A bioluminescent microbial biosensor for in vitro pretreatment assessment of cytarabine efficacy in leukemia

Salisbury, Vyv C.; Hill, Phil J.; Angell, Johanna E.; Ruddock, Mark W.; Martin, Ashley D.; Alloush, Habib M.; Anderson, Elizabeth; Lamont, John; Smith, M. Ann; Smith, J. Graham; Mehta, Priyanka

Abstract

BACKGROUND: The nucleoside analog cytarabine (Ara-C [cytosine arabinoside]) is the key agent for treating acute myeloid leukemia (AML); however, up to 30% of patients fail to respond to treatment. Screening of patient blood samples to determine drug response before commencement of treatment is needed. This project aimed to construct and evaluate a self-bioluminescent reporter strain of Escherichia coli for use as an Ara-C biosensor and to design an in vitro assay to predict Ara-C response in clinical samples. METHODS: Weused transposition mutagenesis to create a cytidine deaminase (cdd)-deficient mutant of E. coli MG1655 that responded to Ara-C. The strain was transformed with the luxCDABE operon and used as a whole-cell biosensor for development an 8-h assay to determine Ara-C uptake and phosphorylation by leukemic cells. RESULTS: Intracellular concentrations of 0.025 μmol/L phosphorylated Ara-C were detected by significantly increased light output (P < 0.05) from the bacterial biosensor. Results using AML cell lines with known response to Ara-C showed close correlation between the 8-h assay and a 3-day cytotoxicity test for Ara-C cell killing. In retrospective tests with 24 clinical samples of bone marrow or peripheral blood, the biosensor-based assay predicted leukemic cell response to Ara-C within 8 h. CONCLUSIONS: The biosensor-based assay may offer a predictor for evaluating the sensitivity of leukemic cells to Ara-C before patients undergo chemotherapy and allow customized treatment of drug-sensitive patients with reduced Ara-C dose levels. The 8-h assay monitors intracellular Ara-CTP (cytosine arabinoside triphosphate) levels and, if fully validated, may be suitable for use in clinical settings. © 2010 American Association for Clinical Chemistry.

• Journal Article Type: Article
• Publication Date: Dec 1, 2010
• Deposit Date: Jun 13, 2011
• Publicly Available Date: Feb 10, 2016
• Journal: Clinical Chemistry
• Print ISSN: 0009-9147
• Electronic ISSN: 1530-8561
• Publisher: American Association for Clinical Chemistry
• Peer Reviewed: Peer Reviewed
• Volume: 56
• Issue: 12
• Pages: 1862-1870
• DOI: https://doi.org/10.1373/clinchem.2010.145581
• Keywords: biolumuinescent, microbial, biosensor, in vitro, pretreatment, cytarabine, Leukemia
• Public URL: https://uwe-repository.worktribe.com/output/972940
• Publisher URL: http://dx.doi.org/10.1373/clinchem.2010.145581
• Contract Date: Feb 10, 2016