Pseudomonas aeruginosa NfsB and nitro-CBI-DEI – a promising enzyme/prodrug combination for gene directed enzyme prodrug therapy

Molecular Cancer

Short Communication

Glenn D Bell¹  Kendall M Carlin¹  Alexandra M Mowday¹  Sophie P Syddall¹  Adam V Patterson²  Michael P Hay²  Jeffrey B Smaill²  Christopher P Guise²  Laura K Green³  David F Ackerley⁴ 

[1] Auckland Cancer Society Research Centre, University of Auckland, Grafton, Auckland, New Zealand;Auckland Cancer Society Research Centre, University of Auckland, Grafton, Auckland, New Zealand;Maurice Wilkins Centre for Molecular Biodiscovery, School of Biological Sciences, University of Auckland, Auckland, New Zealand;School of Biological Sciences, Victoria University of Wellington, Kelburn Parade, Wellington, New Zealand;School of Biological Sciences, Victoria University of Wellington, Kelburn Parade, Wellington, New Zealand;Maurice Wilkins Centre for Molecular Biodiscovery, School of Biological Sciences, University of Auckland, Auckland, New Zealand;Centre for Biodiscovery, School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand;

关键词: Gene therapy;    GDEPT;    Nitroaromatic prodrug;    Nitroreductase;    Nitro-CBI-DEI;    CB1954;    SOS chromotest;    Bystander effect;   

DOI  :  10.1186/1476-4598-12-58

 received in 2013-04-08, accepted in 2013-06-05,  发布年份 2013

来源: Springer

【 摘 要 】

BackgroundThe nitro-chloromethylbenzindoline prodrug nitro-CBI-DEI appears a promising candidate for the anti-cancer strategy gene-directed enzyme prodrug therapy, based on its ability to be converted to a highly cytotoxic cell-permeable derivative by the nitroreductase NfsB from Escherichia coli. However, relative to some other nitroaromatic prodrugs, nitro-CBI-DEI is a poor substrate for E. coli NfsB. To address this limitation we evaluated other nitroreductase candidates from E. coli and Pseudomonas aeruginosa.FindingsInitial screens of candidate genes in the E. coli reporter strain SOS-R2 identified two additional nitroreductases, E. coli NfsA and P. aeruginosa NfsB, as being more effective activators of nitro-CBI-DEI than E. coli NfsB. In monolayer cytotoxicity assays, human colon carcinoma (HCT-116) cells transfected with P. aeruginosa NfsB were >4.5-fold more sensitive to nitro-CBI-DEI than cells expressing either E. coli enzyme, and 23.5-fold more sensitive than untransfected HCT-116. In three dimensional mixed cell cultures, not only were the P. aeruginosa NfsB expressing cells 540-fold more sensitive to nitro-CBI-DEI than pure cultures of untransfected HCT-116, the activated drug that they generated also displayed an unprecedented local bystander effect.ConclusionWe posit that the discrepancy in the fold-sensitivity to nitro-CBI-DEI between the two and three dimensional cytotoxicity assays stems from loss of activated drug into the media in the monolayer cultures. This emphasises the importance of evaluating high-bystander GDEPT prodrugs in three dimensional models. The high cytotoxicity and bystander effect exhibited by the NfsB_Pa/nitro-CBI-DEI combination suggest that further preclinical development of this GDEPT pairing is warranted.

【 授权许可】

Unknown   
© Green et al.; licensee BioMed Central Ltd. 2013. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.