UCI researchers use stem cells as cancer-seeking missiles

Chemotherapy is brutal — a medicinal atomic bomb that destroys large swaths of cells, both cancerous and normal. And as a result, patients are often left physically devastated.

In a new study published in Science Translational Medicine, scientists at UC Irvine say they've come up with a way to use stem cells to help ameliorate those side effects. Think of it as a surgical strike with cancer-seeking missiles.

Professor Weian Zhao and his colleagues from UC Irvine modified stem cells so that they'd be attracted to enzymes released by breast cancer tumors. So, when injected into the body, the stem cells seek out the cells and bond with them. 

The enzymes the scientists identified cause tissue to clump up into bundles of collagen and protein to create stiff tumors. The tumors become lumps that a patient can sometimes feel, and they act as a protective home for the cancerous cells. 

The stem cells release an enzyme of their own, in turn, activating a type of chemotherapy that's been injected into the patient, which is inert until in comes in contact with the enzyme. The idea being that the chemotherapy only causes toxicity to a localized area, instead of destroying everything in its path.

"We can use a stem cells to specifically localize and produce the drugs only at the tumor site, so that we can spare the healthy tissue," said Zhao. "So, we can make the treatment more effective and less toxic to the patient."

"I think this is pretty unique in a way that it can target specific metastatic tissues with reduced toxicity overall," said Min Yu, assistant professor at the department of Stem Cell Biology and Regenerative Medicine at USC. "So, in that sense, I think it's very novel and very unique approach."

Yu, who was not involved in the research, complimented the UCI team's methods and results, especially how effective the treatment was on the particular cancer cell that they focused on. However, she said, from patient to patient and cancer to cancer, there are a myriad of different cells responsible, making treatment notoriously difficult to generalize. The therapy isn't a sure thing.

Zhao acknowledged that his team has a while to go before it can prove that the treatment is effective in people. So far, it's only been tested in mice. As a result, FDA approval and human trials could be years away.