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1.
Pharmacol Res ; 206: 107291, 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38969274

RESUMO

Fibroblast growth factors (FGFs) act as proangiogenic and mitogenic cytokines in several cancers, including multiple myeloma (MM). Indeed, corrupted FGF autocrine and paracrine secretion induces an aberrant activation of the FGF receptor (FGFR) signaling sustaining cancer cell spreading and resistance to pharmacological treatments. Thus, FGF traps may represent a promising anti-cancer strategy to hamper the ligand-dependent activation of the FGF/FGFR system. We previously identified NSC12 as the first orally available small molecule FGF trap able to inhibit the growth and progression of several FGF-dependent tumor models. NSC12 is a pregnenolone derivative carrying a 1,1-bis-trifluoromethyl-1,3-propanediol chain in position 17 of the steroid nucleus. Investigation of structure-activity relationships (SARs) provided more potent and specific NSC12 steroid derivatives and highlighted that the C17-side chain is pivotal for the FGF trap activity. Here, a scaffold hopping approach allowed to obtain two FGF trap compounds (22 and 57) devoid of the steroid nucleus and able to efficiently bind FGF2 and to inhibit FGFR activation in MM cells. Accordingly, these compounds exert a potent anti-tumor activity on MM cell lines both in vitro and in vivo and on MM patient-derived primary cells, strongly affecting the survival of both proteasome-inhibitor sensitive and resistant MM cells. These results propose a new therapeutic option for relapsed/refractory MM patients and set the bases for the development of novel FGF traps prone to chemical diversification to be used in the clinic for the treatment of those tumors in which the FGF/FGFR system plays a pivotal role, including MM.

2.
Environ Res ; 252(Pt 1): 118878, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38582417

RESUMO

Fibrous erionite is the only zeolite classified as Group 1 carcinogen by the International Agency for Research on Cancer (IARC). Carcinogenesis induced by erionite is thought to involve several factors as biopersistence, the iron role and cation exchange processes. To better understand these mechanisms, a detailed investigation at the micro scale was performed, collecting elemental information on iron and cation release and their distribution in biological systems by synchrotron micro-X-ray fluorescence mapping (SR-micro-XRF) and synchrotron micro-X-ray absorption spectroscopy (SR-micro-XANES) at the TwinMic beamline (Elettra synchrotron) and at the ID21 beamline of the European Synchrotron Radiation Facility (ESRF). By microscopy and chemical mapping, highly detailed maps of the chemical and morphological interaction of biological systems with fibres could be produced. In detail, THP-1 cell line derived macrophages, used as in vitro model, were analysed during erionite-Na phagocytosis at different time intervals, after single dose exposure. For comparison, cellular fluorescent probes were also used to evaluate the intracellular free sodium and calcium concentrations. Synchrotron analyses visualised the spatial distribution of both fibre and mineral particle associated metals during the phagocytosis, describing the mechanism of internalisation of erionite-Na and its accessory mineral phases. The intracellular distribution of metals and other cations was mapped to evaluate metal release, speciation changes and/or cation exchange during phagocytosis. The fluorescent probes complemented microchemical data clarifying, and confirming, the cation distribution observed in the SR-micro-XRF maps. The significant cytoplasmic calcium decrease, and the concomitant sodium increase, after the fibre phagocytosis seemed due to activation of plasma membrane cations exchangers triggered by the internalisation while, surprisingly, the ion-exchange capacity of erionite-Na could play a minor role in the disruption of the two cations intracellular homeostasis. These results help to elucidate the role of cations in the toxicity of erionite-treated THP-1 macrophages and add knowledge to its carcinogenicity process.


Assuntos
Macrófagos , Síncrotrons , Zeolitas , Humanos , Zeolitas/toxicidade , Zeolitas/química , Macrófagos/efeitos dos fármacos , Células THP-1 , Cátions , Espectrometria por Raios X , Fagocitose/efeitos dos fármacos , Cálcio/metabolismo , Sódio
3.
Cells ; 13(5)2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38474332

RESUMO

BACKGROUND: Most patients with testicular germ cell tumors (GCTs) are treated with cisplatin (CP)-based chemotherapy. However, some of them may develop CP resistance and therefore represent a clinical challenge. Cyclin-dependent kinase 5 (CDK5) is involved in chemotherapy resistance in different types of cancer. Here, we investigated the possible role of CDK5 and other CDKs targeted by dinaciclib in nonseminoma cell models (both CP-sensitive and CP-resistant), evaluating the potential of the CDK inhibitor dinaciclib as a single/combined agent for the treatment of advanced/metastatic testicular cancer (TC). METHODS: The effects of dinaciclib and CP on sensitive and resistant NT2/D1 and NCCIT cell viability and proliferation were evaluated using MTT assays and direct count methods. Flow cytometry cell-cycle analysis was performed. The protein expression was assessed via Western blotting. The in vivo experiments were conducted in zebrafish embryos xenografted with TC cells. RESULTS: Among all the CDKs analyzed, CDK5 protein expression was significantly higher in CP-resistant models. Dinaciclib reduced the cell viability and proliferation in each cell model, inducing changes in cell-cycle distribution. In drug combination experiments, dinaciclib enhances the CP effect both in vitro and in the zebrafish model. CONCLUSIONS: Dinaciclib, when combined with CP, could be useful for improving nonseminoma TC response to CP.


Assuntos
Cisplatino , Óxidos N-Cíclicos , Indolizinas , Neoplasias Embrionárias de Células Germinativas , Compostos de Piridínio , Neoplasias Testiculares , Masculino , Animais , Humanos , Cisplatino/farmacologia , Peixe-Zebra , Proliferação de Células , Inibidores de Proteínas Quinases/farmacologia
4.
Chem Biodivers ; 21(2): e202301815, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38152840

RESUMO

Pistacia chinensis subsp. integerrima (J.L. Stewart) Rech. f. is a plant known for its therapeutic applications in traditional medicine, which are related to its antimicrobial, anticancer, antioxidant, anti-inflammatory, analgesic, antidiarrheal, and muscle relaxant properties. The galls of P. chinensis are rich in triterpenes and flavonoids, and we here report the extraction of pistagremic acid (1), apigenin (2) and sakuranetin (3) from this source. The isolated compounds were tested against Aspergillus flavus, Candida albicans, Candida glabrata, Fusarium solani, Microsporum canis and Trichoderma longibrachiatum. The results highlighted the antimicrobial activity of flavonoids 2 and 3, suggesting that this class of molecules may be responsible for the effect related to the traditional use. On the other hand, when the compounds and the extract were tested for their antiproliferative activity on a panel of 4 human cancer cell lines, the triterpene pistagremic acid (1) showed a higher potential, thus demonstrating a different bioactivity profile. Structure-based docking and molecular dynamics simulations were used to help the interpretation of experimental results. Taken together, the here reported findings pave the way for the rationalization of the use of P. chinensis extracts, highlighting the contributions of the different components of galls to the observed bioactivity.


Assuntos
Pistacia , Triterpenos , Humanos , Antifúngicos/farmacologia , Triterpenos/farmacologia , Flavonoides/farmacologia , Extratos Vegetais
5.
Bioorg Chem ; 141: 106882, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37839144

RESUMO

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a single-stranded enveloped positive RNA virus and the cause of the ongoing coronavirus disease 2019 (COVID-19) pandemic. Chloroquine (CQ), an antimalarial drug, was reported to be active against several viruses including coronaviruses. The mechanism of host cell invasion by SARS-CoV-2 involves the interaction of angiotensin-converting enzyme (ACE2) with receptor-binding domain (RBD) of spike protein (S). The main protease (Mpro/3CLpro) is an attractive drug target due to its vital function in regulation of polyprotein translated from viral RNA. In this study, a series of novel quinoline-triazole hybrid compounds was synthesized and subjected to evaluations on their cytotoxicity, interactions with different variants of RBD in SARS-CoV-2 and with 3CLpro enzyme by experimental and computational techniques to identify their ability of counteracting viral infection. The results of bio-layer interferometry showed that quinoline derivative 11 has good interaction with delta plus and omicron RBD variants (KD = 3.46 × 10-5 and 6.38 × 10-5 M) while derivative 1 is the best binder for recent variant omicron (KD = 26.9 µM) among the series. Potent compounds 1-4 and 11 also demonstrated a suppressive effect on 3CLpro activity in a non-dose-dependent manner. Further docking study revealed that these compounds interacted within the same area of RBD, while no correlation was found for 3CLpro. Furthermore, the molecular dynamics simulations were carried out to assess the conformational stability of docked complexes for preliminary verification.


Assuntos
Antimaláricos , COVID-19 , Quinolinas , Humanos , SARS-CoV-2 , Cloroquina , Quinolinas/farmacologia , Ligação Proteica , Simulação de Acoplamento Molecular
6.
Front Immunol ; 14: 1247747, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37744340

RESUMO

The release of nanoplastics (NPs) in the environment is a significant health concern for long-term exposed humans. Although their usage has certainly revolutionized several application fields, at nanometer size, NPs can easily interact at the cellular level, resulting in potential harmful effects. Micro/Nanoplastics (M/NPs) have a demonstrated impact on mammalian endocrine components, such as the thyroid, adrenal gland, testes, and ovaries, while more investigations on prenatal and postnatal exposure are urgently required. The number of literature studies on the NPs' presence in biological samples is increasing. However, only a few offer a close study on the model environmental NP-immune system interaction exploited by advanced microscopy techniques. The present study highlights substantial morphological and lipid metabolism alterations in human M1 macrophages exposed to labeled polypropylene and polyvinyl chloride nanoparticles (PP and PVC NPs) (20 µg/ml). The results are interpreted by advanced microscopy techniques combined with standard laboratory tests and fluorescence microscopy. We report the accurate detection of polymeric nanoparticles doped with cadmium selenide quantum dots (CdSe-QDs NPs) by following the Se (L line) X-ray fluorescence emission peak at higher sub-cellular resolution, compared to the supportive light fluorescence microscopy. In addition, scanning transmission X-ray microscopy (STXM) imaging successfully revealed morphological changes in NP-exposed macrophages, providing input for Fourier transform infrared (FTIR) spectroscopy analyses, which underlined the chemical modifications in macromolecular components, specifically in lipid response. The present evidence was confirmed by quantifying the lipid droplet (LD) contents in PP and PVC NPs-exposed macrophages (0-100 µg/ml) by Oil Red O staining. Hence, even at experimental NPs' concentrations and incubation time, they do not significantly affect cell viability; they cause an evident lipid metabolism impairment, a hallmark of phagocytosis and oxidative stress.


Assuntos
Metabolismo dos Lipídeos , Microplásticos , Humanos , Animais , Feminino , Gravidez , Síncrotrons , Macrófagos , Microscopia de Fluorescência , Mamíferos
7.
ACS Med Chem Lett ; 14(8): 1049-1053, 2023 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-37583821

RESUMO

4'-Methyl-4,5'-bithiazoles were previously identified as cystic fibrosis transmembrane regulator (CFTR) correctors, thus being able to correct folding defective mutants of the channel regulating chloride transport through the membrane. Additionally, bithiazole derivative C17 was reported to recover α-sarcoglycan in vitro and in vivo. We report here the synthesis of two new derivatives of C17, in which the two sides of the bithiazole scaffold were modified. The synthesized compounds and the corresponding precursors were tested in myogenic cells to evaluate the expression of α-sarcoglycan. The results highlighted that both substitutions of the bithiazole scaffold are important to achieve the maximum recovery of the α-sarcoglycan mutant. Nonetheless, partial preservation of the activity was observed. Accordingly, this paves the way to further derivatizations/optimization and target fishing studies, which were preliminarily performed in this study as a proof of concept, allowing the investigation of the molecular mechanisms leading to the α-sarcoglycan correction.

8.
Molecules ; 28(5)2023 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-36903316

RESUMO

Ovarian cancer represents a major health concern for the female population: there is no obvious cause, it is frequently misdiagnosed, and it is characterized by a poor prognosis. Additionally, patients are inclined to recurrences because of metastasis and poor treatment tolerance. Combining innovative therapeutic techniques with established approaches can aid in improving treatment outcomes. Because of their multi-target actions, long application history, and widespread availability, natural compounds have particular advantages in this connection. Thus, effective therapeutic alternatives with improved patient tolerance hopefully can be identified within the world of natural and nature-derived products. Moreover, natural compounds are generally perceived to have more limited adverse effects on healthy cells or tissues, suggesting their potential role as valid treatment alternatives. In general, the anticancer mechanisms of such molecules are connected to the reduction of cell proliferation and metastasis, autophagy stimulation and improved response to chemotherapeutics. This review aims at discussing the mechanistic insights and possible targets of natural compounds against ovarian cancer, from the perspective of medicinal chemists. In addition, an overview of the pharmacology of natural products studied to date for their potential application towards ovarian cancer models is presented. The chemical aspects as well as available bioactivity data are discussed and commented on, with particular attention to the underlying molecular mechanism(s).


Assuntos
Produtos Biológicos , Neoplasias Ovarianas , Feminino , Humanos , Produtos Biológicos/química , Proliferação de Células , Neoplasias Ovarianas/tratamento farmacológico
9.
Int J Mol Sci ; 24(4)2023 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-36834956

RESUMO

An improved understanding of an ovary's structures is highly desirable to support advances in folliculogenesis knowledge and reproductive medicine, with particular attention to fertility preservation options for prepubertal girls with malignant tumors. Although currently the golden standard for structural analysis is provided by combining histological sections, staining, and visible 2D microscopic inspection, synchrotron radiation phase-contrast microtomography is becoming a new challenge for three-dimensional studies at micrometric resolution. To this aim, the proper use of contrast agents can improve the visualization of internal structures in ovary tissues, which normally present a low radiopacity. In this study, we report a comparison of four staining protocols, based on iodine or tungsten containing agents, applied to bovine ovarian tissues fixed in Bouin's solution. The microtomography (microCT) analyses at two synchrotron facilities under different set-ups were performed at different energies in order to maximize the image contrast. While tungsten-based agents allow large structures to be well identified, Iodine ones better highlight smaller features, especially when acquired above the K-edge energy of the specific metal. Further scans performed at lower energy where the setup was optimized for overall quality and sensitivity from phase-contrast still provided highly resolved visualization of follicular and intrafollicular structures at different maturation stages, independent of the staining protocol. The analyses were complemented by X-ray Fluorescence mapping on 2D sections, showing that the tungsten-based agent has a higher penetration in this type of tissues.


Assuntos
Imageamento Tridimensional , Iodo , Humanos , Feminino , Animais , Bovinos , Imageamento Tridimensional/métodos , Microscopia , Raios X , Microtomografia por Raio-X/métodos , Ovário , Tungstênio , Meios de Contraste/química
10.
Endocr Relat Cancer ; 30(2)2023 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-36449565

RESUMO

The pharmacological approach to adrenocortical carcinoma (ACC) is based on mitotane with/without etoposide, doxorubicin, and cisplatin, according to the disease stage. Considering the limited efficacy and toxicity of this treatment, new strategies are required. Trabectedin is a marine-derivated antitumoral agent that inhibits oncogenic transcription. We have already demonstrated trabectedin cytotoxic activity at sub-nanomolar concentrations in ACC cells. Here, we expanded the investigation of trabectedin effect on ACC preclinical models, evaluating whether trabectedin could affect ACC cells' invasiveness and metastasis formation. NCI-H295R, MUC-1, and TVBF-7 cell lines were used. Cell tumor xenografts in Danio rerio embryos were performed. The tumor mass areas and the number of embryos with metastasis were evaluated. The in vitro invasiveness of cells was evaluated. Effects of trabectedin of MMP2, TIMP1, and TIMP2 were evaluated at gene level qRT-PCR. MMP2 secreted in the cell medium was evaluated by Western blot and by zymography. Xenograft experiments demonstrated that trabectedin significantly reduced the tumor area in each ACC cell model and metastasis formation in embryos injected with metastasis-derived cell lines. Trabectedin treatment reduced the invasiveness of ACC cells across the matrix, which was greater at baseline for the metastatic models. In metastatic cell models, protein analysis demonstrated a reduction of MMP2 secretion and activity in the culture medium after treatment. Our results indicate that trabectedin interferes with invasiveness and metastasis processes, both dramatic features of ACC. Furthermore, these results support those previously published in providing the rationale for a clinical evaluation of the efficacy of trabectedin in ACC patients.


Assuntos
Neoplasias do Córtex Suprarrenal , Carcinoma Adrenocortical , Humanos , Carcinoma Adrenocortical/genética , Trabectedina/uso terapêutico , Metaloproteinase 2 da Matriz , Neoplasias do Córtex Suprarrenal/genética , Linhagem Celular Tumoral
11.
Sci Total Environ ; 864: 161028, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36549535

RESUMO

BACKGROUND: Endometriosis is a disease affecting 10-15 % of women worldwide, consisting in the ectopic growth of endometrial cells outside the uterine cavity. Whist the pathogenetic mechanisms of endometriosis remain elusive and contemplating even environmental causes, iron deposits are common in endometrial lesions, indicating an altered iron metabolism at this level. This study was undertaken to reveal a possible relationship between iron dysmetabolism and accumulation of environmental metals. METHODS: By combining histological and histochemical analysis (H&E and Perl's staining) with µ- and nano- synchrotron-based (SR-based) X-ray Fluorescence (XRF) microscopy, we investigated the distribution of iron and other elements in the ovarian endometriomas of 12 endometriosis patients and in 7 healthy endometrium samples. RESULTS: XRF microscopy expanded the findings obtained by Perl's staining, revealing with an exceptional sensitivity intracellular features of iron accumulation in the epithelial endometrium, stroma and macrophages of the endometriotic lesions. XRF evidenced that iron was specifically accumulated in multiple micro aggregates, reaching concentrations up to 10-20 % p/p. Moreover, by XRF analysis we revealed for the first time the retention of a number of exogenous and potentially toxic metals such as Pb, Br, Ti, Al Cr, Si and Rb partially or totally co-localizing with iron. CONCLUSION: µXRF reveals accumulation and colocalization of iron and environmental metals in human ovarian endometriosis, suggesting a role in the pathogenesis of endometriosis.


Assuntos
Endometriose , Doenças Uterinas , Humanos , Feminino , Endometriose/metabolismo , Endometriose/patologia , Ferro/toxicidade , Ferro/metabolismo , Endométrio/metabolismo , Endométrio/patologia , Doenças Uterinas/metabolismo , Doenças Uterinas/patologia , Células Epiteliais/patologia
12.
Int J Mol Sci ; 23(24)2022 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-36555489

RESUMO

The work focused on the analysis of two cultivars of tomato (Solanum lycopersicum L.), Aragon and Gladis, under two different treatments of silicon, Low, 2 L of 0.1 mM CaSiO3, and High, 0.5 mM CaSiO3, weekly, for 8 weeks, under stress-free conditions. We subsequently analyzed the morphology, chemical composition, and elemental distribution using synchrotron-based µ-XRF techniques, physiological, and molecular aspects of the response of the two cultivars. The scope of the study was to highlight any significant response of the plants to the Si treatments, in comparison with any response to Si of plants under stress. The results demonstrated that the response was mainly cultivar-dependent, also at the level of mitochondrial-dependent oxidative stress, and that it did not differ from the two conditions of treatments. With Si deposited mainly in the cell walls of the cells of fruits, leaves, and roots, the treatments did not elicit many significant changes from the point of view of the total elemental content, the physiological parameters that measured the oxidative stress, and the transcriptomic analyses focalized on genes related to the response to Si. We observed a priming effect of the treatment on the most responsive cultivar, Aragon, in respect to future stress, while in Gladis the Si treatment did not significantly change the measured parameters.


Assuntos
Solanum lycopersicum , Solanum lycopersicum/genética , Silício/farmacologia , Síncrotrons , Estresse Oxidativo , Perfilação da Expressão Gênica
13.
Sensors (Basel) ; 22(12)2022 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-35746377

RESUMO

In hard X-ray applications that require high detection efficiency and short response times, such as synchrotron radiation-based Mössbauer absorption spectroscopy and time-resolved fluorescence or photon beam position monitoring, III-V-compound semiconductors, and dedicated alloys offer some advantages over the Si-based technologies traditionally used in solid-state photodetectors. Amongst them, gallium arsenide (GaAs) is one of the most valuable materials thanks to its unique characteristics. At the same time, implementing charge-multiplication mechanisms within the sensor may become of critical importance in cases where the photogenerated signal needs an intrinsic amplification before being acquired by the front-end electronics, such as in the case of a very weak photon flux or when single-photon detection is required. Some GaAs-based avalanche photodiodes (APDs) were grown by a molecular beam epitaxy to fulfill these needs; by means of band gap engineering, we realised devices with separate absorption and multiplication region(s) (SAM), the latter featuring a so-called staircase structure to reduce the multiplication noise. This work reports on the experimental characterisations of gain, noise, and charge collection efficiencies of three series of GaAs APDs featuring different thicknesses of the absorption regions. These devices have been developed to investigate the role of such thicknesses and the presence of traps or defects at the metal-semiconductor interfaces responsible for charge loss, in order to lay the groundwork for the future development of very thick GaAs devices (thicker than 100 µm) for hard X-rays. Several measurements were carried out on such devices with both lasers and synchrotron light sources, inducing photon absorption with X-ray microbeams at variable and controlled depths. In this way, we verified both the role of the thickness of the absorption region in the collection efficiency and the possibility of using the APDs without reaching the punch-through voltage, thus preventing the noise induced by charge multiplication in the absorption region. These devices, with thicknesses suitable for soft X-ray detection, have also shown good characteristics in terms of internal amplification and reduction of multiplication noise, in line with numerical simulations.

14.
Int J Mol Sci ; 23(3)2022 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-35163075

RESUMO

Gremlin-1 is a secreted cystine-knot protein that acts as an antagonist of bone morphogenetic proteins (BMPs), and as a ligand of heparin and the vascular endothelial growth factor receptor 2 (VEGFR2), thus regulating several physiological and pathological processes, including embryonic development, tissue fibrosis and cancer. Gremlin-1 exerts all these biological activities only in its homodimeric form. Here, we propose a multi-step approach for the expression and purification of homodimeric, fully active, histidine-tagged recombinant gremlin-1, using mammalian HEK293T cells. Ion metal affinity chromatography (IMAC) of crude supernatant followed by heparin-affinity chromatography enables obtaining a highly pure recombinant dimeric gremlin-1 protein, exhibiting both BMP antagonist and potent VEGFR2 agonist activities.


Assuntos
Proteínas Morfogenéticas Ósseas/antagonistas & inibidores , Cromatografia de Afinidade/métodos , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Proteínas Recombinantes/farmacologia , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/agonistas , Células HEK293 , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/química , Peptídeos e Proteínas de Sinalização Intercelular/genética , Peptídeos e Proteínas de Sinalização Intercelular/isolamento & purificação , Proteínas Recombinantes/genética
15.
Nat Prod Res ; 36(1): 405-410, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32419493

RESUMO

Natural and synthetic small molecules targeting G-quadruplex are currently being studied. These peculiar DNA arrangements arise in guanine-rich sequences located in telomeres, oncogene promoters and in several viruses. Two semi-synthetic derivatives of osajin, a natural isoflavone from Maclura pomifera, were prepared and screened for their binding affinity towards G-quadruplex and double stranded DNA (dsDNA) using electrospray mass spectrometry (ESI-MS). Although an overall decrease in affinity for DNA was observed, one of the derivatives showed improved selectivity for G-quadruplex over dsDNA, retaining structure stabilization properties. Binding motif was studied by collision-induced dissociation (CID) assays and molecular docking, that suggested stacking as the preferential interaction pattern. Moreover, the compound selectively induced DNA damage on the G-quadruplex sequence upon UV irradiation, due to the presence of the photoreactive aryl tosylate group.


Assuntos
Quadruplex G , Isoflavonas , DNA , Simulação de Acoplamento Molecular , Espectrometria de Massas por Ionização por Electrospray
16.
ChemMedChem ; 17(5): e202100665, 2022 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-34882992

RESUMO

Guanine-rich sequences are known to fold into G-quadruplex (G4) arrangements, which are present in oncogenes and in the telomeric regions of chromosomes. In particular, G4s represent an obstacle to functioning of telomerase, an enzyme overexpressed in cancer cells causing their immortalization. Therefore, G4 stabilization using small molecules represents an appealing strategy for the medicinal chemist. Ligands based on an anthraquinone scaffold, to which peptidic side chains were attached by an amide bond, were previously reported. We envisioned improving this ligand concept leveraging the click chemistry approach, which, besides representing a flexible, high yielding synthetic strategy, allows an elongation of the side chains and an increase of π-π stacking and H-bond interactions with the nucleobases through the triazole ring. Compounds were tested for their ability to interact with G4 DNA with a multiple analytical approach, demonstrating an elevated aptitude to stabilize the G4 and high selectivity over double stranded DNA.


Assuntos
Quadruplex G , Aminoácidos , Antraquinonas/farmacologia , Química Click , Humanos , Ligantes , Telômero
17.
Lab Chip ; 21(23): 4618-4628, 2021 11 25.
Artigo em Inglês | MEDLINE | ID: mdl-34679149

RESUMO

Label-free spectromicroscopy methods offer the capability to examine complex cellular phenomena. Electron and X-ray based spectromicroscopy methods, though powerful, have been hard to implement with hydrated objects due to the vacuum incompatibility of the samples and due to the parasitic signals from (or drastic attenuation by) the liquid matrix surrounding the biological object of interest. Similarly, for many techniques that operate at ambient pressure, such as Fourier transform infrared spectromicroscopy (FTIRM), the aqueous environment imposes severe limitations due to the strong absorption of liquid water in the infrared regime. Here we propose a microfabricated multi-compartmental and reusable hydrated sample platform suitable for use with several analytical techniques, which employs the conformal encapsulation of biological specimens by a few layers of atomically thin graphene. Such an electron, X-ray, and infrared transparent, molecularly impermeable and mechanically robust enclosure preserves the hydrated environment around the object for a sufficient time to allow in situ examination of hydrated bio-objects with techniques operating under both ambient and high vacuum conditions. An additional hydration source, provided by hydrogel pads lithographically patterned in the liquid state near/around the specimen and co-encapsulated, has been added to further extend the hydration lifetime. Note that the in-liquid lithographic electron beam-induced gelation procedure allows for addressable capture and immobilization of the biological cells from the solution. Scanning electron microscopy and optical fluorescence microscopy, as well as synchrotron radiation based FTIR and X-ray fluorescence microscopy, have been used to test the applicability of the platform and for its validation with yeast, A549 human carcinoma lung cells and micropatterned gels as biological object phantoms.


Assuntos
Grafite , Elétrons , Humanos , Dispositivos Lab-On-A-Chip , Microscopia Eletrônica de Varredura , Espectroscopia de Infravermelho com Transformada de Fourier , Raios X
18.
Biomolecules ; 11(7)2021 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-34356599

RESUMO

Artemisia annua L. (AA) has shown for many centuries important therapeutic virtues associated with the presence of artemisinin (ART). The aim of this study was to identify and quantify ART and other secondary metabolites in ethanolic extracts of AA and evaluate the biological activity in the presence of an inflammatory stimulus. In this work, after the extraction of the aerial parts of AA with different concentrations of ethanol, ART was quantified by HPLC and HPLC-MS. In addition, anthocyanins, flavanols, flavanones, flavonols, lignans, low-molecular-weight phenolics, phenolic acids, stilbenes, and terpenes were identified and semi-quantitatively determined by UHPLC-QTOF-MS untargeted metabolomics. Finally, the viability of human neuroblastoma cells (SH-SY5Y) was evaluated in the presence of the different ethanolic extracts and in the presence of lipopolysaccharide (LPS). The results show that ART is more concentrated in AA samples extracted with 90% ethanol. Regarding the other metabolites, only the anthocyanins are more concentrated in the samples extracted with 90% ethanol. Finally, ART and all AA samples showed a protective action towards the pro-inflammatory stimulus of LPS. In particular, the anti-inflammatory effect of the leaf extract of AA with 90% ethanol was also confirmed at the molecular level since a reduction in TNF-α mRNA gene expression was observed in SH-SY5Y treated with LPS.


Assuntos
Anti-Inflamatórios , Artemisia annua/química , Etanol/química , Compostos Fitoquímicos , Extratos Vegetais/química , Folhas de Planta/química , Anti-Inflamatórios/química , Anti-Inflamatórios/isolamento & purificação , Anti-Inflamatórios/farmacologia , Linhagem Celular Tumoral , Humanos , Compostos Fitoquímicos/química , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia
19.
Nat Commun ; 12(1): 3996, 2021 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-34183682

RESUMO

Filamentous cable bacteria display long-range electron transport, generating electrical currents over centimeter distances through a highly ordered network of fibers embedded in their cell envelope. The conductivity of these periplasmic wires is exceptionally high for a biological material, but their chemical structure and underlying electron transport mechanism remain unresolved. Here, we combine high-resolution microscopy, spectroscopy, and chemical imaging on individual cable bacterium filaments to demonstrate that the periplasmic wires consist of a conductive protein core surrounded by an insulating protein shell layer. The core proteins contain a sulfur-ligated nickel cofactor, and conductivity decreases when nickel is oxidized or selectively removed. The involvement of nickel as the active metal in biological conduction is remarkable, and suggests a hitherto unknown form of electron transport that enables efficient conduction in centimeter-long protein structures.


Assuntos
Proteínas de Bactérias/química , Deltaproteobacteria/metabolismo , Condutividade Elétrica , Transporte de Elétrons/fisiologia , Níquel/química , Eletricidade
20.
Diagnostics (Basel) ; 11(4)2021 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-33923883

RESUMO

BACKGROUND: Increasing evidences support a correlation between magnesium (Mg) homeostasis and colorectal cancer (CRC). Nevertheless, the role of Mg and its transporters as diagnostic markers in CRC is still a matter of debate. In this study we combined X-ray Fluorescence Microscopy and databases information to investigate the possible correlation between Mg imbalance and CRC. METHODS: CRC tissue samples and their non-tumoural counterpart from four patients were collected and analysed for total Mg level and distribution by X-Ray Fluorescence Microscopy. We also reviewed the scientific literature and the main tissue expression databases to collect data on Mg transporters expression in CRC. RESULTS: We found a significantly higher content of total Mg in CRC samples when compared to non-tumoural tissues. Mg distribution was also impaired in CRC. Conversely, we evidenced an uncertain correlation between Mg transporters expression and colon malignancies. DISCUSSION: Although further studies are necessary to determine the correlation between different cancer types and stages, this is the first report proposing the measurement of Mg tissue localisation as a marker in CRC. This study represents thus a proof-of-concept that paves the way for the design of a larger prospective investigation of Mg in CRC.

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