Quest for a stable Cu-ligand complex with a high catalytic activity to produce reactive oxygen species.

Metal ion-catalyzed overproduction of reactive oxygen species (ROS) is believed to contribute significantly to oxidative stress and be involved in several biological processes, from immune defense to development of diseases. Among the essential metal ions, copper is one of the most efficient catalysts in ROS production in the presence of O2 and a physiological reducing agent such as ascorbate. To control this chemistry, Cu ions are tightly coordinated to biomolecules.

Altering relative metal-binding affinities in multifunctional Metallochaperones for mutant p53 reactivation.

The p53 protein plays a major role in cancer prevention, and over 50% of cancer diagnoses can be attributed to p53 malfunction. p53 incorporates a structural Zn site that is required for proper protein folding and function, and in many cases point mutations can result in loss of the Zn ion, destabilization of the tertiary structure, and eventual amyloid aggregation. Herein, we report a series of compounds designed to act as small molecule stabilizers of mutant p53, and feature Zn-binding fragments to chaperone Zn to the metal depleted site and restore wild-type (WT) function.

Multifunctional metallochaperone modifications for targeting subsite cavities in mutant p53-Y220C.

The p53 protein, known as the 'guardian of the genome', plays an important role in cancer prevention. Unfortunately, p53 mutations result in compromised activity with over 50% of cancers resulting from point mutations to p53. There is considerable interest in mutant p53 reactivation, with the development of small-molecule reactivators showing promise.

Ultrasound and Transcriptomics Identify a Differential Impact of Cisplatin and Histone Deacetylation on Tumor Structure and Microenvironment in a Patient-Derived In Vivo Model of Gastric Cancer.

The reasons behind the poor efficacy of transition metal-based chemotherapies (e.g., cisplatin) or targeted therapies (e.

Gold(III) to Ruthenium(III) Metal Exchange in Dithiocarbamato Complexes Tunes Their Biological Mode of Action for Cytotoxicity in Cancer Cells.

Malignant tumors have affected the human being since the pharaoh period, but in the last century the incidence of this disease has increased due to a large number of risk factors, including deleterious lifestyle habits (i.e., smoking) and the higher longevity.

Bifunctional ligand design for modulating mutant p53 aggregation in cancer.

Protein misfolding and aggregation contributes to the development of a wide range of diseases. In cancer, over 50% of diagnoses are attributed to p53 malfunction due to missense mutations, many of which result in protein misfolding and accelerated aggregation. p53 mutations also frequently result in alteration or loss of zinc at the DNA-binding site, which increases aggregation nucleation with zinc-bound p53.

HDAC4 Levels Control Sensibility toward Cisplatin in Gastric Cancer via the p53-p73/BIK Pathway.

Gastric cancer (GC) remains a health issue due to the low efficiency of therapies, such as cisplatin. This unsatisfactory situation highlights the necessity of finding factors impacting GC sensibility to therapies. We analyzed the cisplatin pangenomic response in cancer cells and found HDAC4 as a major epigenetic regulator being inhibited.

Multifunctional Compounds for Activation of the p53-Y220C Mutant in Cancer.

The p53 protein plays a major role in cancer prevention, and over 50 % of cancer diagnoses can be attributed to p53 malfunction. The common p53 mutation Y220C causes local protein unfolding, aggregation, and can result in a loss of Zn in the DNA-binding domain. Structural analysis has shown that this mutant creates a surface site that can be stabilized using small molecules, and herein a multifunctional approach to restore function to p53-Y220C is reported.

Rollover Cyclometalated Bipyridine Platinum Complexes as Potent Anticancer Agents: Impact of the Ancillary Ligands on the Mode of Action.

Platinum-based anticancer coordination compounds are widely used in the treatment of many tumor types, where they are very effective but also cause severe side effects. Organoplatinum compounds are significantly less investigated than the analogous coordination compounds. We report here rollover cyclometalated Pt compounds based on 2,2'-bipyridine which are demonstrated to be potent antitumor agents both in vitro and in vivo.

Monomeric Ti(iv)-based complexes incorporating luminescent nitrogen ligands: synthesis, structural characterization, emission spectroscopy and cytotoxic activities.

This manuscript describes the synthesis of a series of neutral titanium(iv) monomeric complexes constructed around a TiON core. The two nitrogen atoms that compose the coordination sphere of the metallic center belong to 2,2'-bipyrimidine ligands homo-disubstituted in the 4 and 4' positions by methyl (2a), phenylvinyl (2b), naphthylvinyl (2c) or anthrylvinyl (2d) groups. The crystal structures of these complexes named [Ti(1)(2a)], [Ti(1)(2b)], [Ti(1)(2c)] and [Ti(1)(2d)] (where 1 is a 2,2'-biphenolato ligand substituted in the 6 and 6' positions by phenyl groups) are reported.

Impact of cyclometalated ruthenium(II) complexes on lactate dehydrogenase activity and cytotoxicity in gastric and colon cancer cells.

Lactate dehydrogenase (LDH) is a redox enzyme often overexpressed in cancer cells allowing their survival in stressful metabolic tumor environment. Ruthenium(II) complexes have been shown to impact on the activity of purified horseradish peroxidase and glucose oxidase but the physiological relevance remains unclear. In this study we investigated how ruthenium complexes impact on the activity of LDH in vitro and in cancer cells and performed a comparative study using polypyridine ruthenium(II) complex [Ru(bpy)] (1) and its structurally related cyclometalated 2-phenylpyridinato counterpart [Ru(phpy)(bpy)] (2) (bpy=2,2'-bipyridine, phpyH=2-phenylpyridine).

Expression and functional studies of the GDNF family receptor alpha 3 in the pancreas.

The generation of therapeutic β-cells from human pluripotent stem cells relies on the identification of growth factors that faithfully mimic pancreatic β-cell development in vitro. In this context, the aim of the study was to determine the expression and function of the glial cell line derived neurotrophic factor receptor alpha 3 (GFRα3) and its ligand artemin (Artn) in islet cell development and function. GFRα3 and Artn expression were characterized by in situ hybridization, immunochemistry, and qRT-PCR.

Rfx6 is an Ngn3-dependent winged helix transcription factor required for pancreatic islet cell development.

The transcription factor neurogenin 3 (Neurog3 or Ngn3) controls islet cell fate specification in multipotent pancreatic progenitor cells in the mouse embryo. However, our knowledge of the genetic programs implemented by Ngn3, which control generic and islet subtype-specific properties, is still fragmentary. Gene expression profiling in isolated Ngn3-positive progenitor cells resulted in the identification of the uncharacterized winged helix transcription factor Rfx6.

The transcription factor c-Myb affects pre-mRNA splicing.

c-Myb is a transcription factor which plays a key role in haematopoietic proliferation and lineage commitment. We raised the question of whether c-Myb may have abilities beyond the extensively studied transcriptional activation function. In this report we show that c-Myb influences alternative pre-mRNA splicing.

Transcription factors in pancreatic development. Animal models.

Through the analysis of genetically modified mice a hierarchy of transcription factors regulating pancreas specification, endocrine destiny as well as endocrine subtype specification and differentiation has been established. In addition to conventional approaches such as transgenic technologies and gene targeting, recombinase fate mapping in mice has been key in establishing the lineage relationship between progenitor cells and their progeny in understanding pancreas formation. Moreover, the design of specific mouse models to conditionally express transcription factors in different populations of progenitor cells has revealed to what extent transcription factors required for islet cell development are also sufficient to induce endocrine differentiation and the importance of the competence of progenitor cells to respond to the genetic program implemented by these factors.

Pancreatic islet progenitor cells in neurogenin 3-yellow fluorescent protein knock-add-on mice.

The basic helix-loop-helix transcription factor Neurogenin 3 (NGN3) controls endocrine cell fate specification in uncommitted pancreatic progenitor cells. Ngn3-deficient mice do not develop any islet cells and are diabetic. All the major islet cell types, including insulin-producing beta-cells, derive from Ngn3-positive endocrine progenitor cells.

Multiple functional domains of the oncoproteins Spi-1/PU.1 and TLS are involved in their opposite splicing effects in erythroleukemic cells.

The hematopoietic transcription factor Spi-1/PU.1 is an oncoprotein participating to the malignant transformation of proerythroblasts in the Friend erythroleukemia or in the erythroleukemic process developed in spi-1 transgenic mice. Overexpression of Spi-1 in proerythroblasts blocks their differentiation.

The human neuroendocrine thyrotropin-releasing hormone receptor promoter is activated by the haematopoietic transcription factor c-Myb.

Thyrotropin-releasing hormone (TRH) receptor (TRHR) is a G-protein-coupled receptor playing a crucial role in the anterior pituitary where it controls the synthesis and secretion of thyroid-stimulating hormone and prolactin. Its widespread presence not only in the central nervous system, but also in peripheral tissues, including thymus, indicates other important, but unknown, functions. One hypothesis is that the neuropeptide TRH could play a role in the immune system.