176 research outputs found
The inner centromere is a biomolecular condensate scaffolded by the chromosomal passenger complex.
The inner centromere is a region on every mitotic chromosome that enables specific biochemical reactions that underlie properties, such as the maintenance of cohesion, the regulation of kinetochores and the assembly of specialized chromatin, that can resist microtubule pulling forces. The chromosomal passenger complex (CPC) is abundantly localized to the inner centromeres and it is unclear whether it is involved in non-kinase activities that contribute to the generation of these unique chromatin properties. We find that the borealin subunit of the CPC drives phase separation of the CPC in vitro at concentrations that are below those found on the inner centromere. We also provide strong evidence that the CPC exists in a phase-separated state at the inner centromere. CPC phase separation is required for its inner-centromere localization and function during mitosis. We suggest that the CPC combines phase separation, kinase and histone code-reading activities to enable the formation of a chromatin body with unique biochemical activities at the inner centromere
An open-label, 1-year extension study of the long-term safety and efficacy of once-daily OROS® hydromorphone in patients with chronic cancer pain
<p>Abstract</p> <p>Background</p> <p>Opioid analgesics have proven efficacy in the short-term management of chronic cancer pain, but data on their long-term use is more limited. OROS<sup>® </sup>hydromorphone is a controlled-release formulation of oral hydromorphone that may be particularly well suited to long-term management of chronic cancer pain because it provides stable plasma concentrations and consistent analgesia with convenient once-daily dosing. The objective of this study (DO-118X) was to characterise the pain control achieved with long-term repeated dosing of OROS<sup>® </sup>hydromorphone in patients with chronic cancer pain.</p> <p>Methods</p> <p>In this multicentre, phase III, open-label, single treatment, 1-year extension study, OROS<sup>® </sup>hydromorphone was administered to 68 patients with moderate-to-severe chronic cancer pain, who had successfully completed a short-term equivalence study, and whose pain was controlled with a stable dose of medication (≥ 8 mg OROS<sup>® </sup>hydromorphone or equivalent controlled-release morphine). Patients were started on the dose of OROS<sup>® </sup>hydromorphone equivalent to the opioid dose on which they achieved dose-stable pain control in the equivalence study; dose adjustments were made as necessary and breakthrough pain medication was permitted. Efficacy was assessed with the Brief Pain Inventory (BPI) and patient and investigator global evaluations of treatment effectiveness. No formal statistical analysis was done.</p> <p>Results</p> <p>The mean (standard deviation) duration of exposure to study medication was 139 (129.9) days and the mean (standard deviation) average daily consumption of OROS<sup>® </sup>hydromorphone was 43.7 (28.14) mg/day. All scores were maintained at a mild to moderate severity throughout the study; however, BPI scores for pain at its worst, pain at its least, pain on average, pain right now, and pain relief were slightly worsened at end point compared with baseline. Mean BPI pain interference with daily activities and patient and investigator global evaluation scores also remained generally stable. Treatment effectiveness was rated as fair to good throughout the study. The most frequently reported adverse events were nausea (n = 24, 35.3%), constipation (n = 22, 32.4%), and vomiting (n = 15, 22.1%).</p> <p>Conclusion</p> <p>The results of this extension study suggest that long-term repeated dosing with once-daily OROS<sup>® </sup>hydromorphone can be beneficial in the continuing management of persistent, moderate-to-severe cancer pain.</p
A novel mechanical cleavage method for synthesizing few-layer graphenes
A novel method to synthesize few layer graphene from bulk graphite by mechanical cleavage is presented here. The method involves the use of an ultrasharp single crystal diamond wedge to cleave a highly ordered pyrolytic graphite sample to generate the graphene layers. Cleaving is aided by the use of ultrasonic oscillations along the wedge. Characterization of the obtained layers shows that the process is able to synthesize graphene layers with an area of a few micrometers. Application of oscillation enhances the quality of the layers produced with the layers having a reduced crystallite size as determined from the Raman spectrum. Interesting edge structures are observed that needs further investigation
The Mitochondrial Genome Is a “Genetic Sanctuary” during the Oncogenic Process
Since Otto Warburg linked mitochondrial physiology and oncogenesis in the 1930s, a number of studies have focused on the analysis of the genetic basis for the presence of aerobic glycolysis in cancer cells. However, little or no evidence exists today to indicate that mtDNA mutations are directly responsible for the initiation of tumor onset. Based on a model of gliomagenesis in the mouse, we aimed to explore whether or not mtDNA mutations are associated with the initiation of tumor formation, maintenance and aggressiveness. We reproduced the different molecular events that lead from tumor initiation to progression in the mouse glioma. In human gliomas, most of the genetic alterations that have been previously identified result in the aberrant activation of different signaling pathways and deregulation of the cell cycle. Our data indicates that mitochondrial dysfunction is associated with reactive oxygen species (ROS) generation, leading to increased nuclear DNA (nDNA) mutagenesis, but maintaining the integrity of the mitochondrial genome. In addition, mutational stability has been observed in entire mtDNA of human gliomas; this is in full agreement with the results obtained in the cancer mouse model. We use this model as a paradigm of oncogenic transformation due to the fact that mutations commonly found in gliomas appear to be the most common molecular alterations leading to tumor development in most types of human cancer. Our results indicate that the mtDNA genome is kept by the cell as a “genetic sanctuary” during tumor development in the mouse and humans. This is compatible with the hypothesis that the mtDNA molecule plays an essential role in the control of the cellular adaptive survival response to tumor-induced oxidative stress. The integrity of mtDNA seems to be a necessary element for responding to the increased ROS production associated with the oncogenic process
Association between H-RAS T81C genetic polymorphism and gastrointestinal cancer risk: A population based case-control study in China
<p>Abstract</p> <p>Background</p> <p>Gastrointestinal cancer, such as gastric, colon and rectal cancer, is a major medical and economic burden worldwide. However, the exact mechanism of gastrointestinal cancer development still remains unclear. <it>RAS </it>genes have been elucidated as major participants in the development and progression of a series of human tumours and the single nucleotide polymorphism at <it>H-RAS </it>cDNA position 81 was demonstrated to contribute to the risks of bladder, oral and thyroid carcinoma. Therefore, we hypothesized that this polymorphisms in <it>H-RAS </it>could influence susceptibility to gastrointestinal cancer as well, and we conducted this study to test the hypothesis in Chinese population.</p> <p>Methods</p> <p>A population based case-control study, including 296 cases with gastrointestinal cancer and 448 healthy controls selected from a Chinese population was conducted. <it>H-RAS </it>T81C polymorphism was genotyped by Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) assay.</p> <p>Results</p> <p>In the healthy controls, the TT, TC and CC genotypes frequencies of <it>H-RAS </it>T81C polymorphism, were 79.24%, 19.87% and 0.89%, respectively, and the C allele frequency was 10.83%. Compared with TT genotype, the TC genotype was significantly associated with an increased risk of gastric cancer (adjusted OR = 3.67, 95%CI = 2.21–6.08), while the CC genotype showed an increased risk as well (adjusted OR = 3.29, 95%CI = 0.54–19.86), but it was not statistically significant. In contrast, the frequency of TC genotype was not significantly increased in colon cancer and rectal cancer patients. Further analysis was performed by combining TC and CC genotypes compared against TT genotype. As a result, a statistically significant risk with adjusted OR of 3.65 (95%CI, 2.22–6.00) was found in gastric cancer, while no significant association of <it>H-RAS </it>T81C polymorphism with colon cancer and rectal cancer was observed.</p> <p>Conclusion</p> <p>These findings indicate, for the first time, that there is an <it>H-RAS </it>T81C polymorphism existing in Chinese population, and this SNP might be a low penetrance gene predisposition factor for gastric cancer.</p
Development of a Novel Simplified PBPK Absorption Model to Explain the Higher Relative Bioavailability of the OROS® Formulation of Oxybutynin
Radiogenomic Mapping of Edema/Cellular Invasion MRI-Phenotypes in Glioblastoma Multiforme
Despite recent discoveries of new molecular targets and pathways, the search for an effective therapy for Glioblastoma Multiforme (GBM) continues. A newly emerged field, radiogenomics, links gene expression profiles with MRI phenotypes. MRI-FLAIR is a noninvasive diagnostic modality and was previously found to correlate with cellular invasion in GBM. Thus, our radiogenomic screen has the potential to reveal novel molecular determinants of invasion. Here, we present the first comprehensive radiogenomic analysis using quantitative MRI volumetrics and large-scale gene- and microRNA expression profiling in GBM.Based on The Cancer Genome Atlas (TCGA), discovery and validation sets with gene, microRNA, and quantitative MR-imaging data were created. Top concordant genes and microRNAs correlated with high FLAIR volumes from both sets were further characterized by Kaplan Meier survival statistics, microRNA-gene correlation analyses, and GBM molecular subtype-specific distribution.The top upregulated gene in both the discovery (4 fold) and validation (11 fold) sets was PERIOSTIN (POSTN). The top downregulated microRNA in both sets was miR-219, which is predicted to bind to POSTN. Kaplan Meier analysis demonstrated that above median expression of POSTN resulted in significantly decreased survival and shorter time to disease progression (P<0.001). High POSTN and low miR-219 expression were significantly associated with the mesenchymal GBM subtype (P<0.0001).Here, we propose a novel diagnostic method to screen for molecular cancer subtypes and genomic correlates of cellular invasion. Our findings also have potential therapeutic significance since successful molecular inhibition of invasion will improve therapy and patient survival in GBM
Female preference for blue in Japan blue guppies (Poecilia reticulata)
Guppies (Poecilia reticulata) are widely used as a model species in mate choice studies. Although native to South America, guppies have been introduced to natural water bodies in disparate regions of the globe. Here, for the first time, we examine guppies from one such introduced population in Japan where males have evolved a predominantly blue color pattern. Previous studies of wild-type guppies have shown blue to play a relatively minor role in the mate choice decisions of females compared to other traits, such as orange, and the importance of blue is not universally supported by all studies. The Japanese population therefore presents an ideal opportunity to re-examine the potential significance of blue as a mate choice cue in guppies. Mate choice experiments, in which female Japan blue guppies were given a choice between pairs of males that differed in their area of blue coloration but were matched for other traits, revealed that females prefer males with proportionately larger amounts of blue in their color patterns. We discuss possible factors, including sexual and ecological selection, which may have led to the evolution of unusually large areas of blue at the expense of other colors in Japan blue guppies. However, further studies are needed to distinguish between these scenarios.Web of Scienc
- …