Optical antisense tumor targeting in vivo with an improved fluorescent DNA duplex probe

UMMS Affiliation

Department of Radiology

Publication Date


Document Type



Animals; Base Sequence; Benzothiazoles; Cell Line, Tumor; DNA Probes; DNA, Antisense; Fluorescence; Humans; Male; Mice; Neoplasms; Nucleic Acid Hybridization; Quinolines


Chemistry | Neoplasms | Radiology


Fluorescent conjugated DNA oligonucleotides for antisense targeting of mRNA has the potential of improving tumor/normal tissue ratios over that achievable by nuclear antisense imaging. By conjugating the Cy5.5 emitter to the 3' equivalent end of a 25 mer phosphorothioate (PS) antisense major DNA and hybridizing with a shorter 18 mer phosphodiester (PO) complementary minor DNA (cDNA) with the Black Hole inhibitor BHQ3 on its 5' end (i.e., PS DNA25-Cy5.5/PO cDNA18-BHQ3), we previously achieved antisense optical imaging in mice as a proof of this concept. In a process of optimization, we have now evaluated the stability of a small series of duplexes with variable-length minor strands. From these results, a new study anti-mdr1 antisense duplex was selected with a 10 mer minor strand (i.e., PS DNA25-Cy5.5/PO cDNA10-BHQ3). The new study duplex shows stability in serum environments at 37 degrees C and provides a dramatically enhanced fluorescence in KB-G2 (pgp++) cells when compared with KB-31 (pgp+/-) as evidence of antisense dissociation at its mdr1 mRNA target. The duplex was also administered to KB-G2 tumor bearing mice, and when compared to the duplex used previously, the fluorescence from the tumor thigh was more obvious and the tumor-to-background fluorescence ratio was improved. In conclusion, by a process designed to optimize the duplex for optical antisense tumor targeting, the fluorescence signal was improved both in cells and in tumored mice.

DOI of Published Version



Bioconjug Chem. 2009 Jun;20(6):1223-7. doi: 10.1021/bc9000933. Link to article on publisher's site

Journal/Book/Conference Title

Bioconjugate chemistry

Related Resources

Link to Article in PubMed

PubMed ID