RESUMEN
Immunotherapy has emerged as a game-changing approach for cancer treatment. Although monoclonal antibodies (mAbs) targeting the programmed cell death protein 1/programmed cell death protein 1 ligand 1 (PD-1/PD-L1) axis have entered the market revolutionizing the treatment landscape of many cancer types, small molecules, although presenting several advantages including the possibility of oral administration and/or reduced costs, struggled to enter in clinical trials, suffering of water insolubility and/or inadequate potency compared with mAbs. Thus, the search for novel scaffolds for both the design of effective small molecules and possible synergistic strategies is an ongoing field of interest. In an attempt to find novel chemotypes, a virtual screening approach was employed, resulting in the identification of new chemical entities with a certain binding capability, the most versatile of which was the benzimidazole-containing compound 10. Through rational design, a small library of its derivatives was synthesized and evaluated. The homogeneous time-resolved fluorescence (HTRF) assay revealed that compound 17 shows the most potent inhibitory activity (IC50 ) in the submicromolar range and notably, differently from the major part of PD-L1 inhibitors, exhibits satisfactory water solubility properties. These findings highlight the potential of benzimidazole-based compounds as novel promising candidates for PD-L1 inhibition.
Asunto(s)
Compuestos de Bifenilo , Inhibidores de Puntos de Control Inmunológico , Receptor de Muerte Celular Programada 1 , Antígeno B7-H1 , Ligandos , Relación Estructura-Actividad , Bencimidazoles/farmacología , AguaRESUMEN
Antibiotic resistance is becoming a severe obstacle in the fight against acute and chronic infectious diseases that accompany most degenerative illnesses from neoplasia to osteo-arthritis and obesity. Currently, the race is on to identify pharmaceutical molecules or combinations of molecules able to prevent or reduce the insurgence and/or progression of infectivity. Attempts to substitute antibiotics with antimicrobial peptides have, thus far, met with little success against multidrug-resistant (MDR) bacterial strains. During the last decade, we designed and studied the activity and features of human ß-defensin analogs, which are salt-resistant, and hence active also under high salt concentrations as, for instance, in cystic fibrosis. Herein, we describe the design, synthesis, and major features of a new 21 aa long molecule, peptide γ2. The latter derives from the γ-core of the ß-defensin natural molecules, a small fragment of these molecules still bearing high antibacterial activity. We found that peptide γ2, which contains only one disulphide bond, recapitulates most of the biological properties of natural human ß-defensins and can also counteract both Gram-positive and Gram-negative MDR bacterial strains and biofilm formation. Moreover, it has great stability in human serum thereby enhancing its antibacterial presence and activity without cytotoxicity in human cells. In conclusion, peptide γ2 is a promising new weapon also in the battle against intractable infectious diseases.
Asunto(s)
Antibacterianos/farmacología , Péptidos Antimicrobianos/farmacología , Bacterias/crecimiento & desarrollo , Biopelículas/crecimiento & desarrollo , beta-Defensinas/química , Bacterias/efectos de los fármacos , Biopelículas/efectos de los fármacos , Farmacorresistencia Bacteriana Múltiple , Humanos , Pruebas de Sensibilidad MicrobianaRESUMEN
Synthetic nucleic acid interactors represent an exciting research field due to their biotechnological and potential therapeutic applications. The translation of these molecules into drugs is a long and difficult process that justifies the continuous research of new chemotypes endowed with favorable binding, pharmacokinetic and pharmacodynamic properties. In this scenario, we describe the synthesis of two sets of homo-thymine nucleopeptides, in which nucleobases are inserted in a peptide structure, to investigate the role of the underivatized amino acid residue and the distance of the nucleobase from the peptide backbone on the nucleic acid recognition process. It is worth noting that the CD spectroscopy investigation showed that two of the reported nucleopeptides, consisting of alternation of thymine functionalized L-Orn and L-Dab and L-Arg as underivatized amino acids, were able to efficiently bind DNA and RNA targets and cross both cell and nuclear membranes.
Asunto(s)
Ácidos Nucleicos de Péptidos , Timina , Aminoácidos/química , ADN/química , Ácidos Nucleicos de Péptidos/química , Péptidos/química , ARN/genética , Timina/químicaRESUMEN
αv ß6 Integrin is an epithelial transmembrane protein that recognizes latency-associated peptide (LAP) and primarily activates transforming growth factor beta (TGF-ß). It is overexpressed in carcinomas (most notably, pancreatic) and other conditions associated with αv ß6 integrin-dependent TGF-ß dysregulation, such as fibrosis. We have designed a trimeric Ga-68-labeled TRAP conjugate of the αv ß6 -specific cyclic pentapeptide SDM17 (cyclo[RGD-Chg-E]-CONH2 ) to enhance αv ß6 integrin affinity as well as target-specific in-vivo uptake. Ga-68-TRAP(SDM17)3 showed a 28-fold higher αv ß6 affinity than the corresponding monomer Ga-68-NOTA-SDM17 (IC50 of 0.26 vs. 7.4â nM, respectively), a 13-fold higher IC50 -based selectivity over the related integrin αv ß8 (factors of 662 vs. 49), and a threefold higher tumor uptake (2.1 vs. 0.66 %ID/g) in biodistribution experiments with H2009 tumor-bearing SCID mice. The remarkably high tumor/organ ratios (tumor-to-blood 11.2; -to-liver 8.7; -to-pancreas 29.7) enabled high-contrast tumor delineation in PET images. We conclude that Ga-68-TRAP(SDM17)3 holds promise for improved clinical PET diagnostics of carcinomas and fibrosis.
Asunto(s)
Adenocarcinoma del Pulmón/diagnóstico por imagen , Antígenos de Neoplasias/análisis , Complejos de Coordinación/química , Integrinas/análisis , Neoplasias Pulmonares/diagnóstico por imagen , Tomografía de Emisión de Positrones , Radiofármacos/química , Animales , Compuestos Aza/química , Química Clic , Complejos de Coordinación/síntesis química , Femenino , Radioisótopos de Galio , Humanos , Ratones , Ratones SCID , Estructura Molecular , Neoplasias Experimentales/diagnóstico por imagen , Péptidos Cíclicos/química , Ácidos Fosfínicos/química , Piperidinas/química , Radiofármacos/síntesis química , Células Tumorales CultivadasRESUMEN
Here we investigated the structural and biological effects ensuing from the disulfide bond replacement of a potent and selective C-X-C chemokine receptor type 4 (CXCR4) peptide antagonist, with 1,4- and 1,5- disubstituted 1,2,3-triazole moieties. Both strategies produced candidates that showed high affinity and selectivity against CXCR4. Notably, when assessed for their ability to modulate the CXCL12-mediated cell migration, the 1,4-triazole variant conserved the antagonistic effect in the low-mid nanomolar range, while the 1,5-triazole one displayed the ability to activate the migration, becoming the first in class low-molecular-weight CXCR4 peptide agonist. By combining NMR and computational studies, we provided a valuable model that highlighted differences in the interactions of the two peptidomimetics with the receptor that could account for their different functional profile. Finally, we envisage that our findings could be translated to different GPCR-interacting peptides for the pursuit of novel chemical probes that could assist in dissecting the complex puzzle of this fundamental class of transmembrane receptors.
Asunto(s)
Disulfuros/química , Péptidos/química , Péptidos/farmacología , Receptores CXCR4/química , Triazoles/química , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Quimiocina CXCL12/farmacología , Humanos , Ligandos , Peptidomiméticos , Receptores CXCR4/agonistasRESUMEN
Bis-(3-bromo-4-hydroxy)benzylidene cyclic compounds have been reported by us as epigenetic multiple ligands, but different substitutions at the two wings provided analogues with selective inhibition. Since the 1-benzyl-3,5-bis((E)-3-bromobenzylidene)piperidin-4-one 3 displayed dual p300/EZH2 inhibition joined to cancer-selective cell death in a panel of tumor cells and in in vivo xenograft models, we prepared a series of bis((E)-2-bromobenzylidene) cyclic compounds 4a-n to test in biochemical (p300, PCAF, SIRT1/2, EZH2, and CARM1) and cellular (NB4, U937, MCF-7, SH-SY5Y) assays. The majority of 4a-n exhibited potent dual p300 and CARM1 inhibition, sometimes reaching the submicromolar level, and induction of apoptosis mainly in the tested leukemia cell lines. The most effective compounds in both enzyme and cellular assays carried a 4-piperidone moiety and a methyl (4d), benzyl (4e), or acyl (4k-m) substituent at N1 position. Elongation of the benzyl portion to 2-phenylethyl (4f) and 3-phenylpropyl (4g) decreased the potency of compounds at both the enzymatic and cellular levels, but the activity was promptly restored by introduction of a ketone group into the phenylalkyl substituent (4h-j). Western blot analyses performed in NB4 and MCF-7 cells on selected compounds confirmed their inhibition of p300 and CARM1 through decrease of the levels of acetyl-H3 and acetyl-H4, marks for p300 inhibition, and of H3R17me2, mark for CARM1 inhibition.
Asunto(s)
Antineoplásicos , Apoptosis/efectos de los fármacos , Derivados del Benceno , Proteína p300 Asociada a E1A/antagonistas & inhibidores , Inhibidores Enzimáticos , Proteínas de Neoplasias/antagonistas & inhibidores , Neoplasias/tratamiento farmacológico , Proteína-Arginina N-Metiltransferasas/antagonistas & inhibidores , Antineoplásicos/síntesis química , Antineoplásicos/química , Antineoplásicos/farmacología , Derivados del Benceno/síntesis química , Derivados del Benceno/química , Derivados del Benceno/farmacología , Proteína p300 Asociada a E1A/metabolismo , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Humanos , Células MCF-7 , Proteínas de Neoplasias/metabolismo , Neoplasias/metabolismo , Neoplasias/patología , Proteína-Arginina N-Metiltransferasas/metabolismo , Células U937RESUMEN
Cationic nucleopeptides belong to a family of synthetic oligomers composed by amino acids and nucleobases. Their capability to recognize nucleic acid targets and to cross cellular membranes provided the basis for considering them as novel non-covalent delivery agents for nucleic acid pharmaceuticals. Herein, starting from a 12-mer nucleopeptide model, the number of cationic residues was modulated in order to obtain new nucleopeptides endowed with high solubility in acqueous medium, acceptable bio-stability, low cytotoxicity and good capability to bind nucleic acid. Two candidates were selected to further investigate their potential as nucleic acid carriers, showing higher efficiency to deliver PNA in comparison with RNA. Noteworthy, this study encourages the development of nucleopeptides as new carriers to extend the known strategies for those nucleic acid analogues, especially PNA, that still remain difficult to drive into the cells.
Asunto(s)
Portadores de Fármacos/metabolismo , Ácidos Nucleicos de Péptidos/metabolismo , Polilisina/metabolismo , ARN/metabolismo , Timina/análogos & derivados , Timina/metabolismo , Cationes/síntesis química , Cationes/química , Cationes/metabolismo , Cationes/toxicidad , Línea Celular Tumoral , Permeabilidad de la Membrana Celular , Dicroismo Circular , Portadores de Fármacos/síntesis química , Portadores de Fármacos/química , Portadores de Fármacos/toxicidad , Humanos , Conformación de Ácido Nucleico , Hibridación de Ácido Nucleico , Ácidos Nucleicos de Péptidos/química , Ácidos Nucleicos de Péptidos/genética , Polilisina/síntesis química , Polilisina/química , Polilisina/toxicidad , ARN/química , ARN/genética , Solubilidad , Temperatura , Timina/síntesis química , Timina/toxicidad , Transfección/métodosRESUMEN
The RGD-recognizing αvß6 integrin has only recently emerged as a major target for cancer diagnosis and therapy. Thus, the development of selective, low-molecular-weight ligands of this receptor is still in great demand. Here, a metadynamics-driven design strategy allowed us to successfully convert a helical nonapeptide into a cyclic pentapeptide (6) showing remarkable potency and αvß6 specificity. NMR and docking studies elucidated the reasons for the high affinity and selectivity of this compound, setting the ground for the rational design of new αvß6-specific small peptides or even peptidomimetics. In vivo PET imaging studies demonstrated the potential use of 6 for medical applications.
Asunto(s)
Antígenos de Neoplasias/química , Integrinas/química , Humanos , Simulación del Acoplamiento Molecular , Resonancia Magnética Nuclear BiomolecularRESUMEN
Autophagy is a critical regulator of cellular homeostasis and metabolism. Interference with this process is considered a new approach for the treatment of disease, in particular cancer and neurological disorders. Therefore, novel small-molecule autophagy modulators are in high demand. We describe the discovery of autophinib, a potent autophagy inhibitor with a novel chemotype. Autophinib was identified by means of a phenotypic assay monitoring the formation of autophagy-induced puncta, indicating accumulation of the lipidated cytosolic protein LC3 on the autophagosomal membrane. Target identification and validation revealed that autophinib inhibits autophagy induced by starvation or rapamycin by targeting the lipid kinase VPS34.
Asunto(s)
Autofagia/efectos de los fármacos , Fosfatidilinositol 3-Quinasas Clase III/antagonistas & inhibidores , Inhibidores de Proteínas Quinasas/farmacología , Pirazoles/farmacología , Pirimidinas/farmacología , Autofagosomas/efectos de los fármacos , Descubrimiento de Drogas , Células HEK293 , Células HeLa , Humanos , Células MCF-7 , Inhibidores de Proteínas Quinasas/química , Pirazoles/química , Pirimidinas/química , Sirolimus/farmacología , Relación Estructura-ActividadRESUMEN
Nucleopeptides are promising nucleic acid mimetics in which the peptide backbone bears nucleobases. They can recognize DNA and RNA targets modulating their biological functions. To date, the lack of an effective strategy for the synthesis of nucleopeptides prevents their evaluation for biological and biomedical applications. Herein, we describe an unprecedented approach that enables the synthesis of cationic both homo and heterosequence nucleopeptides wholly on solid support with high yield and purity. Spectroscopic studies indicate advantageous properties of the nucleopeptides in terms of binding, thermodynamic stability and sequence specific recognition. Biostability assay and laser scanning confocal microscopy analyses reveal that the nucleopeptides feature acceptable serum stability and ability to cross the cell membrane.
Asunto(s)
ADN/química , Proteínas Nucleares/síntesis química , Péptidos/síntesis química , ARN/química , Técnicas de Síntesis en Fase Sólida/métodos , Secuencia de Aminoácidos , Línea Celular Tumoral , Dicroismo Circular , Humanos , Proteínas Nucleares/química , Péptidos/químicaRESUMEN
Sirtuins are NAD+-dependent protein lysine deacylases implicated in aging-related diseases. Mammalian Sirtuin 4 (Sirt4) is located in mitochondria and a potential therapeutic target for cancer and metabolic diseases, but no potent and selective Sirt4 inhibitors have been reported. Here, we describe the identification of potent Sirt4-specific small-molecule inhibitors. Testing hits from a target-based virtual screen revealed 12 active compounds. A focused screen based on two top compounds, followed by structure-assisted design of derivatives, yielded four first-in-class potent Sirt4 inhibitors. Kinetic analyses indicate compound competition with the acyl peptide substrate, consistent with the docking models and implicating Sirt4's unique acyl binding site. The compounds indeed show preference for Sirt4 over other isoforms, with one of them (69) being highly isoform selective, and they are active in cells. Our results provide first lead compounds and mechanistic insights for optimization toward Sirt4-specific inhibitors useful as experimental tools and potential therapeutics.
Asunto(s)
Mitocondrias , Sirtuinas , Animales , Mitocondrias/metabolismo , Isoformas de Proteínas/metabolismo , Sitios de Unión , Lisina/química , Proteínas Mitocondriales/metabolismo , Mamíferos/metabolismoRESUMEN
Despite progress in the prevention and diagnosis of cancer, current technologies for tumor detection present several limitations including invasiveness, toxicity, inaccuracy, lengthy testing duration and high cost. Therefore, innovative diagnostic techniques that integrate knowledge from biology, oncology, medicinal and analytical chemistry are now quickly emerging in the attempt to address these issues. Following this approach, here we developed a paper-based electrochemical device for detecting cancer-derived Small Extracellular Vesicles (S-EVs) in fluids. S-EVs were obtained from cancer cell lines known to express, at a different level, the αvß6 integrin receptor, a well-established hallmark of numerous epithelial cancer types. The resulting biosensor turned out to recognize αvß6-containing S-EVs down to a limit of 0.7*103 S-EVs/mL with a linear range up to 105 S-EVs /mL, and a relative standard deviation of 11%, thus it may represent a novel opportunity for αvß6 expressing cancers detection.
RESUMEN
The present study describes a small library of peptides derived from a potent and selective CXCR4 antagonist (3), wherein the native disulfide bond is replaced using a side-chain to tail macrolactamization technique to vary ring size and amino acid composition. The peptides were preliminary assessed for their ability to interfere with the interaction between the receptor and anti-CXCR4 PE-conjugated antibody clone 12G5. Two promising candidates (13 and 17) were identified and further evaluated in a125I-CXCL12 competition binding assay, exhibiting IC50 in the low-nanomolar range. Furthermore, both candidates displayed high selectivity towards CXCR4 with respect to the cognate receptor CXCR7, ability to block CXCL12-dependent cancer cell migration, and receptor internalization, albeit at a higher concentration compared to 3. Molecular modeling studies on 13 and 17 produced a theoretical model that may serve as a guide for future modifications, aiding in the development of analogs with improved affinity. Finally, the study provides valuable insights into developing therapeutic agents targeting CXCR4-mediated processes, demonstrating the adaptability of our lead peptide 3 to alternative cyclization approaches and offering prospects for comprehensive investigations into the receptor region's interaction with its C-terminal region.
Asunto(s)
Disulfuros , Péptidos , Receptores CXCR4 , Receptores CXCR4/antagonistas & inhibidores , Receptores CXCR4/metabolismo , Humanos , Sitios de Unión/efectos de los fármacos , Péptidos/química , Péptidos/farmacología , Péptidos/síntesis química , Disulfuros/química , Disulfuros/farmacología , Relación Estructura-Actividad , Estructura Molecular , Relación Dosis-Respuesta a Droga , Lactamas/química , Lactamas/farmacología , Lactamas/síntesis química , Movimiento Celular/efectos de los fármacos , Modelos Moleculares , Línea Celular TumoralRESUMEN
Herein, we developed an innovative and easily accessible solid-phase synthetic protocol for Peptide Nucleic Acid (PNA) oligomers by systematically investigating the ultrasonication effects in all steps of the PNA synthesis (US-PNAS). When compared with standard protocols, the application of the so-obtained US-PNAS approach succeeded in improving the crude product purities and the isolated yields of different PNA, including small or medium-sized oligomers (5-mer and 9-mer), complex purine-rich sequences (like a 5-mer Guanine homoligomer and the telomeric sequence TEL-13) and longer oligomers (such as the 18-mer anti-IVS2-654 PNA and the 23-mer anti-mRNA 155 PNA). Noteworthy, our ultrasound-assisted strategy is compatible with the commercially available PNA monomers and well-established coupling reagents and only requires the use of an ultrasonic bath, which is a simple equipment generally available in most synthetic laboratories.
Asunto(s)
Ácidos Nucleicos de Péptidos , Ácidos Nucleicos de Péptidos/genética , ARN Mensajero , GuaninaRESUMEN
After over 30 years of research, the development of HDAC inhibitors led to five FDA/Chinese FDA-approved drugs and many others under clinical or preclinical investigation to treat cancer and non-cancer diseases. Herein, based on our recent development of pyridine-based isomers as HDAC inhibitors, we report a series of novel 5-acylamino-2-pyridylacrylic- and -picolinic hydroxamates and 2'-aminoanilides 5-8 as anticancer agents. The hydroxamate 5d proved to be quite HDAC3/6-selective exhibiting IC50 values of 80 and 11 nM, respectively, whereas the congener 5e behaved as inhibitor of HDAC1-3, -6, -8, and -10 (class I/IIb-selective inhibitor) at nanomolar level. Compound 5e provided a huge antiproliferative activity (nanomolar IC50 values) against both haematological and solid cancer cell lines. In leukaemia U937 cells, the hydroxamate 5d and the 2'-aminoanilide 8f induced remarkable cell death after 48 h, with 76% and 100% pre-G1 phase arrest, respectively, showing a stronger effect with respect to SAHA and MS-275 used as reference compounds. In U937 cells, the highest dose- and time-dependent cytodifferentiation was obtained by the 2'-aminoanilide 8d (up to 35% of CD11c positive/propidium iodide negative cells at 5 µM for 48 h). The same 8d and the hydroxamates 5d and 5e were the most effective in inducing p21 protein expression in the same cell line. Mechanistically, 5d, 5e, 8d and 8f increased mRNA expression of p21, BAX and BAK, downregulated cyclin D1 and BCL-2 and modulated pro- and anti-apoptotic microRNAs towards apoptosis induction. Finally, 5e strongly arrested proliferation in nine different haematological cancer cell lines, with dual-digit nanomolar potency towards MV4-11, Kasumi-1, and NB4, being more potent than mocetinostat, used as reference drug.
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Antineoplásicos , MicroARNs , Neoplasias , Humanos , Inhibidores de Histona Desacetilasas/farmacología , Línea Celular Tumoral , Proliferación Celular , Antineoplásicos/farmacología , Ácidos Hidroxámicos/farmacología , Apoptosis , Piridinas/farmacología , Histona Desacetilasa 1RESUMEN
KAT8 is a lysine acetyltransferase primarily catalyzing the acetylation of Lys16 of histone H4 (H4K16). KAT8 dysregulation is linked to the development and metastatization of many cancer types, including non-small cell lung cancer (NSCLC) and acute myeloid leukemia (AML). Few KAT8 inhibitors have been reported so far, none of which displaying selective activity. Based on the KAT3B/KDAC inhibitor C646, we developed a series of N-phenyl-5-pyrazolone derivatives and identified compounds 19 and 34 as low-micromolar KAT8 inhibitors selective over a panel of KATs and KDACs. Western blot, immunofluorescence, and CETSA experiments demonstrated that both inhibitors selectively target KAT8 in cells. Moreover, 19 and 34 exhibited mid-micromolar antiproliferative activity in different cancer cell lines, including NSCLC and AML, without impacting the viability of nontransformed cells. Overall, these compounds are valuable tools for elucidating KAT8 biology, and their simple structures make them promising candidates for future optimization studies.
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Carcinoma de Pulmón de Células no Pequeñas , Leucemia Mieloide Aguda , Neoplasias Pulmonares , Lisina Acetiltransferasas , Humanos , Lisina Acetiltransferasas/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Histonas/metabolismo , Acetilación , Histona Acetiltransferasas/metabolismoRESUMEN
The TRF2 shelterin component is an essential regulator of telomere homeostasis and genomic stability. Mutations in the TRF2TRFH domain physically impair t-loop formation and prevent the recruitment of several factors that promote efficient telomere replication, causing telomeric DNA damage. Here, we design, synthesize, and biologically test covalent cyclic peptides that irreversibly target the TRF2TRFH domain. We identify APOD53 as our most promising compound, as it consistently induces a telomeric DNA damage response in cancer cell lines. APOD53 forms a covalent adduct with a reactive cysteine residue present in the TRF2TRFH domain and induces phenotypes consistent with TRF2TRFH domain mutants. These include induction of a telomeric DNA damage response, increased telomeric replication stress, and impaired recruitment of RTEL1 and SLX4 to telomeres. We demonstrate that APOD53 impairs cancer cell growth and find that co-treatment with APOD53 can exacerbate telomere replication stress caused by the G4 stabilizer RHPS4 and low dose aphidicolin (APH).
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Péptidos Cíclicos , Proteína 2 de Unión a Repeticiones Teloméricas , Daño del ADN , Péptidos Cíclicos/farmacología , Telómero , Proteína 2 de Unión a Repeticiones Teloméricas/antagonistas & inhibidores , Proteína 2 de Unión a Repeticiones Teloméricas/química , Proteína 2 de Unión a Repeticiones Teloméricas/genética , Dominios Proteicos , Línea Celular TumoralRESUMEN
Misregulation and mutations of the transcription factor Nrf2 are involved in the development of a variety of human diseases. In this study, we employed the technology of stapled peptides to address a protein-DNA-complex and designed a set of Nrf2-based derivatives. Varying the length and position of the hydrocarbon staple, we chose the best peptide for further evaluation in both fixed and living cells. Peptide 4 revealed significant enrichment within the nucleus compared to its linear counterpart 5, indicating potent binding to DNA. Our studies suggest that these molecules offer an interesting strategy to target activated Nrf2 in cancer cells.
Asunto(s)
Factor 2 Relacionado con NF-E2 , Péptidos , ADN , Humanos , Hidrocarburos/química , Factor 2 Relacionado con NF-E2/genética , Péptidos/químicaRESUMEN
The pleiotropic role played by melanocortin receptors (MCRs) in both physiological and pathological processes has stimulated medicinal chemists to develop synthetic agonists/antagonists with improved potency and selectivity. Here, by deploying the Chemical Linkage of Peptide onto Scaffolds strategy, we replaced the lactam cyclization of melanotan II (MT-II), a potent and unselective agonist of human MCRs (hMCRs), with different xylene-derived thioethers. The newly designed peptides displayed binding affinities toward MCRs ranging from the low nanomolar to the sub-micromolar range, highlighting a correlation between the explored linkers and the affinity toward hMCRs. In contrast to the parent peptide (MT-II), compound 5 displayed a remarkable functional selectivity toward the hMC1R. Enhanced sampling molecular dynamics simulations were found to be instrumental in outlining how the employed cyclization strategy affects the peptides' conformational behavior and, as a consequence, the detected hMC1R affinity. Additionally, a model of the peptide 5/hMC1R complex employing the very recently reported cryogenic electron microscopy receptor structure was provided.
Asunto(s)
Receptores de Melanocortina , alfa-MSH , Humanos , Péptidos Cíclicos/química , Péptidos Cíclicos/farmacología , Receptores de Melanocortina/química , Relación Estructura-Actividad , alfa-MSH/análogos & derivados , alfa-MSH/químicaRESUMEN
LSD1 is a histone lysine demethylase proposed as therapeutic target in cancer. Chemical modifications applied at C2, C4 and/or C7 positions of the quinazoline core of the previously reported dual LSD1/G9a inhibitor 1 led to a series of non-covalent, highly active, and selective LSD1 inhibitors (2-4 and 6-30) and to the dual LSD1/G9a inhibitor 5 that was more potent than 1 against LSD1. In THP-1 and MV4-11 leukemic cells, the most potent compounds (7, 8, and 29) showed antiproliferative effects at sub-micromolar level without significant toxicity at 1 µM in non-cancer AHH-1 cells. In MV4-11 cells, the new derivatives increased the levels of the LSD1 histone mark H3K4me2 and induced the re-expression of the CD86 gene silenced by LSD1, thereby confirming the inhibition of LSD1 at cellular level. In breast MDA-MB-231 as well as in rhabdomyosarcoma RD and RH30 cells, taken as examples of solid tumors, the same compounds displayed cell growth arrest in the same IC50 range, highlighting a crucial anticancer role for LSD1 inhibition and suggesting no added value for the simultaneous G9a inhibition in these tumor cell lines.