35 research outputs found

    Early expression of the Helicase-Like Transcription Factor (HLTF/SMARCA3) in an experimental model of estrogen-induced renal carcinogenesis

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    BACKGROUND: The Helicase-Like Transcription Factor (HLTF/SMARCA3) belongs to the family of SWI/SNF proteins that use the energy of ATP hydrolysis to remodel chromatin in a variety of cellular processes. Several SWI/SNF genes are disrupted in cancer, suggesting a role of tumor suppressor. Similarly, the HLTF gene was recently found to be inactivated by hypermethylation in a number of advanced colon and gastric tumors. However, other evidences indicated a 20-fold HLTF overexpression in cell lines derived from various neoplasms (ovary, breast, cervix, kidney...). RESULTS: In the present study, we investigated HLTF expression by immunohistochemistry in a model of kidney tumors induced by continuous administration of diethylstilbestrol to male Syrian golden hamsters. A strong labeling was already detected in small tumor buds, making HLTF an early cancer marker in this model. Although every cell stained for HLTF at this early stage, the number of HLTF-positive cells decreased to 10% with cancer progression, and these positive cells were dispersed in the tumor mass. HLTF expression was conserved in the HKT-1097 cell line established from kidney tumors, but again only 10% of positive cells were found in xenografts produced by HKT-1097 cells in nude mice. CONCLUSION: In conclusion, our data suggest that HLTF gene activation is linked to initial steps of carcinogenesis in this model and should be investigated in early stages of other neoplasms

    The collaboration of 5 bacterial genes has destroyed a new antimicrobial hope, vancomycin

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    Thèse de doctorat annexe - UCL, 199

    Two ruthenium complexes capable of storing multiple electrons on a single ligand-photophysical, photochemical and electrochemical properties of [Ru(phen)2(TAPHAT)]2+ and [Ru(phen)2(TAPHAT)Ru(phen)2]4+

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    The photophysical, photochemical and electrochemical properties of two newly synthesized ruthenium complexes, [Ru(phen)2(TAPHAT)]2+ and [Ru(phen)2(TAPHAT)Ru(phen)2]4+, are reported. We have developed a novel synthetic methodology that involves the metal-free oxidative coupling of diamino compounds to form a desired "pyrazine-type" core. This methodology is employed both on the free diamino ligand as well as on the different ruthenium complexes, therefore illustrating the applicability of this reaction. The TAPHAT ligand, which possesses 7 aromatic rings and 10 nitrogen atoms for 20 carbon atoms, gives rise to ruthenium complexes that can undergo up to three consecutive reductions centered on said ligand, a critical parameter for electron storage applications. A temperature-dependent study has confirmed the presence of a 4th MLCT state. Excited-state quenching in the presence of guanine or hydroquinone allows to foresee biomedical applications.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

    A rigid dinuclear ruthenium(II) complex as an efficient photoactive agent for bridging two guanine bases of a duplex or quadruplex oligonucleotide.

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    The rigid dinuclear [(tap)(2)Ru(tpac)Ru(tap)(2)](4+) complex (1) (TAP=1,4,5,8-tetraazaphenanthrene, TPAC=tetrapyridoacridine) is shown to be much more efficient than the mononuclear bis-TAP complexes at photodamaging oligodeoxyribonucleotides (ODNs) containing guanine (G). This is particularly striking with the G-rich telomeric sequence d(T(2)AG(3))(4). Complex 1, which interacts strongly with the ODNs as determined by surface plasmon resonance (SPR) and emission anisotropy experiments, gives rise under illumination to the formation of covalent adducts with the G units of the ODNs. The yield of photocrosslinking of the two strands of duplexes by 1 is the highest when the G bases of each strand are separated by three to four base pairs. This corresponds with each Ru(tap)(2) moiety of complex 1 forming an adduct with the G base. This separation distance of the G units of a duplex could be determined thanks to the rigidity of complex 1. On the basis of results of gel electrophoresis, mass spectrometry, and molecular modelling, it is suggested that such photocrosslinking can also occur intramolecularly in the human telomeric quadruplex d(T(2)AG(3))(4).Journal ArticleResearch Support, Non-U.S. Gov'tFLWINSCOPUS: ar.jinfo:eu-repo/semantics/publishe
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