150 research outputs found
MiR-145 inhibits oral squamous cell carcinoma (OSCC) cell growth by targeting c-Myc and Cdk6
BACKGROUND: MicroRNAs (miRNAs) are a large group of negative gene regulators that potentially play a critical role in tumorigenesis. Increasing evidences indicate that miR-145 acts a tumor suppressor in numerous human cancers. However, its role in oral carcinogenesis remains poorly defined. The aim of this study is to determine expression levels of miR-145 in oral squamous cell carcinomas (OSCCs) and normal mucosa tissues, and explore its biological functions in OSCCs. METHODS: Reverse transcription quantitative real-time PCR (RT-qPCR) assay was used to evaluate expression levels of miR-145. The biological functions of miR-145 were determined by cell proliferation and colony formation, cell cycle and apoptosis, as well as cell invasion assay. RESULTS: MiR-145 was frequently down-regulated in OSCCs compared with normal mucosa tissues. Restoring miR-145 expression in OSCC cells dramatically suppressed cell proliferation and colony formation, and induced G1 phase arrest and cell apoptosis. Importantly, our data showed that miR-145 downregulated the expression of c-Myc and Cdk6, which have previously been identified as two direct targets of miR-145. CONCLUSIONS: Our data suggest that miR-145 exerts its tumor suppressor function by targeting c-Myc and Cdk6, leading to the inhibition of OSCC cell growth. MiR-145 rescue may thus be a rational for diagnostic and therapeutic applications in OSCC
Relation between nodule size and \u3csup\u3e18\u3c/sup\u3eF-FDG-PET SUV for malignant and benign pulmonary nodules.
Abstract
The most common semiquantitative method of evaluation of pulmonary lesions using 18F-FDG PET is FDG standardized uptake value (SUV). An SUV cutoff of 2.5 or greater has been used to differentiate between benign and malignant nodules. The goal of our study was to investigate the correlation between the size of pulmonary nodules and the SUV for benign as well as for malignant nodules.
Methods
Retrospectively, 173 patients were selected from 420 referrals for evaluation of pulmonary lesions. All patients selected had a positive CT and PET scans and histopathology biopsy. A linear regression equation was fitted to a scatter plot of size and SUVmax for malignant and benign nodules together. A dot diagram was created to calculate the sensitivity, specificity, and accuracy using an SUVmax cutoff of 2.5.
Results
The linear regression equations and (R2)s as well as the trendlines for malignant and benign nodules demonstrated that the slope of the regression line is greater for malignant than for benign nodules. Twenty-eight nodules of group one (†1.0 cm) are plotted in a dot diagram using an SUVmax cutoff of 2.5. The sensitivity, specificity, and accuracy were calculated to be 85%, 36% and 54% respectively. Similarly, sensitivity, specificity, and accuracy were calculated for an SUVmax cutoff of 2.5 and found to be 91%, 47%, and 79% respectively for group 2 (1.1â2.0 cm); 94%, 23%, and 76%, respectively for group 3 (2.1â3.0 cm); and 100%, 17%, and 82%,, respectively for group 4 (\u3e 3.0 cm). The previous results of the dot diagram indicating that the sensitivity and the accuracy of the test using an SUVmax cutoff of 2.5 are increased with an increase in the diameter of pulmonary nodules.
Conclusion
The slope of the regression line is greater for malignant than for benign nodules. Although, the SUVmax cutoff of 2.5 is a useful tool in the evaluation of large pulmonary nodules (\u3e 1.0 cm), it has no or minimal value in the evaluation of small pulmonary nodules (†1.0 cm)
Relation between nodule size and 18F-FDG-PET SUV for malignant and benign pulmonary nodules.
The most common semiquantitative method of evaluation of pulmonary lesions using 18F-FDG PET is FDG standardized uptake value (SUV). An SUV cutoff of 2.5 or greater has been used to differentiate between benign and malignant nodules. The goal of our study was to investigate the correlation between the size of pulmonary nodules and the SUV for benign as well as for malignant nodules
An Investigation of the Required MR Bone Attenuation Correction for Quantitative Whole-Body PET/MR Imaging Using Clinical NaF PET/CT Studies
Ai, H. , Mawlawi, O. , Stafford, R. , Bankson, J. , Shao, Y. , Guindani, M. and Wendt III, R. (2018) An Investigation of the Required MR Bone Attenuation Correction for Quantitative Whole-Body PET/MR Imaging Using Clinical NaF PET/CT Studies. International Journal of Medical Physics, Clinical Engineering and Radiation Oncology, 7, 273-295. doi: 10.4236/ijmpcero.2018.73023.https://openworks.mdanderson.org/mdacc_imgphys_pubs/1003/thumbnail.jp
SelfâAssembly of Therapeutic Peptide into StimuliâResponsive Clustered Nanohybrids for CancerâTargeted Therapy
Clinical translation of therapeutic peptides, particularly those targeting intracellular proteinâprotein interactions (PPIs), has been hampered by their inefficacious cellular internalization in diseased tissue. Therapeutic peptides engineered into nanostructures with stable spatial architectures and smart disease targeting ability may provide a viable strategy to overcome the pharmaceutical obstacles of peptides. This study describes a strategy to assemble therapeutic peptides into a stable peptideâAu nanohybrid, followed by further selfâassembling into higherâorder nanoclusters with responsiveness to tumor microenvironment. As a proof of concept, an anticancer peptide termed ÎČâcatenin/Bcl9 inhibitors is copolymerized with gold ion and assembled into a cluster of nanohybrids (pCluster). Through a battery of in vitro and in vivo tests, it is demonstrated that pClusters potently inhibit tumor growth and metastasis in several animal models through the impairment of the Wnt/ÎČâcatenin pathway, while maintaining a highly favorable biosafety profile. In addition, it is also found that pClusters synergize with the PD1/PDâL1 checkpoint blockade immunotherapy. This new strategy of peptide delivery will likely have a broad impact on the development of peptideâderived therapeutic nanomedicine and reinvigorate efforts to discover peptide drugs that target intracellular PPIs in a great variety of human diseases, including cancer.A strategy for clinical translation of therapeutic peptides by assembling them into a stable peptideâAu nanohybrid, followed by further selfâassembling into higherâorder nanoclusters with responsiveness to the tumor microenvironment, is presented. An anticancer peptide termed ÎČâcatenin/Bcl9 inhibitor is assembled into a cluster of nanohybrids termed pCluster, which potently inhibits tumor growth as well as metastasis, and synergizes with immunotherapy, while maintaining a highly favorable biosafety profile.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/148246/1/adfm201807736.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148246/2/adfm201807736-sup-0001-S1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148246/3/adfm201807736_am.pd
Impaired Cognitive Function and Altered Hippocampal Synaptic Plasticity in Mice Lacking Dermatan Sulfotransferase Chst14/D4st1
Chondroitin sulfate (CS) and dermatan sulfate (DS) proteoglycans (PGs) are major extracellular matrix (ECM) components of the central nervous system (CNS). A large body of evidence has shown that CSPGs/DSPGs play critical roles in neuronal growth, axon guidance, and plasticity in the developing and mature CNS. It has been proposed that these PGs exert their function through specific interaction of CS/DS chains with its binding partners in a manner that depends on the sulfation patterns of CS/DS. It has been reported that dermatan 4-O-sulfotransferase-1 (Chst14/D4st1) specific for DS, but not chondroitin 4-O-sulfotransferase-1 (Chst11/C4st1) specific for CS, regulates proliferation and neurogenesis of neural stem cells (NSCs), indicating that CS and DS play distinct roles in the self-renewal and differentiation of NSCs. However, it remains unknown whether specific sulfation profiles of DS has any effect on CNS plasticity. In the present study, Chst14/D4st1-deficient (Chst14â/â) mice was employed to investigate the involvement of DS in synaptic plasticity. First, behavior study using Morris Water Maze (MWM) showed that the spatial learning and memory of Chst14â/â mice was impaired when compared to their wild type (WT) littermates. Corroborating the behavior result, long-term potentiation (LTP) at the hippocampal CA3-CA1 connection was reduced in Chst14â/â mice compared to the WT mice. Finally, the protein levels of N-Methyl-D-aspartate (NMDA) receptor, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor, postsynaptic density 95 (PSD95), growth associated protein 43 (GAP-43), synaptophysin (SYN) and N-ethylmaleimide sensitive factor (NSF) which are important in synaptic plasticity were examined and Chst14/D4st1 deficiency was shown to significantly reduce the expression of these proteins in the hippocampus. Further studies revealed that Akt/mammalian target rapamycin (mTOR) pathway proteins, including protein kinase B (p-Akt), p-mTOR and p-S6, were significantly lower in Chst14â/â mice, which might contribute to the decreased protein expression. Together, this study reveals that specific sulfation of DS is critical in synaptic plasticity of the hippocampus and learning and memory, which might be associated with the changes in the expression of glutamate receptors and other synaptic proteins though Akt/mTOR pathway
Alteration and clinical potential in gut microbiota in patients with cerebral small vessel disease
BackgroundCerebral small vessel disease (CSVD) is a cluster of microvascular disorders with unclear pathological mechanisms. The microbiota-gut-brain axis is an essential regulatory mechanism between gut microbes and their host. Therefore, the compositional and functional gut microbiota alterations lead to cerebrovascular disease pathogenesis. The current study aims to determine the alteration and clinical value of the gut microbiota in CSVD patients.MethodsSixty-four CSVD patients and 18 matched healthy controls (HCs) were included in our study. All the participants underwent neuropsychological tests, and the multi-modal magnetic resonance imaging depicted the changes in brain structure and function. Plasma samples were collected, and the fecal samples were analyzed with 16S rRNA gene sequencing.ResultsBased on the alpha diversity analysis, the CSVD group had significantly decreased Shannon and enhanced Simpson compared to the HC group. At the genus level, there was a significant increase in the relative abundances of Parasutterella, Anaeroglobus, Megasphaera, Akkermansia, Collinsella, and Veillonella in the CSVD group. Moreover, these genera with significant differences in CSVD patients revealed significant correlations with cognitive assessments, plasma levels of the blood-brain barrier-/inflammation-related indexes, and structural/functional magnetic resonance imaging changes. Functional prediction demonstrated that lipoic acid metabolism was significantly higher in CSVD patients than HCs. Additionally, a composite biomarker depending on six gut microbiota at the genus level displayed an area under the curve of 0.834 to distinguish CSVD patients from HCs using the least absolute shrinkage and selection operator (LASSO) algorithm.ConclusionThe evident changes in gut microbiota composition in CSVD patients were correlated with clinical features and pathological changes of CSVD. Combining these gut microbiota using the LASSO algorithm helped identify CSVD accurately
Relative importance of climatic variables, soil properties and plant traits to spatial variability in net CO2 exchange across global forests and grasslands
Compared to the well-known drivers of spatial variability in gross primary productivity (GPP), the relative importance of climatic variables, soil properties and plant traits to the spatial variability in net ecosystem exchange of CO2 between terrestrial ecosystem and atmosphere (NEE) is poorly understood. We used principal component regression to analyze data from 147 eddy flux sites to disentangle effects of climatic variables, soil properties and plant traits on the spatial variation in annual NEE and its components (GPP and ecosystem respiration (RE)) across global forests and grasslands. Our results showed that the largest unique contribution (proportion of variance only explained by one class of variables) to NEE variance came from climatic variables for forests (24%-30%) and soil properties for grasslands (41%-54%). Specifically, mean annual precipitation and potential evapotranspiration were the most important climatic variables driving forest NEE, whereas available soil water capacity, clay content and cation exchange capacity mainly influenced grassland NEE. Plant traits showed a small unique contribution to NEE in both forests and grasslands. However, leaf phosphorus content strongly interacted with soil total nitrogen density and clay content, and these combined factors represented a major contribution for grassland NEE. For GPP and RE, the majority of spatial variance was attributed to the common contribution of climate, soil and plant traits (50% - 62%, proportion of variance explained by more than one class of variables), rather than their unique contributions. Interestingly, those factors with only minor influences on GPP and RE variability (e.g., soil properties) have significant contributions to the spatial variability in NEE. Such emerging factors and the interactions between climatic variables, soil properties and plant traits are not well represented in current terrestrial biosphere models, which should be considered in future model improvement to accurately predict the spatial pattern of carbon cycling across forests and grasslands globally.Peer reviewe
The enormous repetitive Antarctic krill genome reveals environmental adaptations and population insights
Antarctic krill (Euphausia superba) is Earthâsmost abundant wild animal, and its enormous biomass is vital to
the Southern Ocean ecosystem. Here, we report a 48.01-Gb chromosome-level Antarctic krill genome, whose
large genome size appears to have resulted from inter-genic transposable element expansions. Our assembly
reveals the molecular architecture of the Antarctic krill circadian clock and uncovers expanded gene
families associated with molting and energy metabolism, providing insights into adaptations to the cold
and highly seasonal Antarctic environment. Population-level genome re-sequencing from four geographical
sites around the Antarctic continent reveals no clear population structure but highlights natural selection
associated with environmental variables. An apparent drastic reduction in krill population size 10 mya and
a subsequent rebound 100 thousand years ago coincides with climate change events. Our findings uncover
the genomic basis of Antarctic krill adaptations to the Southern Ocean and provide valuable resources for
future Antarctic research
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