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1.
Molecules ; 29(5)2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38474435

RESUMO

Cervical cancer was considered the fourth most common cancer worldwide in 2020. In order to reduce mortality, an early diagnosis of the tumor is required. Currently, this type of cancer occurs mostly in developing countries due to the lack of vaccination and screening against the Human Papillomavirus. Thus, there is an urgent clinical need for new methods aiming at a reliable screening and an early diagnosis of precancerous and cancerous cervical lesions. Vibrational spectroscopy has provided very good results regarding the diagnosis of various tumors, particularly using Fourier transform infrared microspectroscopy, which has proved to be a promising complement to the currently used histopathological methods of cancer diagnosis. This spectroscopic technique was applied to the analysis of cryopreserved human cervical tissue samples, both squamous cell carcinoma (SCC) and non-cancer samples. A dedicated Support Vector Machine classification model was constructed in order to categorize the samples into either normal or malignant and was subsequently validated by cross-validation, with an accuracy higher than 90%.


Assuntos
Carcinoma de Células Escamosas , Neoplasias do Colo do Útero , Feminino , Humanos , Carcinoma de Células Escamosas/patologia , Neoplasias do Colo do Útero/patologia , Espectroscopia de Infravermelho com Transformada de Fourier/métodos
2.
Cancer Cell Int ; 23(1): 310, 2023 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-38057765

RESUMO

This work compared the metabolic profile of a parental MDA-MB-231 cisplatin-sensitive triple negative breast cancer (TNBC) cell line with that of a derived cisplatin-resistant line, to characterize inherent metabolic adaptations to resistance, as a means for marker and new TNBC therapies discovery. Supported by cytotoxic, microscopic and biochemical characterization of both lines, Nuclear Magnetic Resonance (NMR) metabolomics was employed to characterize cell polar extracts for the two cell lines, as a function of time (0, 24 and 48 h), and identify statistically relevant differences both between sensitive and resistant cells and their time course behavior. Biochemical results revealed a slight increase in activation of the NF-κB pathway and a marked decrease of the ERK signaling pathway in resistant cells. This was accompanied by lower glycolytic and glutaminolytic activities, possibly linked to glutamine being required to increase stemness capacity and, hence, higher survival to cisplatin. The TCA cycle dynamics seemed to be time-dependent, with an apparent activation at 48 h preferentially supported by anaplerotic aromatic amino acids, leucine and lysine. A distinct behavior of leucine, compared to the other branched-chain-amino-acids, suggested the importance of the recognized relationship between leucine and in mTOR-mediated autophagy to increase resistance. Suggested markers of MDA-MB-231 TNBC cisplatin-resistance included higher phosphocreatine/creatine ratios, hypotaurine/taurine-mediated antioxidant protective mechanisms, a generalized marked depletion in nucleotides/nucleosides, and a distinctive pattern of choline compounds. Although the putative hypotheses generated here require biological demonstration, they pave the way to the use of metabolites as markers of cisplatin-resistance in TNBC and as guidance to develop therapies.

3.
Chemistry ; 29(53): e202301442, 2023 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-37606898

RESUMO

A new fluorinated manganese porphyrin, (Mn-TPP-p-CF3 ) is reported capable of providing, based on the Mn(III)/Mn(II) equilibrium, dual 1 H relaxivity and 19 F NMR response to redox changes. The physical-chemical characterization of both redox states in DMSO-d6 /H2 O evidenced that the 1 H relaxometric and 19 F NMR properties are appropriate for differential redox MRI detection. The Mn(III)-F distance (dMn-F =9.7-10 Å), as assessed by DFT calculations, is well tailored to allow for adequate paramagnetic effect of Mn(III) on 19 F T1 and T2 relaxation times. Mn-TPP-p-CF3 has a reversible Mn(II)/Mn(III) redox potential of 0.574 V vs. NHE in deoxygenated aqueous HEPES/ THF solution. The reduction of Mn(III)-TPP-p-CF3 in the presence of ascorbic acid is slowly, but fully reversed in the presence of air oxygen, as monitored by UV-Vis spectrometry and 19 F NMR. The broad 1 H and 19 F NMR signals of Mn(III)-TPP-p-CF3 disappear in the presence of 1 equivalent ascorbate replaced by a shifted and broadened 19 F NMR signal from Mn(II)-TPP-p-CF3 . Phantom 19 F MR images in DMSO show a MRI signal intensity decrease upon reduction of Mn(III)-TPP-p-CF3 , retrieved upon complete reoxidation in air within ~24 h. 1 H NMRD curves of the Mn(III)/(II)-TPP-p-CF3 chelates in mixed DMSO/water solvent have the typical shape of Mn(II)/Mn(III) porphyrins.

4.
J Immunol ; 207(1): 55-64, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-34135066

RESUMO

Effector CD4+ T lymphocytes contribute to inflammation and tissue damage in psoriasis, but the underlying molecular mechanisms remain poorly understood. The transcription factor CREMα controls effector T cell function in people with systemic autoimmune diseases. The inhibitory surface coreceptor PD-1 plays a key role in the control of effector T cell function and its therapeutic inhibition in patients with cancer can cause psoriasis. In this study, we show that CD4+ T cells from patients with psoriasis and psoriatic arthritis exhibit increased production of IL-17 but decreased expression of IL-2 and PD-1. In genetically modified mice and Jurkat T cells CREMα expression was linked to low PD-1 levels. We demonstrate that CREMα is recruited to the proximal promoter of PDCD1 in which it trans-represses gene expression and corecruits DNMT3a-mediating DNA methylation. As keratinocytes limit inflammation by PD-1 ligand expression and, in this study, reported reduced expression of PD-1 on CD4+ T cells is linked to low IL-2 and high IL-17A production, our studies reveal a molecular pathway in T cells from people with psoriasis that can deserve clinical exploitation.


Assuntos
Artrite Psoriásica/imunologia , Linfócitos T CD4-Positivos/imunologia , Modulador de Elemento de Resposta do AMP Cíclico/imunologia , Receptor de Morte Celular Programada 1/imunologia , Animais , Humanos , Camundongos , Camundongos Endogâmicos C57BL
5.
Int J Mol Sci ; 24(3)2023 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-36768221

RESUMO

Regarding the development of new antineoplastic agents, with a view to assess the selective antitumoral potential which aims at causing irreversible damage to cancer cells while preserving the integrity of their healthy counterparts, it is essential to evaluate the cytotoxic effects in both healthy and malignant human cell lines. In this study, a complex with two Pd(II) centers linked by the biogenic polyamine spermine (Pd2Spm) was tested on healthy (PNT-2) and cancer (LNCaP and PC-3) prostate human cell lines, using cisplatin as a reference. To understand the mechanisms of action of both cisplatin and Pd2Spm at a molecular level, Fourier Transform Infrared (FTIR) and Raman microspectroscopies were used. Principal component analysis was applied to the vibrational data, revealing the major metabolic changes caused by each drug, which were found to rely on DNA, lipids, and proteins, acting as biomarkers of drug impact. The main changes were observed between the B-DNA native conformation and either Z-DNA or A-DNA, with a higher effect on lipids having been detected in the presence of cisplatin as compared to Pd2Spm. In turn, the Pd-agent showed a more significant impact on proteins.


Assuntos
Antineoplásicos , Neoplasias da Próstata , Masculino , Humanos , Cisplatino/farmacologia , Antineoplásicos/farmacologia , Neoplasias da Próstata/tratamento farmacológico , Espermina/farmacologia , Espermina/metabolismo , Lipídeos , Espectroscopia de Infravermelho com Transformada de Fourier
6.
Int J Mol Sci ; 24(24)2023 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-38139388

RESUMO

This work investigated the mechanisms of action of conventional drugs, cisplatin and oxaliplatin, and the potentially less deleterious drug Pd2Spermine (Spm) and its Pt(II) analog, against osteosarcoma MG-63 cells, using nuclear-magnetic-resonance metabolomics of the cellular lipidome. The Pt(II) chelates induced different responses, namely regarding polyunsaturated-fatty-acids (increased upon cisplatin), suggesting that cisplatin-treated cells have higher membrane fluidity/permeability, thus facilitating cell entry and justifying higher cytotoxicity. Both conventional drugs significantly increased triglyceride levels, while Pt2Spm maintained control levels; this may reflect enhanced apoptotic behavior for conventional drugs, but not for Pt2Spm. Compared to Pt2Spm, the more cytotoxic Pd2Spm (IC50 comparable to cisplatin) induced a distinct phospholipids profile, possibly reflecting enhanced de novo biosynthesis to modulate membrane fluidity and drug-accessibility to cells, similarly to cisplatin. However, Pd2Spm differed from cisplatin in that cells had equivalent (low) levels of triglycerides as Pt2Spm, suggesting the absence/low extent of apoptosis. Our results suggest that Pd2Spm acts on MG-63 cells mainly through adaptation of cell membrane fluidity, whereas cisplatin seems to couple a similar effect with typical signs of apoptosis. These results were discussed in articulation with reported polar metabolome adaptations, building on the insight of these drugs' mechanisms, and particularly of Pd2Spm as a possible cisplatin substitute.


Assuntos
Antineoplásicos , Neoplasias Ósseas , Osteossarcoma , Humanos , Cisplatino/farmacologia , Cisplatino/uso terapêutico , Metabolismo dos Lipídeos , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Osteossarcoma/tratamento farmacológico , Osteossarcoma/metabolismo , Espermina/metabolismo , Apoptose , Neoplasias Ósseas/tratamento farmacológico , Linhagem Celular Tumoral
7.
Molecules ; 28(4)2023 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-36838683

RESUMO

A dinuclear Pt(II) complex with putrescine as bridging polyamine ligand ([Pt2Put2(NH3)4]Cl4) was synthesized and assessed as to its potential anticancer activity against a human non-small cell lung cancer line (A549), as well as towards non-cancer cells (BEAS-2B). This effect was evaluated through in vitro cytotoxicity assays (MTT and SRB) coupled to microFTIR and microRaman spectroscopies, the former delivering information on growth-inhibiting and cytotoxic abilities while the latter provided very specific information on the metabolic impact of the metal agent (at the sub-cellular level). Regarding cancer cells, a major impact of [Pt2Put2(NH3)4]Cl4 was evidenced on cellular proteins and lipids, as compared to DNA, particularly via the Amide I and Amide II signals. The effect of the chelate on non-malignant cells was lower than on malignant ones, evidencing a promising low toxicity towards healthy cells.


Assuntos
Antineoplásicos , Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Platina/farmacologia , Linhagem Celular Tumoral , Antineoplásicos/farmacologia
8.
Analyst ; 147(21): 4919-4932, 2022 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-36190368

RESUMO

Breast cancer is a type of cancer with the highest incidence worldwide in 2021, with early diagnosis and rapid treatment intervention being the reasons for the decreasing mortality rate associated with the disease. The major challenge faced by clinicians and pathologists is the lack of accuracy in the histopathological analysis of biopsy or resection samples, leading to classification misdiagnosis and compromising the prognosis of patients. Spectral histopathology has provided great advances regarding cancer diagnosis, especially through the use of FTIR spectroscopy, proving to be a valuable complement to histopathological analyses. In this study unstained formalin-fixed paraffin embedded breast cancer tissue samples, collected from patients undergoing surgery and mounted on glass slides, were probed through FTIR and Raman microspectrocopy. Two classification models were constructed using the AdaBoost algorithm, both achieving >90% accuracy and successfully discriminating invasive breast carcinoma from surrounding normal tissue. Chemical maps from the interfaces of invasive breast carcinoma-surrounding normal tissue were also generated. This study showed the potential of spectral histopathology, in particular FTIR, for daily use in pathology laboratories, introducing few disruptions to the routine workflow while increasing the sensitivity, specificity and accuracy of the diagnoses.


Assuntos
Neoplasias da Mama , Humanos , Feminino , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/patologia , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Formaldeído/química , Análise Espectral Raman/métodos
9.
Int J Mol Sci ; 23(22)2022 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-36430252

RESUMO

Cisplatin (cDDP)-based chemotherapy is often limited by severe deleterious effects (nephrotoxicity, hepatotoxicity and neurotoxicity). The polynuclear palladium(II) compound Pd2Spermine (Pd2Spm) has emerged as a potential alternative drug, with favorable pharmacokinetic/pharmacodynamic properties. This paper reports on a Nuclear Magnetic Resonance metabolomics study to (i) characterize the response of mice brain and liver to Pd2Spm, compared to cDDP, and (ii) correlate brain-liver metabolic variations. Multivariate and correlation analysis of the spectra of polar and lipophilic brain and liver extracts from an MDA-MB-231 cell-derived mouse model revealed a stronger impact of Pd2Spm on brain metabolome, compared to cDDP. This was expressed by changes in amino acids, inosine, cholate, pantothenate, fatty acids, phospholipids, among other compounds. Liver was less affected than brain, with cDDP inducing more metabolite changes. Results suggest that neither drug induces neuronal damage or inflammation, and that Pd2Spm seems to lead to enhanced brain anti-inflammatory and antioxidant mechanisms, regulation of brain bioactive metabolite pools and adaptability of cell membrane characteristics. The cDDP appears to induce higher extension of liver damage and an enhanced need for liver regeneration processes. This work demonstrates the usefulness of untargeted metabolomics in evaluating drug impact on multiple organs, while confirming Pd2Spm as a promising replacement of cDDP.


Assuntos
Metabolômica , Espermina , Animais , Camundongos , Encéfalo , Fígado , Cisplatino/farmacologia , Espectroscopia de Ressonância Magnética
10.
Int J Mol Sci ; 22(19)2021 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-34639114

RESUMO

The interest in palladium(II) compounds as potential new anticancer drugs has increased in recent years, due to their high toxicity and acquired resistance to platinum(II)-derived agents, namely cisplatin. In fact, palladium complexes with biogenic polyamines (e.g., spermine, Pd2Spm) have been known to display favorable antineoplastic properties against distinct human breast cancer cell lines. This study describes the in vivo response of triple-negative breast cancer (TNBC) tumors to the Pd2Spm complex or to cisplatin (reference drug), compared to tumors in vehicle-treated mice. Both polar and lipophilic extracts of tumors, excised from a MDA-MB-231 cell-derived xenograft mouse model, were characterized through nuclear magnetic resonance (NMR) metabolomics. Interestingly, the results show that polar and lipophilic metabolomes clearly exhibit distinct responses for each drug, with polar metabolites showing a stronger impact of the Pd(II)-complex compared to cisplatin, whereas neither drug was observed to significantly affect tumor lipophilic metabolism. Compared to cisplatin, exposure to Pd2Spm triggered a higher number of, and more marked, variations in some amino acids, nucleotides and derivatives, membrane precursors (choline and phosphoethanolamine), dimethylamine, fumarate and guanidine acetate, a signature that may be relatable to the cytotoxicity and/or mechanism of action of the palladium complex. Putative explanatory biochemical hypotheses are advanced on the role of the new Pd2Spm complex in TNBC metabolism.


Assuntos
Antineoplásicos/farmacologia , Metaboloma/efeitos dos fármacos , Paládio/química , Espermina/farmacologia , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Animais , Apoptose , Proliferação de Células , Cisplatino/farmacologia , Feminino , Humanos , Camundongos , Camundongos Nus , Neoplasias de Mama Triplo Negativas/metabolismo , Neoplasias de Mama Triplo Negativas/patologia , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
11.
Molecules ; 26(16)2021 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-34443394

RESUMO

This paper reports the first metabolomics study of the impact of new chelates Pt2Spm and Pd2Spm (Spm = Spermine) on human osteosarcoma cellular metabolism, compared to the conventional platinum drugs cisplatin and oxaliplatin, in order to investigate the effects of different metal centers and ligands. Nuclear Magnetic Resonance metabolomics was used to identify meaningful metabolite variations in polar cell extracts collected during exposure to each of the four chelates. Cisplatin and oxaliplatin induced similar metabolic fingerprints of changing metabolite levels (affecting many amino acids, organic acids, nucleotides, choline compounds and other compounds), thus suggesting similar mechanisms of action. For these platinum drugs, a consistent uptake of amino acids is noted, along with an increase in nucleotides and derivatives, namely involved in glycosylation pathways. The Spm chelates elicit a markedly distinct metabolic signature, where inverse features are observed particularly for amino acids and nucleotides. Furthermore, Pd2Spm prompts a weaker response from osteosarcoma cells as compared to its platinum analogue, which is interesting as the palladium chelate exhibits higher cytotoxicity. Putative suggestions are discussed as to the affected cellular pathways and the origins of the distinct responses. This work demonstrates the value of untargeted metabolomics in measuring the response of cancer cells to either conventional or potential new drugs, seeking further understanding (or possible markers) of drug performance at the molecular level.


Assuntos
Antineoplásicos/farmacologia , Quelantes/farmacologia , Desenho de Fármacos , Osteossarcoma/patologia , Paládio/química , Platina/química , Antineoplásicos/química , Linhagem Celular Tumoral , Quelantes/química , Humanos
12.
Molecules ; 25(2)2020 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-31936161

RESUMO

The mode of action of Pt- and Pd-based anticancer agents (cisplatin and Pd2Spm) was studied by characterising their impact on DNA. Changes in conformation and mobility at the molecular level in hydrated DNA were analysed by quasi-elastic and inelastic neutron scattering techniques (QENS and INS), coupled to Fourier transform infrared (FTIR) and microRaman spectroscopies. Although INS, FTIR and Raman revealed drug-triggered changes in the phosphate groups and the double helix base pairing, QENS allowed access to the nanosecond motions of the biomolecule's backbone and confined hydration water within the minor groove. Distinct effects were observed for cisplatin and Pd2Spm, the former having a predominant effect on DNA´s spine of hydration, whereas the latter had a higher influence on the backbone dynamics. This is an innovative way of tackling a drug´s mode of action, mediated by the hydration waters within its pharmacological target (DNA).


Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Cisplatino/química , Cisplatino/farmacologia , DNA/química , DNA/efeitos dos fármacos , Elasticidade/efeitos dos fármacos , Metais/química , Metais/farmacologia , Difração de Nêutrons , Nêutrons , Conformação de Ácido Nucleico/efeitos dos fármacos , Paládio/química , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral Raman , Espermina/química , Água/química
13.
Phys Chem Chem Phys ; 21(8): 4162-4175, 2019 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-30656331

RESUMO

Complementary structural and dynamical information on drug-DNA interplay has been achieved at a molecular level, for Pt/Pd-drugs, allowing a better understanding of their pharmacodynamic profile which is crucial for the development of improved chemotherapeutic agents. The interaction of two cisplatin-like dinuclear Pt(ii) and Pd(ii) complexes with DNA was studied through a multidisciplinary experimental approach, using quasi-elastic neutron scattering (QENS) techniques coupled with synchrotron-based extended X-ray absorption fine structure (SR-EXAFS) and Fourier-Transform Infrared Spectroscopy-Attenuated Total Reflectance (SR-FTIR-ATR). DNA extracted from drug-exposed human triple negative breast cancer cells (MDA-MB-231) was used, with a view to evaluate the effect of the unconventional antineoplastic agents on this low prognosis type of cancer. The drug impact on DNA's dynamical profile, via its hydration layer, was provided by QENS, a drug-triggered enhanced mobility having been revealed. Additionally, an onset of anharmonicity was detected for dehydrated DNA, at room temperature. Far- and mid-infrared measurements allowed the first simultaneous detection of the drugs and their primary pharmacological target, as well as the drug-prompted changes in DNA's conformation that mediate cytotoxicity. The local environment of the absorbing Pd(ii) and Pt(ii) centers in the drugs' adducts with adenine, guanine and glutathione was attained by EXAFS.


Assuntos
Antineoplásicos/química , DNA/química , Paládio/química , Compostos de Platina/química , Adenina/química , Linhagem Celular Tumoral , Glutationa/química , Guanina/química , Humanos , Nêutrons , Conformação de Ácido Nucleico , Espectroscopia de Infravermelho com Transformada de Fourier , Síncrotrons , Espectroscopia por Absorção de Raios X
14.
Biochem Soc Trans ; 46(5): 1021-1027, 2018 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-30154095

RESUMO

As part of their life cycle, Gram-negative bacteria produce and release microvesicles (outer membrane vesicles, OMVs) consisting of spherical protrusions of the outer membrane that encapsulate periplasmic contents. OMVs produced by commensal bacteria in the gastrointestinal (GI) tract of animals are dispersed within the gut lumen with their cargo and enzymes being distributed across and throughout the GI tract. Their ultimate destination and fate is unclear although they can interact with and cross the intestinal epithelium using different entry pathways and access underlying immune cells in the lamina propria. OMVs have also been found in the bloodstream from which they can access various tissues and possibly the brain. The nanosize and non-replicative status of OMVs together with their resistance to enzyme degradation and low pH, alongside their ability to interact with the host, make them ideal candidates for delivering biologics to mucosal sites, such as the GI and the respiratory tract. In this mini-review, we discuss the fate of OMVs produced in the GI tract of animals with a focus on vesicles released by Bacteroides species and the use of OMVs as vaccine delivery vehicles and other potential applications.


Assuntos
Proteínas da Membrana Bacteriana Externa/fisiologia , Microbioma Gastrointestinal , Bactérias Gram-Negativas/fisiologia , Vesículas Secretórias/fisiologia , Animais , Bacteroides , Encéfalo/microbiologia , Células Epiteliais/microbiologia , Trato Gastrointestinal/fisiologia , Interações Hospedeiro-Patógeno , Humanos , Sistema Imunitário , Mucosa Intestinal/microbiologia
15.
Adv Exp Med Biol ; 1059: 189-205, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29736574

RESUMO

The osteochondral defect (OD) comprises the articular cartilage and its subchondral bone. The treatment of these lesions remains as one of the most problematic clinical issues, since these defects include different tissues, requiring distinct healing approaches. Among the growing applications of regenerative medicine, clinical articular cartilage repair has been used for two decades, and it is an effective example of translational medicine; one of the most used cell-based repair strategies includes implantation of autologous cells in degradable scaffolds such as alginate, agarose, collagen, chitosan, chondroitin sulfate, cellulose, silk fibroin, hyaluronic acid, and gelatin, among others. Concerning the repair of osteochondral defects, tissue engineering and regenerative medicine started to design single- or bi-phased scaffold constructs, often containing hydroxyapatite-collagen composites, usually used as a bone substitute. Biomolecules such as natural and synthetic have been explored to recreate the cartilage-bone interface through multilayered biomimetic scaffolds. In this chapter, a succinct description about the most relevant natural and synthetic biomolecules used on cartilage and bone repair, describing the procedures to obtain these biomolecules, their chemical structure, common modifications to improve its characteristics, and also their application in the biomedical fields, is given.


Assuntos
Materiais Biocompatíveis/uso terapêutico , Fatores Biológicos/uso terapêutico , Produtos Biológicos/uso terapêutico , Materiais Biomiméticos/uso terapêutico , Doenças Ósseas/terapia , Doenças das Cartilagens/terapia , Medicina Regenerativa/métodos , Engenharia Tecidual/métodos , Animais , Terapia Biológica/métodos , Configuração de Carboidratos , Cartilagem Articular/lesões , Previsões , Humanos , Polímeros/síntese química , Polímeros/uso terapêutico , Polissacarídeos/uso terapêutico , Seda/uso terapêutico , Terapias em Estudo , Alicerces Teciduais
16.
Molecules ; 24(1)2018 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-30586854

RESUMO

In the present study, we developed a green epoxidation approach for the synthesis of the diastereomers of (-)-isopulegol benzyl ether epoxide using molecular oxygen as the oxidant and a hybrid manganese(III)-porphyrin magnetic reusable nanocomposite as the catalyst. High activity, selectivity, and stability were obtained, with up to four recycling cycles without the loss of activity and selectivity for epoxide. The anticancer effect of the newly synthesized isopulegol epoxide diastereomers was evaluated on a human osteosarcoma cell line (MG-63); both diastereomers showed similar in vitro potency. The measured IC50 values were significantly lower than those reported for other monoterpene analogues, rendering these epoxide isomers as promising anti-tumor agents against low prognosis osteosarcoma.


Assuntos
Antineoplásicos/farmacologia , Biomimética , Fenômenos Magnéticos , Metaloporfirinas/química , Nanocompostos/química , Osteossarcoma/patologia , Antineoplásicos/síntese química , Antineoplásicos/química , Varredura Diferencial de Calorimetria , Catálise , Linhagem Celular Tumoral , Monoterpenos Cicloexânicos , Compostos de Epóxi/síntese química , Compostos de Epóxi/química , Humanos , Manganês/química , Nanocompostos/ultraestrutura , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Estereoisomerismo , Terpenos/síntese química , Terpenos/química , Terpenos/farmacologia , Termogravimetria
17.
Adv Funct Mater ; 27(27)2017 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-28747856

RESUMO

The cooperative assembly of biopolymers and small molecules can yield functional materials with precisely tunable properties. Here, the fabrication, characterization, and use of multicomponent hybrid gels as selective gas sensors are reported. The gels are composed of liquid crystal droplets self-assembled in the presence of ionic liquids, which further coassemble with biopolymers to form stable matrices. Each individual component can be varied and acts cooperatively to tune gels' structure and function. The unique molecular environment in hybrid gels is explored for supramolecular recognition of volatile compounds. Gels with distinct compositions are used as optical and electrical gas sensors, yielding a combinatorial response conceptually mimicking olfactory biological systems, and tested to distinguish volatile organic compounds and to quantify ethanol in automotive fuel. The gel response is rapid, reversible, and reproducible. These robust, versatile, modular, pliant electro-optical soft materials possess new possibilities in sensing triggered by chemical and physical stimuli.

18.
J Oral Pathol Med ; 43(7): 499-506, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24527751

RESUMO

BACKGROUND: CD44 and aldehyde dehydrogenase 1 (ALDH1) are considered putative markers of highly tumorigenic cells (i.e., cancer stem-like cells) in head and neck squamous cell carcinomas. This small subset of cells is believed to be the primary responsible for tumor initiation and progression. The objectives of this study were (i) to evaluate the patterns of CD44 and ALDH1 expression in the tumor center and in the invasive front, as well as in adjacent non-tumor epithelium, and (ii) to correlate these findings with clinical parameters. MATERIALS AND METHODS: The sample comprised 44 patients with primary head and neck squamous cell carcinomas. Hematoxylin and eosin (HE) staining was used for histopathological tumor grading and for morphological analysis of adjacent non-tumor epithelium. Semiquantitative analysis was performed in histological sections immunostained for CD44 and ALDH1. RESULTS: ALDH1 immunostaining in the invasive front showed positive association with tumor size, regional metastasis, tumor histopathological grading, and disease progression. Moreover, expression of this marker in both tumor invasive front and adjacent non-tumor epithelium was related with more aggressive tumors. CD44 immunostaining was heterogeneous in all areas evaluated and did not show association with clinical data. CONCLUSION: Collectively, these data suggest that ALDH1 immunostaining in the invasive front and in adjacent non-tumor epithelium may help identify tumors with a more aggressive behavior, potentially contributing to improving treatment customization and the monitoring of patients with head and neck cancer.


Assuntos
Carcinoma de Células Escamosas/patologia , Neoplasias de Cabeça e Pescoço/patologia , Células-Tronco Neoplásicas/patologia , Adulto , Idoso , Família Aldeído Desidrogenase 1 , Biomarcadores Tumorais/análise , Carcinoma de Células Escamosas/secundário , Progressão da Doença , Intervalo Livre de Doença , Epitélio/patologia , Feminino , Seguimentos , Humanos , Receptores de Hialuronatos/análise , Hiperplasia , Isoenzimas/análise , Masculino , Pessoa de Meia-Idade , Neoplasias Bucais/patologia , Gradação de Tumores , Invasividade Neoplásica , Estadiamento de Neoplasias , Lesões Pré-Cancerosas/patologia , Retinal Desidrogenase/análise , Taxa de Sobrevida , Resultado do Tratamento
19.
Biochem J ; 451(2): 289-300, 2013 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-23356867

RESUMO

Non-catalytic cellulosomal CBMs (carbohydrate-binding modules) are responsible for increasing the catalytic efficiency of cellulosic enzymes by selectively putting the substrate (a wide range of poly- and oligo-saccharides) and enzyme into close contact. In the present study we carried out an atomistic rationalization of the molecular determinants of ligand specificity for a family 11 CBM from thermophilic Clostridium thermocellum [CtCBM11 (C. thermocellum CBM11)], based on a NMR and molecular modelling approach. We have determined the NMR solution structure of CtCBM11 at 25°C and 50°C and derived information on the residues of the protein that are involved in ligand recognition and on the influence of the length of the saccharide chain on binding. We obtained models of the CtCBM11-cellohexaose and CtCBM11-cellotetraose complexes by docking in accordance with the NMR experimental data. Specific ligand-protein CH-π and Van der Waals interactions were found to be determinant for the stability of the complexes and for defining specificity. Using the order parameters derived from backbone dynamics analysis in the presence and absence of ligand and at 25°C and 50°C, we determined that the protein's backbone conformational entropy is slightly positive. This data in combination with the negative binding entropy calculated from ITC (isothermal titration calorimetry) studies supports a selection mechanism where a rigid protein selects a defined oligosaccharide conformation.


Assuntos
Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Metabolismo dos Carboidratos , Clostridium thermocellum/metabolismo , Oligossacarídeos/química , Proteínas de Bactérias/genética , Sítios de Ligação , Calorimetria , Celulose/análogos & derivados , Celulose/química , Celulose/metabolismo , Entropia , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Oligossacarídeos/metabolismo , Conformação Proteica , Tetroses/química , Tetroses/metabolismo
20.
Spectrochim Acta A Mol Biomol Spectrosc ; 317: 124389, 2024 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-38710137

RESUMO

Over the years, osteosarcoma therapy has had a significative improvement with the use of a multidrug regime strategy, increasing the survival rates from less than 20 % to circa 70 %. Different types of development of new antineoplastic agents are critical to achieve irreversible damage to cancer cells, while preserving the integrity of their healthy counterparts. In the present study, complexes with two and three Pd(II) centres linked by the biogenic polyamines: spermine (Pd2SpmCl4) and spermidine (Pd3Spd2Cl6) were tested against non-malignant (osteoblasts, HOb) and cancer (osteosarcoma, MG-63) human cell lines. Either alone or in combination according to the EURAMOS-1 protocol, they were used versus cisplatin as a drug reference. By evaluating the cytotoxic effects of both therapeutic approaches (single and drug combination) in HOb and MG-63 cell lines, the selective anti-tumoral potential is assessed. To understand the different treatments at a molecular level, Synchrotron Radiation Fourier Transform Infrared and Raman microspectroscopies were applied. Principal component analysis and hierarchical cluster analysis are applied to the vibrational data, revealing the major metabolic changes caused by each drug, which were found to rely on DNA, lipids, and proteins, acting as biomarkers of drug-to-cell impact. The main changes were observed for the B-DNA native conformation to either Z-DNA (higher in the presence of polynuclear complexes) or A-DNA (preferably after cisplatin exposure). Additionally, a higher effect upon variation in proteins content was detected in drug combination when compared to single drug administration proving the efficacy of the EURAMOS-1 protocol with the new drugs tested.


Assuntos
Antineoplásicos , Osteossarcoma , Análise Espectral Raman , Humanos , Osteossarcoma/tratamento farmacológico , Osteossarcoma/patologia , Osteossarcoma/metabolismo , Análise Espectral Raman/métodos , Antineoplásicos/farmacologia , Antineoplásicos/química , Linhagem Celular Tumoral , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Vibração , Espermina/farmacologia , Espermina/química , Neoplasias Ósseas/tratamento farmacológico , Neoplasias Ósseas/patologia , Neoplasias Ósseas/metabolismo , Espermidina/farmacologia , Espermidina/química , Análise de Componente Principal , Sobrevivência Celular/efeitos dos fármacos
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