Jiemin Guan1, Xiaoping Lai2, Xinna Wang3, Albert Wingnang Leung4, Hongwei Zhang3, Chuanshan Xu5. 1. School of Chinese Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong; School of Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, China. 2. School of Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, China. Electronic address: laixp88@126.com. 3. School of Chinese Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong. 4. School of Chinese Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong. Electronic address: awnleung@cuhk.edu.hk. 5. School of Chinese Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong. Electronic address: xcshan@163.com.
Abstract
BACKGROUND: Osteosarcoma is a common malignant bone tumor which threatens the life of young people worldwide. To explore alternative strategy for combating osteosarcoma, a light-emitting diode (LED) that activates methylene blue (MB) was used in the present study to investigate cell death of osteosarcoma-derived UMR106 cells. MATERIALS AND METHODS: Photocytotoxicity in UMR106 cells was investigated 24h after photodynamic activation of MB using sulforhodamine B (SRB) assay and light microscopy. Apoptosis induction was observed 24h after photodynamic treatment using a confocal laser scanning microscopy (CLSM) with Hoechst 33342 staining. The change in mitochondrial membrane potential (MMP) was analyzed using a flow cytometry with rhodamine 123 staining. RESULTS: MB under red light irradiation caused a drug-concentration (0-100μM) and light-dose (0-32J/cm(2)) dependent cytotoxicity in UMR106 cells. The SRB assay and light microscopy observed a significant decrease in the number of UMR106 cells attached to the bottom of culture well after LED light-activated MB (100μM, 32J/cm(2)). Nuclear shrinkage, chromatin condensation and fragmentation were found in the treated cells by nuclear staining. In addition, flow cytometry showed that the MMP in UMR106 cells was rapidly reduced by photo-activated MB (100μM, 32J/cm(2)). CONCLUSION: Photodynamic action of MB under LED irradiation could remarkably kill osteosarcoma cells and induce cell apoptosis as well as MMP collapse. Crown
BACKGROUND:Osteosarcoma is a common malignant bone tumor which threatens the life of young people worldwide. To explore alternative strategy for combating osteosarcoma, a light-emitting diode (LED) that activates methylene blue (MB) was used in the present study to investigate cell death of osteosarcoma-derived UMR106 cells. MATERIALS AND METHODS: Photocytotoxicity in UMR106 cells was investigated 24h after photodynamic activation of MB using sulforhodamine B (SRB) assay and light microscopy. Apoptosis induction was observed 24h after photodynamic treatment using a confocal laser scanning microscopy (CLSM) with Hoechst 33342 staining. The change in mitochondrial membrane potential (MMP) was analyzed using a flow cytometry with rhodamine 123 staining. RESULTS:MB under red light irradiation caused a drug-concentration (0-100μM) and light-dose (0-32J/cm(2)) dependent cytotoxicity in UMR106 cells. The SRB assay and light microscopy observed a significant decrease in the number of UMR106 cells attached to the bottom of culture well after LED light-activated MB (100μM, 32J/cm(2)). Nuclear shrinkage, chromatin condensation and fragmentation were found in the treated cells by nuclear staining. In addition, flow cytometry showed that the MMP in UMR106 cells was rapidly reduced by photo-activated MB (100μM, 32J/cm(2)). CONCLUSION: Photodynamic action of MB under LED irradiation could remarkably kill osteosarcoma cells and induce cell apoptosis as well as MMP collapse. Crown
Authors: Ancély F Dos Santos; Letícia F Terra; Rosangela A M Wailemann; Talita C Oliveira; Vinícius de Morais Gomes; Marcela Franco Mineiro; Flávia Carla Meotti; Alexandre Bruni-Cardoso; Maurício S Baptista; Leticia Labriola Journal: BMC Cancer Date: 2017-03-15 Impact factor: 4.430