CYP enzymes, expressed within live human suspension cells, are superior to widely-used microsomal enzymes in identifying potent CYP1A1/CYP1B1 inhibitors: Identification of quinazolinones as CYP1A1/CYP1B1 inhibitors that efficiently reverse B[a]P toxicity and cisplatin resistance

Sonawane, Vinay R.; Mohd Usman, Mohd Siddique; Gatchie, Linda; Williams, Ibidapo Stephen; Bharate, Sandip B.; Jayaprakash, Venkatesan; Sinha, Barij N.; Chaudhuri, Bhabatosh

Abstract

Microsomal cytochrome P450 (CYP) enzymes, isolated from recombinant bacterial/insect/yeast cells, are extensively used for drug metabolism studies. However, they may not always portray how a developmental drug would behave in human cells with intact intracellular transport mechanisms. This study emphasizes the usefulness of human HEK293 kidney cells, grown in ‘suspension’ for expression of CYPs, in finding potent CYP1A1/CYP1B1 inhibitors, as possible anticancer agents. With live cell-based assays, quinazolinones 9i/9b were found to be selective CYP1A1/CYP1B1 inhibitors with IC50 values of 30/21 nM, and > 150-fold selectivity over CYP2/3 enzymes, whereas they were far less active using commercially-available CYP1A1/CYP1B1 microsomal enzymes (IC50, >10/1.3–1.7 μM). Compound 9i prevented CYP1A1-mediated benzo[a]pyrene-toxicity in normal fibroblasts whereas 9b completely reversed cisplatin resistance in PC-3/prostate, COR-L23/lung, MIAPaCa-2/pancreatic and LS174T/colon cancer cells, underlining the human-cell-assays' potential. Our results indicate that the most potent CYP1A1/CYP1B1 inhibitors would not have been identified if one had relied merely on microsomal enzymes.

• Journal Article Type: Article
• Acceptance Date: Feb 12, 2019
• Online Publication Date: Feb 15, 2019
• Publication Date: Apr 1, 2019
• Deposit Date: Feb 25, 2019
• Journal: European Journal of Pharmaceutical Sciences
• Print ISSN: 0928-0987
• Electronic ISSN: 1879-0720
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 131
• Pages: 177-194
• DOI: https://doi.org/10.1016/j.ejps.2019.02.016
• Keywords: microsomal CYP450 enzymes, cisplatin resistance, CYP1A1 inhibitors,; CYP1A1-mediated benzo[a]pyrene toxicity, CYP1B1 inhibitors, hard to metabolize medications, live CYP-expressing human cells
• Public URL: https://uwe-repository.worktribe.com/output/849457
• Publisher URL: https://doi.org/10.1016/j.ejps.2019.02.016
• Related Public URLs: https://www.sciencedirect.com/science/article/pii/S0928098719300697?via%3Dihub
• Contract Date: Feb 25, 2019