New MRI contrasting agent detects small, aggressive cancers

A new study published in Nature Communications highlights a newly developed contrasting agent for MRI that detects breast cancer in its earliest stages and can distinguish between aggressive and non-aggressive cancers.

“Despite the continuous efforts in developing novel MRI contrast agents, there is a serious lack of safe and effective-targeted contrast agents for high-sensitivity molecular MRI in clinical practice,” the authors wrote.

The researchers, led by Zheng-Rong Lu, PhD, professor of biomedical engineering at Case Western Reserve University, studied the agent on mouse models.

The contrasting agent is gadolinium-based which is safer and more efficient than traditional contrasting agents and it requires a 20-times smaller doses of gadolinium. This makes for easy exit from the body without accumulation in tissues. At the low dosage, the contrasting agent lights up the cancer during scans.

The agent is a combination of commercially available tri-gadolinium nitride metallofullerene (Gd3N@C80) and a peptide, ZD2, developed in Lu’s laboratory. Compared to gadolinium used in traditional contrasting agents, the structure is different. Lu compared it to a soccer ball, and gadolinium ions are encaged within the structure to prevent any interaction with tissue.

The attached peptide to the gadolinium agent targets the cancer protein extradomain-B fibronectin, which is associated with tumor invasion, metastasis and drug resistance. It is visible around cancer cells in many aggressive forms of human cancer.

The agent detected breast cancer on six mouse models. The signals on three aggressive triple-negative breast cancers were significantly brighter and the three slow moving breast cancers produced less EDB-FN. While the signal was detectable, it was very subdued.