Visualization of mRNA expression in CNS using C-11-labeled phosphorothioate oligodeoxynucleotide

ANTISENSE phosphorothioate oligodeoxynucleotide for mRNA of glial fibrillar y acidic protein (GFAP) was labeled with the positron emitter C-11 and admi nistered i.v. to rats bearing glioma, which were expected to exhibit active expression of GFAP. Antisense oligodeoxynucleotide was retained in tumor c ells, yielding clear images of tumors, while the control 20% mismatch oligo deoxynucleotide and sense-strand oligodeoxynucleotide were not retained in tumor cells. Findings revealed sequence;specific binding of the antisense o ligodeoxynucleotide to the GFAP mRNA. Our methods-can be used directly for non-invasive imaging of human gene expression using PET, a frequently used method of clinical examination. (C) 1999 Lippincott Williams & Wilkins.