11 research outputs found
Transgene-induced CCWGG methylation does not alter CG methylation patterning in human kidney cells
Several reports suggest that C(m)CWGG methylation tends not to co-exist with (m)CG methylation in human cells. We have asked whether or not methylation at CCWGG sites can influence CG methylation. DNA from cells expressing an M.EcoRIIâGFP fusion was actively methylated at CCWGG sites. CG methylation as measured by R.HpaII/R.MspI ratios was unchanged in cells expressing the transgene. Cloned representatives of C(m)CWGG methylated DNA often contained, or were adjacent to an ALU repeat, suggesting that M.EcoRII-GFP actively methylated gene-rich R-band DNA. The transgenic methyltransferase applied C(m)CWGG methylation to a representative human promoter that was heavily methylated at CG dinucleotides (the SERPINB5 promoter) and to a representative promoter that was essentially unmethylated at CG dinucleotides (the APC promoter). In each case, the CG methylation pattern remained in its original state, unchanged by the presence of neighboring C(m)CWGG sites. Q-PCR measurements showed that RNA expression from the APC gene was not significantly altered by the presence of C(m)CWGG in its promoter. Kinetic studies suggested that an adjacent C(m)CWGG methylation site influences neither the maintenance nor the de novo methylation activities of purified human Dnmt1. We conclude that C(m)CWGG methylation does not exert a significant effect on CG methylation in human kidney cells
Human non-CG methylation: Are human stem cells plant-like?
Non-CG methylation is well characterized in plants where it appears to play a role in gene silencing and genomic imprinting. Although strong evidence for the presence of non-CG methylation in mammals has been available for some time, both its origin and function remain elusive. In this review we discuss available evidence on non-CG methylation in mammals in light of evidence suggesting that the human stem cell methylome contains significant levels of methylation outside the CG site
New Fulvalenium Salts of Cobalt Bis(dicarbollide): Crystal Structures and Electrical Conductivities
New radical cation salts (BEDT-TTF)[8,8',(7)-Cl2(Cl0.09)-3,3'-Co(1,2-C2B9H9.91)(1',2'-C2B9H10)] (1), (BEDT-TTF)[8,8'-Br0.75Cl1.25-3,3'-Co(1,2-C2B9H10)2] (2), and (BMDT-TTF)4[8,8'-Br1.16(OH)0.72-3,3'-Co(1,2-C2B9H10.06)2] (3) were synthesized, and their crystal structures and electrical conductivities were determined. All the radical cation salts are semiconductors. Compounds 1 and 2 were found to be isostructural, however their electrical conductivities strongly differ (s293 = 2 Ίâ1cmâ1 and 10â5 Ίâ1cmâ1, respectively)
New Radical-Cation Salts Based on the TMTTF and TMTSF Donors with Iron and Chromium Bis(Dicarbollide) Complexes: Synthesis, Structure, Properties
New radical-cation salts based on tetramethyltetrathiafulvalene (TMTTF) and tetramethyltetraselenefulvalene (TMsTSF) with metallacarborane anions (TMTTF)[3,3â˛-Cr(1,2-C2B9H11)2], (TMTTF)[3,3â˛-Fe(1,2-C2B9H11)2], and (TMTSF)2[3,3â˛-Cr(1,2-C2B9H11)2] were synthesized by electrocrystallization. Their crystal structures were determined by single crystal X-ray diffraction, and their electrophysical properties in a wide temperature range were studied. The first two salts are dielectrics, while the third one is a narrow-gap semiconductor: ĎRT = 5 Ă 10â3 Ohmâ1cmâ1; Ea â 0.04 eV (aprox. 320 cmâ1)
Opportunities for and Prospects of Using Citation Indices in Evaluating the Performance of Research Institution
Detection of melanoma cells in whole blood samples using spectral imaging and optical clearing
Most cancer deaths are associated with metastases resulting from the spread of circulating tumor cells (CTCs) from the primary tumor to vital organs. The existing methods for detection of CTCs as markers of metastasis progression are time consuming with several steps of sample processing, including red blood cell removal, labeling, immunomagnetic capture and isolation, which can lead to loss of CTCs. Here we introduce a method for detection and identification of CTCs using spectral absorption imaging of melanoma cells and optical clearing of whole blood samples. Verification of this approach was performed using phantoms of human melanoma cells and suspensions of mouse melanoma cells of line B16F10 alone and in mixture with blood. A method for improving detection sensitivity has been demonstrated applying optical clearing of mouse blood using biocompatible chemical agents. The findings suggest that the proposed diagnostic platform has the potential to detect quickly CTCs in whole blood samples from patients with melanoma