Fluence Rate Determines PDT Efficiency in Breast Cancer Cells Displaying Different GSH Levels

Autor(es)

dos Santos, Ancely F. ; de Almeida, Daria Raquel Q. ; Terra, Leticia F. ; Wailemann, Rosangela A. M. ; Gomes, Vinicius M. ; Arini, Gabriel S. ; Ravagnani, Felipe G. ; Baptista, Mauricio S. ; Labriola, Leticia

• Tipo de documento: Artigo Científico
• Fonte: Photochemistry and Photobiology; v. 96, n. 3, p. 10-pg., 2019-12-17.

Resumo

Photodynamic therapy (PDT) appears as a promising alternative in the treatment of breast cancer since it can be highly effective in curing cancer while preserving normal tissue. However, predicting outcomes in PDT still constitutes a great challenge. One of the parameters that are usually empirically determined is the rate of photon flux delivered to the tissue (light fluence rate). In the present study, we intended to understand why monolayers of human cells derived from mammary adenocarcinomas (MDA-MB-231 and MCF-7) respond quite differently to fluence rates (cells were irradiated either for 6 or for 16 min) at a fixed light dose (4.5 J cm(-2)) delivered with an array of LEDs in a typical methylene blue PDT protocol. While death rates of MDA-MB-231 cells were insensitive to the fluence rate, MCF-7 cells showed a quite impressive (three times) decrease in cell death levels in the shorter irradiation protocol. Independent on cell type cell death was invariably correlated with the depletion of reduced glutathione intracellular levels and consequently with widespread redox misbalance. Our data show the potential to optimize fluence rates to provide exhaustion of the cell antioxidant responses in order to circumvent therapy resistance of breast tumors. (AU)

• Processo FAPESP: 13/07937-8 - Redoxoma
• Beneficiário: Ohara Augusto
• Modalidade de apoio: Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs
• Processo FAPESP: 17/03618-6 - Estudo da função de HSPB1 na modulação da resposta a proteínas mal dobradas em modelos de Diabetes tipo 1
• Beneficiário: Leticia Labriola
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 19/09517-2 - Avaliação da relação entre variação da fluência de energia e as vias de morte celular induzidas pela terapia fotodinâmica com azul de metileno em tumores mamários
• Beneficiário: Gabriel Santos Arini
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica
• Processo FAPESP: 16/04676-7 - Terapia fotodinâmica para tratamento do câncer de mama: estudos pré-clínicos
• Beneficiário: Ancély Ferreira dos Santos
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado