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1.
PLoS One ; 15(9): e0238238, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32881880

RESUMO

The prognosis for patients with glioblastoma (GB) remains grim. Concurrent temozolomide (TMZ) radiation-the cornerstone of glioma control-extends the overall median survival of GB patients by only a few months over radiotherapy alone. While these survival gains could be partly attributed to radiosensitization, this benefit is greatly minimized in tumors expressing O6-methylguanine DNA methyltransferase (MGMT), which specifically reverses O6-methylguanine lesions. Theoretically, non-O6-methylguanine lesions (i.e., the N-methylpurine adducts), which represent up to 90% of TMZ-generated DNA adducts, could also contribute to radiosensitization. Unfortunately, at concentrations attainable in clinical practice, the alkylation capacity of TMZ cannot overwhelm the repair of N-methylpurine adducts to efficiently exploit these lesions. The current therapeutic application of TMZ therefore faces two main obstacles: (i) the stochastic presence of MGMT and (ii) a blunted radiosensitization potential at physiologic concentrations. To circumvent these limitations, we are developing a novel molecule called NEO212-a derivatization of TMZ generated by coupling TMZ to perillyl alcohol. Based on gas chromatography/mass spectrometry and high-performance liquid chromatography analyses, we determined that NEO212 had greater tumor cell uptake than TMZ. In mouse models, NEO212 was more efficient than TMZ at crossing the blood-brain barrier, preferentially accumulating in tumoral over normal brain tissue. Moreover, in vitro analyses with GB cell lines, including TMZ-resistant isogenic variants, revealed more potent cytotoxic and radiosensitizing activities for NEO212 at physiologic concentrations. Mechanistically, these advantages of NEO212 over TMZ could be attributed to its enhanced tumor uptake presumably leading to more extensive DNA alkylation at equivalent dosages which, ultimately, allows for N-methylpurine lesions to be better exploited for radiosensitization. This effect cannot be achieved with TMZ at clinically relevant concentrations and is independent of MGMT. Our findings establish NEO212 as a superior radiosensitizer and a potentially better alternative to TMZ for newly diagnosed GB patients, irrespective of their MGMT status.


Assuntos
Dacarbazina/análogos & derivados , Resistencia a Medicamentos Antineoplásicos , Glioma/tratamento farmacológico , Radiossensibilizantes/uso terapêutico , Temozolomida/uso terapêutico , Animais , Barreira Hematoencefálica/efeitos dos fármacos , Barreira Hematoencefálica/metabolismo , Encéfalo/metabolismo , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , Dacarbazina/análise , Dacarbazina/metabolismo , Dacarbazina/farmacologia , Dacarbazina/uso terapêutico , Resistencia a Medicamentos Antineoplásicos/genética , Cromatografia Gasosa-Espectrometria de Massas , Glioma/patologia , Humanos , Camundongos , Camundongos Endogâmicos C57BL , O(6)-Metilguanina-DNA Metiltransferase/metabolismo , Radiossensibilizantes/análise , Radiossensibilizantes/metabolismo , Radiossensibilizantes/farmacologia , Temozolomida/análise , Temozolomida/metabolismo , Temozolomida/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto
2.
Int J Mol Sci ; 20(18)2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31540386

RESUMO

Ultrasmall polyaminocarboxylate-coated gold nanoparticles (NPs), Au@DTDTPA and Au@TADOTAGA, that have been recently developed exhibit a promising potential for image-guided radiotherapy. In order to render the radiosensitizing effect of these gold nanoparticles even more efficient, the study of their localization in cells is required to better understand the relation between the radiosensitizing properties of the agents and their localization in cells and in tumors. To achieve this goal, post-functionalization of Au@DTDTPA nanoparticles by near-infrared (NIF) organic dyes (aminated derivative of cyanine 5, Cy5-NH2) was performed. The immobilization of organic Cy5-NH2 dyes onto the gold nanoparticles confers to these radiosensitizers fluorescence properties which can be exploited for monitoring their internalization in cancerous cells, for determining their localization in cells by fluorescence microscopy (a common and powerful imaging tool in biology), and for following up on their accumulation in tumors after intravenous injection.


Assuntos
Carbocianinas/análise , Corantes Fluorescentes/análise , Ouro/análise , Nanopartículas Metálicas/análise , Neoplasias/diagnóstico por imagem , Radiossensibilizantes/análise , Animais , Carbocianinas/administração & dosagem , Linhagem Celular Tumoral , Feminino , Corantes Fluorescentes/administração & dosagem , Ouro/administração & dosagem , Humanos , Nanopartículas Metálicas/administração & dosagem , Nanopartículas Metálicas/ultraestrutura , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Microscopia de Fluorescência/métodos , Imagem Óptica/métodos , Poliaminas/análise , Radiossensibilizantes/administração & dosagem
3.
Adv Exp Med Biol ; 899: 269-90, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27325273

RESUMO

An evolution in radiotherapy practice is leading to greater use of stereotactic body radiotherapy (SBRT), raising the prospect of increased hypoxic cell radioresistance. New clinical interest in nitroimidazole radiosensitisers, combined with appropriate biomarkers, signals a revival for radiosensitisers in the context of SBRT. Our interest in modifiers of radiation therapy led us to revisit this area and we have identified a new class of nitroimidazole radiosensitiser. We have developed an abbreviated screening protocol suitable for an academic drug discovery laboratory which allows expeditious triage of compounds with poor physicochemical and in vitro properties and combines in vitro radiosensitisation data with tumour pharmacokinetic data to efficiently select candidates for further evaluation.


Assuntos
Radiossensibilizantes/análise , Radiossensibilizantes/farmacologia , Animais , Transporte Biológico/efeitos dos fármacos , Biomarcadores/metabolismo , Hipóxia Celular/efeitos dos fármacos , Feminino , Células HCT116 , Humanos , Camundongos Nus , Neoplasias/patologia , Radiossensibilizantes/farmacocinética , Radiocirurgia
4.
Bioanalysis ; 8(9): 871-80, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27072051

RESUMO

The desire for serial microsampling in mice has led to extensive research in this field within the pharmaceutical industry. The ability to profile a compound's in vivo properties with less material and fewer mice has obvious advantages. A new device and workflow was developed at the Takeda Oncology site to allow scientists to isolate plasma from very low volumes of mouse blood (as low as 20 µl) collected using standard microsampling techniques. A side-by-side in vitro comparison of plasma concentrations was performed using this new device and conventional sampling methods with commercial and in-house molecules. The plasma concentrations of the molecules tested were very consistent between the conventional sampling techniques and this new device/workflow. In addition, several in-life studies have also been conducted to validate this new technique as a primary PK screening tool at the Takeda Boston. The new device is simple to use and very cost effective with the added benefit that no additional training is needed for the animal technicians and the same centrifuge equipment can be employed. This device can be used for blood volumes ranging from 20 to 100 µl enabling studies not just in rat and dog but more importantly in mice.


Assuntos
Coleta de Amostras Sanguíneas/instrumentação , Afatinib , Animais , Cães , Desenho de Equipamento , Camundongos , Miniaturização/instrumentação , Quinazolinas/sangue , Radiossensibilizantes/análise , Ratos , Tamanho da Amostra
5.
Chembiochem ; 15(10): 1409-12, 2014 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-24850054

RESUMO

DNA strand breaks (SBs) are among the most cytotoxic forms of DNA damage, and their residual levels correlate directly with cell death. Hence, the type and amount of SBs is directly related to the efficacy of a given anticancer therapy. In this study, we describe a molecular tool that can differentiate between single (SSBs) and double (DSBs) strand breaks and also assess them quantitatively. Our method involves PCR amplification of a linear DNA fragment labeled with a sensitizing nucleotide, circularization of that fragment, and enzymatic introduction of supercoils to transform the circular relaxed form of the synthesized plasmid into a supercoiled one. After exposure of the molecule to a damaging factor, SSB and DSB levels can be easily assayed with gel electrophoresis. We applied this method to prepare an artificial plasmid labeled with 5-bromo-2'-deoxyuridine and to assay SBs photoinduced in the synthesized plasmid.


Assuntos
Bromodesoxiuridina/análise , Quebras de DNA , DNA/genética , Plasmídeos/análise , Radiossensibilizantes/análise , DNA/análise , Quebras de DNA/efeitos da radiação , Plasmídeos/genética , Reação em Cadeia da Polimerase
6.
Photodiagnosis Photodyn Ther ; 10(4): 379-81, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24284089

RESUMO

BACKGROUND: We recently developed a surgical loupe system for observing the fluorescence emitted by protoporphyrin IX (PpIX), a metabolite of 5-aminolevulinic acid. METHODS: This system used a semiconductor laser as the excitation light source. A compact, transparent, and ultraviolet cut-off filter was mounted on an eyepiece lens, which did not require filter on-off manipulation. RESULTS: Good quality protoporphyrin IX fluorescence was acquired using the surgical loupe system during glioblastoma resection, which was nearly identical to that acquired by fluorescent microscopy. In addition, surgeons can perform ordinary surgical procedures using this surgical loupe system under white light. CONCLUSION: This surgical loupe system enables the detection of PpIX fluorescence during resection of high-grade glioma. Further evaluations of this system are required to determine the extent of surgical resection before its practical application.


Assuntos
Aminoácidos Neutros/análise , Neoplasias Encefálicas/química , Neoplasias Encefálicas/cirurgia , Glioblastoma/química , Glioblastoma/cirurgia , Protoporfirinas/análise , Cirurgia Assistida por Computador/instrumentação , Neoplasias Encefálicas/patologia , Desenho de Equipamento , Análise de Falha de Equipamento , Óculos , Fluorescência , Glioblastoma/patologia , Humanos , Aumento da Imagem/instrumentação , Microcirurgia/instrumentação , Gradação de Tumores , Radiossensibilizantes/análise , Resultado do Tratamento
7.
Org Biomol Chem ; 11(25): 4147-53, 2013 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-23715589

RESUMO

JP4-039 is a lead structure in a series of nitroxide conjugates that are capable of accumulating in mitochondria and scavenging reactive oxygen species (ROS). To explore structure-activity relationships (SAR), new analogs with variable nitroxide moieties were prepared. Furthermore, fluorophore-tagged analogs were synthesized and provided the opportunity for visualization in mitochondria. All analogs were tested for radioprotective and radiomitigative effects in 32Dcl3 cells.


Assuntos
Compostos de Boro/análise , Corantes Fluorescentes/análise , Sequestradores de Radicais Livres/análise , Mitocôndrias/ultraestrutura , Óxidos de Nitrogênio/análise , Protetores contra Radiação/análise , Radiossensibilizantes/análise , Linhagem Celular , Sequestradores de Radicais Livres/síntese química , Sequestradores de Radicais Livres/farmacologia , Humanos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/efeitos da radiação , Modelos Moleculares , Óxidos de Nitrogênio/síntese química , Óxidos de Nitrogênio/farmacologia , Protetores contra Radiação/síntese química , Protetores contra Radiação/farmacologia , Radiossensibilizantes/síntese química , Radiossensibilizantes/farmacologia
8.
PLoS One ; 7(6): e38465, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22768044

RESUMO

BACKGROUND: Persistence of γ-H2AX after ionizing radiation (IR) or drug therapy is a robust reporter of unrepaired DNA double strand breaks in treated cells. METHODS: DU-145 prostate cancer cells were treated with a chemical library ±IR and assayed for persistence of γ-H2AX using an automated 96-well immunocytochemistry assay at 4 hours after treatment. Hits that resulted in persistence of γ-H2AX foci were tested for effects on cell survival. The molecular targets of hits were validated by molecular, genetic and biochemical assays and in vivo activity was tested in a validated Drosophila cancer model. RESULTS: We identified 2 compounds, MS0019266 and MS0017509, which markedly increased persistence of γ-H2AX, apoptosis and radiosensitization in DU-145 cells. Chemical evaluation demonstrated that both compounds exhibited structurally similar and biochemical assays confirmed that these compounds inhibit ribonucleotide reductase. DNA microarray analysis and immunoblotting demonstrates that MS0019266 significantly decreased polo-like kinase 1 gene and protein expression. MS0019266 demonstrated in vivo antitumor activity without significant whole organism toxicity. CONCLUSIONS: MS0019266 and MS0017509 are promising compounds that may be candidates for further development as radiosensitizing compounds as inhibitors of ribonucleotide reductase.


Assuntos
Avaliação Pré-Clínica de Medicamentos/métodos , Histonas/metabolismo , Radiossensibilizantes/análise , Radiossensibilizantes/farmacologia , Bibliotecas de Moléculas Pequenas/análise , Bibliotecas de Moléculas Pequenas/farmacologia , Animais , Apoptose/efeitos dos fármacos , Apoptose/efeitos da radiação , Ciclo Celular/efeitos dos fármacos , Ciclo Celular/efeitos da radiação , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/patologia , DNA/biossíntese , Dano ao DNA , Reparo do DNA/efeitos dos fármacos , Reparo do DNA/efeitos da radiação , Modelos Animais de Doenças , Drosophila melanogaster/efeitos dos fármacos , Drosophila melanogaster/metabolismo , Olho/efeitos dos fármacos , Olho/patologia , Olho/efeitos da radiação , Olho/ultraestrutura , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos da radiação , Humanos , Cinética , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Radiação Ionizante , Radiossensibilizantes/administração & dosagem , Ribonucleotídeo Redutases/antagonistas & inibidores , Ribonucleotídeo Redutases/metabolismo , Bibliotecas de Moléculas Pequenas/administração & dosagem , Quinase 1 Polo-Like
9.
Magn Reson Med ; 67(2): 519-30, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21661044

RESUMO

Patients with highly hypoxic primary tumors show increased frequency of locoregional treatment failure and poor survival rates and may benefit from particularly aggressive treatment. The potential of gadolinium diethylene-triamine penta-acetic acid-based dynamic contrast-enhanced-MRI in assessing tumor hypoxia was investigated in this preclinical study. Xenografted tumors of eight human melanoma lines were subjected to dynamic contrast-enhanced-MRI and measurement of the fraction of radiobiologically hypoxic cells and the fraction of pimonidazole-positive hypoxic cells. Tumor images of K(trans) (the volume transfer constant of gadolinium diethylene-triamine penta-acetic acid) and v(e) (the fractional distribution volume of gadolinium diethylene-triamine penta-acetic acid) were produced by pharmacokinetic analysis of the dynamic contrast-enhanced-MRI data, and K(trans) and v(e) frequency distributions of the non-necrotic tumor tissue were established and related to the extent of hypoxia. Tumors showing high K(trans) values and high v(e) values had low fractions of hypoxic cells, whereas tumors showing both low K(trans) values and low v(e) values had high hypoxic fractions. K(trans) differentiated better between tumors with low and high hypoxic fractions than did v(e). This study supports the current attempts to establish dynamic contrast-enhanced-MRI as a method for assessing the extent of hypoxia in human tumors, and it provides guidelines for the clinical development of valid assays.


Assuntos
Hipóxia Celular/fisiologia , Meios de Contraste/administração & dosagem , Gadolínio DTPA , Aumento da Imagem/métodos , Processamento de Imagem Assistida por Computador/métodos , Melanoma Experimental/patologia , Animais , Linhagem Celular Tumoral , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Transplante de Neoplasias , Nitroimidazóis/análise , Radiossensibilizantes/análise , Sensibilidade e Especificidade , Imagem Corporal Total/métodos
10.
Acta Pharm ; 61(4): 415-25, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22202200

RESUMO

Sulfonamides and quinoxaline derivatives possess many types of biological activities and have been recently reported to show substantial antitumor activity. This paper reports the synthesis of novel thioureido sulfaquinoxaline derivatives. All the newly synthesized compounds were evaluated for their in vitro anticancer activity against a human liver cell line (HEPG2) and showed higher activity than the reference drug doxorubicin. 4-(3-(4-Ethylbenzoate) thioureido)-N-(quinoxalin-2-yl)benzenesulfonamide (9) (IC50 = 15.6 µmol L⁻¹), N-(pyridin-2-yl)-4-(3-(4-(N-quinoxalin-2-yl-sulfamoyl)phenyl)thioureido)benzenesulfonamide (10) (IC50 = 26.8 µmol L⁻¹) and N-(quinoxalin-2-yl)-4-(3-(4-(N-thiazol-2-ylsulfamoyl)phenyl)thioureido)benzenesulfonamide (11) (IC50 = 24.4 µmol L⁻¹) were the most potent compared to doxorubicin (IC50 = 71.8 µmol L⁻¹). The most potent compounds 9, 10 and 11 were evaluated as radiosensitizing agents by subjecting the compounds to γ-irradiation (8 kGy).


Assuntos
Quinoxalinas/análise , Quinoxalinas/síntese química , Radiossensibilizantes/análise , Radiossensibilizantes/síntese química , Sulfonamidas/análise , Sulfonamidas/síntese química , Ensaios de Seleção de Medicamentos Antitumorais/métodos , Ensaios de Seleção de Medicamentos Antitumorais/normas , Células Hep G2 , Humanos , Benzenossulfonamidas
11.
Biopharm Drug Dispos ; 32(6): 319-32, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21815170

RESUMO

PURPOSE: The sonodynamically induced anti-tumor effect of chlorin-e6 (Ce6) was studied in mice bearing hepatoma-22 solid tumors. METHODS: In order to determine the optimum timing of ultrasound exposure after administration of Ce6, the Ce6 concentrations in plasma, skin, muscle and tumor were estimated by measuring the fluorescence intensity of tissue extractions with a fluorescence photometer based on the standard curve. A three-dimensional optical imaging system (IVIS spectrum) was used further to characterize the distribution of Ce6 in H-22 tumor. The anti-tumor effects were estimated by measuring tumor size after sonodynamic therapy. RESULTS: Similar pharmacokinetic trends of Ce6 in mice were observed either by fluorescence spectrophotometry or by bio-optical imaging. The results also demonstrated that Ce6 has a preferential localization in tumors, but low accumulation and rapid clearance in normal tissues. The results of anti-tumor effects revealed that at an ultrasound intensity of 4 W/cm(2) and a Ce6 dose of ≥10 mg/kg, a significant synergistic effect of ultrasound combined with Ce6 was observed, reducing the tumor volume significantly. CONCLUSION: Chlorin-e6 is a potential sonosensitizer for fluorescence imaging as well as for sonodynamic therapy for cancer. The anti-tumor effect of ultrasound could be enhanced in the presence of Ce6, which might be involved in a sonochemical mechanism.


Assuntos
Antineoplásicos/farmacocinética , Carcinoma Hepatocelular/terapia , Neoplasias Hepáticas/terapia , Porfirinas/farmacocinética , Radiossensibilizantes/farmacocinética , Ensaios Antitumorais Modelo de Xenoenxerto , Animais , Antineoplásicos/análise , Antineoplásicos/metabolismo , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Clorofilídeos , Avaliação Pré-Clínica de Medicamentos , Feminino , Fluorescência , Humanos , Camundongos , Camundongos Endogâmicos ICR , Porfirinas/sangue , Porfirinas/metabolismo , Porfirinas/farmacologia , Radiossensibilizantes/análise , Radiossensibilizantes/metabolismo , Radiossensibilizantes/farmacologia , Espectrometria de Fluorescência , Resultado do Tratamento , Terapia por Ultrassom/métodos
12.
Appl Radiat Isot ; 67(7-8 Suppl): S345-7, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19406648

RESUMO

In the present study, we aimed to evaluate a T2 corrected quantification method of l-p-boronophenylalanine (BPA) concentration using proton magnetic resonance spectroscopy (MRS). We used five phantoms containing BPA (1.5, 3.0, 5.0, 7.5, and 10 mmol/kg=15, 30, 50, 75, and 100 microg(10)B/g), N-acetyl-aspartic acid (NAA: 3.0 mmol/kg), creatine (Cr: 5.0 mmol/kg), and choline (Cho: 3.0 mmol/kg). The signal intensities of BPA and internal water were corrected by T2 relaxation time. The absolute concentrations of BPA were calculated by proton MRS using an internal water signal as a standard. The major BPA peaks were detected between 7.1 and 7.6 ppm. Mean T2 relaxation time was 314.3+/-10.8 ms in BPA, 885.1+/-39.7 ms in internal water. The calculated BPA concentrations were almost same as the actual concentration of BPA and the correlation coefficient was 0.99. Our BPA quantification method was very simple and non-invasive, also it had high accuracy. Therefore, our results indicate that proton MRS can be potentially useful technique for in vivo BPA quantification in boron neutron capture therapy (BNCT).


Assuntos
Compostos de Boro/análise , Compostos de Boro/uso terapêutico , Terapia por Captura de Nêutron de Boro/métodos , Espectroscopia de Ressonância Magnética/métodos , Fenilalanina/análogos & derivados , Radiossensibilizantes/análise , Radiossensibilizantes/uso terapêutico , Terapia por Captura de Nêutron de Boro/estatística & dados numéricos , Humanos , Isótopos/análise , Isótopos/uso terapêutico , Espectroscopia de Ressonância Magnética/instrumentação , Espectroscopia de Ressonância Magnética/estatística & dados numéricos , Imagens de Fantasmas , Fenilalanina/análise , Fenilalanina/uso terapêutico , Prótons
13.
Anal Bioanal Chem ; 388(2): 499-503, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17345067

RESUMO

A dual-detection technique, consisting of a combination of reversed-phase high-performance liquid chromatography and on-line detection of elemental boron in the column effluents by inductively coupled plasma optical emission spectrometry, was tested for drug analysis. The method was applied to assessing the chemical purity of p-boronophenylalanine (BPA), isotopically enriched in 10B. This compound is employed as a fructose complex solution for biodistribution studies in laboratory and clinical trials of boron neutron capture therapy. Besides the determination of the content of BPA, required for chemical quality controls of solutions of the complex used for infusions, resolution of mixtures of BPA and two usually accompanying residual impurities (phenylalanine and tyrosine) was achieved with UV detection. The limits of detection (in solution) were 1.5 and 0.6 ng ml-1, respectively. In addition, by monitoring a sensitive-element emission wavelength it was possible to jointly observe the elution of boron-containing compounds that may be transparent to UV radiation or to confirm the presence of boron in potential impurities accompanying the drug. Those impurities may arise from the BPA synthesis or may be produced by degradation during the aging of the solutions. Chromatographic peaks corresponding to the amino acids and also to a related inorganic compound were detected in BPA-fructose complex solutions that were stored for different times and under different conditions. An increase in the areas of the peaks attributed to tyrosine and phenylalanine was observed for BPA-fructose solutions stored refrigerated for 1 month to 1 year, suggesting that degradation processes able to reduce the amount of bioavailable BPA could be active.


Assuntos
Compostos de Boro/análise , Boro/química , Cromatografia Líquida de Alta Pressão/métodos , Fenilalanina/análogos & derivados , Espectrofotometria/métodos , Compostos de Boro/química , Soluções Tampão , Estabilidade de Medicamentos , Concentração de Íons de Hidrogênio , Fenilalanina/análise , Fenilalanina/química , Radiossensibilizantes/análise , Radiossensibilizantes/química , Espectrofotometria Ultravioleta , Tirosina/análise
15.
Appl Opt ; 44(11): 2213-20, 2005 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-15835366

RESUMO

A system based on a femtosecond white-light continuum and a streak camera was used for recordings of the in vivo absorption spectra of the tumor-seeking agent disulphonated aluminum phthalocyanine. Measurements for different drug doses were performed on tumor tissue (muscle-implanted adenocarcinoma) and normal muscle tissue in rats. It was found that the shape of the spectrum is tissue dependent. The peak of the absorption spectrum is blueshifted in tumor tissue as compared with the muscle. Thus the contrast in the drug-related absorption can be altered by up to a factor of 2 from the primary drug molecular-concentration contrast between normal muscle and tumor by the proper selection of the illumination wavelength.


Assuntos
Neoplasias do Colo/metabolismo , Indóis/análise , Indóis/farmacocinética , Compostos Organometálicos/análise , Compostos Organometálicos/farmacocinética , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Absorção , Animais , Neoplasias do Colo/tratamento farmacológico , Feminino , Indóis/química , Indóis/uso terapêutico , Luz , Compostos Organometálicos/química , Compostos Organometálicos/uso terapêutico , Fotoquimioterapia/métodos , Radiossensibilizantes/análise , Radiossensibilizantes/química , Radiossensibilizantes/farmacocinética , Radiossensibilizantes/uso terapêutico , Ratos , Ratos Endogâmicos WF
16.
Radiother Oncol ; 72(2): 159-68, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15297134

RESUMO

BACKGROUND AND PURPOSE: Hypoxia and proliferation are important determinants of radiation responsiveness; prospective measures of these before radiotherapy may enable individualisation of treatment schedules. Immunohistochemical techniques offer a potential means of achieving this in routine biopsy material. MATERIAL AND METHODS: Cellular hypoxia as measured by pimonidazole fixation and immunohistochemistry has been evaluated in a series of human bladder cancers with dual staining of sections for pimonidazole and either the vascular markers, CD31/34, or proliferation markers, Ki-67 or cyclin A. Twenty one tumour specimens were examined suitable for the double staining technique. RESULTS: The median hypoxic fraction was 9% (range 0-38). Seven tumours did not stain for pimonidazole and 11 exhibited necrosis. The mean vascular density ranged from 16.7 to 160.6 vessels per mm2. The median hot spot count was 30 (range 16-43). There was a statistically significant increase in vessel density in hypoxic compared to oxic regions measured by both vessel density (P = 0.02) and hot spot count (P = 0.004). Proliferation indices decreased from oxic to hypoxic areas close to blood vessels. CONCLUSIONS: We have demonstrated that bladder cancer exhibits a range of hypoxia, proliferation and vascular density which may be used to form the basis for patient selection for hypoxia modification, accelerated radiotherapy and vascular targeting agents.


Assuntos
Biomarcadores Tumorais/análise , Carcinoma de Células de Transição/química , Carcinoma de Células de Transição/patologia , Neovascularização Patológica/metabolismo , Neoplasias da Bexiga Urinária/química , Neoplasias da Bexiga Urinária/patologia , Antígenos CD34/análise , Carcinoma de Células de Transição/irrigação sanguínea , Hipóxia Celular , Proliferação de Células , Ciclina A/análise , Feminino , Humanos , Imuno-Histoquímica , Antígeno Ki-67/análise , Masculino , Estadiamento de Neoplasias , Nitroimidazóis/análise , Molécula-1 de Adesão Celular Endotelial a Plaquetas/análise , Radiossensibilizantes/análise , Coloração e Rotulagem/métodos , Neoplasias da Bexiga Urinária/irrigação sanguínea
17.
J Pharmacol Exp Ther ; 297(3): 888-94, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11356908

RESUMO

Motexafin gadolinium (MGd) is a unique therapeutic agent that localizes in cancer cells and increases tumor response to ionizing radiation and certain chemotherapeutics. The in vitro intracellular localization, accumulation, and retention of MGd in murine EMT6 mammary sarcoma and Rif-1 fibrosarcoma cell lines were studied using interferometric Fourier fluorescence microscopy. MGd cellular uptake was semiquantified using its characteristic fluorescence emission band centered at 758 nm. Colocalization studies were performed using mitochondrial, endoplasmic reticulum, Golgi apparatus, nuclear, and lysosomal fluorescent organelle probes, and verified using interferometric Fourier spectroscopy. Cellular uptake was gradual and increased significantly with incubation time. MGd localized primarily within the lysosomes and endoplasmic reticulum, and to a lesser extent within the Golgi apparatus and mitochondria. Mitochondrial staining was increased in media without serum. No nuclear uptake was detected in the Rif-1 cells, but after 48 h nuclear uptake was observed in 15% of EMT6 cells. These results indicated that MGd accumulates within cytoplasmic compartments. The sustained intracellular localization of MGd may, in part, account for its unique radiation and chemotherapy enhancement properties. Interferometric Fourier fluorescence microscopy is a potentially powerful tool in delineating and verifying localization sites of therapeutic agents.


Assuntos
Metaloporfirinas/análise , Microscopia de Interferência , Neoplasias Experimentais/metabolismo , Radiossensibilizantes/análise , Sarcoma/metabolismo , Animais , Transporte Biológico/efeitos dos fármacos , Núcleo Celular/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Meios de Cultura Livres de Soro/farmacologia , Retículo Endoplasmático/metabolismo , Corantes Fluorescentes , Complexo de Golgi/metabolismo , Lisossomos/metabolismo , Metaloporfirinas/farmacocinética , Camundongos , Microscopia de Fluorescência/métodos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Transplante de Neoplasias , Fotoquímica/métodos , Radiossensibilizantes/farmacocinética , Espectrometria de Fluorescência , Células Tumorais Cultivadas
18.
Nucl Med Biol ; 28(1): 59-65, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11182565

RESUMO

76Br-bromodeoxyuridine has previously been suggested as a PET tracer to characterize proliferation potential. However, in animal studies a large fraction of the tissue radioactivity is due to 76Br-bromide, which remains extracellular for extensive periods and contributes significantly to the level of radioactivity. The present project aimed at investigating whether in human brain tumors, sufficient amounts of 76Br-bromodeoxyuridine would be incorporated into DNA, to motivate further attempts with this tracer. Eight patients with brain tumors: 3 meningiomas, 2 astrocytoma grade IV, 1 astrocytoma oligodendroglioma grade II-IV and 2 metastases, were examined with PET and 76Br-BrdU on three occasions: immediately after injection of the tracer, at 4-6, and at 18-20 hours after administration. After the first PET study, diuresis was introduced and maintained for about 12 hours. About 20 hours after tracer administration, 200 mg/m(2) bromodeoxyuridine was administered to 7 patients median 5.8 (range 1-22) hours prior to operation allowing the immunohistochemical analysis of the proliferation potential. During the operation, tumor samples were taken and radioactivity in DNA extracted and measured. The uptake of radioactivity was higher in the tumors than in brain parenchyma. However, in the operative samples only 1-27% (average: 9%) of the radioactivity was found in the DNA fraction. The plasma radioactivity remained high throughout the study with only minimal signs of elimination by the diuresis. 76Br-BrdU is extensively metabolized to 76Br-bromide, and only a minor fraction of the radioactivity is found in the DNA fraction, making it unlikely that this tracer can be used for assessment of proliferation potential.


Assuntos
Astrocitoma/metabolismo , Neoplasias Encefálicas/metabolismo , Bromodesoxiuridina/farmacocinética , DNA de Neoplasias/metabolismo , Meningioma/metabolismo , Radiossensibilizantes/farmacocinética , Tomografia Computadorizada de Emissão , Idoso , Astrocitoma/química , Astrocitoma/diagnóstico por imagem , Neoplasias Encefálicas/química , Neoplasias Encefálicas/diagnóstico por imagem , Radioisótopos de Bromo , Bromodesoxiuridina/análise , Bromodesoxiuridina/sangue , DNA de Neoplasias/química , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Meningioma/química , Meningioma/diagnóstico por imagem , Pessoa de Meia-Idade , Radiossensibilizantes/análise
19.
J Neurosurg ; 93(3): 449-54, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10969943

RESUMO

OBJECT: The development of hypoxia in human gliomas is closely related to functional vasculature and the presence of hypoxia has important biological and therapeutic consequences. Assessment of hypoxia is necessary to understand its role in treatment response and to evaluate treatment strategies to improve tumor oxygenation. In this study, the authors report findings of their analysis of the degree of hypoxia in relation to other vascular parameters in a human intracerebral glioma xenograft. METHODS: In sections of tumor, hypoxic regions were identified immunohistochemically by using the hypoxic marker pimonidazole. The S-phase marker bromodeoxyuridine was used to detect cell proliferation, and the perfusion marker Hoechst 33342 was used to delineate perfused vessels. Vascular structures were stained with an endothelial marker. Hypoxic tumor regions were clearly present in this human intracerebral glioma model. Hypoxic areas were usually found in nonperfused regions, whereas tumor cell proliferation was especially marked in perfused tumor areas. Furthermore, by using in situ hybridization the authors identified infiltrating tumor cells in the normal brain. This feature is often observed in gliomas in patients. CONCLUSIONS: This model is a representative human glioma model that provides the researcher with the opportunity to analyze the relationship between the degree of hypoxia and vascular parameters, as well as to examine the effects of treatments aimed at modification of the oxygenation status of a tumor.


Assuntos
Neoplasias Encefálicas/fisiopatologia , Glioma/fisiopatologia , Hipóxia/fisiopatologia , Animais , Neoplasias Encefálicas/irrigação sanguínea , Neoplasias Encefálicas/patologia , Divisão Celular , Modelos Animais de Doenças , Glioma/irrigação sanguínea , Glioma/patologia , Camundongos , Camundongos Endogâmicos BALB C , Microcirculação , Nitroimidazóis/análise , Radiossensibilizantes/análise
20.
Int J Radiat Oncol Biol Phys ; 46(3): 653-9, 2000 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-10701745

RESUMO

PURPOSE: Changes in the sensitivity of intratumor quiescent (Q) and total cells to gamma-rays following thermal neutron irradiation with or without 10B-compound were examined. METHODS AND MATERIALS: 5-Bromo-2'-deoxyuridine (BrdU) was injected to SCC VII tumor-bearing mice intraperitoneally 10 times to label all the proliferating (P) tumor cells. As priming irradiation, thermal neutrons alone or thermal neutrons with 10B-labeled sodium borocaptate (BSH) or dl-p-boronophenylalanine (BPA) were administered. The tumor-bearing mice then received a series of gamma-ray radiation doses, 0 through 24 h after the priming irradiation. During this period, no BrdU was administered. Immediately after the second irradiation, the tumors were excised, minced, and trypsinized. Following incubation of tumor cells with cytokinesis blocker, the micronucleus (MN) frequency in cells without BrdU labeling (= Q cells at the time of priming irradiation) was determined using immunofluorescence staining for BrdU. The MN frequency in the total (P + Q) tumor cells was determined from the tumors that were not pretreated with BrdU before the priming irradiation. To determine the BrdU-labeled cell ratios in the tumors at the time of the second irradiation, each group also included mice that were continuously administered BrdU until just before the second irradiation using mini-osmotic pumps which had been implanted subcutaneously 5 days before the priming irradiation. RESULTS: In total cells, during the interval between the two irradiations, the tumor sensitivity to gamma-rays relative to that immediately after priming irradiation decreased with the priming irradiation ranking in the following order: thermal neutrons only > thermal neutrons with BSH > thermal neutrons with BPA. In contrast, in Q cells, during that time the sensitivity increased in the following order: thermal neutrons only < thermal neutrons with BSH < thermal neutrons with BPA. The longer the interval between the two irradiations, the higher was the BrdU-labeled cell ratio at the second irradiation. The labeled cell ratio at the same time point after each priming irradiation increased in the following order: thermal neutrons only < thermal neutrons with BSH < thermal neutrons with BPA. CONCLUSION: These findings indicated that the use of 10B-compound, especially BPA, in thermal neutron irradiation causes the recruitment from the Q to P population.


Assuntos
Terapia por Captura de Nêutron de Boro/métodos , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/radioterapia , Raios gama/uso terapêutico , Neoplasias Experimentais/patologia , Neoplasias Experimentais/radioterapia , Animais , Bromodesoxiuridina/administração & dosagem , Bromodesoxiuridina/análise , Carcinoma de Células Escamosas/química , Divisão Celular , Relação Dose-Resposta à Radiação , Feminino , Camundongos , Camundongos Endogâmicos C3H , Testes para Micronúcleos , Neoplasias Experimentais/química , Tolerância a Radiação , Radiossensibilizantes/administração & dosagem , Radiossensibilizantes/análise , Radiobiologia
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