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The oxidative stress response regulates DKK1 expression through the JNK signaling cascade in multiple myeloma plasma

Simona Colla1, Fenghuang Zhan, Wei Xiong

  • 1Donna D. and Donald M. Lambert Laboratory of Myeloma Genetics at the Myeloma Institute for Research and Therapy, University of Arkansas for Medical Sciences, Little Rock, AR, USA.

Blood
|January 27, 2007
PubMed

Insights

Multiple myeloma plasma cells express DKK1, contributing to bone lesions by blocking Wnt signaling. Targeting the JNK pathway may inhibit DKK1, potentially treating myeloma and associated bone disease.

Area of Science:

  • Oncology
  • Molecular Biology
  • Bone Biology

Background:

  • Multiple myeloma (MM) plasma cells uniquely express DKK1, a Wnt-signaling antagonist.
  • DKK1 secreted by MM cells contributes to osteolytic bone lesions by inhibiting essential Wnt signaling for osteoblast survival.
  • Mechanisms regulating DKK1 expression in MM remain largely unknown.

Purpose of the Study:

  • To investigate the mechanisms controlling DKK1 expression in multiple myeloma cells.
  • To explore the role of oxidative stress and cell-cell interactions in DKK1 regulation.
  • To determine if DKK1 mediates apoptosis or affects MM cell response to standard therapies.

Main Methods:

  • Analysis of DKK1 expression in MM cells versus control groups.
  • Investigating the involvement of the JNK signaling cascade.
  • In vitro studies involving oxidative stress and MM cell-osteoclast interactions.
  • Assessing DKK1's effect on MM cell apoptosis and drug sensitivity.

Main Results:

  • DKK1 expression in MM cells is linked to perturbations in the JNK signaling pathway.
  • JNK signaling modulation is influenced by oxidative stress and MM cell-osteoclast interactions.
  • DKK1 does not mediate apoptotic signaling in MM, is not TP53-activated, and its overexpression doesn't sensitize MM cells to thalidomide or lenalidomide.

Conclusions:

  • Persistent JNK pathway activation in MM contributes to DKK1 expression.
  • Targeting the JNK pathway to inhibit DKK1 may offer a strategy for managing MM progression and bone disease.
  • DKK1's role in MM appears distinct from its tumor suppressor functions in other cell types.

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