA sequencing, we find that human RA-gastruloids progress further than other human or mouse embryo models, aligning to E9.5 mouse and CS11 cynomolgus monkey embryos. We leverage chemical and genetic perturbations of RA-gastruloids to confirm that WNT and BMP signalling regulate somite formation and neural tube length in the human context, while transcription factors TBX6 and PAX3 underpin presomitic mesoderm and neural crest, respectively. Looking forward, RA-gastruloids are a robust, scalable model for decoding early human embryogenesis.
Hamazaki, Yang et al. report that an early pulse of retinoic acid robustly induces human gastruloids with a neural tube, segmented somites and more advanced cell types than conventional gastruloids.
Journal Article
Germline Elongator mutations in Sonic Hedgehog medulloblastoma
2020
Cancer genomics has revealed many genes and core molecular processes that contribute to human malignancies, but the genetic and molecular bases of many rare cancers remains unclear. Genetic predisposition accounts for 5 to 10% of cancer diagnoses in children
1
,
2
, and genetic events that cooperate with known somatic driver events are poorly understood. Pathogenic germline variants in established cancer predisposition genes have been recently identified in 5% of patients with the malignant brain tumour medulloblastoma
3
. Here, by analysing all protein-coding genes, we identify and replicate rare germline loss-of-function variants across
ELP1
in 14% of paediatric patients with the medulloblastoma subgroup Sonic Hedgehog (MB
SHH
)
.
ELP1
was the most common medulloblastoma predisposition gene and increased the prevalence of genetic predisposition to 40% among paediatric patients with MB
SHH
. Parent–offspring and pedigree analyses identified two families with a history of paediatric medulloblastoma.
ELP1
-associated medulloblastomas were restricted to the molecular SHHα subtype
4
and characterized by universal biallelic inactivation of
ELP1
owing to somatic loss of chromosome arm 9q. Most
ELP1
-associated medulloblastomas also exhibited somatic alterations in
PTCH1
, which suggests that germline
ELP1
loss-of-function variants predispose individuals to tumour development in combination with constitutive activation of SHH signalling. ELP1 is the largest subunit of the evolutionarily conserved Elongator complex, which catalyses translational elongation through tRNA modifications at the wobble (U
34
) position
5
,
6
. Tumours from patients with
ELP1
-associated MB
SHH
were characterized by a destabilized Elongator complex, loss of Elongator-dependent tRNA modifications, codon-dependent translational reprogramming, and induction of the unfolded protein response, consistent with loss of protein homeostasis due to Elongator deficiency in model systems
7
–
9
. Thus, genetic predisposition to proteome instability may be a determinant in the pathogenesis of paediatric brain cancers. These results support investigation of the role of protein homeostasis in other cancer types and potential for therapeutic interference.
Germline mutations in the Elongator complex gene
ELP1
predispose individuals to the development of childhood medulloblastoma.
Journal Article
Multi-site study of additive genetic effects on fractional anisotropy of cerebral white matter: Comparing meta and megaanalytical approaches for data pooling
2014
Combining datasets across independent studies can boost statistical power by increasing the numbers of observations and can achieve more accurate estimates of effect sizes. This is especially important for genetic studies where a large number of observations are required to obtain sufficient power to detect and replicate genetic effects. There is a need to develop and evaluate methods for joint-analytical analyses of rich datasets collected in imaging genetics studies. The ENIGMA-DTI consortium is developing and evaluating approaches for obtaining pooled estimates of heritability through meta-and mega-genetic analytical approaches, to estimate the general additive genetic contributions to the intersubject variance in fractional anisotropy (FA) measured from diffusion tensor imaging (DTI). We used the ENIGMA-DTI data harmonization protocol for uniform processing of DTI data from multiple sites. We evaluated this protocol in five family-based cohorts providing data from a total of 2248 children and adults (ages: 9–85) collected with various imaging protocols. We used the imaging genetics analysis tool, SOLAR-Eclipse, to combine twin and family data from Dutch, Australian and Mexican-American cohorts into one large “mega-family”. We showed that heritability estimates may vary from one cohort to another. We used two meta-analytical (the sample-size and standard-error weighted) approaches and a mega-genetic analysis to calculate heritability estimates across-population. We performed leave-one-out analysis of the joint estimates of heritability, removing a different cohort each time to understand the estimate variability. Overall, meta- and mega-genetic analyses of heritability produced robust estimates of heritability.
[Display omitted]
•Data pooling using analytical approaches leads to improved power of genetic analyses.•In the largest DTI study to date we evaluated three metaanalytical methods.•Data from 2248 subjects were normalized using ENIGMA-DTI protocol.•Heritability estimates varied substantially for five cohort that contributed subjects.•Meta-analyses boosted power and improved stability of heritability estimates.
Journal Article