RESUMO
BACKGROUND: Photosensitizer based fluorescence imaging and spectroscopy is fast becoming a promising approach for cancer detection. The purpose of this study was to examine the use of the photosensitizer chlorin e6 (Ce6) formulated in polyvinylpyrrolidone (PVP) as a potential exogenous fluorophore for fluorescence imaging and spectroscopic detection of human cancer tissue xenografted in preclinical models as well as in a patient. METHODS: Fluorescence imaging was performed on MGH human bladder tumor xenografted on both the chick chorioallantoic membrane (CAM) and the murine model using a fluorescence endoscopy imaging system. In addition, fiber optic based fluorescence spectroscopy was performed on tumors and various normal organs in the same mice to validate the macroscopic images. In one patient, fluorescence imaging was performed on angiosarcoma lesions and normal skin in conjunction with fluorescence spectroscopy to validate Ce6-PVP induced fluorescence visual assessment of the lesions. RESULTS: Margins of tumor xenografts in the CAM model were clearly outlined under fluorescence imaging. Ce6-PVP-induced fluorescence imaging yielded a specificity of 83% on the CAM model. In mice, fluorescence intensity of Ce6-PVP was higher in bladder tumor compared to adjacent muscle and normal bladder. Clinical results confirmed that fluorescence imaging clearly captured the fluorescence of Ce6-PVP in angiosarcoma lesions and good correlation was found between fluorescence imaging and spectral measurement in the patient. CONCLUSION: Combination of Ce6-PVP induced fluorescence imaging and spectroscopy could allow for optical detection and discrimination between cancer and the surrounding normal tissues. Ce6-PVP seems to be a promising fluorophore for fluorescence diagnosis of cancer.
Assuntos
Membrana Corioalantoide/patologia , Modelos Animais de Doenças , Medições Luminescentes/métodos , Microscopia de Fluorescência/métodos , Povidona , Protoporfirinas , Espectrometria de Fluorescência/métodos , Neoplasias da Bexiga Urinária/patologia , Animais , Linhagem Celular Tumoral , Embrião de Galinha , Clorofilídeos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Nus , Porfirinas , Povidona/análise , Protoporfirinas/análise , Sensibilidade e EspecificidadeRESUMO
Tumor response to photodynamic therapy (PDT) is dependent on treatment parameters used. In particular, the light fluence rate may be an important determinant of the treatment outcome. In this clinical case report, we describe the response of angiosarcoma to PDT carried out using different fluence rates and drug and light doses. A patient with recurrent multifocal angiosarcoma of the head and neck was recruited for PDT. A new generation chlorin-based photosensitizer, Fotolon, was administered at a dose of 2.0 to 5.7 mg/kg. The lesions were irradiated with 665 nm laser light for a light dose of 65 to 200 J/cm2 delivered at a fluence rate of 80 or 150 mW/cm2. High dose PDT carried out at a high fluence rate resulted in local control of the disease for up to a year; however, the disease recurred and PDT had to be repeated. PDT of new lesions carried out at a lower fluence rate resulted in tumor eradication. More significantly, it also resulted in spontaneous remission of neighboring and distant untreated lesions. Repeat PDT carried out on a recurrent lesion at a lower fluence rate resulted in eradication of both treated and untreated lesions despite the lower total light dose delivered. Immunohistochemical examination of biopsy samples implies that PDT could have activated a cell-mediated immune response against untreated lesions. Subsequent histopathological examination of the lesion sites showed negative for disease. Our clinical observations show that lower fluence rate PDT results in better outcome and also indicate that the fluence rate, rather than the total light dose, is a more crucial determinant of the treatment outcome. Specifically, lower fluence rate PDT appears to activate the body's immune response against untreated lesions.
Assuntos
Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Hemangiossarcoma/tratamento farmacológico , Recidiva Local de Neoplasia , Fotoquimioterapia/métodos , Neoplasias Cutâneas/tratamento farmacológico , Clorofilídeos , Relação Dose-Resposta a Droga , Relação Dose-Resposta à Radiação , Neoplasias de Cabeça e Pescoço/imunologia , Neoplasias de Cabeça e Pescoço/patologia , Hemangiossarcoma/imunologia , Hemangiossarcoma/patologia , Humanos , Imunidade Celular/efeitos dos fármacos , Imunidade Celular/efeitos da radiação , Lasers , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/imunologia , Fármacos Fotossensibilizantes/administração & dosagem , Fármacos Fotossensibilizantes/uso terapêutico , Porfirinas , Povidona , Protoporfirinas/administração & dosagem , Protoporfirinas/uso terapêutico , Neoplasias Cutâneas/imunologia , Neoplasias Cutâneas/patologiaRESUMO
BACKGROUND: Photodynamic therapy (PDT) involves the administration of a tumor-localizing photosensitizing drug, which is activated by light of specific wavelength in the presence of molecular oxygen thus generating reactive oxygen species that is toxic to the tumor cells. PDT selectively destroys photosensitized tissue leading to various cellular and molecular responses. The present study was designed to examine the angiogenic responses at short (0.5 h) and long (6 h) drug light interval (DLI) hypericin-PDT (HY-PDT) treatment at 24 h and 30 days post treatment in a human bladder carcinoma xenograft model. As short DLI targets tumor vasculature and longer DLI induces greater cellular damage, we hypothesized a differential effect of these treatments on the expression of angiogenic factors. RESULTS: Immunohistochemistry (IHC) results showed minimal CD31 stained endothelium at 24 h post short DLI PDT indicating extensive vascular damage. Angiogenic proteins such as vascular endothelial growth factor (VEGF), tumor necrosis growth factor-alpha (TNF-alpha), interferon-alpha (IFN-alpha) and basic fibroblast growth factor (bFGF) were expressed to a greater extent in cellular targeting long DLI PDT compared to vascular mediated short DLI PDT. Gene expression profiling for angiogenesis pathway demonstrated downregulation of adhesion molecules - cadherin 5, collagen alpha 1 and 3 at 24 h post treatment. Hepatocyte growth factor (HGF) and Ephrin-A3 (EFNA3) were upregulated in all treatment groups suggesting a possible activation of c-Met and Ephrin-Eph signaling pathways. CONCLUSION: In conclusion, long DLI HY-PDT induces upregulation of angiogenic proteins. Differential expression of genes involved in the angiogenesis pathway was observed in the various groups treated with HY-PDT.
Assuntos
Proteínas Angiogênicas/genética , Perfilação da Expressão Gênica , Neovascularização Patológica/tratamento farmacológico , Perileno/análogos & derivados , Fotoquimioterapia , Fármacos Fotossensibilizantes/farmacologia , Neoplasias da Bexiga Urinária/tratamento farmacológico , Proteínas Angiogênicas/metabolismo , Animais , Antracenos , Western Blotting , Linhagem Celular Tumoral , Endoscopia/métodos , Fluorescência , Humanos , Imuno-Histoquímica , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Microscopia Confocal , Neovascularização Patológica/genética , Neovascularização Patológica/metabolismo , Neovascularização Patológica/patologia , Perileno/farmacologia , Reação em Cadeia da Polimerase , Análise Serial de Proteínas , Fatores de Tempo , Neoplasias da Bexiga Urinária/irrigação sanguínea , Neoplasias da Bexiga Urinária/genética , Neoplasias da Bexiga Urinária/metabolismo , Neoplasias da Bexiga Urinária/patologia , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
BACKGROUND: Photodynamic therapy (PDT) is an effective local cancer treatment that involves light activation of a photosensitizer, resulting in oxygen-dependent, free radical-mediated cell death. Little is known about the comparative efficacy of PDT in treating non-small cell lung carcinoma (NSCLC) and small cell lung carcinoma (SCLC), despite ongoing clinical trials treating lung cancers. The present study evaluated the potential use of chlorin e6 - polyvinylpyrrolidone (Ce6-PVP) as a multimodality photosensitizer for fluorescence detection and photodynamic therapy (PDT) on NSCLC and SCLC xenografts. RESULTS: Human NSCLC (NCI-H460) and SCLC (NCI-H526) tumor cell lines were used to establish tumor xenografts in the chick chorioallantoic membrane (CAM) model as well as in the Balb/c nude mice. In the CAM model, Ce6-PVP was applied topically (1.0 mg/kg) and fluorescence intensity was charted at various time points. Tumor-bearing mice were given intravenous administration of Ce6-PVP (2.0 mg/kg) and laser irradiation at 665 nm (fluence of 150 J/cm2 and fluence rate of 125 mW/cm2). Tumor response was evaluated at 48 h post PDT. Studies of temporal fluorescence pharmacokinetics in CAM tumor xenografts showed that Ce6-PVP has a selective localization and a good accuracy in demarcating NSCLC compared to SCLC from normal surrounding CAM after 3 h post drug administration. Irradiation at 3 h drug-light interval showed greater tumor necrosis against human NSCLC xenografts in nude mice. SCLC xenografts were observed to express resistance to photosensitization with Ce6-PVP. CONCLUSION: The formulation of Ce6-PVP is distinctly advantageous as a diagnostic and therapeutic agent for fluorescence diagnosis and PDT of NSCLC.
Assuntos
Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma de Células Pequenas/tratamento farmacológico , Porfirinas/uso terapêutico , Povidona/uso terapêutico , Radiossensibilizantes/uso terapêutico , Animais , Carcinoma Pulmonar de Células não Pequenas/diagnóstico , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma de Células Pequenas/diagnóstico , Carcinoma de Células Pequenas/patologia , Linhagem Celular Tumoral , Embrião de Galinha , Clorofilídeos , Membrana Corioalantoide/metabolismo , Fluorescência , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Fotoquimioterapia , Porfirinas/farmacocinética , Povidona/farmacocinética , Radiossensibilizantes/farmacocinética , Transplante HeterólogoRESUMO
The current study investigates the potential of the photosensitizer Fotolon as a photodynamic diagnostic agent in an in vivo system of human nasopharyngeal carcinoma (NPC) cells. Fotolon (formerly known as Photolon) represents a complex of trisodium salt Chlorin e6 and polyvinylpyrrolidone (PVP). It is a photosensitizing agent that selectively accumulates in tumour tissues. A poorly differentiated human nasopharyngeal carcinoma cell line CNE-2 was xenografted on 6-8 weeks old male balb/c nude mice for our photodynamic diagnostic (PDD) studies. A fluorescence endoscope system was used to perform the in vivo macroscopic fluorescence digital imaging of tumours on the mice. The macroscopic images were further analyzed for distribution of fluorescence intensity. Laser fluorescence confocal microscopy was used to capture microscopic fluorescence images of the tumour tissue. In our PDD studies, we observed intense fluorescence in the tumour and tumour vasculature of human NPC xenografts on nude mice as early as 15-min post administration of Fotolon. High fluorescence selectivity in the tumour tissue was observed between 3-h and 6-h time points. The tumour to normal tissue selectivity ratio was highest at 6 h. The microfluorescence tumour imaging shows similar trends confirming the macroscopic fluorescence data. Fotolon shows much promise as a good photodiagnostic agent.