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1.
Mol Cell ; 79(2): 203-204, 2020 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-32679074

RESUMO

In this issue of Molecular Cell, Hu et al. (2020) show that the cytosolic E3 ligase RNF126 reubiquitinates membrane proteins after their extraction from the membrane of the endoplasmic reticulum to target them for proteasomal degradation.


Assuntos
Proteínas de Membrana , Ubiquitina-Proteína Ligases , Retículo Endoplasmático , Degradação Associada com o Retículo Endoplasmático , Proteólise
2.
Chemistry ; 29(3): e202202604, 2023 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-36239701

RESUMO

To advance the design of self-assembled metallosupramolecular architectures as new generation theranostic agents, the synthesis of 18 F-labelled [Pd2 L4 ]4+ metallacages is reported. Different spectroscopic and bio-analytical methods support the formation of the host-guest cage-cisplatin complex. The biodistribution profiles of one of the cages, alone or encapsulating cisplatin have been studied by PET/CT imaging in healthy mice in vivo, in combination to ICP-MS ex vivo.


Assuntos
Antineoplásicos , Cisplatino , Camundongos , Animais , Cisplatino/química , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Distribuição Tecidual , Tomografia por Emissão de Pósitrons , Antineoplásicos/química
3.
Inorg Chem ; 62(50): 20710-20720, 2023 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-37556427

RESUMO

Self-assembled supramolecular coordination complexes (SCCs) hold promise for biomedical applications in cancer therapy, although their potential in the field of nuclear medicine is still substantially unexplored. Therefore, in this study an exo-functionalized cationic [Pd2L2]4+ metallacycle (L = 3,5-bis(3-ethynylpyridine)phenyl), targeted to the somatostatin-2 receptor (sst2R) and featuring the DOTA chelator (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) in order to bind the ß-- and γ-emitter lutetium-177, was synthesized by self-assembly following ligand synthesis via standard solid-phase peptide synthesis (SPPS). This metallacycle was then characterized by reverse-phase high-performance liquid chromatography (RP-HPLC), electrospray ionization mass spectrometry (ESI-MS), and 1H and 1H-DOSY NMR (DOSY = diffusion-ordered spectroscopy). A procedure for the radiolabeling of the metallacycle with 177Lu was also optimized. The resulting [nat/177Lu]Lu-DOTA-metallacycle, termed [nat/177Lu]Lu-Cy, was evaluated concerning its stability and in vitro properties. The compound was more lipophilic compared to the reference [177Lu]Lu-DOTA-TATE (logPOct/H2O = -0.85 ± 0.10 versus -3.67 ± 0.04, respectively). While [natLu]Lu-Cy revealed low stability in a DMEM/F12 GlutaMax medium, it demonstrated good stability in other aqueous media as well as in DMSO. A high sst2R binding affinity (expressed as IC50) was determined in CHOsst2 cells (Chinese hamster ovary cells that were stably transfected with human sst2R). Moreover, the metallacycle exhibited high human serum albumin binding, as assessed by high-performance affinity chromatography (HPAC), and moderate stability in human serum compared to [177Lu]Lu-DOTA-TATE (TATE = (Tyr3)-octreotate). In order to improve stability, a heteroleptic approach was used to develop a less sterically hindered cage-like SCC that is potentially endowed with host-guest chemistry capability, which has been preliminarily characterized by RP-HPLC and ESI-MS. Overall, our initial results encourage future studies on sst2R-directed SCCs and have led to new insights into the chemistry of ss2R-directed SCCs for radiopharmaceutical applications.


Assuntos
Medicina Nuclear , Compostos Radiofarmacêuticos , Animais , Cricetinae , Humanos , Células CHO , Cricetulus , Compostos Radiofarmacêuticos/uso terapêutico , Compostos Radiofarmacêuticos/química , Lutécio/química , Medicina Nuclear/métodos , Somatostatina
4.
Int J Mol Sci ; 24(3)2023 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-36768814

RESUMO

(1) Background: Sympathetic overactivity is a major contributor to resistant hypertension (RH). According to animal studies, sympathetic overactivity increases immune responses, thereby aggravating hypertension and cardiovascular outcomes. Renal denervation (RDN) reduces sympathetic nerve activity in RH. Here, we investigate the effect of RDN on T-cell signatures in RH. (2) Methods: Systemic inflammation and T-cell subsets were analyzed in 17 healthy individuals and 30 patients with RH at baseline and 6 months after RDN. (3) Results: The patients with RH demonstrated higher levels of pro-inflammatory cytokines and higher frequencies of CD4+ effector memory (TEM), CD4+ effector memory residential (TEMRA) and CD8+ central memory (TCM) cells than the controls. After RDN, systolic automated office blood pressure (BP) decreased by -17.6 ± 18.9 mmHg. Greater BP reductions were associated with higher CD4+ TEM (r -0.421, p = 0.02) and CD8+ TCM (r -0.424, p = 0.02) frequencies at baseline. The RDN responders, that is, the patients with ≥10mmHg systolic BP reduction, showed reduced pro-inflammatory cytokine levels, whereas the non-responders had unchanged inflammatory activity and higher CD8+ TEMRA frequencies with increased cellular cytokine production. (4) Conclusions: The pro-inflammatory state of patients with RH is characterized by altered T-cell signatures, especially in non-responders. A detailed analysis of T cells might be useful in selecting patients for RDN.


Assuntos
Hipertensão , Hipotensão , Humanos , Simpatectomia , Resultado do Tratamento , Linfócitos T , Rim , Pressão Sanguínea/fisiologia , Citocinas
5.
Angew Chem Int Ed Engl ; 62(10): e202217233, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36628505

RESUMO

AuI -carbene and PtIV -AuI -carbene prodrugs display low to sub-µM activity against several cancer cell lines and overcome cisplatin (cisPt) resistance. Linking a cisPt-derived PtIV (phenylbutyrate) complex to a AuI -phenylimidazolylidene complex 2, yielded the most potent prodrug. While in vivo tests against Lewis Lung Carcinoma showed that the prodrug PtIV (phenylbutyrate)-AuI -carbene (7) and the 1 : 1 : 1 co-administration of cisPt: phenylbutyrate:2 efficiently inhibited tumor growth (≈95 %), much better than 2 (75 %) or cisPt (84 %), 7 exhibited only 5 % body weight loss compared to 14 % for 2, 20 % for cisPt and >30 % for the co-administration. 7 was much more efficient than 2 at inhibiting TrxR activity in the isolated enzyme, in cells and in the tumor, even though it was much less efficient than 2 at binding to selenocysteine peptides modeling the active site of TrxR. Organ distribution and laser-ablation (LA)-ICP-TOFMS imaging suggest that 7 arrives intact at the tumor and is activated there.


Assuntos
Antineoplásicos , Pró-Fármacos , Antineoplásicos/química , Fenilbutiratos , Pró-Fármacos/química , Linhagem Celular Tumoral , Cisplatino/química
6.
Proteomics ; 22(17): e2200061, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35666003

RESUMO

Ionophores are small molecules or peptides that transport metal ions across biological membranes. Their transport capabilities are typically characterized in vitro using vesicles and single ion species. It is difficult to infer from these data which effects ionophores have on living cells in a complex environment (e.g., culture medium), since net ion movement is influenced by many factors including ion composition of the medium, concentration gradients, pH gradient, and protein-mediated transport processes across the membrane. To gain insights into the antibacterial mechanism of action of the semisynthetic polyether ionophore 4-Br-A23187, known to efficiently transport zinc and manganese in vitro, we investigated its effects on the gram-positive model organism Bacillus subtilis. In addition to monitoring cellular ion concentrations, the physiological impact of treatment was assessed on the proteome level. 4-Br-A23187 treatment resulted in an increase in intracellular copper levels, the extent of which depended on the copper concentration of the medium. Effects of copper accumulation mirrored by the proteomic response included oxidative stress, disturbance of proteostasis, metal and sulfur homeostasis. The antibiotic effect of 4-Br-A23187 is further aggravated by a decrease in intracellular manganese and magnesium. A liposome model confirmed that 4-Br-A23187 acts as copper ionophore in vitro.


Assuntos
Bacillus subtilis , Lipossomas Unilamelares , Antibacterianos/farmacologia , Calcimicina/análogos & derivados , Calcimicina/farmacologia , Cálcio , Cobre/farmacologia , Ionóforos/farmacologia , Manganês/farmacologia , Proteômica
7.
J Cogn Neurosci ; 34(11): 2016-2027, 2022 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-35900867

RESUMO

Recent evidence in healthy participants suggests that a motor subcomponent of working memory (mWM) may exist. We investigated whether this mWM is impaired in patients with a motor-dominant left hemisphere (LH) stroke and apraxia. Furthermore, we hypothesized that a deficient mWM contributes to deficits in motor cognition, that is, apraxia, in LH stroke. The study included 52 patients with LH stroke and 25 age-matched controls. Patients were classified into LH stroke patients with and without apraxia based on deficits in gesture imitation and object use. All participants were examined using the block span test (visuospatial WM), the digit span test (verbal WM), and a novel mWM task. In the latter, participants were presented with static pictures depicting three different actions: actions with objects, meaningless actions, and meaningful actions. In the mWM task, LH stroke patients with apraxia performed worse than age-matched controls. Notably, LH stroke patients with apraxia showed more pronounced mWM deficits than those without apraxia. These results remained significant even after controlling for visuospatial and verbal WM deficits. Regression analyses revealed that LH stroke patients' mWM deficits predicted deficits in imitation. Data provide neuropsychological evidence for a motor subsystem of WM and suggest that deficits in mWM contribute to the severity of apraxia in LH stroke patients.


Assuntos
Apraxias , Acidente Vascular Cerebral , Apraxias/etiologia , Apraxias/psicologia , Humanos , Comportamento Imitativo , Memória de Curto Prazo , Testes Neuropsicológicos , Acidente Vascular Cerebral/complicações
8.
Am J Transplant ; 22(2): 634-639, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34551181

RESUMO

Kidney transplant recipients (KTRs) are extremely vulnerable to SARS-CoV-2 infection and show an impaired immune response to SARS-CoV-2 vaccination. We analyzed factors related to vaccination efficiency in KTRs. In a multicenter prospective observational study (NCT04743947), IgG antibodies levels against SARS-CoV-2 spike S1 subunit and their neutralization capacity after SARS-CoV-2 vaccination were analyzed in 225 KTRs and compared to 176 controls. After the vaccination, 56 (24.9%) KTRs became seropositive of whom 68% had neutralizing antibodies. This immune response was significantly lower compared to controls (239 [78-519] BAU/ml versus 1826 [560-3180] BAU/ml for KTRs and controls, p < .0001). The strongest predictor for an impaired response was mycophenolate mofetil (MMF) treatment. Multivariate regression analysis revealed that MMF-free regimen was highly associated with seroconversion (OR 13.25, 95% CI 3.22-54.6; p < .001). In contrast, other immunosuppressive drugs had no significant influence. 187 out of 225 KTRs were treated with MMF of whom 26 (13.9%) developed antibodies. 23 of these seropositive KTRs had a daily MMF dose ≤1 g. Furthermore, higher trough MMF concentrations correlated with lower antibody titers (R -0.354, p < .001) supporting a dose-dependent unfavorable effect of MMF. Our data indicate that MMF dose modification could lead to an improved immune response.


Assuntos
COVID-19 , Transplante de Rim , Anticorpos Antivirais , Vacinas contra COVID-19 , Humanos , Imunidade , Transplante de Rim/efeitos adversos , Ácido Micofenólico/uso terapêutico , SARS-CoV-2 , Transplantados , Vacinação
9.
Clin Transplant ; 36(11): e14790, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35997031

RESUMO

Modification of vaccination strategies is necessary to improve the immune response to SARS-CoV-2 vaccination in kidney transplant recipients (KTRs). This multicenter observational study analyzed the effects of the third SARS-CoV-2 vaccination in previously seronegative KTRs with the focus on temporary mycophenolate mofetil (MMF) dose reduction within propensity matched KTRs. 56 out of 174 (32%) previously seronegative KTRs became seropositive after the third vaccination with only three KTRs developing neutralizing antibodies against the omicron variant. Multivariate logistic regression revealed that initial antibody levels, graft function, time after transplantation and MMF trough levels had an influence on seroconversion (P < .05). After controlling for confounders, the effect of MMF dose reduction before the third vaccination was calculated using propensity score matching. KTRs with a dose reduction of ≥33% showed a significant decrease in MMF trough levels to 1.8 (1.2-2.5) µg/ml and were more likely to seroconvert than matched controls (P = .02). Therefore, a MMF dose reduction of 33% or more before vaccination is a promising approach to improve success of SARS-CoV-2 vaccination in KTRs.


Assuntos
COVID-19 , Transplante de Rim , Humanos , Ácido Micofenólico/uso terapêutico , Vacinas contra COVID-19 , Rejeição de Enxerto , Imunossupressores/uso terapêutico , Imunossupressores/farmacologia , SARS-CoV-2 , COVID-19/prevenção & controle , Transplantados , Imunidade
10.
Inorg Chem ; 61(50): 20405-20423, 2022 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-36484812

RESUMO

With the aim to improve the design of metal complexes as stabilizers of noncanonical DNA secondary structures, namely, G-quadruplexes (G4s), a series of cyclic dinuclear Au(I) N-heterocyclic carbene complexes based on xanthine and benzimidazole ligands has been synthesized and characterized by various methods, including X-ray diffraction. Fluorescence resonance energy transfer (FRET) and CD DNA melting assays unraveled the compounds' stabilization properties toward G4s of different topologies of physiological relevance. Initial structure-activity relationships have been identified and recognize the family of xanthine derivatives as those more selective toward G4s versus duplex DNA. The binding modes and free-energy landscape of the most active xanthine derivative (featuring a propyl linker) with the promoter sequence cKIT1 have been studied by metadynamics. The atomistic simulations evidenced that the Au(I) compound interacts noncovalently with the top G4 tetrad. The theoretical results on the Au(I) complex/DNA Gibbs free energy of binding were experimentally validated by FRET DNA melting assays. The compounds have also been tested for their antiproliferative properties in human cancer cells in vitro, showing generally moderate activity. This study provides further insights into the biological activity of Au(I) organometallics acting via noncovalent interactions and underlines their promise for tunable targeted applications by appropriate chemical modifications.


Assuntos
Quadruplex G , Humanos , Ligantes , DNA/química , Transferência Ressonante de Energia de Fluorescência , Xantinas
11.
J Virol ; 94(5)2020 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-31801860

RESUMO

Merkel cell polyomavirus (MCPyV) is the major cause for Merkel cell carcinoma (MCC), a rare but highly aggressive skin cancer predominantly found in elderly and immunosuppressed patients. The early viral gene products large T-antigen (LT) and small T-antigen (sT) are important for efficient viral DNA replication, and both contribute to transformation processes. These functions are executed mainly through interactions with host factors. Here, we identify the cellular ubiquitin-specific processing protease 7 (Usp7) as a new interaction partner of the MCPyV LT. Using glutathione S-transferase pulldown experiments, we show that MCPyV LT directly binds to Usp7 and that N- as well as C-terminal regions of LT bind to the TRAF (tumor necrosis factor receptor-associated) domain of Usp7. We demonstrate that endogenous Usp7 coprecipitates with MCPyV T-antigens and relocalizes to viral DNA replication centers in cells actively replicating MCPyV genomes. We show that Usp7 does not alter ubiquitination levels of the T-antigens; however, Usp7 binding increases the binding affinity of LT to the origin of replication, thereby negatively regulating viral DNA replication. Together, these data identify Usp7 as a restriction factor of MCPyV replication. In contrast to other DNA viruses, Usp7 does not affect MCPyV gene expression via its ubiquitination activity but influences MCPyV DNA replication solely via a novel mechanism that modulates binding of LT to viral DNA.IMPORTANCE MCPyV is the only human polyomavirus that is associated with cancer; the majority of Merkel cell cancers have a viral etiology. While much emphasis was placed on investigations to understand the transformation process by MCPyV oncoproteins and cellular factors, we have only limited knowledge of cellular factors participating in the MCPyV life cycle. Here, we describe Usp7, a cellular deubiquitination enzyme, as a new factor involved in MCPyV replication. Usp7 is known in the context of large DNA tumor viruses, Epstein-Barr virus (EBV) and Kaposi's sarcoma herpesvirus, to restrict viral replication. Similar to EBV, where Usp7 binding to EBNA1 increases EBNA1 binding affinity to viral DNA, we find MCPyV LT binding to the origin of replication to be increased in the presence of Usp7, resulting in restriction of viral DNA replication. However, Usp7-induced restriction of MCPyV replication is independent of its enzymatic activity, thereby constituting a novel mechanism of Usp7-induced restriction of viral replication.


Assuntos
Antígenos Virais de Tumores/metabolismo , DNA Viral/metabolismo , Poliomavírus das Células de Merkel/genética , Poliomavírus das Células de Merkel/metabolismo , Peptidase 7 Específica de Ubiquitina/metabolismo , Replicação Viral/fisiologia , Carcinoma de Célula de Merkel/virologia , Linhagem Celular , Proliferação de Células , Células HEK293 , Humanos , Poliomavírus das Células de Merkel/crescimento & desenvolvimento , Infecções por Polyomavirus/virologia , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Infecções Tumorais por Vírus/virologia
12.
Bioconjug Chem ; 32(7): 1399-1408, 2021 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-33440122

RESUMO

The biomedical application of discrete supramolecular metal-based structures, specifically self-assembled metallacages, is still an emergent field of study. Capitalizing on the knowledge gained in recent years on the development of 3-dimensional (3D) metallacages as novel drug delivery systems and theranostic agents, we explore here the possibility to target [Pd2L4]4+ cages (L = 3,5-bis(3-ethynylpyridine)phenyl ligand) to the brain. In detail, a new water-soluble homoleptic cage (CPepH3) tethered to a blood brain barrier (BBB)-translocating peptide was synthesized by a combination of solid-phase peptide synthesis (SPPS) and self-assembly procedures. The cage translocation efficacy was assessed by inductively coupled mass spectrometry (ICP-MS) in a BBB cellular model in vitro. Biodistribution studies of the radiolabeled cage [[99mTcO4]- ⊂ CPepH3] in the CD1 mice model demonstrate its brain penetration properties in vivo. Further DFT studies were conducted to model the structure of the [[99mTcO4]- ⊂ cage] complex. Moreover, the encapsulation capabilities and stability of the cage were investigated using the [ReO4]- anion, the "cold" analogue of [99mTcO4]-, by 1H NMR spectroscopy. Overall, our study constitutes another proof-of-concept of the unique potential of supramolecular coordination complexes for modifying the physiochemical and biodistribution properties of diagnostic species.


Assuntos
Barreira Hematoencefálica , Paládio/química , Animais , Teoria da Densidade Funcional , Sistemas de Liberação de Medicamentos/métodos , Técnicas In Vitro , Ligantes , Espectrometria de Massas/métodos , Camundongos , Espectroscopia de Prótons por Ressonância Magnética/métodos , Distribuição Tecidual , Tomografia Computadorizada de Emissão de Fóton Único
13.
J Biol Inorg Chem ; 26(6): 667-674, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34378103

RESUMO

The known ruthenium complex [Ru(tpy)(bpy)(Hmte)](PF6)2 ([1](PF6)2, where tpy = 2,2':6',2″-terpyridine, bpy = 2,2'-bipyridine, Hmte = 2-(methylthio)ethanol) is photosubstitutionally active but non-toxic to cancer cells even upon light irradiation. In this work, the two analogs complexes [Ru(tpy)(NN)(Hmte)](PF6)2, where NN = 3,3'-biisoquinoline (i-biq, [2](PF6)2) and di(isoquinolin-3-yl)amine (i-Hdiqa, [3](PF6)2), were synthesized and their photochemistry and phototoxicity evaluated to assess their suitability as photoactivated chemotherapy (PACT) agents. The increase of the aromatic surface of [2](PF6)2 and [3](PF6)2, compared to [1](PF6)2, leads to higher lipophilicity and higher cellular uptake for the former complexes. Such improved uptake is directly correlated to the cytotoxicity of these compounds in the dark: while [2](PF6)2 and [3](PF6)2 showed low EC50 values in human cancer cells, [1](PF6)2 is not cytotoxic due to poor cellular uptake. While stable in the dark, all complexes substituted the protecting thioether ligand upon light irradiation (520 nm), with the highest photosubstitution quantum yield found for [3](PF6)2 (Φ[3] = 0.070). Compounds [2](PF6)2 and [3](PF6)2 were found both more cytotoxic after light activation than in the dark, with a photo index of 4. Considering the very low singlet oxygen quantum yields of these compounds, and the lack of cytotoxicity of the photoreleased Hmte thioether ligand, it can be concluded that the toxicity observed after light activation is due to the photoreleased aqua complexes [Ru(tpy)(NN)(OH2)]2+, and thus that [2](PF6)2 and [3](PF6)2 are promising PACT candidates.


Assuntos
Compostos de Rutênio/síntese química , Compostos de Rutênio/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Humanos , Modelos Moleculares , Estrutura Molecular , Rutênio , Compostos de Rutênio/química
14.
Phys Chem Chem Phys ; 24(1): 477-487, 2021 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-34901976

RESUMO

Treatment of Na+-based hectorite LAPONITE® (LAP) and of Na+-montmorillonite (MMT) with a homologous series of γ-aminopropyl(methyl)x(ethoxy)ysilanes (x + y = 3, y > 0) in toluene was studied by means of thermogravimetric analysis coupled with mass spectrometry, infrared spectroscopy, 29Si and 23Na solid-state nuclear magnetic resonance spectroscopy and powder X-ray diffraction. The triethoxy silane (APTS) exclusively grafts on the clays' edges as branched oligomers whereas both the monoethoxy silane (APMS) and the diethoxy silane (APDS) are also intercalated, the latter as linear oligomers. Intercalation of APMS varies for MMT and LAP: MMT hosts the smallest amounts of the silanes with marginal increase of the basal distance and no stabilization of water. On the contrary, LAP accommodates the largest amount of guests in the form of monomeric APMS which yields the largest increase of the basal distance and stabilizes water up to 200 °C when APMS dimerizes. APMS stabilization is attributed to intramolecular Si-O-H-NH2 hydrogen bonds and the hydrophobic geminal methyl groups together with the trimethylene sides of the cyclic monomers are thought to compartmentalize the hydrated sodium sites. The high temperature release of water from APMS@LAP is discussed in the light of potentially triggered interphase degradation in composite materials for recycling purposes.

15.
Int J Mol Sci ; 22(19)2021 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-34638879

RESUMO

Colorectal cancer (CRC) is one of the most frequently diagnosed cancers in humans. At early stages CRC is treated by surgery and at advanced stages combined with chemotherapy. We examined here the potential effect of glucosylceramide synthase (GCS)-inhibition on CRC biology. GCS is the rate-limiting enzyme in the glycosphingolipid (GSL)-biosynthesis pathway and overexpressed in many human tumors. We suppressed GSL-biosynthesis using the GCS inhibitor Genz-123346 (Genz), NB-DNJ (Miglustat) or by genetic targeting of the GCS-encoding gene UDP-glucose-ceramide-glucosyltransferase- (UGCG). GCS-inhibition or GSL-depletion led to a marked arrest of the cell cycle in Lovo cells. UGCG silencing strongly also inhibited tumor spheroid growth in Lovo cells and moderately in HCT116 cells. MS/MS analysis demonstrated markedly elevated levels of sphingomyelin (SM) and phosphatidylcholine (PC) that occurred in a Genz-concentration dependent manner. Ultrastructural analysis of Genz-treated cells indicated multi-lamellar lipid storage in vesicular compartments. In mice, Genz lowered the incidence of experimentally induced colorectal tumors and in particular the growth of colorectal adenomas. These results highlight the potential for GCS-based inhibition in the treatment of CRC.


Assuntos
Ciclo Celular/efeitos dos fármacos , Neoplasias do Colo , Dioxanos/farmacologia , Glicoesfingolipídeos , Pirrolidinas/farmacologia , Esferoides Celulares , Animais , Neoplasias do Colo/induzido quimicamente , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/genética , Neoplasias do Colo/metabolismo , Glucosiltransferases/antagonistas & inibidores , Glucosiltransferases/metabolismo , Glicoesfingolipídeos/biossíntese , Glicoesfingolipídeos/genética , Células HCT116 , Humanos , Camundongos , Proteínas de Neoplasias/antagonistas & inibidores , Proteínas de Neoplasias/metabolismo , Neoplasias Experimentais/induzido quimicamente , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/genética , Neoplasias Experimentais/metabolismo , Esferoides Celulares/metabolismo , Esferoides Celulares/patologia
16.
Int J Mol Sci ; 22(24)2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34948263

RESUMO

A series of bifunctional Ru(III) complexes with lonidamine-modified ligands (lonidamine is a selective inhibitor of aerobic glycolysis in cancer cells) was described. Redox properties of Ru(III) complexes were characterized by cyclic voltammetry. An easy reduction suggested a perspective for these agents as their whole mechanism of action seems to be based on activation by metal atom reduction. New compounds demonstrated a more pronounced antiproliferative potency than the parental drug; individual new agents were more cytotoxic than cisplatin. Stability studies showed an increase in the stability of complexes along with the linker length. A similar trend was noted for antiproliferative activity, cellular uptake, apoptosis induction, and thioredoxin reductase inhibition. Finally, at concentrations that did not alter water solubility, the selected new complex evoked no acute toxicity in Balb/c mice.


Assuntos
Indazóis/química , Rutênio/química , Rutênio/farmacologia , Animais , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Complexos de Coordenação/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Ligantes , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Estrutura Molecular , Oxirredução , Relação Estrutura-Atividade , Tiorredoxina Dissulfeto Redutase/metabolismo
17.
Inorg Chem ; 59(7): 5182-5193, 2020 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-32207294

RESUMO

Multiaction Pt(IV) prodrugs can overcome resistance associated with the FDA approved Pt(II) drugs like cisplatin. Intracellular reduction of the octahedral Pt(IV) derivatives of cisplatin releases cisplatin and the two axial ligands. When the released axial ligands act synergistically with cisplatin to kill the cancer cells, we have multiaction prodrugs. Most Pt(IV) multiaction prodrugs have bioactive ligands possessing a carboxylate that is conjugated to the Pt(IV) because breaking the Pt(IV)-ligand bond releases the active moiety. As many drugs that act synergistically with cisplatin do not have carboxylates, a major challenge is to prepare multiaction Pt(IV) complexes with drugs that have amino groups or hydroxyl groups such that following reduction, the drugs are released in their active form. Our objective was to prepare multiaction Pt(IV) prodrugs that release bioactive molecules having amino groups. Because we cannot conjugate amino groups to the axial position of Pt(IV), we developed a novel and efficient approach for the synthesis of Pt(IV)-carbamato complexes and demonstrated that following reduction of the Pt(IV), the released carbamates undergo rapid decarboxylation, releasing the free amine, as in the case of the PARP-1 inhibitor 3-aminobenzamide and the amino derivative of the HDAC inhibitor SAHA. Pt(IV)-carbamato complexes are stable in cell culture medium and are reduced by ascorbate. They are reduced slower than their carboxylato and carbonato analogues. We believe that this approach paves the way for preparing novel classes of multiaction Pt(IV) prodrugs with amino containing bioactive molecules that up to now were not accessible.


Assuntos
Antineoplásicos/farmacologia , Carbamatos/farmacologia , Complexos de Coordenação/farmacologia , Pró-Fármacos/farmacologia , Antineoplásicos/síntese química , Benzamidas/farmacologia , Carbamatos/síntese química , Linhagem Celular Tumoral , Cisplatino/farmacologia , Complexos de Coordenação/síntese química , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Ligantes , Oxirredução , Platina/química , Pró-Fármacos/síntese química
18.
Artigo em Alemão | MEDLINE | ID: mdl-32960295

RESUMO

BACKGROUND: Identification of child abuse is a daily challenge in medical work. The estimated number of unreported cases of child abuse and neglect is high. OBJECTIVES: The aim of this study was to investigate the effectiveness of the redesigned clinical child protection program of a major German pediatric hospital and to improve programs in other hospitals for children and physicians through presentation of the advantages of the new structure. METHODS: All cases of child protection at the Altona Children's Hospital were retrospectively analyzed before and after restructuring of the clinic's child protection program for a two-year period each, and a comparison was made. The child protection program was restructured and the new program subsequently managed by a fulltime coordinator. RESULTS: The prevalence of both suspected and substantiated cases of child abuse was significantly higher after restructuring of the child protection program. Before the change, 24 cases were investigated, of which 23 were substantiated; afterward, 124 cases were investigated and 89 were substantiated. Despite the high number of false-positive suspected cases, stigmatization of the families during the clarification progress was avoided by using a very sensitive approach, and the family was not confronted until the suspicion was affirmed. CONCLUSION: The presented concept of child protection in medical clinics seems to facilitate a higher detection rate of child abuse cases. The reduction in the number of undetected cases and thereby prevention of possible escalation of abuse, as well as the decline in the immense social follow-up costs, justifies the increased personnel costs.


Assuntos
Maus-Tratos Infantis/diagnóstico , Maus-Tratos Infantis/prevenção & controle , Criança , Proteção da Criança , Família , Alemanha/epidemiologia , Humanos , Estudos Retrospectivos
19.
Angew Chem Int Ed Engl ; 59(38): 16795-16800, 2020 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-32529715

RESUMO

A novel alkynyl phosphane gold(I) complex (trimethylphosphane)(3-(1,3-dimethylxanthine-7-yl)prop-1-yn-1-yl)gold(I) 1 displayed mutiple biological activites including selective proliferation inhibitory, anti-metastatic, and anti-angiogenic effects. The complex also induced effects related to aneuploidy in HCT-116 colon carcinoma cells, which might be mainly ascribed to the dysfunction of mitochondrial bioenergetics and downregulation of glycolysis. Induction of aneuploidy beyond a critical level can provide an effective strategy to target cancer, in particular colorectal tumours with a low tolerance of aneuploidy, and could be of relevance for 1 and other metallodrugs.


Assuntos
Aneuploidia , Antineoplásicos/farmacologia , Neoplasias do Colo/tratamento farmacológico , Compostos Organoáuricos/farmacologia , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Galinhas , Membrana Corioalantoide/efeitos dos fármacos , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Células HCT116 , Humanos , Estrutura Molecular , Compostos Organoáuricos/síntese química , Compostos Organoáuricos/química , Óvulo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Relação Estrutura-Atividade
20.
Clin Gastroenterol Hepatol ; 17(11): 2227-2235.e1, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-30716477

RESUMO

BACKGROUND & AIMS: Epidemiology studies of circulating concentrations of 25 hydroxy vitamin D (25(OH)D) and risk of esophageal adenocarcinoma (EAC) have produced conflicting results. We conducted a Mendelian randomization study to determine the associations between circulating concentrations of 25(OH)D and risks of EAC and its precursor, Barrett's esophagus (BE). METHODS: We conducted a Mendelian randomization study using a 2-sample (summary data) approach. Six single-nucleotide polymorphisms (SNPs; rs3755967, rs10741657, rs12785878, rs10745742, rs8018720, and rs17216707) associated with circulating concentrations of 25(OH)D were used as instrumental variables. We collected data from 6167 patients with BE, 4112 patients with EAC, and 17,159 individuals without BE or EAC (controls) participating in the Barrett's and Esophageal Adenocarcinoma Consortium, as well as studies from Bonn, Germany, and Cambridge and Oxford, United Kingdom. Analyses were performed separately for BE and EAC. RESULTS: Overall, we found no evidence for an association between genetically estimated 25(OH)D concentration and risk of BE or EAC. The odds ratio per 20 nmol/L increase in genetically estimated 25(OH)D concentration for BE risk estimated by combining the individual SNP association using inverse variance weighting was 1.21 (95% CI, 0.77-1.92; P = .41). The odds ratio for EAC risk, estimated by combining the individual SNP association using inverse variance weighting, was 0.68 (95% CI, 0.39-1.19; P = .18). CONCLUSIONS: In a Mendelian randomization study, we found that low genetically estimated 25(OH)D concentrations were not associated with risk of BE or EAC.


Assuntos
Adenocarcinoma/genética , Esôfago de Barrett/genética , Neoplasias Esofágicas/genética , Análise da Randomização Mendeliana/métodos , Polimorfismo de Nucleotídeo Único , Medição de Risco , Vitamina D/sangue , Adenocarcinoma/sangue , Adenocarcinoma/epidemiologia , Esôfago de Barrett/sangue , Esôfago de Barrett/epidemiologia , Biomarcadores Tumorais/sangue , DNA de Neoplasias/genética , Neoplasias Esofágicas/sangue , Neoplasias Esofágicas/epidemiologia , Europa (Continente)/epidemiologia , Feminino , Humanos , Masculino , Morbidade , América do Norte/epidemiologia , Fatores de Risco
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