Abstract
Autophagy is an intracellular recycling mechanism that helps cells to survive against environmental stress and nutritional starvation. We have recently shown that prostate cancers undergo metabolic stress and caspase-independent cell death following exposure to arginine deiminase (ADI, an enzyme that degrades arginine in tissue). The aims of our current investigation into the application of ADI as a novel cancer therapy are to identify the components mediating tumor cell death, and to determine the role of autophagy (stimulated by ADI and/or rapamycin) on cell death. Using advanced fluorescence microscopy techniques including 3D deconvolution and superresolution structured-illumination microscopy (SIM), we show that prostate tumor cells that are killed after exposure to ADI for extended periods, exhibit a morphology that is distinct from caspase-dependent apoptosis; and that autophagosomes forming as a result of ADI stimulation contain DAPI-stained nuclear material. Fluorescence imaging (as well as cryo-electron microscopy) show a breakdown of both the inner and outer nuclear membranes at the interface between the cell nucleus and aggregated autophagolysosomes. Finally, the addition of N-acetyl cysteine (or NAC, a scavenger for reactive oxygen species) effectively abolishes the appearance of autophagolysosomes containing nuclear material. We hope to continue this research to understand the processes that govern the survival or death of these tumor cells, in order to develop methods to improve the efficacy of cancer pharmacotherapy.
Original language | English (US) |
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Title of host publication | Progress in Biomedical Optics and Imaging - Proceedings of SPIE |
Volume | 8587 |
DOIs | |
State | Published - 2013 |
Event | Imaging, Manipulation, and Analysis of Biomolecules, Cells, and Tissues XI - San Francisco, CA, United States Duration: Feb 2 2013 → Feb 5 2013 |
Other
Other | Imaging, Manipulation, and Analysis of Biomolecules, Cells, and Tissues XI |
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Country | United States |
City | San Francisco, CA |
Period | 2/2/13 → 2/5/13 |
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Keywords
- autophagy
- cancer biology
- cell death
- fluorescence microscopy
- metabolic stress
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Electronic, Optical and Magnetic Materials
- Biomaterials
- Radiology Nuclear Medicine and imaging
Cite this
Microscopic analysis of cell death by metabolic stress-induced autophagy in prostate cancer. / Changou, Chun; Cheng, R. Holland; Bold, Richard J; Kung, Hsing-Jien; Chuang, Frank.
Progress in Biomedical Optics and Imaging - Proceedings of SPIE. Vol. 8587 2013. 85870D.Research output: Chapter in Book/Report/Conference proceeding › Conference contribution
}
TY - GEN
T1 - Microscopic analysis of cell death by metabolic stress-induced autophagy in prostate cancer
AU - Changou, Chun
AU - Cheng, R. Holland
AU - Bold, Richard J
AU - Kung, Hsing-Jien
AU - Chuang, Frank
PY - 2013
Y1 - 2013
N2 - Autophagy is an intracellular recycling mechanism that helps cells to survive against environmental stress and nutritional starvation. We have recently shown that prostate cancers undergo metabolic stress and caspase-independent cell death following exposure to arginine deiminase (ADI, an enzyme that degrades arginine in tissue). The aims of our current investigation into the application of ADI as a novel cancer therapy are to identify the components mediating tumor cell death, and to determine the role of autophagy (stimulated by ADI and/or rapamycin) on cell death. Using advanced fluorescence microscopy techniques including 3D deconvolution and superresolution structured-illumination microscopy (SIM), we show that prostate tumor cells that are killed after exposure to ADI for extended periods, exhibit a morphology that is distinct from caspase-dependent apoptosis; and that autophagosomes forming as a result of ADI stimulation contain DAPI-stained nuclear material. Fluorescence imaging (as well as cryo-electron microscopy) show a breakdown of both the inner and outer nuclear membranes at the interface between the cell nucleus and aggregated autophagolysosomes. Finally, the addition of N-acetyl cysteine (or NAC, a scavenger for reactive oxygen species) effectively abolishes the appearance of autophagolysosomes containing nuclear material. We hope to continue this research to understand the processes that govern the survival or death of these tumor cells, in order to develop methods to improve the efficacy of cancer pharmacotherapy.
AB - Autophagy is an intracellular recycling mechanism that helps cells to survive against environmental stress and nutritional starvation. We have recently shown that prostate cancers undergo metabolic stress and caspase-independent cell death following exposure to arginine deiminase (ADI, an enzyme that degrades arginine in tissue). The aims of our current investigation into the application of ADI as a novel cancer therapy are to identify the components mediating tumor cell death, and to determine the role of autophagy (stimulated by ADI and/or rapamycin) on cell death. Using advanced fluorescence microscopy techniques including 3D deconvolution and superresolution structured-illumination microscopy (SIM), we show that prostate tumor cells that are killed after exposure to ADI for extended periods, exhibit a morphology that is distinct from caspase-dependent apoptosis; and that autophagosomes forming as a result of ADI stimulation contain DAPI-stained nuclear material. Fluorescence imaging (as well as cryo-electron microscopy) show a breakdown of both the inner and outer nuclear membranes at the interface between the cell nucleus and aggregated autophagolysosomes. Finally, the addition of N-acetyl cysteine (or NAC, a scavenger for reactive oxygen species) effectively abolishes the appearance of autophagolysosomes containing nuclear material. We hope to continue this research to understand the processes that govern the survival or death of these tumor cells, in order to develop methods to improve the efficacy of cancer pharmacotherapy.
KW - autophagy
KW - cancer biology
KW - cell death
KW - fluorescence microscopy
KW - metabolic stress
UR - http://www.scopus.com/inward/record.url?scp=84877961512&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84877961512&partnerID=8YFLogxK
U2 - 10.1117/12.2004759
DO - 10.1117/12.2004759
M3 - Conference contribution
AN - SCOPUS:84877961512
SN - 9780819493569
VL - 8587
BT - Progress in Biomedical Optics and Imaging - Proceedings of SPIE
ER -