GSK3β inactivation induces apoptosis of leukemia cells by repressing the function of c-Myb

Fangfang Zhou1, Long Zhang, Theo van Laar

  • 1Department of Molecular Cell Biology and Centre for Biomedical Genetics, Leiden University Medical Center, 2300 RC Leiden, Netherlands.

Insights

Glycogen synthase kinase 3β (GSK3β) inhibition triggers apoptosis in leukemia cells by degrading transcription factor c-Myb. This blocks antiapoptotic genes, revealing a novel GSK3β role in cancer cell survival.

Area of Science:

  • Molecular Biology
  • Cell Biology
  • Biochemistry

Background:

  • Glycogen synthase kinase 3β (GSK3β) is a key regulator of numerous cellular processes.
  • GSK3β kinase activity is implicated in various cancers, but its precise role in leukemia survival is unclear.

Purpose of the Study:

  • To elucidate the mechanism by which GSK3β regulates leukemia cell survival.
  • To identify the key molecular targets of GSK3β in leukemia.

Main Methods:

  • GSK3β kinase inhibition assays in leukemia cell lines.
  • Western blotting to assess protein levels and degradation.
  • Coimmunoprecipitation and chromatin immunoprecipitation assays.
  • Reporter assays and gene knockdown studies.

Main Results:

  • GSK3β inhibition induces apoptosis and proliferation defects in leukemia cells.
  • Transcription factor c-Myb is identified as a primary target of GSK3β.
  • GSK3β inactivation promotes c-Myb degradation via ubiquitination.
  • Reduced c-Myb expression leads to decreased Bcl2 and survivin antiapoptotic gene expression.
  • c-Myb cooperates with transcription factor LEF-1 to activate Bcl2 and survivin.

Conclusions:

  • GSK3β controls leukemia cell survival through the c-Myb/LEF-1 transcriptional complex.
  • Targeting GSK3β represents a potential therapeutic strategy for leukemia by disrupting this survival pathway.

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