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1.
J Biomed Mater Res A ; 112(5): 754-769, 2024 05.
Artigo em Inglês | MEDLINE | ID: mdl-38084898

RESUMO

The therapeutic effectiveness of anticancer drugs, including nanomedicines, can be enhanced with active receptor-targeting strategies. Epidermal growth factor receptor (EGFR) is an important cancer biomarker, constitutively expressed in sarcoma patients of different histological types. The present work reports materials and in vitro biomedical analyses of silanized (passive delivery) and/or EGF-functionalized (active delivery) ceria nanorods exhibiting highly defective catalytically active surfaces. The EGFR-targeting efficiency of nanoceria was confirmed by receptor-binding studies. Increased cytotoxicity and reactive oxygen species (ROS) production were observed for EGF-functionalized nanoceria owing to enhanced cellular uptake by HT-1080 fibrosarcoma cells. The uptake was confirmed by TEM and confocal microscopy. Silanized nanoceria demonstrated negligible/minimal cytotoxicity toward healthy MRC-5 cells at 24 and 48 h, whereas this was significant at 72 h owing to a nanoceria accumulation effect. In contrast, considerable cytotoxicity toward the cancer cells was exhibited at all three times points. The ROS generation and associated cytotoxicity were moderated by the equilibrium between catalysis by ceria, generation of cell debris, and blockage of active sites. EGFR-targeting is shown to enhance the uptake levels of nanoceria by cancer cells, subsequently enhancing the overall anticancer activity and therapeutic performance of ceria.


Assuntos
Cério , Nanopartículas , Humanos , Espécies Reativas de Oxigênio/metabolismo , Fator de Crescimento Epidérmico , Nanopartículas/química , Receptores ErbB , Cério/farmacologia , Cério/química
2.
Drug Discov Today ; 27(12): 103386, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36182068

RESUMO

Inorganic nanoparticles for drug delivery in cancer treatment offer many potential advantages because they can maximize therapeutic effect through targeting ligands while minimizing off-target side-effects through drug adsorption and infiltration. Although inorganic nanoparticles were introduced as drug carriers, they have emerged as having the capacity for combined therapeutic capabilities, including anticancer effects through cytotoxicity, suppression of oncogenes and cancer cell signaling pathway inhibition. The most promising advanced strategies for cancer therapy are as synergistic platforms for RNA interference (siRNA, miRNA, shRNA) and as synergistic drug delivery agents for the inhibition of cancer cell signaling pathways. The present work summarizes relevant current work, the promise of which is suggested by a projected compound annual growth rate of âˆ¼ 20% for drug delivery alone.


Assuntos
Nanopartículas , Neoplasias , Humanos , Portadores de Fármacos/uso terapêutico , Sistemas de Liberação de Medicamentos , RNA Interferente Pequeno , Neoplasias/tratamento farmacológico
3.
Biomater Sci ; 10(14): 3671-3694, 2022 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-35686620

RESUMO

Cerium-based nanoparticles (CeNPs), particularly cerium oxide (CeO2), have been studied extensively for their antioxidant and prooxidant properties. However, their complete redox and enzyme-mimetic mechanisms of therapeutic action at the molecular level remain elusive, constraining their potential for clinical translation. Although the therapeutic effects of both antioxidant and prooxidant mechanisms generally are attributed to Ce3+ ↔ Ce4+ redox switching mediation, some studies have hinted at the involvement of unknown pathways in therapeutic effects. While redox switching is recognised increasingly as playing a key role in ROS-dependent cancer therapy, ROS-independent cytotoxicity mechanisms, such as Ce4+ dissolution and autophagy, also are emerging as being of importance. Although ROS-mediated prooxidant therapies are the most intensively studied, particularly in the context of cancer, the antioxidant activity deriving from the redox switching, particularly during radiation therapy, also plays an important role in the protection of normal cells during radiation therapy, hence reducing adverse effects. Since cancer cell proliferation results in aberrant behaviour of the tumour microenvironment (TME), then CeNP-based therapies are being used to address a multiplicity of known and unknown factors that aim to normalise the TME and thus prevent this aberrant behaviour. Although it is perceived that the pH plays a key role in the therapeutic performance of cerium-based nanoparticles, this is not conclusive because the relative importances of other factors, particularly Ce dissolution, Ce3+/Ce4+ ratio, cellular H2O2 level, and the role of anions, remain poorly understood. Consequently, the present work explores these multiple chemistry-driven mechanisms, which are both ROS-dependent and ROS-independent, in cancer therapy.


Assuntos
Cério , Nanopartículas , Antioxidantes/química , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Cério/química , Peróxido de Hidrogênio , Nanopartículas/química , Espécies Reativas de Oxigênio/metabolismo
5.
J Clin Oncol ; 40(15): 1681-1692, 2022 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-35263150

RESUMO

PURPOSE: To ascertain if preoperative short-term radiotherapy followed by chemotherapy is not inferior to a standard schedule of long-term chemoradiotherapy in patients with locally advanced rectal cancer. MATERIALS AND METHODS: Patients with distal or middle-third, clinical primary tumor stage 3-4 and/or regional lymph node-positive rectal cancer were randomly assigned (1:1) to short-term radiotherapy (25 Gy in five fractions over 1 week) followed by four cycles of chemotherapy (total neoadjuvant therapy [TNT]) or chemoradiotherapy (50 Gy in 25 fractions over 5 weeks, concurrently with capecitabine [chemoradiotherapy; CRT]). Total mesorectal excision was undertaken 6-8 weeks after preoperative treatment, with two additional cycles of CAPOX (intravenous oxaliplatin [130 mg/m2, once a day] on day 1 and capecitabine [1,000 mg/m2, twice a day] from days 1 to 14) in the TNT group and six cycles of CAPOX in the CRT group. The primary end point was 3-year disease-free survival (DFS). RESULTS: Between August 2015 and August 2018, a total of 599 patients were randomly assigned to receive TNT (n = 302) or CRT (n = 297). At a median follow-up of 35.0 months, 3-year DFS was 64.5% and 62.3% in TNT and CRT groups, respectively (hazard ratio, 0.883; one-sided 95% CI, not applicable to 1.11; P < .001 for noninferiority). There was no significant difference in metastasis-free survival or locoregional recurrence, but the TNT group had better 3-year overall survival than the CRT group (86.5% v 75.1%; P = .033). Treatment effects on DFS and overall survival were similar regardless of prognostic factors. The prevalence of acute grade III-V toxicities during preoperative treatment was 26.5% in the TNT group versus 12.6% in the CRT group (P < .001). CONCLUSION: Short-term radiotherapy with preoperative chemotherapy followed by surgery was efficacious with acceptable toxicity and could be used as an alternative to CRT for locally advanced rectal cancer.


Assuntos
Segunda Neoplasia Primária , Neoplasias Retais , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Capecitabina/uso terapêutico , Quimiorradioterapia/efeitos adversos , Fluoruracila/uso terapêutico , Humanos , Terapia Neoadjuvante/efeitos adversos , Recidiva Local de Neoplasia/patologia , Estadiamento de Neoplasias , Segunda Neoplasia Primária/patologia , Neoplasias Retais/patologia
6.
Molecules ; 27(3)2022 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-35164276

RESUMO

A series of new thiazole-based stilbene analogs were designed, synthesized and evaluated for DNA topoisomerase IB (Top1) inhibitory activity. Top1-mediated relaxation assays showed that the synthesized compounds possessed variable Top1 inhibitory activity. Among them, (E)-2-(3-methylstyryl)-4-(4-fluorophenyl)thiazole (8) acted as a potent Top1 inhibitor with high Top1 inhibition of ++++ which is comparable to that of CPT. A possible binding mode of compound 8 with Top1-DNA complex was further provided by molecular docking. An MTT assay against human breast cancer (MCF-7) and human colon cancer (HCT116) cell lines revealed that the majority of these compounds showed high cytotoxicity, with IC50 values at micromolar concentrations. Compounds 8 and (E)-2-(4-tert-butylstyryl)-4-(4-fluorophenyl)thiazole (11) exhibited the most potent cytotoxicity with IC50 values of 0.78 and 0.62 µM against MCF-7 and HCT116, respectively. Moreover, the preliminary structure-activity relationships of thiazole-based stilbene analogs was also discussed.


Assuntos
Antineoplásicos/química , Estilbenos/química , Tiazóis/química , Inibidores da Topoisomerase/química , Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Desenho de Fármacos , Células HCT116 , Humanos , Células MCF-7 , Simulação de Acoplamento Molecular , Neoplasias/tratamento farmacológico , Estilbenos/síntese química , Estilbenos/farmacologia , Tiazóis/síntese química , Tiazóis/farmacologia , Inibidores da Topoisomerase/síntese química , Inibidores da Topoisomerase/farmacologia
7.
Gastrointest Endosc ; 96(1): 140-147, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35065045

RESUMO

BACKGROUND AND AIMS: Effective countertraction is a main challenging issue in endoscopic submucosal dissection (ESD). Several countertraction methods have been developed to address this issue. The aim of this study was to compare the efficacy of ESD using a novel simplified robot, the flexible auxiliary single-arm transluminal endoscopic robot (FASTER), with a traditional technique. METHODS: This was a prospective, randomized animal study. Forty-eight ESDs in 6 pigs were carried out at 8 different locations (gastric antrum, gastric body, lower esophagus, and middle esophagus) by the conventional method (n = 24) and by the FASTER-assisted method (n = 24). The primary outcomes were total procedure time, dissection time, and rate of direct-vision dissection. Secondary endpoints were completeness of en-bloc resection and adverse event rate. RESULTS: The total procedure time was significantly shorter in FASTER-assisted ESD than in conventional ESD (18.8 vs 32.8 minutes; P < .001). In contrast to the median direct-vision dissection rate of 73% with conventional ESD, the FASTER-assisted group had a significantly higher rate of 96% (P < .001). The number of sites of muscular damage was significantly lower using the FASTER-assisted method than the conventional method (6 vs 21, respectively; P = .018). This improvement was more apparent in esophageal lesions compared with gastric lesions. CONCLUSIONS: This study demonstrated that using a simplified robot during ESD is technically feasible and enables the endoscopist to dynamically use countertraction. This device could significantly reduce procedure time compared with conventional ESD techniques.


Assuntos
Ressecção Endoscópica de Mucosa , Robótica , Gastropatias , Animais , Dissecação/métodos , Ressecção Endoscópica de Mucosa/métodos , Esôfago/cirurgia , Humanos , Estudos Prospectivos , Suínos , Resultado do Tratamento
8.
Angew Chem Int Ed Engl ; 60(51): 26837-26846, 2021 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-34636126

RESUMO

Although ether-based electrolytes have been extensively applied in anode evaluation of batteries, anodic instability arising from solvent oxidability is always a tremendous obstacle to matching with high-voltage cathodes. Herein, by rational design for solvation configuration, the fully coordinated ether-based electrolyte with strong resistance against oxidation is reported, which remains anodically stable with high-voltage Na3 V2 (PO4 )2 O2 F (NVPF) cathode under 4.5 V (versus Na+ /Na) protected by an effective interphase. The assembled graphite//NVPF full cells display superior rate performance and unprecedented cycling stability. Beyond that, the constructed full cells coupling the high-voltage NVPF cathode with hard carbon anode exhibit outstanding electrochemical performances in terms of high average output voltage up to 3.72 V, long-term cycle life (such as 95 % capacity retention after 700 cycles) and high energy density (247 Wh kg-1 ). In short, the optimized ether-based electrolyte enriches systematic options, the ability to maintain oxidative stability and compatibility with various anodes, exhibiting attractive prospects for application.

9.
Mater Sci Eng C Mater Biol Appl ; 120: 111663, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33545829

RESUMO

The application of nanoparticulate therapies for cancer depends largely on the uptake and redox activity of the particles. The present work reports the fabrication of different morphologies of nanoceria (CeO2-x) as nanooctahedra (NO), nanorods (NR), and nanocubes (NC) by hydrothermal synthesis at different temperatures (100 °C, 180 °C) of solutions of 0.05 M Ce(NO3)3·6H2O and different concentrations of NaOH (0.01 M, 6.00 M). The characteristics of these nanomorphologies are compared in terms of the crystallinity (XRD), grain size (TEM), surface area (BET), tendency to agglomerate, and the oxygen vacancy concentration ([VO••]) as reflected by the [Ce3+]/[Ce4+] ratio (XPS). The effects of these parameters on the potential cellular uptake are canvassed, suggesting that the nonpolarity of the {111} planes of NO and NR facilitate the preferential uptake of these nanomorphologies. These experimental variables then were normalized through the use of NC as a model substrate for the functionalization using gum arabic (GA) and collagen in order to assess their roles in enhancing redox activity. Both the unfunctionalized and functionalized NC were noncytotoxic in in vitro tests with Kuramochi ovarian cancer cells. However, the antioxidant behavior of the collagen-functionalized NC was superior to that of the unfunctionalized NC, which was superior to that of the controls. These results demonstrate that, while the intrinsic VO•• of CeO2-x enhance the destruction of reactive oxygen species (ROS), functionalization by gum arabic and collagen crosslinking as extrinsic additions to the system enhances ROS destruction to an even greater extent. The antioxidant behavior and potential to neutralize superoxide and hydroxyl radicals of these materials offers new potential for the improvement of nanoparticulate cancer therapies.


Assuntos
Cério , Nanopartículas , Neoplasias , Colágeno , Neoplasias/tratamento farmacológico , Oxirredução
10.
Commun Biol ; 3(1): 341, 2020 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-32620903

RESUMO

Malignant melanoma displays a high degree of cellular plasticity during disease progression. Signals in the tumor microenvironment are believed to influence melanoma plasticity through changes in the epigenetic state to guide dynamic differentiation and de-differentiation. Here we uncover a relationship between geometric features at perimeter regions of melanoma aggregates, and reprogramming to a stem cell-like state through histone marks H3K4Me2 and H3K9Ac. Using an in vitro tumor microengineering approach, we find spatial enrichment of these histone modifications with concurrent expression of stemness markers. The epigenetic modifier PRDM14 overlaps with H3K9Ac and shows elevated expression in cells along regions of perimeter curvature. siRNA knockdown of PRDM14 abolishes the MIC phenotype suggesting a role in regulating melanoma heterogeneity. Our results suggest mechanotransduction at the periphery of melanoma aggregates may orchestrate the activity of epigenetic modifiers to regulate histone state, cellular plasticity, and tumorigenicity.


Assuntos
Reprogramação Celular , Epigênese Genética , Regulação Neoplásica da Expressão Gênica , Histonas/química , Histonas/genética , Melanoma/patologia , Animais , Diferenciação Celular , Humanos , Melanoma/genética , Camundongos , Microambiente Tumoral
11.
Adv Biosyst ; 4(5): e2000056, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32402124

RESUMO

During cancer progression, a growing tumor encounters variation in the surrounding microenvironment leading to a diverse landscape at the tumor-matrix interface. Topological cues at the interface are believed to influence invasive characteristics; however, most laboratory models involve tumor spheroids that develop a uniform geometry within a homogenous hydrogel. In this communication, a method for templating hydrogels in well-defined 3D architectures is reported. Using melanoma as a model cancer, fabrication of geometrically structured model tumors in a myriad of shapes and sizes is demonstrated. These microtumors can be encapsulated in virtually any polymeric matrix, with demonstrations using poly(ethylene glycol) and gelatin-based hydrogels. Light sheet imaging reveals uniform viability throughout with regions of high curvature at the periphery influencing cellular heterogeneity. These hydrogel encapsulated microtumors can be harvested and implanted in animal models, providing a unique xenograft system where relationships between geometry, progression, and invasion may be systematically studied.


Assuntos
Matriz Extracelular/química , Hidrogéis/química , Melanoma Experimental , Impressão Tridimensional , Animais , Bovinos , Linhagem Celular Tumoral , Humanos , Melanoma Experimental/metabolismo , Melanoma Experimental/patologia , Camundongos
12.
Oncotarget ; 11(1): 46-61, 2020 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-32002123

RESUMO

Our group previously demonstrated that sarcoma cell lines were insensitive to epidermal growth factor receptor (EGFR) inhibitor gefitinib monotherapy. PENAO, an anti-tumour metabolic compound created in our laboratory, is currently in clinical trials. Considering the positive regulation of tumour energy production by both the EGFR signalling and tumour metabolism pathways, this study aimed to investigate the effect and mechanisms of combination therapy using gefitinib and PENAO in sarcoma cell lines in vitro and in vivo. PENAO monotherapy reduced proliferation in 12 sarcoma cell lines. Combining gefitinib and PENAO resulted in synergistic inhibition in both a time- and dose-dependent manner in 3 sarcoma cell lines with less prominent monotherapy effects. Combined treatment significantly enhanced cell death and perturbed mitochondrial function. In vivo combination therapy with PENAO and gefitinib was non-toxic to mice and significantly delayed tumour growth and prolonged survival. At 20 days after treatment, tumours from the combination treated mice were significantly smaller than those from untreated and single drug treated mice. The survival curves also showed significant difference across and between groups. The combination of PENAO and gefitinib in vitro and in vivo, shows promise as a treatment pathway in this poor outcome tumour.

13.
Mol Cell Endocrinol ; 494: 110492, 2019 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-31255731

RESUMO

Approximately 20% of Graves' disease (GD) patients may result eventually in hypothyroidism in their natural course. Uterus globulin-associated protein 1 (UGRP1) was associated with GD in our previous study. Here we investigated the role of UGRP1 in the development of autoimmune thyroid disease (AITD). The results showed that UGRP1 was expressed in the thyrocytes of most Hashimoto's thyroiditis (HT) patients and a proportion of GD patients (293 HT and 198 GD). The pathologic features of UGRP1-positive thyrocytes resembled "Hürthle cells", and were surrounded by infiltrated leukocytes. The positivity rate of TPOAb in UGRP1-positive GD patients was much higher than that in -negative GD patients. Moreover, UGRP1 was co-expressed with Fas and HLA-DR in the thyrocytes of AITD patients. We also found IL-1ß but not Th1 or Th2 cytokines was able to upregulate the expression of UGRP1. Our findings indicated that UGRP1 may be a novel marker in thyrocytes to predict GD patients who develop hypothyroidism.


Assuntos
Progressão da Doença , Doença de Graves/metabolismo , Doença de Graves/patologia , Hipotireoidismo/metabolismo , Hipotireoidismo/patologia , Secretoglobinas/metabolismo , Biomarcadores/metabolismo , Antígenos HLA-DR/metabolismo , Humanos , Interleucina-1beta/metabolismo , Secretoglobinas/genética , Células Epiteliais da Tireoide/metabolismo , Glândula Tireoide/metabolismo , Glândula Tireoide/patologia , Regulação para Cima/genética , Receptor fas/metabolismo
14.
ANZ J Surg ; 89(5): 524-528, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30414221

RESUMO

BACKGROUND: Current surgical practice often leads to excision of all papillary lesions of the breast diagnosed on percutaneous biopsy. This study aims to identify a subset of patients with papillary lesions who may be able to avoid surgery. METHODS: Between January 2000 and December 2015, 157 cases of papillary lesions with complete surgical excision pathology results were reviewed retrospectively to compare the clinical, imaging and pathology features. Of these, 50 patients with benign papillary lesions without atypia and 19 patients with benign papillary lesions with atypia on needle biopsy were analysed to determine the rate of upgrade to malignancy after surgery. RESULTS: Of the 50 patients with benign papillary lesions without atypia on biopsy, two (4%) were upgraded to low grade ductal carcinoma in situ after surgical excision. Both these patients had suspicious features on imaging. Of the 19 patients with papillary lesions with atypia diagnosed on needle biopsy, eight (42%) were upgraded to malignancy after surgery. The differences between benign, atypical and malignant papillary lesions were further compared. Malignant lesions were more suspicious radiologically (P = 0.001), more likely to have architectural distortion (P = 0.001), more peripherally located (P = 0.001) and were larger in size (P = 0.01). Patients diagnosed with malignant lesions were also older (P = 0.001). CONCLUSION: Younger patients diagnosed with small central benign papillary lesions without atypia on needle biopsy, and without suspicious imaging, may be managed conservatively with surveillance.


Assuntos
Biópsia com Agulha de Grande Calibre/métodos , Neoplasias da Mama/diagnóstico , Mama/patologia , Carcinoma Papilar/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/terapia , Carcinoma Papilar/terapia , Tratamento Conservador/métodos , Diagnóstico Diferencial , Feminino , Humanos , Pessoa de Meia-Idade , Prognóstico , Reprodutibilidade dos Testes , Estudos Retrospectivos
15.
Int J Oncol ; 52(6): 2143-2154, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29620166

RESUMO

The 5-year survival rate for metastatic sarcoma is 16%. Although the phosphorylated human epidermal growth factor receptor (pEGFR/HER1) has been shown to be an independent predictor of overall survival in patients with sarcoma, we have previously demonstrated that sarcoma cell lines exhibit resistance, despite gefitinib blocking p-EGFR and signal transducers in EGFR downstream pathways. Gefitinib failed to decrease the ratio of phosphorylated (p-)signal transducer and activator of transcription (STAT3)/p-STAT1, suggesting that relative STAT3 abundance and activation may be involved in drug resistance. In this study, we used the panHER inhibitor, dacomitinib, to further block HER2-dependent activation, applying multiple methods, such as proliferation assay, clonogenic survival assay, anti-anoikis assay and western blot analysis. Although dacomitinib inhibited EGFR, HER2, AKT and Erk activation more effectively than gefitinib, it still only exerted minimal anti-proliferative effects on sarcoma cell lines due to the STAT3 escape pathway. However, the addition of the STAT3 inhibitor, S3I-201, to dacomitinib achieved a significant enhancement in growth inhibition, by perturbing p-STAT3/p-STAT1. Using a panel of sarcoma cell lines with different histological types, we identified that the addition of the STAT3 inhibitor enhanced the growth inhibitory effects of the panHER inhibitor, dacomitinib, on sarcoma cells. Our findings may have clinical implications on overcoming the resistance caused by the STAT3 escape pathway and optimising EGFR/panHER-targeted therapy in sarcoma.


Assuntos
Benzenossulfonatos/farmacologia , Receptores ErbB/metabolismo , Quinazolinonas/farmacologia , Fator de Transcrição STAT3/metabolismo , Sarcoma/metabolismo , Ácidos Aminossalicílicos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Sinergismo Farmacológico , Humanos , Fosforilação/efeitos dos fármacos , Receptor ErbB-2/metabolismo , Sarcoma/tratamento farmacológico
16.
Bioconjug Chem ; 29(2): 546-558, 2018 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-29346731

RESUMO

PENAO (4-(N-(S-penicillaminylacetyl)amino) phenylarsonous acid), which is a mitochondria inhibitor that reacts with adenine nucleotide translocator (ANT), is currently being trialed in patients with solid tumors. To increase the stability of the drug, the formation of nanoparticles has been proposed. Herein, the direct synthesis of polymeric micelles based on the anticancer drug PENAO is presented. PENAO is readily available for amidation reaction to form PENAO MA (4-(N-(S-penicillaminylacetyl) amino) phenylarsonous acid methacrylamide) which undergoes RAFT (reversible addition-fragmentation chain transfer) polymerization with poly(ethylene glycol methyl ether methacrylate) as comonomer and poly(methyl methacrylate) (pMMA) as chain transfer agent, resulting in p(MMA)-b-p(PEG-co-PENAO) block copolymers with 3-15 wt % of PENAO MA. The different block copolymers self-assembled into micelle structures, varying in size and stability (Dh = 84-234 nm, cmc = 0.5-82 µg mol-1) depending on the hydrophilic to hydrophobic ratio of the polymer blocks and the amount of drug in the corona of the particle. The more stable micelle structures were investigated toward 143B human osteosarcoma cells, showing an enhanced cytotoxicity and cellular uptake compared to the free drug PENAO (IC50 (PENAO) = 2.7 ± 0.3 µM; IC50 (micelle M4) = 0.8 ± 0.02 µM). Furthermore, PENAOs arsonous acid residue remains active when incorporated into a polymer matrix and conjugates to small mono and closely spaced dithiols and is able to actively target the mitochondria, which is PENAO's main target to introduce growth inhibition in cancer cells. As a result, no cleavable linker between drug and polymer was necessary for the delivery of PENAO to osteosarcoma cells. These findings provide a rationale for in vivo studies of micelle M4 versus PENAO in an osteosarcoma animal model.


Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Arsenicais/química , Arsenicais/farmacologia , Nanopartículas/química , Polímeros/química , Polímeros/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Portadores de Fármacos/química , Humanos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/patologia , Osteossarcoma/tratamento farmacológico , Osteossarcoma/patologia , Polimerização , Compostos de Sulfidrila/química
17.
ACS Biomater Sci Eng ; 4(3): 1064-1072, 2018 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-33418790

RESUMO

The present work reports structural/microstructural correlations with biological performance for three nanoceria morphologies, aiming to elucidate the major factors in their interactions with fibrosarcoma. These include the pH of the in vitro medium and the crystallinities, stoichiometries, surface areas and chemistries, and maximal oxygen vacancy concentrations ([VO••]Max). Although the [VO••]Max is dominant in the redox behavior, the role of the morphology was manifested in the order of effectiveness of the redox regulation, which was nanocubes (NC) < nanorods (NR) < nanooctahedra (NO). The proposed mechanism illustrates the role of VO•• in explaining antioxidant behavior at physiological pH 7.4 and prooxidant behavior in the tumor microenvironment pH 6.4. Cellular uptake at pH 7.4 was dominated by the morphology of the nanoparticle, demonstrating the order NO < NC < NR. Control of the [VO••]Max, morphology, and dependent structural and microstructural parameters can be used to optimize the uptake and redox performance of nanoceria.

18.
Int J Mol Sci ; 18(6)2017 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-28556791

RESUMO

Abstract: Previous studies have shown that total epidermal growth factor receptor (EGFR) protein is highly expressed in soft tissue sarcoma (STS). We aimed to investigate the significance of phosphorylated-EGFR (pEGFR) and its activated-downstream signal transducers in STS tissue samples. A tissue microarray comprising 87 STS samples was assessed for total EGFR, pEGFR and its phosphorylated signal transducers and expression was correlated with clinicopathlogical parameters including patient outcome. Although the expression of total EGFR was significantly associated with adverse STS histologic grade (p = 0.004) and clinical stage (p = 0.012) similar to pEGFR, phosphorylated protein kinase B (pAkt) and phosphorylated extracellular signal regulated kinase (pERK), it is not a prognostic factor for survival. By contrast, the expression of pEGFR is an independent factor for cancer specific survival, while pERK is an independent prognostic factor for both overall and cancer specific survival in STS (p < 0.05, Cox proportional hazard model and log-rank test) in addition to the recognised factors of tumour grade and clinical stage. pERK and pEGFR are new independent prognostic factors for overall and/or cancer specific survival in STS. The expression of EGFR/pEGFR, and their associated downstream signal transducers, was associated with STS progression, suggesting that EGFR downstream signalling pathways may jointly support STS cell survival.


Assuntos
Receptores ErbB/metabolismo , Sarcoma/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Receptores ErbB/genética , Feminino , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Fosforilação/genética , Fosforilação/fisiologia , Prognóstico , Sarcoma/genética , Sarcoma/patologia , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , Adulto Jovem
19.
Anticancer Res ; 36(11): 5765-5771, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27793898

RESUMO

BACKGROUND/AIM: Sarcoma carries a poor prognosis prompting the need for targeted therapies aimed at deregulated signaling pathways. These include the PI3K/Akt/mTOR pathway commonly up-regulated in malignancies attributed to loss of PTEN expression. However, PTEN status and activation state of PI3K/Akt/mTOR pathway have not been comprehensively studied in sarcoma. The aims of this study were to characterise PTEN and Akt expression in a panel of sarcoma cell lines and then to examine mTOR inhibition using ridaforolimus. MATERIALS AND METHODS: PTEN genomic expression was analyzed using Sanger sequencing. PTEN, total Akt (tAkt) and phosphorylated Akt (pAkt) expression were quantified with western blot analysis. Antiproliferative effects of treatment regimens were designed using Chou & Talalay's isobologram and determined with crystal violet assay. RESULTS: Four cell lines had wild-type PTEN (exons 2 to 8), with normal protein expression. The GCT cell line had a missense mutation in exon 6 (C>T), associated with loss of PTEN protein expression. Increased pAkt expression was found in all cell lines following epidermal growth factor (EGF) stimulation, indicating that wild-type PTEN expression in four cell lines did not inhibit constitutive activation of PI3K/Akt/mTOR pathway. Nonetheless, all cell lines demonstrated sensitivity to ridaforolimus within a clinically relevant dose-range (half-maximal inhibitory concentration (IC50)=0.7-10 nM). CONCLUSION: PTEN mutation is rare in sarcoma cell lines and constitutive activation of PI3K/Akt/mTOR is independent of PTEN status.


Assuntos
PTEN Fosfo-Hidrolase/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Sarcoma/tratamento farmacológico , Serina-Treonina Quinases TOR/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Humanos , PTEN Fosfo-Hidrolase/genética , Sarcoma/patologia
20.
Onco Targets Ther ; 9: 5461-73, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27660463

RESUMO

Tyrosine kinase inhibitors (TKIs) against human epidermal growth factor receptor (EGFR/HER) family have been introduced into the clinic to treat cancers, particularly non-small-cell lung cancer (NSCLC). There have been three generations of the EGFR/HER-TKIs. First-generation EGFR/HER-TKIs, binding competitively and reversibly to the ATP-binding site of the EGFR TK domain, show a significant breakthrough treatment in selected NSCLC patients with activating EGFR mutations (actEGFRm) EGFR (L858R) and EGFR (Del19), in terms of safety, efficacy, and quality of life. However, all those responders inevitably develop acquired resistance within 12 months, because of the EGFR (T790M) mutation, which prevents TKI binding to ATP-pocket of EGFR by steric hindrance. The second-generation EGFR/HER-TKIs were developed to prolong and maintain more potent response as well as overcome the resistance to the first-generation EGFR/HER-TKIs. They are different from the first-generation EGFR/HER-TKIs by covalently binding to the ATP-binding site, irreversibly blocking enzymatic activation, and targeting EGFR/HER family members, including EGFR, HER2, and HER4. Preclinically, these compounds inhibit the enzymatic activation for actEGFRm, EGFR (T790M), and wtEGFR. The second-generation EGFR/HER-TKIs improve overall survival in cancer patients with actEGFRm in a modest way. However, they are not clinically active in overcoming EGFR (T790M) resistance, mainly because of dose-limiting toxicity due to simultaneous inhibition against wtEGFR. The third-generation EGFR/HER-TKIs selectively and irreversibly target EGFR (T790M) and actEGFRm while sparing wtEGFR. They yield promising efficacy in NSCLC patients with actEGFRm as well as EGFR (T790M) resistant to the first- and second-generation EGFR-TKIs. They also appear to have a lower incidence of toxicity due to the reduced inhibitory effect on wtEGFR. Currently, the first-generation EGFR/HER-TKIs gefitinib and erlotinib and second-generation EGFR/HER-TKI afatinib have been approved for use as the first-line treatment of metastatic NSCLC with actEGFRm. This review will summarize and evaluate a broad range of evidence of recent development of EGFR/HER-TKIs, with a focus on the second- and third-generation EGFR/HER-TKIs, in the treatment of patients with NSCLC harboring EGFR mutations.

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