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Published on: September 26, 2019

Rhabdoid tumor growth is inhibited by flavopiridol

Melissa E Smith1, Velasco Cimica, Srinivasa Chinni

  • 1Department of Molecular Genetics, Albert Einstein College Cancer Center, Bronx, NY 10461, USA.

Clinical Cancer Research : an Official Journal of the American Association for Cancer Research
|January 29, 2008
PubMed
Abstract

Insights

Flavopiridol effectively targets cyclin D1 and p21 in aggressive rhabdoid tumors, inducing cell cycle arrest and apoptosis. This pan-cyclin-dependent kinase inhibitor shows promise as a novel therapeutic for these pediatric malignancies.

Area of Science:

  • Oncology
  • Molecular Biology
  • Pediatric Malignancies

Background:

  • Rhabdoid tumors are aggressive pediatric cancers often linked to INI1/hSNF5 tumor suppressor inactivation.
  • INI1/hSNF5 normally represses cyclin D1, a protein crucial for rhabdoid tumor growth and survival.
  • Targeting the cyclin/cyclin-dependent kinase (CDK) axis presents a potential therapeutic strategy for these tumors.

Purpose of the Study:

  • To investigate the efficacy of flavopiridol, a pan-CDK inhibitor, against rhabdoid tumors.
  • To evaluate flavopiridol's effects on cell cycle, apoptosis, and specific protein expression in rhabdoid tumor models.

Main Methods:

  • In vitro studies utilized survival, cell cycle, and apoptosis assays on rhabdoid cells.
  • In vivo efficacy was assessed using xenografted rhabdoid tumor models.
  • Immunoblot and immunohistochemical analyses measured cyclin D1 and p21 expression.

Main Results:

  • Flavopiridol demonstrated potent inhibition of rhabdoid cell growth in vitro (IC50 ~200 nmol/L).
  • The drug induced G1 and G2 cell cycle arrest and apoptosis, correlated with cyclin D1 downregulation and p21 upregulation.
  • In vivo, flavopiridol (7.5 mg/kg) significantly inhibited tumor growth, with similar molecular changes observed.

Conclusions:

  • Flavopiridol effectively induces cell cycle arrest and cytotoxicity in rhabdoid tumors.
  • The therapeutic effects are linked to modulating cyclin D1 and p21 expression.
  • Flavopiridol represents a potential novel chemotherapeutic agent for rhabdoid tumors.

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