Researchers at the Mayo Clinic’s Cancer Nanotechnology and Tumor Immunology Laboratory have used cancer-fighting nanoparticles to shrink breast tumors in mice.
The treatment proved highly effective, both in shrinking tumors and preventing their recurrence. Mice injected with the nanoparticles experienced a reduction in the size of breast tumors of between 70 and 80 percent.
The nanoparticles are spherical and of a similar size to DNA molecules. The nanoparticles – termed the Multivalent Bi-specific Nano-Bioconjugate Engager – have been engineered to bind to HER2 receptors and trigger the immune system to attack the tumors. The HER-2 receptor is found in 40% of breast cancers. Tumors with high levels of the HER2 protein are particularly aggressive and more likely to metastasize quickly.
The researchers discovered the nanoparticles trigger a full immune system response, increasing macrophage and phagocyte activity to destroy the tumors while passing on information to the T-cells that finish off the job. The T-cells also retain memory of the attacked cells which can reduce recurrences of tumors.
Mice treated with the nanoparticles were monitored and found to be more resistant to the recurrence of tumors than the control group. While the group was confident that the nanoparticles could be used to help shrink tumors, they were surprised that the treatment had a lasting effect.
Betty Kim, who led the research said, “Unlike existing cancer immunotherapies that target only a portion of the immune system, our custom-designed nanomaterials actively engage the entire immune system to kill cancer cells, prompting the body to create its own memory system to minimize tumor recurrence.”
The team is now analyzing the ability of the nanoparticles to prevent recurrences of tumors, including their effect on metastases in other areas of the body.
The results of this proof-of-concept study are highly promising and show the effectiveness of nanoparticles for the treatment of cancer. However, clinical trials in humans are still some way off. The demonstration of the effectiveness of the treatment at shrinking breast tumors is just the first step in the process. Clinical trials using the nanoparticles on human patients are unlikely to be conducted for three to four years, according to Kim.
Kim said nanoparticles have potential for use in the treatment of other cancers and could “turn these deadly diseases into a chronic condition.” The nanoparticles can be developed to bind to a range of different cells, triggering the immune system to attack them. Nanoparticles can therefore be used in the treatment of a range of diseases, not only cancer. Kim says nanoparticles could potentially be used in innovative new treatments for neurovascular and neurodegenerative disorders such as Alzheimer’s disease.
The study was recently published in Nature Nanotechnology.