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Regulation of an ATG7-beclin 1 program of autophagic cell death by caspase-8

Li Yu1, Ajjai Alva, Helen Su

  • 1Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.

Science (New York, N.Y.)
|May 8, 2004
PubMed

Insights

Scientists discovered a new cell death pathway involving autophagy, regulated by receptor-interacting protein kinase and Jun amino-terminal kinase. Caspase inhibition unexpectedly triggers this autophagic cell death, impacting cancer therapies.

Area of Science:

  • Molecular Biology
  • Cell Death Research
  • Biochemistry

Background:

  • Caspases are key regulators of apoptosis, a programmed cell death process.
  • The mechanisms and regulation of other cell death pathways, such as autophagy and necrosis, remain poorly understood.
  • The relationship between apoptosis and other cell death modalities is unclear.

Purpose of the Study:

  • To define a novel molecular pathway inducing cell death with autophagic morphology.
  • To investigate the role of receptor-interacting protein (RIP) and Jun amino-terminal kinase (JNK) in this pathway.
  • To explore the relationship between this autophagic death and caspase activity.

Main Methods:

  • Investigated cell death induction via RIP and JNK activation.
  • Utilized gene knockout studies for ATG7 and beclin 1 to assess autophagic death requirements.
  • Examined the effect of caspase-8 inhibition on cell death morphology and pathways.

Main Results:

  • Activation of RIP and JNK induced cell death exhibiting autophagic characteristics.
  • Autophagic cell death was dependent on the genes ATG7 and beclin 1.
  • Inhibition of caspase-8 led to the induction of this autophagic cell death pathway.

Conclusions:

  • A novel cell death pathway, distinct from classical apoptosis, has been identified.
  • This pathway is regulated by RIP and JNK signaling and requires key autophagy genes.
  • Caspase inhibitors, used in clinical therapies, may inadvertently promote autophagic cell death, necessitating further investigation.

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