[Basic studies on the 111In labeled antisense oligonucleotide for tumor imaging]

Area of Science:

• Molecular Biology
• Radiochemistry
• Oncology

Context:

• Antisense oligonucleotides (ASOs) are investigated as targeted radiopharmaceuticals.
• Detecting abnormal gene expression is crucial for diagnosing and monitoring diseases, particularly cancer.
• Short-lived radionuclides offer advantages for diagnostic imaging due to their decay properties.

Purpose:

• To evaluate the feasibility of using 32P or 111In-labeled oligonucleotides as radiopharmaceuticals.
• To assess the antisense strategy for detecting specific mRNA targets, using c-erbB-2 protooncogene mRNA as a model.
• To explore the potential of 111In-labeled oligonucleotides for in vivo tumor imaging.

Summary:

• Sequence-specific accumulation of 32P-labeled oligonucleotide was observed in cells expressing c-erbB-2 mRNA, validating the antisense approach.
• Synthesis of 111In-labeled isothiocyanobenzyl-EDTA (IBE)-oligonucleotide was achieved, though purification presented challenges.
• 111In-IBE-oligonucleotide demonstrated superior stability compared to 32P-oligonucleotide, with biodistribution data suggesting its potential for tumor imaging.

Impact:

• This research validates the fundamental possibility of using antisense oligonucleotides labeled with radionuclides for diagnostic purposes.
• The findings support the development of novel targeted radiopharmaceuticals for detecting aberrant gene expression in diseases like cancer.
• Further optimization of labeling and purification methods could lead to effective 111In-based ASO radiotracers for clinical imaging.