Radiolabeled choline as a proliferation marker: comparison with radiolabeled acetate

Area of Science:

• Oncology
• Nuclear Medicine
• Biochemistry

Background:

• [11C]Choline is a positron emission tomography (PET) imaging tracer with potential for detecting tumors, particularly brain and prostate cancers.
• Tumor detection using [11C]choline relies on its metabolic patterns, reflecting its role as a precursor to phosphatidylcholine, a key membrane lipid component.
• Increased membrane lipid and DNA synthesis are hallmarks of active cell proliferation in tumors.

Purpose of the Study:

• To investigate the relationship between [14C]choline metabolism and cellular proliferative activity.
• To assess the potential of [11C]choline as a tracer for evaluating tumor proliferation.

Main Methods:

• Utilized 10 different tumor cell lines and fibroblasts for metabolic studies.
• Measured [14C]choline uptake and its metabolic products, specifically [14C]phosphocholine.
• Compared [14C]choline uptake with [1-14C]acetate in relation to proliferative activity.

Main Results:

• [14C]Choline uptake was significantly higher in tumor cells compared to fibroblasts.
• Choline uptake demonstrated a positive correlation with proliferative activity across cell lines.
• [14C]Phosphocholine, a product of choline phosphorylation, was the primary contributor to the observed accumulation.

Conclusions:

• [11C]Choline uptake is indicative of tumor cell proliferation.
• The accumulation of [11C]choline in tumors is mainly due to its phosphorylation by choline kinase.
• [11C]Choline PET imaging can be utilized to estimate tumor proliferation by assessing choline kinase activity.