Dihydroartemisinin and its derivative induce apoptosis in acute myeloid leukemia through Noxa-mediated pathway requiring iron and endoperoxide moiety

Area of Science:

• Oncology
• Molecular Biology
• Pharmacology

Background:

• Anti-apoptotic protein Mcl-1 is crucial for cell survival in acute myeloid leukemia (AML).
• The BH3-only protein Noxa inhibits Mcl-1's anti-apoptotic function.
• Targeting Mcl-1 or its regulators is a key strategy in AML treatment.

Purpose of the Study:

• To investigate the potential of dihydroartemisinin (DHA) and its derivative X-11 as apoptosis inducers in AML cells.
• To elucidate the molecular pathway through which DHA and X-11 exert their effects.
• To assess the role of Noxa and reactive oxygen species in DHA and X-11-mediated apoptosis.

Main Methods:

• Treatment of AML cell lines with DHA and X-11.
• Silencing of Noxa using RNA interference.
• Analysis of apoptosis induction and Noxa expression.
• Investigation of the role of FOXO3a, reactive oxygen species, and intracellular iron.
• Assessment of sensitivity in AML cells with varying Bcl-xL and Bcl-2 expression levels.

Main Results:

• DHA and X-11 are potent inducers of apoptosis in AML cells, with X-11 being four times more active than DHA.
• Apoptosis induction is mediated by a Noxa-dependent pathway, as silencing Noxa blocks the effect.
• DHA and X-11 upregulate Noxa expression via the transcription factor FOXO3a in a reactive oxygen species-dependent manner.
• The endoperoxide moiety and intracellular iron are essential for the activity of DHA and X-11.
• AML cells with high Bcl-xL or Bcl-2 expression show reduced sensitivity, which can be overcome by ABT-737.

Conclusions:

• DHA and X-11 represent a new class of apoptosis-inducing compounds for AML.
• Their mechanism involves Noxa upregulation through a pathway utilizing the endoperoxide moiety and intracellular iron.
• Targeting the Noxa pathway offers a promising therapeutic avenue for AML treatment.