Microscopic analysis of cell death by metabolic stress-induced autophagy in prostate cancer

Chun Changou, R. Holland Cheng, Richard J Bold, Hsing-Jien Kung, Frank Chuang

Research output: Chapter in Book/Report/Conference proceedingConference contribution

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 languageEnglish (US)
Title of host publicationProgress in Biomedical Optics and Imaging - Proceedings of SPIE
Volume8587
DOIs
StatePublished - 2013
EventImaging, Manipulation, and Analysis of Biomolecules, Cells, and Tissues XI - San Francisco, CA, United States
Duration: Feb 2 2013Feb 5 2013

Other

OtherImaging, Manipulation, and Analysis of Biomolecules, Cells, and Tissues XI
CountryUnited States
CitySan Francisco, CA
Period2/2/132/5/13

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

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  • Cite this

    Changou, C., Cheng, R. H., Bold, R. J., Kung, H-J., & Chuang, F. (2013). Microscopic analysis of cell death by metabolic stress-induced autophagy in prostate cancer. In Progress in Biomedical Optics and Imaging - Proceedings of SPIE (Vol. 8587). [85870D] https://doi.org/10.1117/12.2004759