Magnetic resonance tumor targeting imaging using gadolinium labeled human telomerase reverse transcriptase antisense...

Area of Science:

• Molecular Imaging
• Biomedical Engineering
• Oncology

Background:

• Telomerase reverse transcriptase (hTERT) is a key marker in many human cancers.
• Current methods for detecting hTERT mRNA expression have limitations in sensitivity and specificity.
• Development of targeted molecular probes for non-invasive detection is crucial for cancer diagnosis and management.

Purpose of the Study:

• To develop and evaluate a novel gadolinium-labeled antisense oligonucleotide (Gd-DOTA-ASON) probe for MRI detection of hTERT mRNA.
• To assess the probe's stability, cellular uptake, biodistribution, and efficacy in a preclinical lung cancer model.

Main Methods:

• Synthesis and characterization of Gd-DOTA-ASON probe.
• In vitro assessment of probe stability and cellular uptake using radiolabeled technetium-99m (99mTc-DOTA-ASON).
• In vivo MRI imaging of A549 lung adenocarcinoma xenografts in mice after Gd-DOTA-ASON administration.
• Immunohistochemical analysis of telomerase activity in tumor tissues.

Main Results:

• Gd-DOTA-ASON exhibited high binding efficiency (71.7%) and excellent stability in human serum.
• The probe showed significantly higher uptake in cancer cells compared to normal lung cells.
• In vivo MRI demonstrated enhanced signal intensity in tumors with a tumor-to-muscle SNR of 2.37 within 6 hours.
• Gd-DOTA-ASON effectively suppressed hTERT activity in A549 tumors.

Conclusions:

• Gd-DOTA-ASON serves as a promising intracellular MR contrast agent for targeting telomerase-positive carcinomas.
• This molecular probe holds potential for non-invasive detection and monitoring of hTERT mRNA expression in tumors.
• Further research may validate its clinical utility in cancer diagnostics.