RESUMO
Integrin α4ß1 belongs to the leukocyte integrin family and represents a therapeutic target of relevant interest given its primary role in mediating inflammation, autoimmune pathologies and cancer-related diseases. The focus of the present work is the design, synthesis and characterization of new peptidomimetic compounds that are potentially able to recognize α4ß1 integrin and interfere with its function. To this aim, a collection of seven new cyclic peptidomimetics possessing both a 4-aminoproline (Amp) core scaffold grafted onto key α4ß1-recognizing sequences and the (2-methylphenyl)ureido-phenylacetyl (MPUPA) appendage, was designed, with the support of molecular modeling studies. The new compounds were synthesized through SPPS procedures followed by in-solution cyclization maneuvers. The biological evaluation of the new cyclic ligands in cell adhesion assays on Jurkat cells revealed promising submicromolar agonist activity in one compound, namely, the c[Amp(MPUPA)Val-Asp-Leu] cyclopeptide. Further investigations will be necessary to complete the characterization of this class of compounds.
Assuntos
Adesão Celular/efeitos dos fármacos , Integrina alfa4beta1/química , Peptidomiméticos/química , Peptidomiméticos/farmacologia , Prolina/análogos & derivados , Humanos , Integrina alfa4beta1/antagonistas & inibidores , Células Jurkat , Ligantes , Modelos Moleculares , Oligopeptídeos/química , Oligopeptídeos/farmacologia , Peptídeos Cíclicos/química , Peptídeos Cíclicos/farmacologia , Prolina/química , Prolina/farmacologia , Ligação Proteica , Conformação ProteicaRESUMO
Many bacteria and actinomycetales use L-cysteine biosynthesis to increase their tolerance to antibacterial treatment and establish a long-lasting infection. In turn, this might lead to the onset of antimicrobial resistance that currently represents one of the most menacing threats to public health worldwide. The biosynthetic machinery required to synthesise L-cysteine is absent in mammals; therefore, its exploitation as a drug target is particularly promising. In this article, we report a series of inhibitors of Salmonella thyphimurium serine acetyltransferase (SAT), the enzyme that catalyzes the rate-limiting step of L-cysteine biosynthesis. The development of such inhibitors started with the virtual screening of an in-house library of compounds that led to the selection of seven structurally unrelated hit derivatives. A set of molecules structurally related to hit compound 5, coming either from the original library or from medicinal chemistry efforts, were tested to determine a preliminary structure-activity relationship and, especially, to improve the inhibitory potency of the derivatives, that was indeed ameliorated by several folds compared to hit compound 5 Despite these progresses, at this stage, the most promising compound failed to interfere with bacterial growth when tested on a Gram-negative model organism, anticipating the need for further research efforts.
RESUMO
In Ï-proteobacteria and Actinomycetales, cysteine biosynthetic enzymes are indispensable during persistence and become dispensable during growth or acute infection. The biosynthetic machinery required to convert inorganic sulfur into cysteine is absent in mammals; therefore, it is a suitable drug target. We searched for inhibitors of Salmonella serine acetyltransferase (SAT), the enzyme that catalyzes the rate-limiting step of l-cysteine biosynthesis. The virtual screening of three ChemDiv focused libraries containing 91â¯243 compounds was performed to identify potential SAT inhibitors. Scaffold similarity and the analysis of the overall physicochemical properties allowed the selection of 73 compounds that were purchased and evaluated on the recombinant enzyme. Six compounds displaying an IC50 <100 µM were identified via an indirect assay using Ellman's reagent and then tested on a Gram-negative model organism, with one of them being able to interfere with bacterial growth via SAT inhibition.
RESUMO
Pelargonidins are anthocyanidins thought to be beneficial for the human health, although controversies exist over the doses needed and the unclear mechanism of action, along with poor systemic bioavailability. One putative target of pelargonidins is the aryl hydrocarbon receptor (AhR). A synthetic pelargonidin (Mt-P) was synthesized by the methylation of the pelargonidin (the natural compound indicated as P). Mt-P transactivated the AhR with an EC50 of 1.97 µM and was ~2-fold more potent than the natural compound. In vitro Mt-P attenuated pro-inflammatory activities of Raw264.7 macrophage cells in an AhR-dependent manner. In vivo, administration of the Mt-P in Balb/c mice resulted in a dose-dependent attenuation of signs and symptoms of colitis induced by TNBS. A dose of 5 mg/kg Mt-P, but not the natural compound P, reversed intestinal inflammation and increased expression of Tnf-α, Ifn-Æ´, and Il-6, while promoted the expansion of regulatory T cells and M2 macrophages. In C57BL/6J mice fed a high fat diet (HFD), Mt-P attenuated body weight gain, intestinal and liver inflammation, and ameliorated insulin sensitivity, while worsened liver steatosis by up-regulating the liver expression of Cd36 and Apo100b. These effects were abrogated by AhR gene ablation. Mt-P is a synthetic pelargonidin endowed with robust AhR agonist activity that exerts beneficial effects in murine models of inflammation and metabolic dysfunction.
Assuntos
Antocianinas/farmacologia , Anti-Inflamatórios/farmacologia , Inflamação/tratamento farmacológico , Receptores de Hidrocarboneto Arílico/fisiologia , Animais , Antocianinas/química , Células CACO-2 , Colite/induzido quimicamente , Colite/tratamento farmacológico , Fígado Gorduroso/tratamento farmacológico , Células Hep G2 , Humanos , Macrófagos/efeitos dos fármacos , Macrófagos/fisiologia , Metilação , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Células RAW 264.7 , Receptores de Hidrocarboneto Arílico/efeitos dos fármacos , Receptores de Hidrocarboneto Arílico/genéticaRESUMO
Sirtuins (SIRTs) are a class of NAD+-dependent protein histone deacetylases (HDACs) that catalyse the reversible deacetylation of lysine residues in the histones or non-histone substrates. Mammalian sirtuins consist of seven isoforms (SIRT1-7), which show different subcellular localizations and enzymatic functions. Among the seven human sirtuins, SIRT2 predominantly located in the cytoplasm but is enriched in the nucleus during mitosis. Its activity has been found to be modulate the pathophysiology of various diseases such as cancer, metabolic and neurodegenerative disorders. Therefore, selective SIRT2 inhibitors are of growing interest as potentially candidate therapeutic agents to treat SIRT2-driven pathologies as well as valuable tools to investigate and define the biological roles of SIRT2. Herein, in order to identify potent leads against SIRT2, a multi-step pharmacophore based-virtual screening campaign was performed and 31 predicted compounds were subjected to in vitro biological evaluation. Finally, compound 2 and 3 showing better SIRT2 inhibition potency were selected for further in vitro cytotoxic assays against a panel of three human cancer cell lines. This study will hopefully provide a basis for developing potent and selective SIRT2 inhibitors.
Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Inibidores de Histona Desacetilases/química , Inibidores de Histona Desacetilases/farmacologia , Modelos Moleculares , Sirtuína 2/química , Linhagem Celular , Simulação por Computador , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Conformação Molecular , Estrutura Molecular , Curva ROC , Sirtuína 2/antagonistas & inibidores , Relação Estrutura-AtividadeRESUMO
Several bacteria rely on the reductive sulphur assimilation pathway, absent in mammals, to synthesise cysteine. Reduction of virulence and decrease in antibiotic resistance have already been associated with mutations on the genes that codify cysteine biosynthetic enzymes. Therefore, inhibition of cysteine biosynthesis has emerged as a promising strategy to find new potential agents for the treatment of bacterial infection. Following our previous efforts to explore OASS inhibition and to expand and diversify our library, a scaffold hopping approach was carried out, with the aim of identifying a novel fragment for further development. This novel chemical tool, endowed with favourable pharmacological characteristics, was successfully developed, and a preliminary Structure-Activity Relationship investigation was carried out.
Assuntos
Cisteína Sintase/antagonistas & inibidores , Desenho de Fármacos , Bibliotecas de Moléculas Pequenas/química , Antibacterianos/síntese química , Antibacterianos/química , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Bactérias/enzimologia , Bactérias/genética , Sítios de Ligação , Bioensaio , Simulação por Computador , DNA Recombinante/química , DNA Recombinante/genética , Ligantes , Modelos Moleculares , Bibliotecas de Moléculas Pequenas/síntese química , Bibliotecas de Moléculas Pequenas/farmacologia , Relação Estrutura-AtividadeRESUMO
Saturation transfer difference (STD) is an NMR technique conventionally applied in drug discovery to identify ligand moieties relevant for binding to protein cavities. This is important to direct medicinal chemistry efforts in small-molecule optimization processes. However, STD does not provide any structural details about the ligand-target complex under investigation. Herein, we report the application of a new integrated approach, which combines enhanced sampling methods with STD experiments, for the characterization of ligand-target complexes that are instrumental for drug design purposes. As an example, we have studied the interaction between StOASS-A, a potential antibacterial target, and an inhibitor previously reported. This approach allowed us to consider the ligand-target complex from a dynamic point of view, revealing the presence of an accessory subpocket which can be exploited to design novel StOASS-A inhibitors. As a proof of concept, a small library of derivatives was designed and evaluated in vitro, displaying the expected activity.
Assuntos
Cisteína Sintase/antagonistas & inibidores , Cisteína Sintase/metabolismo , Descoberta de Drogas/métodos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Salmonella typhimurium/enzimologia , Antibacterianos/química , Antibacterianos/farmacologia , Sítios de Ligação , Cisteína Sintase/química , Desenho de Fármacos , Ligantes , Espectroscopia de Ressonância Magnética/métodos , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Salmonella typhimurium/efeitos dos fármacos , TermodinâmicaRESUMO
Together with estrogen receptors ERα and ERß, the Gâ protein-coupled estrogen receptor (GPER) mediates important pathophysiological signaling pathways induced by estrogens and is currently regarded as a promising target for ER-negative (ER-) and triple-negative (TN) breast cancer. Only a few selective GPER modulators have been reported to date, and their use in cancer cell lines has often led to contradictory results. Herein we report the application of virtual screening and cell-based studies for the identification of new chemical scaffolds with a specific antiproliferative effect against GPER-expressing breast cancer cell lines. Out of the four different scaffolds identified, 8-chloro-4-(4-chlorophenyl)pyrrolo[1,2-a]quinoxaline 14 c was found to be the most promising compound able to induce: 1)â antiproliferative activity in GPER-expressing cell lines (MCF7 and SKBR3), similarly to G15; 2)â no effect on cells that do not express GPER (HEK293); 3)â a decrease in cyclinâ D1 expression; and 4)â a sustained induction of cell-cycle negative regulators p53 and p21.
Assuntos
Antineoplásicos/metabolismo , Quinoxalinas/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Antineoplásicos/química , Antineoplásicos/farmacologia , Sítios de Ligação , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ciclina D1/metabolismo , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Receptor alfa de Estrogênio/antagonistas & inibidores , Receptor alfa de Estrogênio/metabolismo , Receptor beta de Estrogênio/antagonistas & inibidores , Receptor beta de Estrogênio/metabolismo , Feminino , Células HEK293 , Humanos , Células MCF-7 , Simulação de Acoplamento Molecular , Estrutura Terciária de Proteína , Quinoxalinas/química , Quinoxalinas/farmacologia , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Proteína Supressora de Tumor p53/metabolismoRESUMO
Cysteine is a building block for many biomolecules that are crucial for living organisms. O-Acetylserine sulfhydrylase (OASS), present in bacteria and plants but absent in mammals, catalyzes the last step of cysteine biosynthesis. This enzyme has been deeply investigated because, beside the biosynthesis of cysteine, it exerts a series of "moonlighting" activities in bacteria. We have previously reported a series of molecules capable of inhibiting Salmonella typhimurium (S. typhymurium) OASS isoforms at nanomolar concentrations, using a combination of computational and spectroscopic approaches. The cyclopropane-1,2-dicarboxylic acids presented herein provide further insights into the binding mode of small molecules to OASS enzymes. Saturation transfer difference NMR (STD-NMR) was used to characterize the molecule/enzyme interactions for both OASS-A and B. Most of the compounds induce a several fold increase in fluorescence emission of the pyridoxal 5'-phosphate (PLP) coenzyme upon binding to either OASS-A or OASS-B, making these compounds excellent tools for the development of competition-binding experiments.
Assuntos
Ciclopropanos/farmacologia , Cisteína Sintase/antagonistas & inibidores , Ácidos Dicarboxílicos/farmacologia , Inibidores Enzimáticos/farmacologia , Fluorometria , Ciclopropanos/síntese química , Ciclopropanos/química , Cisteína Sintase/química , Cisteína Sintase/metabolismo , Ácidos Dicarboxílicos/síntese química , Ácidos Dicarboxílicos/química , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Espectroscopia de Ressonância Magnética , Simulação de Acoplamento Molecular , Estrutura Molecular , Relação Estrutura-AtividadeRESUMO
Estrogens exert their action mainly by binding three receptors, namely estrogen receptors α and ß (ERα and ERß) and GPER-1 (G-protein coupled estrogen receptor 1). While the patho-physiological role of both ERα and ERß has been deeply investigated, the role of GPER-1 in estrogens' signaling has not been clearly defined yet. Unfortunately, only few GPER-1 selective ligands were discovered so far, and the real efficiency of such compounds is still matter of debate. To better understand the physiological relevance of GPER-1, new selective chemical probes are higly needed. In this scenario, we report herein the generation and validation of a three-dimensional (3-D) GPER-1 homology model by means of docking studies and molecular dynamics simulations. The model thus generated was employed to (i) decipher the structural basis underlying the ability of estrogens and some Selective Estrogen Receptor Modulators (SERMs) to bind GPER-1 and classical ERα and ERß, and (ii) generate a reliable G1/GPER-1 complex useful in rationalizing the pharmacological profile of G1 reported in the literature. The G1/GPER-1 complex herein reported could be further exploited in drug design approaches aimed at improving the pharmacological profile of G1 or at identifying new chemical entities (NCEs) as potential modulators of GPER-1.
Assuntos
Receptores de Estrogênio/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Receptor alfa de Estrogênio/metabolismo , Receptor beta de Estrogênio/metabolismo , Estrogênios/metabolismo , Humanos , Ligantes , Modelos Moleculares , Simulação de Dinâmica Molecular , Ligação Proteica/fisiologia , Moduladores Seletivos de Receptor Estrogênico/metabolismo , Transdução de Sinais/fisiologia , Homologia Estrutural de ProteínaRESUMO
Inhibition of the mechanistic target of rapamycin (mTOR) is a promising treatment strategy for several cancer types. Rapamycin derivatives such as everolimus are allosteric mTOR inhibitors acting through interaction with the intracellular immunophilin FKBP12, a prolyl isomerase with different cellular functions. Although mTOR inhibitors have significantly improved survival of different cancer patients, resistance and lack of predictive factors of response remain unsolved issues. To elucidate the mechanisms of resistance to everolimus, we evaluated Met activation in everolimus-sensitive/resistant human cancer cells, in vitro and in vivo. Biochemical and computational analyses were performed. Everolimus-resistant cells were xenografted into mice (10/group) and studied for their response to everolimus and Met inhibitors. The statistical significance of the in vitro results was evaluated by Student's t test.Everolimus reduced Met phosphorylation in everolimus-sensitive cells. This event was mediated by the formation of a Met-FKBP12 complex, which in turn is disrupted by everolimus. Aberrant Met activation in everolimus-resistant cells and overexpression of wild-type/mutant Met caused everolimus resistance. Pharmacological inhibition and RNA silencing of Met are effective in condition of everolimus resistance (P<0.01). In mice xenografted with everolimus-resistant cells, the combination of everolimus with the Met inhibitor PHA665752 reduced tumor growth and induced a statistically significant survival advantage (combination vs control P=0.0005).FKBP12 binding is required for full Met activation and everolimus can inhibit Met. Persistent Met activation might sustain everolimus resistance. These results identify a novel everolimus mechanism of action and suggest the development of clinical strategies based on Met inhibitors in everolimus-resistant cancers.
Assuntos
Resistencia a Medicamentos Antineoplásicos , Everolimo/farmacologia , Regulação Neoplásica da Expressão Gênica , Receptores Proteína Tirosina Quinases/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Sítio Alostérico , Animais , Linhagem Celular Tumoral , Feminino , Células HCT116 , Humanos , Camundongos , Camundongos Nus , Transplante de Neoplasias , Fosforilação , Interferência de RNARESUMO
Upon binding, ligands can chaperone their protein targets by preventing them from misfolding and aggregating. Thus, an organic molecule that works as folding chaperone for a protein might be its specific ligand, and, similarly, the chaperone potential could represent an alternative readout in a molecular screening campaign toward the identification of new hits. Here we show that small molecules selected for acting as pharmacological chaperones on a misfolded mutant of the Frizzled4 (Fz4) receptor bind and modulate wild-type Fz4, representing what are to our knowledge the first organic ligands of this until-now-undruggable GPCR. The novelty and the advantages of the screening platform, the allosteric binding site addressed by these new ligands and the mechanism they use to modulate Fz4 suggest new avenues for development of inhibitors of the Wnt-ß-catenin pathway and for drug discovery.
Assuntos
Receptores Frizzled/química , Chaperonas Moleculares/química , Sítio Alostérico , Motivos de Aminoácidos , Sequência de Bases , Linhagem Celular Tumoral , Química Farmacêutica/métodos , Relação Dose-Resposta a Droga , Desenho de Fármacos , Glicerol/química , Células HEK293 , Células HeLa , Humanos , Ligantes , Microscopia de Fluorescência , Dados de Sequência Molecular , Mutagênese , Ligação Proteica , Dobramento de Proteína , Receptores Acoplados a Proteínas G/químicaRESUMO
Stimulation of A2A adenosine receptors (AR) promotes anti-inflammatory responses in animal models of allergic rhinitis, asthma, chronic obstructive pulmonary disease, and rheumatic diseases. Herein we describe the results of a research program aimed at identifying potent and selective agonists of the A2AAR as potential anti-inflammatory agents. The recent crystallographic analysis of A2AAR agonists and antagonists in complex with the receptor provided key information on the structural determinants leading to receptor activation or blocking. In light of this, we designed a new series of 2-((4-aryl(alkyl)piperazin-1-yl)alkylamino)-5'-N-ethylcarboxamidoadenosines with high A2AAR affinity, activation potency and selectivity obtained by merging distinctive structural elements of known agonists and antagonists of the investigated target. Docking-based SAR optimization allowed us to identify compound 42 as one of the most potent and selective A2A agonist discovered so far (Ki hA2AAR = 4.8 nM, EC50 hA2AAR = 4.9 nM, Ki hA1AR > 10â¯000 nM, Ki hA3AR = 1487 nM, EC50 hA2BAR > 10â¯000 nM).
Assuntos
Agonistas do Receptor A2 de Adenosina/química , Agonistas do Receptor A2 de Adenosina/farmacologia , Receptor A2A de Adenosina/química , Agonistas do Receptor A2 de Adenosina/síntese química , Agonistas do Receptor A2 de Adenosina/metabolismo , Adenosina-5'-(N-etilcarboxamida)/química , Animais , Células CHO/efeitos dos fármacos , Técnicas de Química Sintética , Cricetulus , Cristalografia por Raios X , Desenho de Fármacos , Avaliação Pré-Clínica de Medicamentos/métodos , Humanos , Simulação de Acoplamento Molecular , Receptor A2A de Adenosina/genética , Receptor A2A de Adenosina/metabolismo , Relação Estrutura-AtividadeRESUMO
The CB2 receptor is a therapeutic target of increasing importance for several diseases, including pain, inflammation, neurodegeneration, cancer and osteoporosis. While several compounds showing CB2-selective agonist or inverse agonist properties have been developed, only few CB2 receptor selective neutral antagonists are actually known. Such type of compounds could be useful to study more in depth the role of the CB2 receptor, because they lack the ability to counteract its "constitutive" activity. Here we describe the synthesis and biological activity of a series of biphenylic carboxamides as a new class of CB2 receptor selective ligands. In binding assays, one of these compounds showed good CB2 receptor affinity and selectivity (Ki = 11.48 nM; Selectivity Index = 130). Furthermore, in functional assays, the same compound showed a very interesting pharmacological profile as CB2 receptor selective neutral antagonist. These results pave the way to further developments, including structural optimization, with the aim to obtain more potent CB2 receptor ligands with this peculiar feature.
Assuntos
Amidas/farmacologia , Compostos de Bifenilo/síntese química , Compostos de Bifenilo/farmacologia , Receptor CB2 de Canabinoide/metabolismo , Amidas/síntese química , Amidas/química , Compostos de Bifenilo/química , Relação Dose-Resposta a Droga , Humanos , Ligantes , Modelos Moleculares , Estrutura Molecular , Receptor CB2 de Canabinoide/antagonistas & inibidores , Relação Estrutura-AtividadeRESUMO
Structure-activity relationships (SARs) within the 4-phenylquinazoline-2-carboxamide series of translocator protein (TSPO) ligands have been explored further by the synthesis and TSPO binding affinity evaluation of N-benzyl-N-ethyl/methyl derivatives variously decorated at the 6-, 2'-, 4'-, and 4â³-positions. Most of the compounds showed high affinity with K(i) values in the nanomolar/subnanomolar range. A pharmacophore model was developed and employed to better address SAR data presented by the new TSPO ligands. A subset of the new compounds (5, 8, 12, and 19) were tested for their ability to inhibit the viability of human glioblastoma cell line U343. The observed antiproliferative effect was demonstrated to be specific for compound 19, endowed with the best combination of binding affinity and efficacy. Furthermore, the ability of 19 to induce mitochondrial membrane dissipation (Δψ(m)) substantiated the intracellular pro-apoptotic mechanism activated by the binding of this class of ligands to TSPO.
Assuntos
Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Neoplasias Encefálicas/tratamento farmacológico , Glioblastoma/tratamento farmacológico , Receptores de GABA/efeitos dos fármacos , Animais , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Biologia Computacional , Relação Dose-Resposta a Droga , Glioblastoma/patologia , Humanos , Rim/efeitos dos fármacos , Rim/metabolismo , Cinética , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Modelos Moleculares , Conformação Molecular , Ligação Proteica , Ratos , Relação Estrutura-AtividadeRESUMO
Cannabinoid type 1 Receptor (CB1) belongs to the GPCR family and it has been targeted, so far, for the discovery of drugs aimed at the treatment of neuropathic pain, nausea, vomit, and food intake disorders. Here, we present the development of the first fluorescent assay enabling the measurement of kinetic binding constants for CB1 orthosteric ligands. The assay is based on the use of T1117, a fluorescent analogue of AM251. We prove that T1117 binds endogenous and recombinant CB1 receptors with nanomolar affinity. Moreover, T1117 binding to CB1 is sensitive to the allosteric ligand ORG27569 and thus it is applicable to the discovery of new allosteric drugs. The herein presented assay constitutes a sustainable valid alternative to the expensive and environmental impacting radiodisplacement techniques and paves the way for an easy, fast and cheap high-throughput drug screening toward CB1 for identification of new orthosteric and allosteric modulators.
Assuntos
Descoberta de Drogas/métodos , Ligantes , Receptor CB1 de Canabinoide/química , Receptor CB1 de Canabinoide/metabolismo , Regulação Alostérica , Animais , Linhagem Celular , Membrana Celular/metabolismo , Humanos , Concentração Inibidora 50 , Cinética , Modelos Moleculares , Ligação Proteica , Conformação Proteica , Ratos , Receptor CB1 de Canabinoide/genética , Espectrometria de Fluorescência/métodosRESUMO
Recent advances in the knowledge of thyroid carcinomas development identified receptor tyrosine kinases, like VEGFR2 and RET, as viable and promising targets. Accordingly, their inhibition is emerging as the major therapeutic strategy to treat these pathologies. In this study we describe the synthesis and the functional evaluation of three different series of 4-substituted pyrazolo[3,4-d]pyrimidine derivatives, 8a-g, 9a-g, and 10a-g, designed exploiting a structure-based optimization of the previously developed inhibitor CLM3. Compared to the lead, the novel compounds markedly improved both their inhibitory profile against the target proteins, VEGFR2 and RET, and their antiproliferative efficacy against the medullary thyroid cancer cell line TT. Significantly, compounds 8b, 9c, and 10c proved to block the kinase activity of the mutant RET(V804L), which still lacks effective inhibitors.
Assuntos
Inibidores de Proteínas Quinases/farmacologia , Desenho de Fármacos , Modelos Moleculares , Estrutura Molecular , Inibidores de Proteínas Quinases/químicaRESUMO
The epulis or giant cell granuloma is a benign tumor of the connective tissue of the gingival mucosa frequent in an advanced period of life but much more rare in its congenital form. We present the case of a female newborn, otherwise healthy, presenting with a giant swelling protruding from her mouth and originating from upper left alveolar ridge. The size of the mass has created great anxiety in parents and pediatricians, however this clinical presentation suggested us a diagnosis of congenital epulis with a differential diagnosis of teratoma. We perform surgical resection of the mass under general anesthesia, through diathermy. There wasn't blood loss and postoperative recovery was uneventful. A definite diagnosis of giant congenital epulis was disclosed by histopathological and immunohistochemical analysis. Although it has not been yet clarified the etiology of this tumor and the role of hormonal influences on its appearance and development and despite have been reported cases of spontaneous regression, the treatment of choice is the early surgical excision. Nevertheless, particularly in the small centers, due to the rarity and large size of presentation, the diagnosis is often delayed or wrong, exposing so the newborn parents to useless days of waiting and anxiety In our opinion all pediatricians and surgeons should be aware of this malformation and of its simple, safe and effective surgical treatment, considering the excellent prognosis of this rare disease.
Assuntos
Diatermia , Gengiva/patologia , Granuloma de Células Gigantes/diagnóstico , Granuloma de Células Gigantes/cirurgia , Diagnóstico Diferencial , Diatermia/métodos , Feminino , Humanos , Recém-Nascido , Resultado do TratamentoRESUMO
Over the past years, lipofilling has been used for many pathologies and sequelae; recently, its use has also widened for burn outcomes. A total of 93 burn scars were assessed (from September 2011 to February 2012). Half of scar area was treated through injection of adipose tissue harvested from subcutaneous fat and processed in accordance with the Coleman technique. Biopsy specimens were taken before treatment and at 3 and 6 months after the treatment. Histologic and immunohistochemical evaluations were conducted. In the samples examined, a marked improvement was observed, which can be seen in 3 months, but most of all, documented at 6 months. In addition, from a clinical point of view, an improvement has been documented, both functional and aesthetic. Lipofilling for burn scar complete and improve the results of standard surgical procedures, with long-term care setting and long-acting results.