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Despite advancements in therapeutic strategies, the development of drug resistance and metastasis remains a serious concern for the efficacy of chemotherapy against colorectal cancer (CRC). We have previously demonstrated that low expression of ribosomal protein uL3 positively correlates with chemoresistance in CRC patients. Here, we demonstrated that the loss of uL3 increased the metastatic capacity of CRC cells in chick embryos. Metabolomic analysis revealed large perturbations in amino acid and glutathione metabolism in resistant uL3-silenced CRC cells, indicating that uL3 silencing dramatically triggered redox metabolic reprogramming. RNA-Seq data revealed a notable dysregulation of 108 genes related to ferroptosis in CRC patients. Solute Carrier Family 7 Member 11 (SLC7A11) is one of the most dysregulated genes; its mRNA stability is negatively regulated by uL3, and its expression is inversely correlated with uL3 levels. Inhibition of SLC7A11 with erastin impaired resistant uL3-silenced CRC cell survival by inducing ferroptosis. Of interest, the combined treatment erastin plus uL3 enhanced the chemotherapeutic sensitivity of uL3-silenced CRC cells to erastin. The antimetastatic potential of the combined strategy was evaluated in chick embryos. Overall, our study sheds light on uL3-mediated chemoresistance and provides evidence of a novel therapeutic approach, erastin plus uL3, to induce ferroptosis, establishing individualized therapy by examining p53, uL3 and SLC7A11 profiles in tumors.
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A protocol exploiting isocyanides as carbamoylating agents for the α-C(sp3)-H functionalization of cyclic ethers has been optimized via a combined visible light-driven hydrogen atom transfer/Lewis acid-catalyzed approach. The isocyanide substrate scope revealed an exquisite functional group compatibility (18 examples, with yields up to 99 %). Both radical and polar trapping, kinetic isotopic effect and real-time NMR studies support the mechanistic hypothesis and provide insightful details for the design of new chemical processes involving the generation of oxocarbenium ions.
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A novel class of compounds designed to hit two anti-tumour targets, G-quadruplex structures and human carbonic anhydrases (hCAs) IX and XII is proposed. The induction/stabilisation of G-quadruplex structures by small molecules has emerged as an anticancer strategy, disrupting telomere maintenance and reducing oncogene expression. hCAs IX and XII are well-established anti-tumour targets, upregulated in many hypoxic tumours and contributing to metastasis. The ligands reported feature a berberine G-quadruplex stabiliser scaffold connected to a moiety inhibiting hCAs IX and XII. In vitro experiments showed that our compounds selectively stabilise G-quadruplex structures and inhibit hCAs IX and XII. The crystal structure of a telomeric G-quadruplex in complex with one of these ligands was obtained, shedding light on the ligand/target interaction mode. The most promising ligands showed significant cytotoxicity against CA IX-positive HeLa cancer cells in hypoxia, and the ability to stabilise G-quadruplexes within tumour cells.
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Antineoplásicos , Anhidrasa Carbónica IX , Inhibidores de Anhidrasa Carbónica , Anhidrasas Carbónicas , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , G-Cuádruplex , Humanos , G-Cuádruplex/efectos de los fármacos , Inhibidores de Anhidrasa Carbónica/farmacología , Inhibidores de Anhidrasa Carbónica/química , Inhibidores de Anhidrasa Carbónica/síntesis química , Antineoplásicos/farmacología , Antineoplásicos/química , Antineoplásicos/síntesis química , Relación Estructura-Actividad , Estructura Molecular , Anhidrasa Carbónica IX/antagonistas & inhibidores , Anhidrasa Carbónica IX/metabolismo , Anhidrasas Carbónicas/metabolismo , Proliferación Celular/efectos de los fármacos , Ligandos , Células HeLa , Antígenos de Neoplasias/metabolismo , Modelos MolecularesRESUMEN
INTRODUCTION: Guanine-rich DNA sequences can fold into four-stranded noncanonical secondary structures called G-quadruplexes (G4s) which are widely distributed in functional regions of the human genome, such as telomeres and gene promoter regions. Compelling evidence suggests their involvement in key genome functions such as gene expression and genome stability. Notably, the abundance of G4-forming sequences near transcription start sites suggests their potential involvement in regulating oncogenes. AREAS COVERED: This review provides an overview of current knowledge on G4s in human oncogene promoters. The most representative G4-binding ligands have also been documented. The objective of this work is to present a comprehensive overview of the most promising targets for the development of novel and highly specific anticancer drugs capable of selectively impacting the expression of individual or a limited number of genes. EXPERT OPINION: Modulation of G4 formation by specific ligands has been proposed as a powerful new tool to treat cancer through the control of oncogene expression. Actually, most of G4-binding small molecules seem to simultaneously target a range of gene promoter G4s, potentially influencing several critical driver genes in cancer, thus producing significant therapeutic benefits.
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Antineoplásicos , G-Cuádruplex , Neoplasias , Humanos , ADN/química , ADN/genética , ADN/metabolismo , Patentes como Asunto , Regiones Promotoras Genéticas , Antineoplásicos/farmacología , Ligandos , Neoplasias/tratamiento farmacológico , Neoplasias/genéticaRESUMEN
Gadolinium-based contrast agents (GBCAs) are massively employed in radiology to increase the diagnostic power of MRI. However, investigations aiming at detecting possible metabolic perturbations or adverse health effects due to gadolinium deposition are still lacking. In this work, aqueous organs extract and plasma samples were analyzed by GC-MS and 1H-NMR, respectively, to investigate the effects of multiple administrations of one linear (Omniscan) and one macrocyclic (ProHance) GBCA, on the main metabolic pathways in healthy mice. Multivariate analysis revealed that plasma metabolome was not differently perturbed by the two GBCAs, while, the multiorgan analysis displayed a clear separation of the Omniscan-treated from the control and the ProHance-treated groups. Interestingly, the most affected organs were the brain, cerebellum and liver. Thus, this work paves the way to both the safest use of the commercially available GBCAs and the development of new GBCAs characterized by lower general toxicity.
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Gadolinio , Compuestos Organometálicos , Ratones , Animales , Gadolinio/toxicidad , Gadolinio/metabolismo , Gadolinio DTPA/metabolismo , Compuestos Organometálicos/toxicidad , Medios de Contraste/toxicidad , Medios de Contraste/metabolismo , Encéfalo/metabolismo , Imagen por Resonancia MagnéticaRESUMEN
The single-stranded RNA genome of SARS-CoV-2 contains some G-quadruplex-forming G-rich elements which are putative drug targets. Here, we performed a ligand-based pharmacophore virtual screening of FDA approved drugs to find candidates targeting such RNA structures. Further in silico and in vitro assays identified three drugs as emerging SARS-CoV-2 RNA G-quadruplex binders.
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Tratamiento Farmacológico de COVID-19 , Reposicionamiento de Medicamentos , Humanos , Antivirales/farmacología , Antivirales/química , Ligandos , Simulación del Acoplamiento Molecular , ARN Viral/genética , SARS-CoV-2 , G-CuádruplexRESUMEN
Besides the well-known double-helical conformation, DNA is capable of folding into various noncanonical arrangements, such as G-quadruplexes (G4s) and i-motifs (iMs), whose occurrence in gene promoters, replication origins, and telomeres highlights the breadth of biological processes that they might regulate. Particularly, previous studies have reported that G4 and iM structures may play different roles in controlling gene transcription. Anyway, molecular tools able to simultaneously stabilize/destabilize those structures are still needed to shed light on what happens at the biological level. Herein, a multicomponent reaction and a click chemistry functionalization were combined to generate a set of 31 bis-triazolyl-pyridine derivatives which were initially screened by circular dichroism for their ability to interact with different G4 and/or iM DNAs and to affect the thermal stability of these structures. All the compounds were then clustered through multivariate data analysis, based on such capability. The most promising compounds were subjected to a further biophysical and biological characterization, leading to the identification of two molecules simultaneously able to stabilize G4s and destabilize iMs, both in vitro and in living cells.
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Antineoplásicos/síntesis química , Antineoplásicos/farmacología , Compuestos Azo/química , ADN/metabolismo , G-Cuádruplex , Osteosarcoma/tratamiento farmacológico , Piridinas/química , Neoplasias Óseas/tratamiento farmacológico , Neoplasias Óseas/patología , ADN/química , Humanos , Osteosarcoma/patología , Células Tumorales CultivadasRESUMEN
DNA G-quadruplex (G4) structures, either within gene promoter sequences or at telomeres, have been extensively investigated as potential small-molecule therapeutic targets. However, although G4s forming at the telomeric DNA have been extensively investigated as anticancer targets, few studies focus on the telomeric repeat-containing RNA (TERRA), transcribed from telomeres, as potential pharmacological targets. Here, a virtual screening approach to identify a library of drug-like putative TERRA G4 binders, in tandem with circular dichroism melting assay to study their TERRA G4-stabilizing properties, led to the identification of a new hit compound. The affinity of this compound for TERRA RNA and some DNA G4s was analyzed through several biophysical techniques and its biological activity investigated in terms of antiproliferative effect, DNA damage response (DDR) activation, and TERRA RNA expression in high vs. low TERRA-expressing human cancer cells. The selected hit showed good affinity for TERRA G4 and no binding to double-stranded DNA. In addition, biological assays showed that this compound is endowed with a preferential cytotoxic effect on high TERRA-expressing cells, where it induces a DDR at telomeres, probably by displacing TERRA from telomeres. Our studies demonstrate that the identification of TERRA G4-targeting drugs with potential pharmacological effects is achievable, shedding light on new perspectives aimed at discovering new anticancer agents targeting these G4 structures.
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ARN/genética , Telómero/genética , Antineoplásicos/farmacología , Sitios de Unión/efectos de los fármacos , Sitios de Unión/genética , ADN/genética , Daño del ADN/efectos de los fármacos , Daño del ADN/genética , G-Cuádruplex/efectos de los fármacos , Humanos , Ligandos , Neoplasias/tratamiento farmacológico , Neoplasias/genética , Relación Estructura-Actividad , Telómero/efectos de los fármacosRESUMEN
The i-motif DNA, also known as i-DNA, is a non-canonical DNA secondary structure formed by cytosine-rich sequences, consisting of two intercalated parallel-stranded duplexes held together by hemi-protonated cytosine-cytosine+ (C:C+ ) base pairs. The growing interest in the i-DNA structure as a target in anticancer therapy increases the need for tools for a rapid and meaningful interpretation of the spectroscopic data of i-DNA samples. Herein, we analyzed the circular dichroism (CD) and thermal difference UV-absorbance spectra (TDS) of 255 DNA sequences by means of multivariate data analysis, aiming at unveiling peculiar spectral regions that could be used as diagnostic features during the analysis of i-DNA-forming sequences.
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ADN/química , Dicroismo Circular , Conformación de Ácido Nucleico , Espectrofotometría UltravioletaRESUMEN
G-quadruplexes (G4s) are non-canonical DNA secondary structures. The identification of selective tools to probe individual G4s over the â¼700 000 found in the human genome is key to unravel the biological significance of specific G4s. We took inspiration from a crystal structure of the bovine DHX36 helicase bound to the G4 formed in the promoter region of the oncogene c-MYC to identify a short peptide that preferentially binds MYC G4 with nM affinity over a small panel of parallel and non-parallel G4s tested.
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G-Cuádruplex , Péptidos/metabolismo , Proteínas Proto-Oncogénicas c-myc/genética , Secuencia de Aminoácidos , Animales , Bovinos , ARN Helicasas DEAD-box/química , ARN Helicasas DEAD-box/metabolismo , Polarización de Fluorescencia , Humanos , Conformación de Ácido Nucleico , Péptidos/química , Regiones Promotoras Genéticas , Unión ProteicaRESUMEN
G-quadruplex (G4) nucleic acid structures are involved in a number of different diseases and their drug-induced stabilization is deemed to be a promising therapeutic approach. Herein is reported a proof of principle study on the use of nano differential scanning fluorimetry for a rapid and accurate analysis of G4-stabilizing ligands, exploiting the fluorescence properties of a 2-aminopurine modified G4-forming oligonucleotide.
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ADN/análisis , Fluorometría/métodos , G-Cuádruplex , Acridinas/química , Acridinas/metabolismo , Aminoquinolinas/química , Aminoquinolinas/metabolismo , Dicroismo Circular , ADN/genética , ADN/metabolismo , Humanos , Ligandos , Ácidos Picolínicos/química , Ácidos Picolínicos/metabolismo , Prueba de Estudio Conceptual , Temperatura de TransiciónRESUMEN
The i-motif is a biologically relevant non-canonical DNA structure formed by cytosine-rich sequences. Despite the importance of the factors affecting the formation/stability of such a structure, like pH, cation type and concentration, no systematic study that simultaneously analysed their effect on the i-motif in vitro has been carried out so far. Therefore, here we report a systematic study that aims to evaluate the effect of these factors, and their possible interaction, on the formation of an i-motif structure. Our results confirm that pH plays the main role in i-motif formation. However, we demonstrate that the effect of the cation concentration on the i-motif is strictly dependent on the pH, while no significant differences are observed among the investigated cation types. Graphical abstract.
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Cationes , ADN/química , Concentración de Iones de Hidrógeno , Conformación de Ácido Nucleico , Dicroismo Circular , Espectroscopía de Protones por Resonancia MagnéticaRESUMEN
Phytosterols are known to reduce plasma cholesterol levels and thereby reduce cardiovascular risk. Studies conducted on human and animal models have demonstrated that these compounds have also anti-inflammatory effects. Recently, an experimental colitis model (dextran sulphate sodium-induced) has shown that pre-treatment with phytosterols decreases infiltration of inflammatory cells and accelerates mucosal healing. This study aims to understand the mechanism underlying the colitis by analysing the end-products of the metabolism in distal colon and liver excised from the same mice used in the previous work. In particular, an unsupervised gas chromatography-mass spectrometry (GC-MS) and NMR based metabolomics approach was employed to identify the metabolic pathways perturbed by the dextran sodium sulphate (DSS) insult (i.e. Krebs cycle, carbohydrate, amino acids, and nucleotide metabolism). Interestingly, phytosterols were able to restore the homeostatic equilibrium of the hepatic and colonic metabolome.
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Colitis/tratamiento farmacológico , Colon/efectos de los fármacos , Modelos Animales de Enfermedad , Hígado/efectos de los fármacos , Fitosteroles/farmacología , Animales , Colitis/metabolismo , Colitis/patología , Colon/metabolismo , Cromatografía de Gases y Espectrometría de Masas , Hígado/metabolismo , Masculino , Metabolómica , Ratones , Ratones Endogámicos BALB CRESUMEN
G-quadruplex (G4) and i-motif (iM) are four-stranded non-canonical nucleic acid structural arrangements. Recent evidences suggest that these DNA structures exist in living cells and could be involved in several cancer-related processes, thus representing an attractive target for anticancer drug discovery. Efforts toward the development of G4 targeting compounds have led to a number of effective bioactive ligands. Herein, employing several biophysical methodologies, we studied the ability of some well-known G4 ligands to interact with iM-forming DNA. The data showed that the investigated compounds are actually able to interact with both DNA in vitro, thus acting de facto as multi-target-directed agents. Interestingly, while all the compounds stabilize the G4, some of them significantly reduce the stability of the iM. The present study highlights the importance, when studying G4-targeting compounds, of evaluating also their behavior toward the i-motif counterpart.