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

Area of Science:

• Molecular Biology
• Neuro-oncology
• Medical Imaging

Background:

• Glial fibrillary acidic protein (GFAP) is a key biomarker in glioma.
• Targeting GFAP mRNA offers a potential strategy for glioma diagnosis and monitoring.
• Non-invasive imaging of gene expression is crucial for clinical applications.

Purpose of the Study:

• To develop and evaluate a novel PET imaging method for detecting GFAP mRNA expression in vivo.
• To assess the sequence-specific retention of antisense oligodeoxynucleotides in glioma cells.

Main Methods:

• Antisense phosphorothioate oligodeoxynucleotides targeting GFAP mRNA were synthesized and labeled with 11C.
• The radiolabeled oligodeoxynucleotides were administered intravenously to rats bearing glioma xenografts.
• Tumor uptake and retention were evaluated using PET imaging, compared to mismatch and sense-strand controls.

Main Results:

• 11C-labeled antisense oligodeoxynucleotides demonstrated sequence-specific retention within tumor cells expressing GFAP.
• Clear PET images of gliomas were obtained, correlating with GFAP expression.
• Control oligodeoxynucleotides (mismatch and sense) showed minimal retention in tumor cells.

Conclusions:

• The developed method allows for non-invasive, sequence-specific imaging of GFAP mRNA expression in gliomas.
• This approach holds promise for clinical application in gene expression imaging using PET.
• Antisense oligodeoxynucleotide-based PET imaging can facilitate diagnosis and treatment monitoring of gliomas.