RESUMO
Clinical outcome of patients suffering from head neck squamous cell carcinomas is still poor due to recurrent disease and surgical limitations. There is still a demand for multimodality approaches and new therapeutic options. Hypericin is a promising phototoxic drug which was investigated for its effects on head neck squamous cell carcinoma cells in vitro. FaDu cells incubated with or without hypericin were illuminated (450-700 nm, 50,000 lx) for different time periods. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide- and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay were used to score metabolic and apoptotic activity. Even after the shortest illumination FaDu cells incubated with hypericin showed massive reduction of metabolism and excessive apoptosis. This was present even with the lowest hypericin concentration. Cells without hypericin or without illumination were not affected. These photosensitizing effects of hypericin could be suitable for clinical application and could lead to the development of an intraoperative photodynamic therapy of head neck squamous cell carcinomas.
Assuntos
Carcinoma de Células Escamosas/patologia , Neoplasias de Cabeça e Pescoço/patologia , Perileno/análogos & derivados , Fármacos Fotossensibilizantes/farmacologia , Antracenos , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Humanos , Marcação In Situ das Extremidades Cortadas , Perileno/farmacologia , Fotoquimioterapia , Carcinoma de Células Escamosas de Cabeça e PescoçoRESUMO
Alport syndrome is a hereditary type IV collagen disease leading to progressive renal fibrosis, hearing loss and ocular changes. End stage renal failure usually develops during adolescence. COL4A3-/- mice serve as an animal model for progressive renal scarring in Alport syndrome. The present study evaluates the role of Discoidin Domain Receptor 1 (DDR1) in cell-matrix interaction involved in pathogenesis of Alport syndrome including renal inflammation and fibrosis. DDR1/COL4A3 Double-knockouts were compared to COL4A3-/- mice with 50% or 100% expression of DDR1, wildtype controls and to DDR1-/- COL4A3+/+ controls for over 6years. Double-knockouts lived 47% longer, mice with 50% DDR1 lived 29% longer and showed improved renal function (reduction in proteinuria and blood urea nitrogen) compared to animals with 100% DDR1 expression. Loss of DDR1 reduced proinflammatory, profibrotic cells via signaling of TGFbeta, CTGF, NFkappaB and IL-6 and decreased deposition of extracellular matrix. Immunogold-staining and in-situ hybridisation identified podocytes as major players in DDR1-mediated fibrosis and inflammation within the kidney. In summary, glomerular epithelial cells (podocytes) express DDR1. Loss of DDR1-expression in the kidney delayed renal fibrosis and inflammation in hereditary type IV collagen disease. This supports our hypothesis that podocyte-matrix interaction via collagen receptors plays an important part in progression of renal fibrosis in Alport disease. The blockade of collagen-receptor DDR1 might serve as an important new therapeutic concept in progressive fibrotic and inflammatory diseases in the future.
Assuntos
Colágeno Tipo IV/metabolismo , Fibrose/fisiopatologia , Glomérulos Renais/fisiopatologia , Nefrite Hereditária/fisiopatologia , Receptores Proteína Tirosina Quinases/metabolismo , Animais , Complexo CD3/metabolismo , Colágeno Tipo IV/genética , Fator de Crescimento do Tecido Conjuntivo/metabolismo , Receptor com Domínio Discoidina 1 , Feminino , Fibrose/metabolismo , Humanos , Imuno-Histoquímica , Hibridização In Situ , Glomérulos Renais/metabolismo , Glomérulos Renais/ultraestrutura , Longevidade , Masculino , Camundongos , Camundongos Endogâmicos ICR , Camundongos Knockout , Microscopia Eletrônica , NF-kappa B/metabolismo , Nefrite Hereditária/metabolismo , Proteinúria/metabolismo , RNA/química , RNA/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator de Crescimento Transformador beta/metabolismo , Ureia/sangueRESUMO
The renal cell carcinoma (RCC) is extremely resistant to chemotherapy and radiotherapy. The prognosis of patients with metastatic RCC still remains poor, the median survival is less than 12 months. Therefore, new therapeutic options are desirable. The aim of this study was to investigate the photosensitizing and radiosensitizing effects of hypericin on human RCC cells in vitro. First the RCC-derived cell lines A498 and ACHN were incubated with different concentrations of hypericin. In vitro uptake and intracellular distribution of hypericin were confirmed by fluorescence microscopy. Subsequently cells were illuminated and irradiated with a dose of 2-8 Gy, respectively. Finally, metabolic activity, apoptosis and clonogenic survival were investigated. Uptake of hypericin was observed for almost all cells. Hypericin treatment combined with illumination led to a 94-97% decrease in metabolic activity and caused apoptosis in nearly 100% of RCC cells. Hypericin enhanced the radiosensitivity of A498 cells in vitro. The clonogenic survival after irradiation was significantly reduced by hypericin treatment. Taken together, the photosensitizing and radiosensitizing effects of hypericin on human RCC cells we found in this investigation could be of clinical relevance, e.g. for radiotherapy and intraoperative photodynamic therapy, respectively.
