Standardized and reproducible preclinical models that recapitulate the dynamics of prostate cancer are urgently needed. We established a bank of transplantable patient-derived prostate cancer ...xenografts that capture the biologic and molecular heterogeneity currently confounding prognostication and therapy development. Xenografts preserved the histopathology, genome architecture, and global gene expression of donor tumors. Moreover, their aggressiveness matched patient observations, and their response to androgen withdrawal correlated with tumor subtype. The panel includes the first xenografts generated from needle biopsy tissue obtained at diagnosis. This advance was exploited to generate independent xenografts from different sites of a primary site, enabling functional dissection of tumor heterogeneity. Prolonged exposure of adenocarcinoma xenografts to androgen withdrawal led to castration-resistant prostate cancer, including the first-in-field model of complete transdifferentiation into lethal neuroendocrine prostate cancer. Further analysis of this model supports the hypothesis that neuroendocrine prostate cancer can evolve directly from adenocarcinoma via an adaptive response and yielded a set of genes potentially involved in neuroendocrine transdifferentiation. We predict that these next-generation models will be transformative for advancing mechanistic understanding of disease progression, response to therapy, and personalized oncology.
This paper describes the behavior of top-gated transistors fabricated using carbon, specifically epitaxial graphene on SiC, as the active material. Although graphene devices have been built before, ...in this paper, we provide the first demonstration and systematic evaluation of arrays of a large number of transistors produced using standard microelectronics methods. The graphene devices presented feature high-k dielectric, mobilities up to 5000 cm 2 /Vldr s, and I on /I off ratios of up to seven, and are methodically analyzed to provide insight into the substrate properties. Typical of graphene, these micrometer-scale devices have negligible band gaps and, therefore, large leakage currents.
Purpose
This study investigates the cellular uptake and trafficking of liposomes in Caco-2 cells, using vesicles with distinct average diameters ranging from 40.6 nm to 276.6 nm. Liposomes were ...prepared by microfluidic hydrodynamic flow focusing, producing nearly-monodisperse populations and enabling size-dependent uptake to be effectively evaluated.
Methods
Populations of PEG-conjugated liposomes of various distinct sizes were prepared in a disposable microfluidic device using a simple continuous-flow microfluidic technique. Liposome cellular uptake was investigated using flow cytometry and confocal microscopy.
Results
Liposome uptake by Caco-2 cells was observed to be strongly size-dependent for liposomes with mean diameters ranging from 40.6 nm to 276.6 nm. When testing these liposomes against endocytosis inhibitors, cellular uptake of the largest (97.8 nm and 162.1 nm in diameter) liposomes were predominantly subjected to clathrin-dependent uptake mechanisms, the medium-sized (72.3 nm in diameter) liposomes seemed to be influenced by all investigated pathways and the smallest liposomes (40.6 nm in diameter) primarily followed a dynamin-dependent pathway. In addition, the 40.6 nm, 72.3 nm, and 162.1 nm diameter liposomes showed slightly decreased accumulation within endosomes after 1 h compared to liposomes which were 97.8 nm in diameter. Conversely, liposome co-localization with lysosomes was consistent for liposomes ranging from 40.6 nm to 97.8 nm in diameter.
Conclusions
The continuous-flow synthesis of nearly-monodisperse populations of liposomes of distinct size
via
a microfluidic hydrodynamic flow focusing technique enabled unique
in vitro
studies in which specific effects of particle size on cellular uptake were elucidated. The results of this study highlight the significant influence of liposome size on cellular uptake mechanisms and may be further exploited for increasing specificity, improving efficacy, and reducing toxicity of liposomal drug delivery systems.
A central goal of evolutionary biology is to link genomic change to phenotypic evolution. The origin of new transcription factors is a special case of genomic evolution since it brings opportunities ...for novel regulatory interactions and potentially the emergence of new biological properties.
We demonstrate that a group of four homeobox gene families (Argfx, Leutx, Dprx, Tprx), plus a gene newly described here (Pargfx), arose by tandem gene duplication from the retinal-expressed Crx gene, followed by asymmetric sequence evolution. We show these genes arose as part of repeated gene gain and loss events on a dynamic chromosomal region in the stem lineage of placental mammals, on the forerunner of human chromosome 19. The human orthologues of these genes are expressed specifically in early embryo totipotent cells, peaking from 8-cell to morula, prior to cell fate restrictions; cow orthologues have similar expression. To examine biological roles, we used ectopic gene expression in cultured human cells followed by high-throughput RNA-seq and uncovered extensive transcriptional remodelling driven by three of the genes. Comparison to transcriptional profiles of early human embryos suggest roles in activating and repressing a set of developmentally-important genes that spike at 8-cell to morula, rather than a general role in genome activation.
We conclude that a dynamic chromosome region spawned a set of evolutionarily new homeobox genes, the ETCHbox genes, specifically in eutherian mammals. After these genes diverged from the parental Crx gene, we argue they were recruited for roles in the preimplantation embryo including activation of genes at the 8-cell stage and repression after morula. We propose these new homeobox gene roles permitted fine-tuning of cell fate decisions necessary for specification and function of embryonic and extra-embryonic tissues utilised in mammalian development and pregnancy.
The effective work function of a reactively sputtered TiN metal gate is shown to be tunable from 4.30 to 4.65 eV. The effective work function decreases with nitrogen flow during reactive sputter ...deposition. Nitrogen annealing increases the effective work function and reduces D it . Thinner TiN improves the variation in effective work function and reduces gate dielectric charge. Doping of the polysilicon above the TiN metal gate with B or P has negligible effect on the effective work function. The work-function-tuned TiN is integrated into ultralow-power fully depleted silicon-on-insulator CMOS transistors optimized for subthreshold operation at 0.3 V. The following performance metrics are achieved: 64-80-mV/dec subthreshold swing, PMOS/NMOS on-current ratio near 1, 71% reduction in C gd , and 55% reduction in V t variation when compared with conventional transistors, although significant short-channel effects are observed.
The rationale and development of a wafer-scale three-dimensional (3-D) integrated circuit technology are described. The essential elements of the 3-D technology are integrated circuit fabrication on ...silicon-on-insulator wafers, precision wafer-wafer alignment using an in-house-developed alignment system, low-temperature wafer-wafer bonding to transfer and stack active circuit layers, and interconnection of the circuit layers with dense-vertical connections with sub-Omega 3-D via resistances. The 3-D integration process is described as well as the properties of the four enabling technologies. The wafer-scale 3-D technology imposes constraints on the placement of the first lithographic level in a wafer-stepper process. Control of wafer distortion and wafer bow is required to achieve submicrometer vertical vias. Three-tier digital and analog 3-D circuits were designed and fabricated. The performance characteristics of a 3-D ring oscillator, a 1024 times 1024 visible imager with an 8-mum pixel pitch, and a 64 times 64 Geiger-mode laser radar chip are described
There is a critical need for more effective therapeutic approaches for prostate cancer. Research in this area, however, has been seriously hampered by a lack of clinically relevant, experimental in ...vivo models of the disease. This review particularly focuses on the development of prostate cancer xenograft models based on subrenal capsule grafting of patients＇ tumor tissue into nonobese diabetic/ severe combined immunodeficient （NOD/ SCID） mice. This technique allows successful development of transplantable, patient-derived cancer tissue xenograft lines not only from aggressive metastatic, but also from localized prostate cancer tissues. The xenografts have been found to retain key biological properties of the original malignancies, including histopathological and molecular characteristics, tumor heterogeneity, response to androgen ablation and metastatic ability. As such, they are highly clinically relevant and provide valuable tools for studies of prostate cancer progression at cellular and molecular levels, drug screening for personalized cancer therapy and preclinical drug efficacy testing; especially when a panel of models is used to cover a broader spectrum of the disease. These xenograft models could therefore be viewed as next-generation models of prostate cancer.
Selective serotonin-reuptake inhibitors (SSRIs) are increasingly being used as first-line therapy for severe premenstrual syndrome (PMS). We undertook a meta-analysis on the efficacy of SSRIs in this ...disorder.
We searched medical and scientific databases, approached pharmaceutical companies, and reviewed citations of relevant articles to identify 29 studies of the use of SSRIs in PMS. 14 were excluded (no placebo group, preliminary report of included trial, or low quality). 15 randomised placebo-controlled trials were included. Information on study design, participants, drugs used and dosing regimens, outcome measures, sideeffects, and sources of funding was extracted. Standardised mean differences between treatment and placebo groups were calculated to obtain an overall estimate of efficacy. The primary outcome measure was a reduction in overall PMS symptoms.
The primary analysis included data on 904 women (570 assigned active treatment and 435 assigned placebo, including 101 in crossover trials). The overall standardised mean difference was −1·066 (95% CI −1·381 to −0·750), which corresponds to an odds ratio of 6·91 (3·90 to 12·2) in favour of SSRIs. SSRIs were effective in treating physical and behavioural symptoms. There was no significant difference in symptom reduction between continuous and intermittent dosing or between trials funded by pharmaceutical companies and those independently funded. Withdrawal due to sideeffects was 2·5 times more likely in the active-treatment group than in the placebo group.
SSRIs are an effective first-line therapy for severe PMS. The safety of these drugs has been demonstrated in trials of affective disorder, and the side-effects at low doses are generally acceptable.
Ultralow-power electronics will expand the technological capability of handheld and wireless devices by dramatically improving battery life and portability. In addition to innovative low-power design ...techniques, a complementary process technology is required to enable the highest performance devices possible while maintaining extremely low power consumption. Transistors optimized for subthreshold operation at 0.3 V may achieve a 97% reduction in switching energy compared to conventional transistors. The process technology described in this article takes advantage of the capacitance and performance benefits of thin-body silicon-on-insulator devices, combined with a workfunction engineered mid-gap metal gate.
Neuroendocrine prostate cancer (NEPC) is an aggressive subtype of prostate cancer which does not respond to hormone therapy. Research of NEPC has been hampered by a lack of clinically relevant in ...vivo models. Recently, we developed a first-in-field patient tissue-derived xenograft model of complete neuroendocrine transdifferentiation of prostate adenocarcinoma. By comparing gene expression profiles of a transplantable adenocarcinoma line (LTL331) and its NEPC subline (LTL331R), we identified DEK as a potential biomarker and therapeutic target for NEPC. In the present study, elevated DEK protein expression was observed in all NEPC xenograft models and clinical NEPC cases, as opposed to their benign counterparts (0%), hormonal naïve prostate cancer (2.45%) and castration-resistant prostate cancer (29.55%). Elevated DEK expression was found to be an independent clinical risk factor, associated with shorter disease-free survival of hormonal naïve prostate cancer patients. DEK silencing in PC-3 cells led to a marked reduction in cell proliferation, cell migration and invasion. The results suggest that DEK plays an important role in the progression of prostate cancer, especially to NEPC, and provides a potential biomarker to aid risk stratification of prostate cancer and a novel target for therapy of NEPC.
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