Human NQO1 as a Selective Target for Anticancer Therapeutics and Tumor Imaging

Area of Science:

• Biochemistry
• Oncology
• Molecular Biology

Background:

• Human NAD(P)H-quinone oxidoreductase1 (NQO1) is an antioxidant enzyme upregulated in malignancies.
• NQO1 expression is driven by the NRF2 transcription factor in a prooxidant cancer environment.
• Elevated NQO1 levels (up to 200-fold) in cancer distinguish neoplastic tissue from normal body tissues.

Purpose of the Study:

• To review quinones activated by NQO1, their inhibitors, and cell death mechanisms.
• To explore the diagnostic, prognostic, and therapeutic potential of NQO1 in cancer.
• To discuss NQO1-targeted small molecule probes for cancer imaging and therapy.

Main Methods:

• Review of literature on NQO1 substrates, inhibitors, and cell death pathways.
• Analysis of NQO1's role in cancer-specific bioactivation of quinones.
• Examination of engineered NQO1-activated fluorescent probes for cancer detection.

Main Results:

• NQO1 catalyzes futile redox cycling of quinones, generating cytotoxic reactive oxygen species (ROS) and H2O2.
• Elevated NQO1 in tumors enables tumor-specific quinone bioactivation for therapeutic strategies.
• Engineered NQO1-activated probes provide sensitive near-infrared fluorescence for cancer cell/tissue visualization.

Conclusions:

• NQO1's cancer-selective expression is a valuable marker for diagnosis and prognosis.
• NQO1-mediated quinone bioactivation presents a promising tumor-specific therapeutic strategy.
• NQO1-targeted probes offer theranostic potential for guided surgery and chemotherapy.