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Subcellular localization of NAD(P)H:quinone oxidoreductase 1 in human cancer cells

Shannon L Winski1, Yiannis Koutalos, David L Bentley

  • 1Department of Pharmaceutical Sciences, University of Colorado Health Sciences Center, Denver, Colorado 80017, USA.

Cancer Research
|March 13, 2002
PubMed

Insights

Nuclear NAD(P)H:quinone oxidoreductase 1 (NQO1) was identified in human cancer cells. This finding impacts understanding of chemoprevention and bioactivation of antitumor agents.

Area of Science:

  • Biochemistry
  • Cell Biology
  • Cancer Research

Background:

  • NAD(P)H:quinone oxidoreductase 1 (NQO1) plays a dual role in chemoprevention and bioactivation of antitumor agents.
  • The cellular localization of NQO1, particularly within tumor cells, is not fully understood, with a primary known cytosolic distribution.

Purpose of the Study:

  • To investigate the presence and location of NQO1 in the nucleus of human cancer cells.
  • To determine if nuclear NQO1 retains catalytic activity.

Main Methods:

  • Confocal microscopy and immunoelectron microscopy were used to visualize NQO1 in HT29 colon carcinoma and H661 non-small cell lung cancer cells.
  • Purified intact nuclei from HT29 cells were analyzed for NQO1 presence and activity.

Main Results:

  • Nuclear NQO1 was detected in HT29 and H661 cancer cells.
  • NQO1 was not found in mitochondria, Golgi apparatus, or endoplasmic reticulum.
  • Purified nuclei contained catalytically active NQO1.

Conclusions:

  • The study confirms the presence of nuclear NQO1 in human cancer cells.
  • The nuclear localization of NQO1 has significant implications for its roles in chemoprotection and the bioactivation of DNA-damaging antitumor drugs.

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