Nanoparticle plant virus treatment shows promise in fighting metastatic cancers in mice

An experimental treatment made from a plant virus is effective at protecting against a broad range of metastatic cancers in mice, according to a new study from the University of California San Diego.

The treatment, composed of nanoparticles fashioned from the cowpea mosaic virus – a virus that infects black-eyed pea plants – showed remarkable success in improving survival rates and suppressing the growth of metastatic tumors across various cancer models, including colon, ovarian, melanoma and breast cancer. Similar outcomes were also observed when the treatment was administered to mice whose tumors were surgically removed.

The new study builds upon previous research by the lab of Nicole Steinmetz, a professor of nanoengineering, director of the Center for Nano-ImmunoEngineering and co-director of the Center for Engineering in Cancer, all at UC San Diego. Steinmetz and colleagues have been using cowpea mosaic virus nanoparticles to trigger the immune system to fight cancer and prevent it from spreading and recurring.

In early studies, the approach involved injecting the plant virus nanoparticles directly into tumors to stimulate an immune response. Even though the virus is non-infectious in mammals, the body's immune cells still recognize it as foreign, triggering a robust immune reaction against the existing tumor, as well as any future tumors.

Now, Steinmetz and her team show that the plant virus nanoparticles do not need to be injected directly into tumors to be effective. Administering the nanoparticles systemically improved survival rates and inhibited metastasis across various cancer types.

Image source: Chung et al. (2024), Advanced Science.