Design of a bioreductively-activated fluorescent pH probe for tumor hypoxia imaging
作者:Eiji Nakata、Yoshihiro Yukimachi、Hirokazu Kariyazono、Seongwang Im、Chiaki Abe、Yoshihiro Uto、Hiroshi Maezawa、Toshihiro Hashimoto、Yasuko Okamoto、Hitoshi Hori
DOI:10.1016/j.bmc.2009.08.037
日期:2009.10
We have designed and evaluated UTX-12 as a novel fluorescent pH probe for tumor hypoxia imaging. UTX-12 consists of a p-nitro benzyl moiety, which is a latent hypoxia-selective leaving group activated by nitro reduction, directly linked to SNARF. Although UTX-12 itself is colorless and non-fluorescent in aqueous solution, nitro reduction triggers the release of SNARF which has well-characterized long wavelength absorption and fluorescence that is sensitive to pH. The resultant SNARF, released intracellularly by enzymatic reduction of UTX-12, allows measurement of pH by pH-dependent dual emission shifts. UTX-12 showed clear differences in fluorescence behavior between hypoxic and aerobic conditions in liver microsomes and inside V79 cells. These data are confirmation that UTX-12 is biologically reduced inside tumor cells and the released SNARF should monitor intracellular pH of tumor cells selectively with reduced background signal. (C) 2009 Elsevier Ltd. All rights reserved.