Unveiling the molecular mechanisms involved in the cytotoxicity induced by photodynamic therapy in human breast cancer cells (original) (raw)

Photodiagnosis and Photodynamic Therapy, 2015

Abstract

s / Photodiagnosis and Photodynamic Therapy 12 (2015) 325–375 349 treatment outcome as an attempt to predict the PDT efficiency. The clinical study is being conducted at Hospital Amaral Carvalho in Jahu, and 100 lesions of the basal cell carcinoma types treated with PDT using Aminolevulinic Acid with photosensitizer. The thermal changes of the lesions are registeredwith a thermal imager (Fluke® FLK-Ti400) during four phases: lesion initial, lesion curetted, after the drug incubation and after the illumination in the two sessions. The temperature variation was compared with the result of the tissue biopsies after 30 days. Significant results are being collect in order to better understand the PDT response. http://dx.doi.org/10.1016/j.pdpdt.2015.07.095 Unveiling the molecular mechanisms involved in the cytotoxicity induced by photodynamic therapy in human breast cancer cells A.F. dos Santos, L.F. Terra, R.A.M. Wailemann, T.C. Oliveira, M.S. Baptista, L. Labriola Biochemistry Department, Chemistry Institute, University of Sao Paulo (USP), Sao Paulo, Brazil The efficacy of photodynamic therapy (PDT) on mammary tumors as well as the mechanisms of cell death remains unclear. We evaluated the cytotoxicity of PDT by using methylene blue (MB-PDT) in two (2D) and three (3D) dimension cultures of human breast tumor cells and the death pathways involved. Invasive, non-invasive and non-tumorigenic cells were incubated with different MB concentrations and irradiated ( =640nm) at 4.5 J/cm2. Fluorescence microscopy was used to evaluate cell viability and death. Autophagy was evaluated also by Western blotting. The role of autophagy was investigated using chloroquine (CQ) and LY294002 (LY) as inhibitors and rapamycin (RAPA) as activator. MB-PDT increased cell death of both tumoral cell lines in 2D or 3D culture, but was significantly lower in non-tumorigenic cells despite the higher intracellular concentration ofMB. No dark effect and no morphological signs of apoptotic were observed, but there were autophagy increase. After cotreatmentwith CQor LY the cytotoxicity was increased and with RAPA it was lowered. We showed that MB-PDT induced selective cell death in a model that recapitulates the morphology of glandular epithelium, and that autophagy is mainly related with cytoprotection. Our observations indicate that PDT is an effective therapy displaying minimal side effects. http://dx.doi.org/10.1016/j.pdpdt.2015.07.096 Comparison of the response and mechanisms of MAL-PDT of different squamous carcinoma cell lines Daniela Leon1, Ramon Silva1, Natalia Inada2, Cristina Kurachi2, Aleida Vivallo1, Priscilla Brebi1, Juan Carlos Roa3 1 Departamento de Anatomia Patologica, Laboratorio de Patologia Molecular BIOREN-CEGIN, Universidad de La Frontera, Chile 2 Sao Carlos Institute of Physics, University of Sao Paulo, Brazil 3 Departamento de Patologia, Facultad de Medicina, Pontificia Universidad Catolica de Chile, Chile Introduction: Non-melanoma skin cancer (NMSC) is the most common neoplasia worldwide and can be treated with Photodynamic Therapy (PDT). NMSC has good outcome after PDT, however, recurrent lesions has been reported. The aim of this study was to compare the effect of PDT on two non-melanoma skin cancer cell lines. Methodology: A keratinocytes cell line and two squamous carcinoma cell lines, A-431 and HSC-1, were used. PDT was carried outusingmethyl aminolevulinate (MAL) as aprecursor of Protoporphyrin IX. All cell lineswere incubatedwith distinct concentrations ofMAL and irradiatedwith different red light fluences. Cell viability wasevaluated24hafter PDTbyMTT, TrypanBluedyeexclusionand flow cytometry assays. In addition, ROS production was measured by flow cytometry. Results: A-431 cells were more resistant to PDT cytotoxic effect than HSC-1 cells compared the same condition of treatment. Meanwhile, keratinocyteswere themost sensitive to PDT. ROS production after PDT varied among the skin cell type. Conclusion: Cells from squamous skin cancer have a different response to the same PDT conditions.Wewill investigate the resistant phenotype of those cells for improving the effect of PDT on them. http://dx.doi.org/10.1016/j.pdpdt.2015.07.097 Penetration depth of the 664-nm semiconductor laser light with talaporfin sodium into human brain tissue with glioma Soko Ikuta1, Yuki Kawase2, Yoshihiro Muragaki1,3, Takashi Maruyama1,3, Masayuki Nitta3, Taiichi Saito3, Hiroshi Iseki1 1 Institute of Advanced Biomedical Engineering & Science, Tokyo Women’s Medical University, Japan 2 Panasonic Healthcare Co., Ltd., Japan 3 Department of Neurosurgery, Tokyo Women’s Medical University, Japan Glioma cell has characteristicswhich invasively spread into normal brain tissue. Talaporfin-PDT is assumed to be a promising to affect infiltrating glioma cells where the extirpation cavity, but there is no data showed about its optical penetration depth and cellular cytotoxicity in human brain tissue. This study evaluated these affections with…

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