96 research outputs found
Aberrant overexpression of an epithelial marker, 14-3-3σ, in a subset of hematological malignancies
<p>Abstract</p> <p>Background</p> <p>14-3-3σ is a p53-mediated cell-cycle inhibitor in epithelial cells. The expression of 14-3-3σ is frequently altered in cancers of epithelial origin associated with altered DNA methylation. Since its involvement in a non-epithelial tumor is unknown, we examined 14-3-3σ expression in patients with haematological malignancies.</p> <p>Methods</p> <p>We analyzed 41 hematopoietic cell lines and 129 patients with a variety of hematological malignancies for 14-3-3σ expression with real-time RT-PCR. We also examined protein levels by Western blot analysis and DNA methylation status of the 14-3-3σ gene by methylation-specific PCR analysis of bisulfite-treated DNA. In addition, mutations of p53 gene were identified by RT-PCR-SSCP analysis and the expression levels of 14-3-3σ were compared with those of other cell-cycle inhibitor genes, CDKN2A and ARF.</p> <p>Results</p> <p>The expression levels of 14-3-3σ mRNA in almost all cell lines were low and comparable to those in normal hematopoietic cells except for 2 B-cell lines. On the contrary, 14-3-3σ mRNA was aberrantly overexpressed frequently in mature lymphoid malignancies (30 of 93, 32.3%) and rarely in acute leukemia (3 of 35, 8.6%). 14-3-3σ protein was readily detectable and roughly reflected the mRNA level. In contrast to epithelial tumors, methylation status of the 14-3-3σ gene was not associated with expression in hematological malignancies. Mutations of p53 were identified in 12 patients and associated with lower expression of 14-3-3σ. The expression levels of 14-3-3σ, CDKN2A and ARF were not correlated with but rather reciprocal to one another, suggesting that simultaneous overexpression of any two of them is incompatible with tumor growth.</p> <p>Conclusion</p> <p>14-3-3σ, an epithelial cell marker, was overexpressed significantly in a subset of mature lymphoid malignancies. This is the first report of aberrant 14-3-3σ expression in non-epithelial tumors <it>in vivo</it>. Since the significance of 14-3-3σ overexpression is unknown even in epithelial tumors such as pancreatic cancers, further analysis of regulation and function of the 14-3-3σ gene in non-epithelial as well as epithelial tumors is warranted.</p
mRNA expression of the DNA replication-initiation proteins in epithelial dysplasia and squamous cell carcinoma of the tongue
<p>Abstract</p> <p>Background</p> <p>The tongue squamous cell carcinomas (SCCs) are characterized by high mitotic activity, and early detection is desirable. Overexpression of the DNA replication-initiation proteins has been associated with dysplasia and malignancy. Our aim was to determine whether these proteins are useful biomarkers for assessing the development of tongue SCC.</p> <p>Methods</p> <p>We analyzed the mRNA expression of CDC6, CDT1, MCM2 and CDC45 in formalin-fixed, paraffin-embedded benign and malignant tongue tissues using quantitative real-time PCR followed by statistical analysis.</p> <p>Results</p> <p>We found that the expression levels are significantly higher in malignant SCC than mild precancerous epithelial dysplasia, and the expression levels in general increase with increasing grade of precancerous lesions from mild, moderate to severe epithelial dysplasia. CDC6 and CDC45 expression is dependent of the dysplasia grade and lymph node status. CDT1 expression is higher in severe dysplasia than in mild and moderate dysplasia. MCM2 expression is dependent of the dysplasia grade, lymph node status and clinical stage. The expression of the four genes is independent of tumor size or histological grade. A simple linear regression analysis revealed a linear increase in the mRNA levels of the four genes from the mild to severe dysplasia and SCC. A strong association was established between CDC6 and CDT1, and between MCM2 and CDC45 expression. The nonparametric receiver operating characteristic analysis suggested that MCM2 and CDC45 had a higher accuracy than CDC6 and CDT1 for distinguishing dysplasia from tongue SCC.</p> <p>Conclusion</p> <p>These proteins can be used as biomarkers to distinguish precancerous dysplasia from SCC and are useful for early detection and diagnosis of SCC as an adjunct to clinicopathological parameters.</p
Rate limiting P-O(5') bond cleavage of RNA fragment: ab initio molecular orbital calculations on the base-catalyzed hydrolysis of phosphate
Solutions notes on clean textile waste
In the contemporary moment, the textile and clothing industries are practicing and passing through a transition period into their management systems (specially on waste) due to consumer change in social behavior, which can, potentially, ensure the sustenance and well-being for the generations to come. Into this context, the present research aims to analyze sustainable strategies that are being implemented by the textile and clothing industry, searching for solutions for the management of clean solid waste, concerns with processed and non-processed textile fibers waste. In addition, it is mapped and pointed some gaps for the development of further and future researches. In order to achieve the proposed goal, it was searched a rigorous selection of projects and studies that expressed innovative solutions, concerning practices and theories application about the possibilities in the management of the clean textile waste. The results are optimistic, as they already point to some real action in terms of companies aware of the need for sustainable practices in their production.This work is supported by FEDER funds through the Competitiveness Factors Operational
Programme - COMPETE and by national funds through FCT – Foundation for
Science and Technology within the scope of the project POCI-01-0145-FEDER007136”info:eu-repo/semantics/publishedVersio
Multinuclear palladium compounds containing palladium centers ligated by five silicon atoms
Palladium (Pd) generally prefers low oxidation states. So far, no stable Pd compound with a +5 oxidation state is known. Here, we report two multinuclear Pd compounds containing Pd centers ligated by five silicon (Si) atoms. A thermal condensation reaction of [{1,2-C6H4(SiMe2)(SiH2)}PdII(Me2PCH2CH2PMe2)] (Me = methyl) afforded two stereoisomers of dinuclear PdII compounds and a trinuclear Pd compound as major products and a tetranuclear Pd compound as a minor product. The structures of the four Pd compounds were confirmed by single-crystal x-ray structure analysis. The dinuclear Pd compounds have a dimeric structure of [{1,2-C6H4(SiMe2)(SiH)}PdII(Me2PCH2CH2PMe2)] connected through a Si–Si single bond formed by dehydrogenation of two molecules of the starting compound. The trinuclear and tetranuclear Pd compounds proved to have Pd centers bonded to five Si atoms with normal Pd–Si single-bond distances. Theoretical calculations of the trinuclear and tetranuclear Pd compounds accurately reproduced their x-ray structures and suggested that all of the Pd–Si bonds of the central Pd atoms have a relatively high single-bond character
Complex analysis of cyclin D1 expression in mantle cell lymphoma: two cyclin D1-negative cases detected
Synthesis of Organosilicon Macrocycles. Palladium-Catalyzed Ring-Enlargement Oligomerization of Cyclic Disilanes via Si−Si σ-Bond Metathesis
Platinum-Catalyzed Novel Reactions of Nitriles and an Azirine with o-Bis(dimethylsilyl)benzene.
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