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Cucurbitacin I inhibits Stat3 and induces apoptosis in Sézary cells

Marloes S van Kester1, Jacoba J Out-Luiting, Peter A von dem Borne

  • 1Department of Dermatology, Leiden University Medical Center, Leiden, the Netherlands.

The Journal of Investigative Dermatology
|January 18, 2008
PubMed

Insights

Sézary syndrome (Sz) involves malignant T-cells expressing phosphorylated Stat3. Inhibiting Stat3 with Cucurbitacin I induced apoptosis in Sz cells, suggesting Stat3 is a therapeutic target.

Area of Science:

  • Oncology
  • Immunology
  • Molecular Biology

Background:

  • Sézary syndrome (Sz) is an aggressive cutaneous T-cell lymphoma.
  • Tumor cells in Sz are found in skin, lymph nodes, and blood.
  • The role of Stat3 signaling in Sz pathogenesis requires further elucidation.

Purpose of the Study:

  • To investigate the expression and activation of Stat3 in Sézary syndrome.
  • To evaluate the effect of Stat3 inhibition on Sz cells.

Main Methods:

  • Western blotting to detect phosphorylated Stat3 (P-Stat3) and Stat3 expression.
  • In vitro culture of Sz cell lines and primary Sz cells.
  • Treatment with Jak/Stat3 inhibitor Cucurbitacin I.
  • Apoptosis assays to assess cell death.

Main Results:

  • P-Stat3 was detected in Sz cell lines and primary Sz cells.
  • Stat3 activation was not constitutive and decreased upon cytokine withdrawal.
  • Cucurbitacin I reduced P-Stat3 and Stat3 levels in a time- and dose-dependent manner.
  • Cucurbitacin I induced significant apoptosis in primary Sz cells.

Conclusions:

  • Stat3 activation is crucial for the malignant transformation in Sézary syndrome.
  • Targeting Stat3 with inhibitors like Cucurbitacin I shows therapeutic potential for Sz.
  • These findings support Stat3 as a viable therapeutic target in Sézary syndrome treatment.

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