Ibuprofen-induced Walker 256 tumor cell death: cytochrome c release from functional mitochondria and enhancement by calcineurin inhibition

BackgroundThe immune response to cancer is often conceptualized with the cancer immunity cycle. An essential step in this interpretation is that antigens released by dying tumors are presented by dendritic cells to naive or memory T cells in the tumor-draining lymph nodes. Whether tumor cell death resulting from cytotoxicity, as mediated by T cells or natural killer (NK) lymphocytes, is actually immunogenic currently remains unknown.MethodsIn this study, tumor cells were killed by antigen-specific T-cell receptor (TCR) transgenic CD8 T cells or activated NK cells. Immunogenic cell death was studied analyzing the membrane exposure of calreticulin and the release of high mobility group box 1 (HMGB1) by the dying tumor cells. Furthermore, the potential immunogenicity of the tumor cell debris was evaluated in immunocompetent mice challenged with an unrelated tumor sharing only one tumor-associated antigen and by class I major histocompatibility complex (MHC)-multimer stainings. Mice deficient inBatf3,Ifnar1andSting1were used to study mechanistic requirements.ResultsWe observe in cocultures of tumor cells and effector cytotoxic cells, the presence of markers of immunogenic cell death such as calreticulin exposure and soluble HMGB1 protein. Ovalbumin (OVA)-transfected MC38 colon cancer cells, exogenously pulsed to present the gp100 epitope are killed in culture by mouse gp100-specific TCR transgenic CD8 T cells. Immunization of mice with the resulting destroyed cells induces epitope spreading as observed by detection of OVA-specific T cells by MHC multimer staining and rejection of OVA+EG7 lymphoma cells. Similar results were observed in mice immunized with cell debris generated by NK-cell mediated cytotoxicity. Mice deficient inBatf3-dependent dendritic cells (conventional dendritic cells type 1, cDC1) fail to develop an anti-OVA response when immunized with tumor cells killed by cytotoxic lymphocytes. In line with this, cultured cDC1 dendritic cells uptake and can readily cross-present antigen from cytotoxicity-killed tumor cells to cognate CD8+T lymphocytes.ConclusionThese results support that an ongoing cytotoxic antitumor immune response can lead to immunogenic tumor cell death.

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DNA polymerase activities in fractionated walker-256 tumor cell nuclei

Biochemical and Biophysical Research Communications ◽

10.1016/0006-291x(70)90923-x ◽

1970 ◽

Vol 40 (5) ◽

pp. 1201-1208 ◽

Cited By ~ 6

Author(s):

N. Raghuveer Ballal ◽

Michael S. Collins ◽

Richard M. Halpern ◽

Roberts A. Smith

Keyword(s):

Tumor Cell ◽

Dna Polymerase ◽

Cell Nuclei ◽

Walker 256 ◽

Walker 256 Tumor

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Photodynamic Therapy with Liposomal Zinc Phthalocyanine and Tirapazamine Increases Tumor Cell Death via DNA Damage

Journal of Biomedical Nanotechnology ◽

10.1166/jbn.2017.2327 ◽

2017 ◽

Vol 13 (2) ◽

pp. 204-220 ◽

Cited By ~ 7

Author(s):

Mans Broekgaarden ◽

Ruud Weijer ◽

AlbertC. van Wijk ◽

RuudC. Cox ◽

MaartenR. Egmond ◽

...

Keyword(s):

Dna Damage ◽

Cell Death ◽

Photodynamic Therapy ◽

Tumor Cell ◽

Zinc Phthalocyanine ◽

Tumor Cell Death

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Metformin inhibits mitochondrial permeability transition and cell death: a pharmacological in vitro study

Biochemical Journal ◽

10.1042/bj20040885 ◽

2004 ◽

Vol 382 (3) ◽

pp. 877-884 ◽

Cited By ~ 102

Author(s):

Bruno GUIGAS ◽

Dominique DETAILLE ◽

Christiane CHAUVIN ◽

Cécile BATANDIER ◽

Frédéric De OLIVEIRA ◽

...

Keyword(s):

Cell Death ◽

Cytochrome C ◽

Mitochondrial Permeability Transition ◽

Permeability Transition ◽

Cytochrome C Release ◽

Intact Cells ◽

Human Carcinoma ◽

Butyl Hydroperoxide ◽

Mitochondrial Permeability ◽

New Findings

Metformin, a drug widely used in the treatment of Type II diabetes, has recently received attention owing to new findings regarding its mitochondrial and cellular effects. In the present study, the effects of metformin on respiration, complex 1 activity, mitochondrial permeability transition, cytochrome c release and cell death were investigated in cultured cells from a human carcinoma-derived cell line (KB cells). Metformin significantly decreased respiration both in intact cells and after permeabilization. This was due to a mild and specific inhibition of the respiratory chain complex 1. In addition, metformin prevented to a significant extent mitochondrial permeability transition both in permeabilized cells, as induced by calcium, and in intact cells, as induced by the glutathione-oxidizing agent t-butyl hydroperoxide. This effect was equivalent to that of cyclosporin A, the reference inhibitor. Finally, metformin impaired the t-butyl hydroperoxide-induced cell death, as judged by Trypan Blue exclusion, propidium iodide staining and cytochrome c release. We propose that metformin prevents the permeability transition-related commitment to cell death in relation to its mild inhibitory effect on complex 1, which is responsible for a decreased probability of mitochondrial permeability transition.

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