Cells (Nov 2023)

Development of Bexarotene Analogs for Treating Cutaneous T-Cell Lymphomas

  • Ankedo Warda,
  • Lech J. P. Staniszewski,
  • Zhela Sabir,
  • Sarah Livingston,
  • Michael Sausedo,
  • Sabeeha Reshi,
  • Eyal Ron,
  • Michael T. Applegate,
  • Dena Haddad,
  • Madleen Khamisi,
  • Pamela A. Marshall,
  • Carl E. Wagner,
  • Peter W. Jurutka

DOI
https://doi.org/10.3390/cells12212575
Journal volume & issue
Vol. 12, no. 21
p. 2575

Abstract

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Bexarotene, a drug approved for treatment of cutaneous T-cell lymphoma (CTCL), is classified as a rexinoid by its ability to act as a retinoid X receptor (RXR) agonist with high specificity. Rexinoids are capable of inducing RXR homodimerization leading to the induction of apoptosis and inhibition of proliferation in human cancers. Numerous studies have shown that bexarotene is effective in reducing viability and proliferation in CTCL cell lines. However, many treated patients present with cutaneous toxicity, hypothyroidism, and hyperlipidemia due to crossover activity with retinoic acid receptor (RAR), thyroid hormone receptor (TR), and liver X receptor (LXR) signaling, respectively. In this study, 10 novel analogs and three standard compounds were evaluated side-by-side with bexarotene for their ability to drive RXR homodimerization and subsequent binding to the RXR response element (RXRE). In addition, these analogs were assessed for proliferation inhibition of CTCL cells, cytotoxicity, and mutagenicity. Furthermore, the most effective analogs were analyzed via qPCR to determine efficacy in modulating expression of two critical tumor suppressor genes, ATF3 and EGR3. Our results suggest that these new compounds may possess similar or enhanced therapeutic potential since they display enhanced RXR activation with equivalent or greater reduction in CTCL cell proliferation, as well as the ability to induce ATF3 and EGR3. This work broadens our understanding of RXR–ligand relationships and permits development of possibly more efficacious pharmaceutical drugs. Modifications of RXR agonists can yield agents with enhanced biological selectivity and potency when compared to the parent compound, potentially leading to improved patient outcomes.

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