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1.
Environ Sci Technol ; 55(23): 16078-16087, 2021 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-34633787

RESUMO

Graphitized nanodiamonds (ND) exhibit outstanding capability in activating peroxymonosulfate (PMS) for the removal of aqueous organic micropollutants (OMPs). However, controversial observation and interpretation regarding the effect of graphitization degree on ND's activity and the role of singlet oxygen (1O2) in OMP degradation need to be clarified. Herein, we investigated graphitized ND-mediated PMS activation. Experiments show that the activity of ND increases first and then decreases with the monotonically increased graphitization degree. Further experimental and theoretical studies unveil that the intensified surface graphitization alters the degradation mechanism from singlet oxygenation to an electron-transfer pathway. Moreover, for the first time, we applied a self-constructed, time-resolved phosphorescence detection system to provide direct evidence for 1O2 production in the PMS-based system. This work not only elucidates the graphitization degree-dependent activation mechanism of PMS but also provides a reliable detection system for in situ analysis of 1O2 in future studies.


Assuntos
Nanodiamantes , Transporte de Elétrons , Elétrons , Peróxidos
2.
Bioorg Chem ; 85: 413-419, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30665035

RESUMO

Retinoid X receptor alpha (RXRα), a central member of the nuclear receptor superfamily and a key regulator of many signal transduction pathways, has been an attractive drug target. We previously discovered that an N-terminally truncated form of RXRα can be induced by specific ligands to form homotetramers, which, as a result of conformational selection, forms the basis for inhibiting the nongenomic activation of RXRα. Here, we report the identification and characterization of atorvastatin as a new RXRα tetramer stabilizer by using structure-based virtual screening and demonstrate that virtual library screening can be used to aid in identifying RXRα ligands that can induce its tetramerization. In this study, docking was applied to screen the FDA-approved small molecule drugs in the DrugBank 4.0 collection. Two compounds were selected and purchased for testing. We showed that the selected atorvastatin could bind to RXRα to promote RXRα-LBD tetramerization. We also showed that atorvastatin possessed RXRα-dependent apoptotic effects. In addition, we used a chemical approach to aid in the studies of the binding mode of atorvastatin.


Assuntos
Atorvastatina/farmacologia , Multimerização Proteica/efeitos dos fármacos , Receptor X Retinoide alfa/metabolismo , Antineoplásicos/química , Antineoplásicos/metabolismo , Antineoplásicos/farmacologia , Atorvastatina/química , Atorvastatina/metabolismo , Sítios de Ligação , Avaliação Pré-Clínica de Medicamentos , Humanos , Ligantes , Células MCF-7 , Ligação Proteica/efeitos dos fármacos , Domínios Proteicos , Estabilidade Proteica/efeitos dos fármacos , Sulindaco/análogos & derivados , Sulindaco/metabolismo
3.
Analyst ; 142(23): 4503-4510, 2017 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-29098214

RESUMO

Optical Coherence Tomography (OCT) is a valuable technology that has been used to obtain microstructure images of tissue, and has several advantages, though its applications are limited in high-scattering tissues. Therefore, semiconducting polymer nanoparticles (SPNs) that possess strong absorption characteristics are applied to decrease light scattering in tissues and used as exogenous contrast agents for enhancing the contrast of OCT imaging detection. In this paper, we prepared two kinds of SPNs, termed PIDT-TBZ SPNs and PBDT-TBZ SPNs, as the contrast agents for OCT detection to enhance the signal. Firstly, we proved that they were good contrast agents for OCT imaging in agar-TiO2. After that, the contrast effects of these two SPNs were quantitatively analyzed, and then cerebral blood vessels were monitored by a home-made SD-OCT system. Finally, we created OCT images in vitro and in vivo with these two probes and performed quantitative analysis using the images. The results indicated that these SPNs created a clear contrast enhancement of small vessels in the OCT imaging process, which provides a basis for the application of SPNs as contrast agents for bioimaging studies.


Assuntos
Vasos Sanguíneos/diagnóstico por imagem , Encéfalo/irrigação sanguínea , Nanopartículas , Tomografia de Coerência Óptica , Animais , Encéfalo/diagnóstico por imagem , Camundongos , Camundongos Endogâmicos BALB C , Estrutura Molecular , Polímeros
4.
Opt Lett ; 41(13): 2986-9, 2016 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-27367082

RESUMO

Light scattering leads to a severe loss of axial and transverse resolution with depth into tissue, limiting accuracy and value of biomedical luminescence imaging techniques. High-resolution imaging beyond a few-millimeter depth is prohibited because diffusive transport dominates beyond a few scattering distances. In this study, light sheet imaging through scattering media is demonstrated using a radiotherapy linear accelerator to deliver well-defined thin scanned sheets of x-rays. These sheets produce Cherenkov light within the medium, which in turn excites luminescence of an optical probe across the sheet plane. This luminescence can then be imaged by an intensified camera positioned perpendicular to the sheet plane. The precise knowledge of the light sheet position within the medium allowed for efficient attenuation correction of the signal with depth as well as spatial deconvolution of the excitation light. Together these methods allowed for the first time, to the best of our knowledge, high-resolution imaging of tissue-equivalent phantoms up to 3 cm thick, yielding the precise position and shape of luminescent lesions located deep in tissue without the need for nonlinear image reconstruction.

5.
Photodiagnosis Photodyn Ther ; 46: 104080, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38583747

RESUMO

SIGNIFICANCE: Photodynamic therapy (PDT) can be targeted toward different subcellular localizations, and it is proposed that different subcellular targets vary in their sensitivity to photobiological damage. Since singlet oxygen (1O2) has a very short lifetime with a limited diffusion length in cellular environments, measurement of cumulative 1O2 luminescence is the most direct approach to compare the PDT sensitivity of mitochondria and plasma membrane. APPROACH: PDT-generated near-infrared 1O2 luminescence at 1270 nm was measured together with cell viability for 5-aminolevulinic acid (ALA)-induced protoporphyrin IX (PpIX) and exogenous PpIX, at different incubation times. Confocal fluorescence microscopy indicated that ALA-induced PpIX (2 h) localized in the mitochondria, whereas exogenous PpIX (1 h) mainly localized to the plasma membrane. Cell viability was determined at several time points during PDT treatments using colony-forming assays, and the surviving fraction correlated well with cumulative 1O2 luminescence counts from PpIX in mitochondria and plasmas membrane, respectively. RESULTS: The mitochondria are more sensitive than the plasma membrane by a factor of 1.7. CONCLUSIONS: Direct 1O2 luminescence dosimetry's potential value for comparing the PDT sensitivity of different subcellular organelles was demonstrated. This could be useful for developing subcellular targeted novel photosensitizers to enhance PDT efficiency.


Assuntos
Ácido Aminolevulínico , Membrana Celular , Sobrevivência Celular , Mitocôndrias , Fotoquimioterapia , Fármacos Fotossensibilizantes , Protoporfirinas , Oxigênio Singlete , Protoporfirinas/farmacologia , Oxigênio Singlete/metabolismo , Fármacos Fotossensibilizantes/farmacologia , Fotoquimioterapia/métodos , Mitocôndrias/metabolismo , Mitocôndrias/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Membrana Celular/efeitos dos fármacos , Ácido Aminolevulínico/farmacologia , Humanos
6.
Eye (Lond) ; 38(8): 1535-1541, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38307989

RESUMO

BACKGROUND: Retinoblastoma is a potentially fatal disease, and its incidence and mortality varies among different countries and periods. METHODS: This is a nationwide population-based retrospective study from January 1980 to December 2019 in Taiwan. Patients diagnosed as retinoblastoma were identified from the Taiwan National Cancer Registry. To update the literature on retinoblastoma incidence, mortality and trends in Taiwan, we analysed changes in incidence and survival rates over time according to sex, diagnostic age, laterality and treatment. RESULTS: During 1980-2019, the incidence of retinoblastoma in Taiwan was 1 per 16 489 live births (95% CI: 13 415-19 564). The diagnostic age decreased from 2.21 ± 0.26 during 1980-1984 to 1.24 ± 0.26 during 1985-2019. Compared with that observed during 1980-1989, the incidence rate observed after 1990 increased significantly in children aged <10 years (RR: 1.62-2.40, P = 0.0049 to < 0.0001). From 1980 to 2019, the incidence rate for the 0-4-year age group increased and that for the 5-9-year age group remained constant. The mean diagnostic age for bilateral retinoblastoma (0.36 ± 0.47 years) was significantly less than that for unilateral retinoblastoma (1.37 ± 0.35 years) during 2007-2019 (P < 0.0001). The 10-year survival rate was highest in the enucleation group (89.8%) compared with radiotherapy (52.2%) and others (70.0%; P < 0.0001). CONCLUSIONS: During 1980-2019 in Taiwan, the incidence of retinoblastoma increased significantly, and the diagnostic age decreased, which are similar to the ones from other developed countries. However, the survival rate was still lower than that of most developed countries.


Assuntos
Sistema de Registros , Neoplasias da Retina , Retinoblastoma , Humanos , Retinoblastoma/epidemiologia , Retinoblastoma/mortalidade , Retinoblastoma/terapia , Taiwan/epidemiologia , Incidência , Masculino , Neoplasias da Retina/epidemiologia , Neoplasias da Retina/mortalidade , Neoplasias da Retina/terapia , Estudos Retrospectivos , Feminino , Lactente , Pré-Escolar , Criança , Taxa de Sobrevida/tendências , Recém-Nascido , Distribuição por Idade , Distribuição por Sexo
7.
J Fluoresc ; 23(1): 41-7, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22914972

RESUMO

The purpose of this study is to investigate the feasibility for quantitative measurement of singlet oxygen ((1)O(2)) generation by using a newly developed (1)O(2)-specific fluorescence probe Singlet Oxygen Sensor Green reagent (SOSG). (1)O(2) generation from photoirradiation of a model photosensitizer Rose Bengal (RB), in initially air-statured phosphate buffered saline (PBS) was indirectly monitored with SOSG. In the presence of (1)O(2), SOSG can react with (1)O(2) to produce SOSG endoperoxides (SOSG-EP) that emit strong green fluorescence with the maximum at 531 nm. The green fluorescence of SOSG-EP is mainly dependent on the initial concentrations of RB and SOSG, and the photoirradiation time for (1)O(2) generation. Furthermore, kinetic analysis of the RB-sensitized photooxidation of SOSG is performed that, for the first time, allows quantitative measurement of (1)O(2) generation directly from the determination of reaction rate. In addition, the obtained (1)O(2) quantum yield of porphyrin-based photosensitizer hematoporphyrin monomethyl ether (HMME) in PBS by using SOSG is in good agreement with the value that independently determined by using direct measurement of (1)O(2) luminescence. The results of this study clearly demonstrate that the quantitative measurement of (1)O(2) generation using SOSG can be achieved by determining the reaction rate with an appropriate measurement protocol.


Assuntos
Corantes Fluorescentes/química , Oxigênio Singlete/química , Estudos de Viabilidade , Hematoporfirinas/química , Cinética , Medições Luminescentes , Oxirredução
8.
Int J Biol Sci ; 19(15): 4849-4864, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37781518

RESUMO

Heat stress, clinically known as hyperthermia, is a promising adjunctive modality in cancer treatment. However, the efficacy of hyperthermia as a monotherapy is limited and the underlying mechanism remains poorly understood. Targeting histone modifications is an emerging strategy for cancer therapy, but little is known regarding the role of heat stress in altering these modifications. Here, we report that heat shock inhibits H3K9 acetylation (H3K9ac) via histone deacetylase 6 (HDAC6) regulation. Heat shock inhibits the interaction between HDAC6 and heat shock protein 90 (HSP90), enhances nuclear localization of HDAC6, and promotes HDAC6 phosphorylation, which is regulated by protein phosphatase 2A (PP2A). Combining hyperthermia with HDAC inhibitors vorinostat or panobinostat leads to better anti-cancer effects compared to monotherapy. KEAP1 and DPP7 as genes affected by heat-induced inhibition of H3K9ac, and combining them with hyperthermia can better induce apoptosis in tumor cells. This study reveals previously unknown mechanisms of H3K9ac decreased by heat shock in cancer cells and highlights a potential combinational therapy involving hyperthermia and targeting of these new mechanisms.


Assuntos
Hipertermia Induzida , Neoplasias , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Histona Desacetilases/metabolismo , Acetilação , Ácidos Hidroxâmicos/farmacologia , Fator 2 Relacionado a NF-E2/metabolismo , Resposta ao Choque Térmico , Neoplasias/terapia
9.
Eur J Med Chem ; 261: 115787, 2023 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-37690263

RESUMO

Since tyrosine kinase inhibitor (TKI) could reverse ABCG2-mediated drug-resistance, novel chlorin e6-based conjugates of Dasatinib and Imatinib as photosensitizer (PS) were designed and synthesized. The results demonstrated that conjugate 10b showed strongest phototoxicity against HepG2 and B16-F10 cells, which was more phototoxic than chlorin e6 and Talaporfin. It could reduce efflux of intracellular PS by inhibiting ABCG2 in HepG2 cells, and localize in mitochondria, lysosomes, golgi and ER, resulting in higher cell apoptosis rate and ROS production than Talaporfin. Moreover, it could induce cell autophagy and block cell cycle in S phase, and significantly inhibit tumor growth and prolong survival time on BALB/c nude mice bearing HepG2 xenograft tumor to a greater extent than chlorin e6. Consequently, compound 10b could be applied as a promising candidate PS due to its good water-solubility and stability, low drug-resistance, high quantum yield of 1O2 and excellent antitumor efficacy in vitro and in vivo.


Assuntos
Fotoquimioterapia , Porfirinas , Animais , Camundongos , Humanos , Fármacos Fotossensibilizantes , Camundongos Nus , Linhagem Celular Tumoral , Fotoquimioterapia/métodos , Porfirinas/farmacologia
10.
J Cell Mol Med ; 16(12): 3037-51, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22985252

RESUMO

Metastasis is a major cause of death from malignant diseases, and the underlying mechanisms are still largely not known. A detailed probe into the factors which may regulate tumour invasion and metastasis contributes to novel anti-metastatic therapies. We previously identified a novel metastasis-associated gene 1 (mag-1) by means of metastatic phenotype cloning. Then we characterized the gene expression profile of mag-1 and showed that it promoted cell migration, adhesion and invasion in vitro. Importantly, the disruption of mag-1 via RNA interference not only inhibited cellular metastatic behaviours but also significantly reduced tumour weight and restrained mouse breast cancer cells to metastasize to lungs in spontaneous metastatic assay in vivo. Furthermore, we proved that mag-1 integrates dual regulating mechanisms through the stabilization of HIF-1α and the activation of mTOR signalling pathway. We also found that mag-1-induced metastatic promotion could be abrogated by mTOR specific inhibitor, rapamycin. Taken together, the findings identified a direct role that mag-1 played in metastasis and implicated its function in cellular adaptation to tumour microenvironment.


Assuntos
1-Acilglicerol-3-Fosfato O-Aciltransferase/genética , Neoplasias da Mama/genética , Invasividade Neoplásica/genética , Metástase Neoplásica/genética , Microambiente Tumoral , Animais , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Células COS , Adesão Celular/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Chlorocebus aethiops , Feminino , Regulação Neoplásica da Expressão Gênica , Células HEK293 , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Neoplasias Pulmonares/secundário , Camundongos , Camundongos Endogâmicos BALB C , Interferência de RNA , Transdução de Sinais , Sirolimo , Serina-Treonina Quinases TOR/antagonistas & inibidores , Serina-Treonina Quinases TOR/metabolismo , Transcriptoma
11.
Zhonghua Bing Li Xue Za Zhi ; 41(9): 613-7, 2012 Sep.
Artigo em Zh | MEDLINE | ID: mdl-23157830

RESUMO

OBJECTIVE: To study the clinicopathologic features of pure mucinous carcinomas of the breast with diffuse micropapillary pattern. METHODS: Twenty-six cases of micropapillary variant of pure mucinous carcinoma of the breast were retrospectively reviewed by light microscopy, immunohistochemistry and clinical data analyses. RESULTS: The age of 26 female patients ranged from 30 to 77 years old, of which 12 cases with clinical details available were mean 54 years old. The tumor diameter ranged from 0.8 to 9.0 cm (mean 3.2 cm). Ipsilateral axillary nodal metastases were identified in 3 cases. Cutaneous involvement was also found in 2 cases. The tumor cells showed the similar architectural arrangement as in invasive micropapillary carcinoma, with peripheral borders of the cell clusters highlighted by epithelial membrane antigen. Various amount of mucin occupied the retraction spaces around the tumor cells. Compared with conventional pure mucinous carcinoma of the breast, mucinous carcinomas with micropapillary pattern showed different nuclear grades (19 cases of grade I, 2 cases of grade II, 5 cases of grade III). The micropapillary cell clusters varied in size (22 cases of big micropapillary and 4 cases of small). Intraductal carcinoma was observed in 12 cases. Calcification and psammoma bodies were observed in 8 cases. Immunophenotyping, the tumor cells were with higher expression of hormone receptors, but HER2 were negative. Ki-67 positive index was 1% ∼ 70%. Neuroendocrine differentiation was observed in 6 cases. CONCLUSIONS: The micropapillary variant of pure mucinous carcinoma of the breast, which mainly occurs in younger women, may carry the similar propensity for angioinvasion and nodal metastasis as infiltrating micropapillary carcinoma at least in cases with high nuclear grade. This morphologic subtype needs to be distinguished from conventional pure mucinous carcinoma of the breast and treated properly.


Assuntos
Adenocarcinoma Mucinoso/patologia , Neoplasias da Mama/patologia , Carcinoma Papilar/patologia , Adenocarcinoma Mucinoso/metabolismo , Adenocarcinoma Mucinoso/cirurgia , Adulto , Idoso , Neoplasias da Mama/metabolismo , Neoplasias da Mama/cirurgia , Caderinas/metabolismo , Carcinoma Papilar/metabolismo , Carcinoma Papilar/cirurgia , Cateninas/metabolismo , Feminino , Seguimentos , Humanos , Imuno-Histoquímica , Antígeno Ki-67/metabolismo , Excisão de Linfonodo , Metástase Linfática , Mastectomia Radical Modificada/métodos , Pessoa de Meia-Idade , Mucina-1/metabolismo , Receptores de Estrogênio/metabolismo , Receptores de Progesterona/metabolismo , Estudos Retrospectivos , delta Catenina
12.
Zhonghua Bing Li Xue Za Zhi ; 40(9): 604-9, 2011 Sep.
Artigo em Zh | MEDLINE | ID: mdl-22177244

RESUMO

OBJECTIVE: To study the clinical features and histopathology of the neuroendocrine carcinoma (NEC) of the breast. METHODS: Twenty-two cases of NEC of the breast were analysed by morphology and immunohistochemistry using synaptophysin, chromogranin A, NSE, CD56, estrogen receptor (ER), progesterone receptor (PR), HER2, EGFR, CK5/6, CK14, p63, E-cadherin, p120, p53 and Ki-67 staining. HER2 gene amplification was detected by fluorescence in situ hybridization (FISH) for cases with HER2 protein expression 2+. The diagnosis of breast NEC relies on the expression of neuroendocrine markers expression in more than 50% of tumor cells, and no evidence of neuroendocrine carcinoma in any other parts of the body at the same time. RESULTS: The patients aged from 31 to 96 years (mean 65.2 years), and all were female but one. Amongst the 22 patients studied, the NECs were in the left breast in 15 cases (68.2%) and in the right breast in seven cases (31.8%); the tumor size was 0.5 to 5.5 cm (mean 2.7 cm). Lymph node metastasis was found in six cases. Basing on the morphologic features, these 22 cases were categorized into six subtypes including nine cases of solid cohesive, six of mucinous, three of solid papillary, two of small cell, one of large cell and one of alveolar variants. Immunohistochemically, the expression rate of markers was 100% (22/22) for synaptophysin, 12/13 for NSE, 54.5% (12/22) for chromogranin A, and 5/16 for CD56. Also, 90.5% (19 of 21) of cases expressed ER, 81.0% (17 of 21) of cases expressed PR, and none expressed EGFR, CK5/6, CK14 and p63. HER2 protein over-expression (3+) and gene amplification was not detected in any case. All cases (19/19) were positive for membrane staining for E-cadherin and p120. p53 expression was seen in 6 of 17 cases. Ki-67 labeling index was less than 3% in 9.5% (2/21) of the cases, 3% to 20% in 66.7% (14/21) of the cases and more than 20% in 23.8% (5/21) of the cases. Both cases of HER2 (2+) did not show gene amplification by FISH. On the basis of immunophenotypes, most of the breast NECs were of the luminal molecular subtype, but not HER2-overexpression or basal-like subtypes. CONCLUSIONS: NEC of breast more likely occurs in elderly patients and in the left breast than the right breast. The most common morphology is the solid cohesive subtype, followed by the mucinous variant.


Assuntos
Neoplasias da Mama/patologia , Carcinoma Neuroendócrino/patologia , Sinaptofisina/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/classificação , Neoplasias da Mama/metabolismo , Neoplasias da Mama/cirurgia , Neoplasias da Mama Masculina/classificação , Neoplasias da Mama Masculina/metabolismo , Neoplasias da Mama Masculina/patologia , Neoplasias da Mama Masculina/cirurgia , Caderinas/metabolismo , Carcinoma Neuroendócrino/classificação , Carcinoma Neuroendócrino/metabolismo , Carcinoma Neuroendócrino/cirurgia , Cromograninas/metabolismo , Feminino , Seguimentos , Humanos , Metástase Linfática , Masculino , Mastectomia/métodos , Pessoa de Meia-Idade , Fosfopiruvato Hidratase/metabolismo , Prognóstico , Receptores de Estrogênio/metabolismo , Receptores de Progesterona/metabolismo
13.
Photodiagnosis Photodyn Ther ; 36: 102467, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34333147

RESUMO

BACKGROUND: Singlet oxygen (1O2) is highly reactive to biological components such as lipids, proteins and DNA, which induces oxidative damage to cells and tissues. Natural antioxidants may function as 1O2 quencher to prevent 1O2 involved photosensitized oxidation in biological system. METHODS: Time-resolved measurement of 1O2 luminescence was employed to evaluate the 1O2 quenching abilities of natural antioxidants in air-statured phosphate buffered saline (PBS), including (-)-Epigallocatechin gallate (EGCG), Proanthocyanidins, L-carnosine and Vitamin C. The 1O2 quenching effects and rate constant of EGCG were investigated by detecting the absorption, fluorescence and 1H-NMR spectroscopy and 1O2 luminescence decay curves, respectively. In addition, the protective activity of EGCG against 1O2 oxidative damage caused by Ce6-mediated photodynamic therapy (PDT) was verified in cells. RESULTS: EGCG, proanthocyanidins, L-carnosine and Vitamin C efficiently quenched 1O2 luminescence at 1270 nm. The triplet-state quenching rate constants of EGCG for Rose Bengal (RB), Chlorin e6, AlPcS and HiPorfin are 2.21 × 109, 4.90 × 108, 3.30 × 108, 1.78 × 109 M-1s-1, while the 1O2 quenching rate constants are 2.80 × 108, 1.50 × 108, 1.30 × 108, 1.70 × 108 M-1s-1, respectively. Furthermore, EGCG could effectively quench 1O2 production to prevent NIH/3T3 cells oxidative damage induced by Ce6-mediated PDT. CONCLUSIONS: EGCG is an efficient quencher for both triplet-state photosensitizers and 1O2. The quenching ability of EGCG during photosensitization for selected photosensitizers is: RB > HiPorfin > Ce6 > AlPcS. EGCG could be used to protect normal cells and tissue against oxidative damage.


Assuntos
Fotoquimioterapia , Oxigênio Singlete , Animais , Catequina/análogos & derivados , Camundongos , Estresse Oxidativo , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/farmacologia
14.
Photochem Photobiol ; 96(3): 646-651, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32220067

RESUMO

Singlet oxygen (1 O2 ) is widely regarded as the main cytotoxic substance that induces the biological damage for photodynamic therapy (PDT). In this study, the previously developed near-infrared (NIR) optical imaging system was optimized for fast imaging of 1 O2 luminescence. The optical imaging system enables direct imaging of 1 O2 luminescence in blood vessels within 2 s during vascular-targeted PDT (V-PDT), which makes this system extremely practical for in vivo studies. The dependence of RB concentration on 1 O2 luminescence image was investigated for V-PDT, and the data imply that 1270 nm signal is attributed to 1 O2 luminescence. The imaging system operates with a field of view of 9.60 × 7.68 mm2 and a spatial resolution of 30 µm, which holds the potential to elucidate the correlation between cumulative 1 O2 luminescence and vasoconstriction for V-PDT.


Assuntos
Vasos Sanguíneos/efeitos dos fármacos , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/farmacologia , Oxigênio Singlete/metabolismo , Animais , Humanos , Luminescência , Camundongos , Camundongos Endogâmicos BALB C , Vasoconstrição/efeitos dos fármacos
15.
Oncol Rep ; 21(3): 697-706, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19212629

RESUMO

Tumor metastasis, the important characteristic of malignant tumors, is closely associated with a series of changes in the expressions of genes and proteins. A novel gene MAG-2, which may have close correlation with lung cancer metastasis, was identified in our laboratory through an approach of suppressed subtractive hybridization using lung cancer cell strains with the same origin but different metastatic potential as models. The relations between MAG-2 gene and aspects of cancer metastasis including invasion, mobility, anchorage-independent growth capability and adherence to ECM, were investigated in our experiment models. MAG-2 gene was proved to be genuine and have mRNA and deduced proteins from itself by methods of expression profile analysis and fluorescence staining. Cytological experiments had demonstrated that hyper- or hypo-expressing of MAG-2 by gene transfection or RNAi leads to significant increase or decrease in the metastatic ability of cancer cells. In addition, CD44, MMP-2 and free calcium ion concentration intracellularly, were proved to be metastasis promoting factors, and found to be regulated by MAG-2 in lung cancer cells, this might be the mechanism of the metastasis promoting function of MAG-2 gene. The positive rate of MAG-2 mRNA was found to be significantly higher in tumor tissue from patients with metastatic lung cancer than tissues from patients with non-metastatic lung cancer. These data suggest that MAG-2 may be a novel causal gene for lung cancer invasion and metastasis.


Assuntos
Cálcio/metabolismo , Adesão Celular/genética , Receptores de Hialuronatos/metabolismo , Neoplasias Pulmonares/genética , Metaloproteinase 2 da Matriz/metabolismo , Metástase Neoplásica/genética , Sequência de Aminoácidos , Western Blotting , Linhagem Celular Tumoral , Movimento Celular/genética , Imunofluorescência , Perfilação da Expressão Gênica , Humanos , Immunoblotting , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Microscopia Confocal , Dados de Sequência Molecular , Invasividade Neoplásica/genética , Interferência de RNA , RNA Mensageiro/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa
16.
Eur J Med Chem ; 164: 562-575, 2019 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-30634084

RESUMO

Nuclear receptor RXRα plays an important role in many biological and pathological processes. The nongenomic action of RXRα is implicated in many cancers. K-8008, a non-canonical RXRα ligand derived from sulindac, inhibits the TNFα-activated PI3K/AKT pathway by mediating the interaction between a truncated form of RXRα (tRXRα) and the p85α regulatory subunit of PI3K and exerts potent anticancer activity in animal model. Herein we report our studies of a novel series of K-8008 analogs as potential anticancer agents targeting RXRα. Two compounds 8b and 18a were identified to have slightly stronger binding to RXRα and improved apoptotic activities in breast cancer cells.


Assuntos
Antineoplásicos/síntese química , Desenho de Fármacos , Receptor X Retinoide alfa , Tetrazóis/farmacologia , Animais , Apoptose/efeitos dos fármacos , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Humanos , Ligantes , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Tetrazóis/síntese química , Tetrazóis/química , Tetrazóis/metabolismo , Fator de Necrose Tumoral alfa
17.
Radiat Res ; 189(2): 197-204, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29251551

RESUMO

In this work, Cherenkov-excited molecular sensing was used to assess the potential for simultaneous quantitative sensing of two NIR fluorophores within tissue-simulating phantoms through spectral separation of signals. Cherenkov emissions induced by external beam gamma photon radiation treatment to tissues/tissue-simulating phantoms were detectable over the 500-900-nm wavelength range. The presence of blood was demonstrated to reduce the integrated intensity of detected Cherenkov emissions by nearly 50%, predominantly at wavelengths below 620 nm. The molecular dyes, IRDye 680RD and IRDye 800CW, have excitation and emission spectra at longer wavelengths than the strongest blood absorption peaks, and also where the intensity of Cherenkov light is at its lowest, so that the emission signal relative to background signal is maximized. Tissue phantoms composed of 1% intralipid and 1% blood were used to simulate human breast tissue, and vials containing fluorophore were embedded in the media, and irradiated with gamma photons for Cherenkov excitation. We observed that fluorescence emissions excited by the Cherenkov signal produced within the phantom could be detected at 5-mm depth into the media within a 0.1-25 µ M fluorophore concentration range. The detected fluorescence signals from these dyes showed linear relationships with radiation doses down to the cGy level. In vivo tests were successful only within the range near a µ M, suggesting that these could be used for metabolic probes in vivo where the local concentrations are near this range.


Assuntos
Imagens de Fantasmas , Radioterapia/instrumentação , Animais , Raios Infravermelhos , Camundongos
18.
Nat Biomed Eng ; 2(4): 254-264, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30899599

RESUMO

Low signal-to-noise ratios and limited imaging depths restrict the ability of optical-imaging modalities to detect and accurately quantify molecular emissions from tissue. Here, by using a scanning external X-ray beam from a clinical linear accelerator to induce Cherenkov excitation of luminescence in tissue, we demonstrate in vivo mapping of the oxygenation of tumours at depths of several millimetres, with submillimetre resolution and nanomolar sensitivity. This was achieved by scanning thin sheets of the X-ray beam orthogonally to the emission-detection plane, and by detecting the signal via a time-gated CCD camera synchronized to the radiation pulse. We also show with experiments using phantoms and with simulations that the performance of Cherenkov-excited luminescence scanned imaging (CELSI) is limited by beam size, scan geometry, probe concentration, radiation dose and tissue depth. CELSI might provide the highest sensitivity and resolution in the optical imaging of molecular tracers in vivo.

20.
J Biophotonics ; 9(11-12): 1314-1325, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27136270

RESUMO

Photodynamic therapy (PDT) uses photosensitizers and visible light in combination with molecular oxygen to produce reactive oxygen species (ROS) that kill malignant cells by apoptosis and/or necrosis, shut down the tumor microvasculature and stimulate the host immune system. The excited singlet state of oxygen (1 O2 ) is recognized to be the main cytotoxic ROS generated during PDT for the majority of photosensitizers used clinically and for many investigational new agents, so that maximizing its production within tumor cells and tissues can improve the therapeutic response, and several emerging and novel approaches for this are summarized. Quantitative techniques for 1 O2 production measurement during photosensitization are also of immense importance of value for both preclinical research and future clinical practice. In this review, emerging strategies for enhanced photosensitized 1 O2 generation are introduced, while recent advances in direct detection and imaging of 1 O2 luminescence are summarized. In addition, the correlation between cumulative 1 O2 luminescence and PDT efficiency will be highlighted. Meanwhile, the validation of 1 O2 luminescence dosimetry for PDT application is also considered. This review concludes with a discussion on future demands of 1 O2 luminescence detection for PDT dosimetry, with particular emphasis on clinical translation. Eye-catching color image for graphical abstract.


Assuntos
Neoplasias/tratamento farmacológico , Fotoquimioterapia , Fármacos Fotossensibilizantes/farmacologia , Oxigênio Singlete/farmacologia , Humanos , Espécies Reativas de Oxigênio/metabolismo
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