Drug-delivering nanoparticles seek, destroy cancer stem cells: study

CHICAGO, Nov. 28 (Xinhua) -- Researchers at the University of Illinois (UI) are trying to use tiny drug-laden nanoparticles to seek and destroy cancer stem cells.

They used the nanoparticles to deliver niclosamide that targets a protein called CD44 only appearing on the surface of cancer stem cells, and found the cancer stem cells lost their stemlike properties after treatment with the niclosamide-bearing targeted nanoparticles, and are less able to cause the cancer to recur or metastasize.

The researchers also detected a significant decrease in overall cancer cell growth, both in the cell cultures and in the mice, according to a report released Monday on the UI website.

"I call them 'GPS-enabled nanoparticles,' because they seek out only the cells that have cancer stem cell properties. Then they latch onto the cells and deliver the drug," said Dipanjan Pan, a UI professor of bioengineering. "To the best of our knowledge, this is the first demonstration of delivering cancer stem-cell-targeted therapy with a nanoparticle."

Cancer stem cells represent a tiny fraction of cells in a tumor, but it only takes one or two to seed a new tumor, Pan said. The challenge for physicians and researchers is not only finding these cells, but treating them.

Previous study found that niclosamide works on a particular gene-regulation pathway in cancer stem cells. Niclosamide is on the World Health Organization's List of Essential Medicines, which is an index of the safest and most effective drugs in the world, and is a drug commonly prescribed to treat tapeworm infections.

"This work is important to future researchers working in the field of cancer stem cells," said postdoctoral researcher Santosh Misra, the first author of the study. "We described and confirmed the proteins and genes responsible for vital processes in these cells, and that is opening up new avenues to make better therapies."

UI researchers are now working to create a combination therapy that can deliver drugs for the primary cancer, such as traditional chemotherapies, as well as targeted agents that can treat cancer stem cells. They are also testing the nanoparticle drug-delivery system in large animal models to bring it a step closer to the clinic.

The study has been published in the journal Molecular Cancer Therapeutics. Enditem