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RIP3 expression induces a death profile change in U2OS osteosarcoma cells after 5‐ALA‐PDT
Author(s) -
Coupienne Isabelle,
Fettweis Grégory,
Piette Jacques
Publication year - 2011
Publication title -
lasers in surgery and medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 112
eISSN - 1096-9101
pISSN - 0196-8092
DOI - 10.1002/lsm.21088
Subject(s) - apoptosis , programmed cell death , necrosis , autophagy , caspase , wild type , cell culture , viability assay , tumor necrosis factor alpha , caspase 3 , transfection , cancer research , chemistry , biology , microbiology and biotechnology , immunology , biochemistry , genetics , gene , mutant
Background and Objective The receptor‐interacting protein 3 (RIP3) has recently been outlined as a key necrosis mediator but is also thought to participate in the regulation of apoptosis. The aim of this study is to compare the cell death profile induced by 5‐aminolevulic acid (5‐ALA)‐mediated photodynamic therapy (PDT) in the RIP3‐deficient cell line U2OS and in U2OS cells in which the expression of RIP3 was restored. Materials and Methods RIP3‐expressing U2OS cells (RIP3‐U2OS) were obtained after transfection and antibiotic selection. Wild type and RIP3‐U2OS cells were treated by 5‐ALA‐PDT. Overall cell viability was evaluated and different parameters characteristic of apoptosis, autophagy, and necrosis were studied. Results Surprisingly, the survival of RIP3‐U2OS cells was higher compared to that of the wild type cells. In addition, RIP3‐U2OS cell death was decreased by a zVAD‐fmk pre‐treatment. A higher cleavage of caspase‐3, 7, 8, 9, and PARP was also detected in these cells, pointing out to the activation of caspase‐dependent apoptosis. In parallel, a thrust of autophagy was clearly identified in the RIP3‐U2OS cells. Conversely, RIP3‐U2OS exhibited a lower level of necrosis than the wild types. Interestingly, necrostatin‐1 efficiently decreased necrosis level in RIP3‐U2OS but not in wild type cells. Conclusion Expression of RIP3 in U2OS cells led to a better survival but also to a death profile change in response to PDT. The apoptotic and autophagic pathways were clearly up‐regulated compared to the RIP3‐deficient wild type cells. However, induction of necrosis was weaker in the RIP3‐U2OS cells. In this context, autophagy is likely to play a protective role against PDT‐induced cell death and to allow a better survival of RIP3‐U2OS cells. This work also highlights the important role played by RIP3 in the apoptotic pathway, although the modalities are still widely unknown. Lasers Surg. Med. 43:557–564, 2011. © 2011 Wiley‐Liss, Inc.