When will resistance be futile?

Katherine L B Borden1

  • 1Department of Pathology and Cell Biology, Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, Canada. katherine.borden@umontreal.ca.

Cancer Research
|December 6, 2014
PubMed

Insights

Cancer cells develop drug resistance through inducible drug glucuronidation, driven by Gli1 and UGT1A enzymes. Inhibiting Gli1 restores drug sensitivity, offering new strategies against cancer treatment failure.

Area of Science:

  • Oncology
  • Cancer Biology
  • Pharmacology

Background:

  • Cancer cells develop resistance to chemotherapy drugs.
  • Existing strategies to overcome drug resistance are insufficient for durable treatment.
  • Inducible drug modifications represent a significant challenge in cancer therapy.

Purpose of the Study:

  • To investigate a novel form of multidrug resistance: inducible drug glucuronidation.
  • To explore the role of eukaryotic translation initiation factor 4E (eIF4E) and its inhibitor ribavirin in cancer.
  • To understand the mechanisms underlying relapse in patients treated with ribavirin.

Main Methods:

  • Clinical studies involving ribavirin treatment for cancer patients.
  • Investigating the role of the sonic hedgehog transcription factor Gli1 and UDP glucuronsyltransferase (UGT1A) enzymes.
  • Assessing the impact of Gli1 inhibition on drug metabolism and sensitivity.

Main Results:

  • Ribavirin treatment initially showed clinical responses but patients relapsed due to drug resistance.
  • Overexpression of Gli1 led to elevated UGT1A enzymes, causing drug glucuronidation and resistance to ribavirin and Ara-C.
  • Inhibition of Gli1 reduced UGT1A levels, decreased drug glucuronides, and restored sensitivity to chemotherapy.

Conclusions:

  • Cancer cells metabolize drugs differently than normal cells, particularly under resistance conditions.
  • Inducible drug glucuronidation, mediated by Gli1 and UGT1As, is a key mechanism of acquired multidrug resistance.
  • Targeting Gli1 and understanding inducible drug modifications are crucial for developing effective, durable cancer treatments.

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