101 research outputs found
Novel cis-trans interactions are involved in post-transcriptional regulation of cyclin-dependent kinase inhibitor p21WAF1/CIP1 mRNA
BACKGROUND: A variety of pathways target CDKI p21WAF1/CIP1 expression at transcriptional, post-transcriptional as well as translational levels. We previously found that cell growth suppressing retinoid CD437 enhanced expression of p21WAF1/CIP1 and DNA damage inducible GADD45 proteins in part by elevating their mRNA stability.
RESULTS: Here, we investigated molecular mechanisms of CD437-dependent post-transcriptional regulation of p21WAF1/CIP1 expression. By utilizing MDA-MB-468 HBC cells expressing chimeric rabbit beta-globin-p21WAF1/CIP1 transcripts we mapped multiple CD437-responsive sequences located within positions 1195 to 1795 of the 3\u27-untranslated region of p21WAF1/CIP1 mRNA. Several cytoplasmic proteins present in MDA-MB-468, MCF-7 HBC as well as HL-60R leukemia cells bound specifically, in vitro, with these CD437-responsive sequences. CD437 treatment of cells resulted in elevated binding of ~85 kD and ~55 kD cytoplasmic proteins with putative CD437-responsive sequences. A 12 nt RNA sequence (5\u27-UGUGGUGGCACA-3\u27) present within CD437-responsive region of p21WAF1/CIP1 mRNA displayed specific and elevated binding with the above noted proteins. Treatment of cells with ActD or CHX prior to CD437 exposure did not abrogate RNA-protein interactions. However, treatment of cytoplasmic protein extracts with proteinase K or alkaline phosphatase resulted in loss of RNA-protein interactions.
CONCLUSIONS: CD437 regulates cell growth in part by regulating stability of p21WAF1/CIP1 mRNA that involves specific RNA-protein interactions that are phosphorylation-dependent, while not requiring nascent transcription or protein synthesis
Novel cis-trans interactions are involved in post-transcriptional regulation of cyclin-dependent kinase inhibitor p21\u3csup\u3eWAF1/CIP1 \u3c/sup\u3emRNA
Abstract
Background
A variety of pathways target CDKI p21WAF1/CIP1 expression at transcriptional, post-transcriptional as well as translational levels. We previously found that cell growth suppressing retinoid CD437 enhanced expression of p21WAF1/CIP1 and DNA damage inducible GADD45 proteins in part by elevating their mRNA stability.
Results
Here, we investigated molecular mechanisms of CD437-dependent post-transcriptional regulation of p21WAF1/CIP1 expression. By utilizing MDA-MB-468 HBC cells expressing chimeric rabbit ÎČ-globin-p21WAF1/CIP1 transcripts we mapped multiple CD437-responsive sequences located within positions 1195 to 1795 of the 3\u27-untranslated region of p21WAF1/CIP1 mRNA. Several cytoplasmic proteins present in MDA-MB-468, MCF-7 HBC as well as HL-60R leukemia cells bound specifically, in vitro, with these CD437-responsive sequences. CD437 treatment of cells resulted in elevated binding of ~85 kD and ~55 kD cytoplasmic proteins with putative CD437-responsive sequences. A 12 nt RNA sequence (5\u27-UGUGGUGGCACA-3\u27) present within CD437-responsive region of p21WAF1/CIP1 mRNA displayed specific and elevated binding with the above noted proteins. Treatment of cells with ActD or CHX prior to CD437 exposure did not abrogate RNA-protein interactions. However, treatment of cytoplasmic protein extracts with proteinase K or alkaline phosphatase resulted in loss of RNA-protein interactions.
Conclusions
CD437 regulates cell growth in part by regulating stability of p21WAF1/CIP1 mRNA that involves specific RNA-protein interactions that are phosphorylation-dependent, while not requiring nascent transcription or protein synthesis
Functionalized self-assembled monolayers on mesoporous silica nanoparticles with high surface coverage
This paper proposes three content-based image classification techniques based on fusing various low-level MPEG-7 visual descriptors. Fusion is necessary as descriptors would be otherwise incompatible and inappropriate to directly include e.g. in a Euclidean distance. Three approaches are described: A âmergingâ fusion combined with an SVM classifier, a back-propagation fusion combined with a KNN classifier and a Fuzzy-ART neurofuzzy network. In the latter case, fuzzy rules can be extracted in an effort to bridge the âsemantic gapâ between the low-level descriptors and the high-level semantics of an image. All networks were evaluated using content from the repository of the aceMedia project1 and more specifically in a beach/urban scene classification problem
Functionalized self-assembled monolayers on mesoporous silica nanoparticles with high surface coverage
Mesoporous silica nanoparticles (MSNs) containing vinyl-, propyl-, isobutyl- and phenyl functionalized monolayers were reported. These functionalized MSNs were prepared via molecular self-assembly of organosilanes on the mesoporous supports. The relative surface coverage of the organic monolayers can reach up to 100% (about 5.06 silanes/nm(2)). These monolayer functionalize MSNs were analyzed by a number of techniques including transmission electron microscope, fourier transform infrared spectroscopy, X-ray diffraction pattern, cross-polarized Si(29) MAS NMR spectroscopy, and nitrogen sorption measurement. The main elements (i.e., the number of absorbed water, the reactivity of organosilanes, and the stereochemistry of organosilane) that greatly affected the surface coverage and the quality of the organic functionalized monolayers on MSNs were fully discussed. The results show that the proper amount of physically absorbed water, the use of high active trichlorosilanes, and the functional groups with less steric hindrance are essential to generate MSNs with high surface coverage of monolayers
A novel mechanism of cell growth regulation by Cell Cycle and Apoptosis Regulatory Protein (CARP)-1
Abstract
Background
CARP-1/CCAR1, a perinuclear phospho-protein, regulates signaling by adriamycin, steroids, or growth factors. However, intracellular events that regulate CARP-1-dependent cell growth are not fully understood.
Results
Here we investigated whether CARP-1 is involved in signaling induced by the protein kinase A inhibitor H89. Treatments of human breast cancer cells with H89 resulted in apoptosis that involved enhanced CARP-1 threonine phosphorylation and expression. Depletion of CARP-1, on the other hand, abrogates apoptosis induced by H89. CARP-1 binds with signal transducer TAZ and over-expression of TAZ inhibits apoptosis by CARP-1. CARP-1 (651-759) interacts with a novel, N-terminal epitope of TAZ. H89 treatment stimulates threonine phosphorylation of CARP-1 (651-759), while substitution of threonine667 to alanine interferes with its binding with TAZ and apoptosis by H89. In addition, expression of wild type or CARP-1 (651-759) causes loss of c-myc expression due, in part, to suppression of c-myc transcription.
Conclusions
CARP-1 threonine667 regulates H89-dependent signaling by a novel pathway that involves modulation of CARP-1 interaction with TAZ and transcriptional down-regulation of c-myc
Comprehensive analysis identifies novel targets of gemcitabine to improve chemotherapy treatment strategies for colorectal cancer
BackgroundGemcitabine (GEM) is a second-line anticancer drug of choice for some colorectal cancer (CRC) patients, and GEM inability to be commonly available in the clinic due to the lack of clarity of the exact action targets.MethodsThe half maximal inhibitory concentration (IC50) of GEM treatment for 42 CRC cell lines were accessed from the Genomics of Drug sensitivity in Cancer (GDSC) database. High-throughput sequencing data of CRC patients were captured in The Cancer Genome Atlas (TCGA) and Weighted correlation network analysis (WGCNA) was conducted. Pearson correlations were derived for GEM potency-related genes. Differential analysis was conducted in the TCGA cohort to obtain CRC development-related genes (CDRGs), and univariate COX model analysis was performed on CDRGs overlapping with GEM potency-related genes to obtain CDRGs affecting CRC prognosis. Hub genes affecting GEM potency were identified by Spearman correlation.ResultsCALB2 and GPX3 were identified as potential targets for GEM treatment of CRC via prognostic analysis, which we also observed to be elevated with elevated clinical stage in CRC patients. The enhanced expression of CALB2 and GPX3 genes identified in the pathway analysis might inhibit the body metabolism as well as activate immune and inflammation related pathways. In addition, we found that CALB2 and GPX3 could also be considered as prognostic biomarkers in pan-cancer. Finally, we found that CALB2 and GPX3 were remarkably associated with the drug sensitivity of MG-132, Dasatinib, Shikonin, Midostaurin, MS-275, and Z-LNle-CHO, which were expected to be the drugs of choice for GEM combination.ConclusionCALB2 and GPX3 represent prognostic biomarkers for CRC and they might be potential action targets for GEM. Our study offered innovative ideas for GEM administration strategies
Combined QTL and Genome Scan Analyses With the Help of 2b-RAD Identify Growth-Associated Genetic Markers in a New Fast-Growing Carp Strain
Common carp is one of the oldest and most popular cultured freshwater fish species both globally and in China. In a previous study, we used a carp strain with a long breeding tradition in China, named Huanghe, to create a new fast-growing strain by selection for fast growth for 6 years. The growth performance at 8 months of age has been improved by 20.84%. To achieve this, we combined the best linear unbiased prediction with marker-assisted selection techniques. Recent progress in genome-wide association studies and genomic selection in livestock breeding inspired common carp breeders to consider genome-based breeding approaches. In this study, we developed a 2b-RAD sequence assay as a means of investigating the quantitative trait loci in common carp. A total of 4,953,017,786 clean reads were generated for 250 specimens (average reads/specimen = 19,812,071) with BsaXI Restriction Enzyme. From these, 56,663 SNPs were identified, covering 50 chromosomes and 3,377 scaffolds. Principal component analysis indicated that selection and control groups are relatively clearly distinct. Top 1% of Fst values was selected as the threshold signature of artificial selection. Among the 244 identified loci, genes associated with sex-related factors and nutritional metabolism (especially fat metabolism) were annotated. Eighteen QTL were associated with growth parameters. Body length at 3 months of age and body weight (both at 3 and 8 months) were controlled by polygenic effects, but body size (length, depth, width) at 8 months of age was controlled mainly by several loci with major effects. Importantly, a single shared QTL (IGF2 gene) partially controlled the body length, depth, and width. By merging the above results, we concluded that mainly the genes related to neural pathways, sex and fatty acid metabolism contributed to the improved growth performance of the new Huanghe carp strain. These findings are one of the first investigations into the potential use of genomic selection in the breeding of common carp. Moreover, our results show that combining the Fst, QTL mapping and CRISPRâCas9 methods can be an effective way to identify important novel candidate molecular markers in economic breeding programs
DeepSeek LLM: Scaling Open-Source Language Models with Longtermism
The rapid development of open-source large language models (LLMs) has been
truly remarkable. However, the scaling law described in previous literature
presents varying conclusions, which casts a dark cloud over scaling LLMs. We
delve into the study of scaling laws and present our distinctive findings that
facilitate scaling of large scale models in two commonly used open-source
configurations, 7B and 67B. Guided by the scaling laws, we introduce DeepSeek
LLM, a project dedicated to advancing open-source language models with a
long-term perspective. To support the pre-training phase, we have developed a
dataset that currently consists of 2 trillion tokens and is continuously
expanding. We further conduct supervised fine-tuning (SFT) and Direct
Preference Optimization (DPO) on DeepSeek LLM Base models, resulting in the
creation of DeepSeek Chat models. Our evaluation results demonstrate that
DeepSeek LLM 67B surpasses LLaMA-2 70B on various benchmarks, particularly in
the domains of code, mathematics, and reasoning. Furthermore, open-ended
evaluations reveal that DeepSeek LLM 67B Chat exhibits superior performance
compared to GPT-3.5
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