Researchers may have a new weapon against invading cancer cells.
The team found a way to allow cancer-killing proteins to "hitch a ride" on the back of white blood cells so that they can attack metastasizing cancer cells, a Cornell University news release reported.
"These circulating cancer cells are doomed," Michael King, Cornell professor of biomedical engineering and the study's senior author, said in the news release. "About 90 percent of cancer deaths are related to metastases, but now we've found a way to dispatch an army of killer white blood cells that cause apoptosis - the cancer cell's own death - obliterating them from the bloodstream. When surrounded by these guys, it becomes nearly impossible for the cancer cell to escape."
Metastasis occurs when cancer cells spread to areas outside of their original stomping grounds. Treatments such as "surgery and radiation" have proven effective in treating original cancer tumors, but once metastasis occurs the prognosis tends to be much grimmer.
A research team injected both human and rodent blood samples with the proteins E-selectin ("an adhesive") and TRAIL ("Tumor Necrosis Factor Related Apoptosis-Inducing Ligand").
The E-selectin made TRAIL "sticky," allowing it to stick to white blood cells (leukocytes) in the blood stream. When the cancer cells encounter TRAIL in the blood stream (which is almost inevitable) it causes them to "kill themselves."
"The mechanism is surprising and unexpected in that this repurposing of white blood cells in flowing blood is more effective than directly targeting the cancer cells with liposomes or soluble protein," the authors said in the news release.
The team concluded the new method was about 60 percent effective at killing cancer cells.
Under laboratory conditions the saline solution does not contain white blood cells to piggy-back the proteins. When the proteins were added "flowing blood that mimicked human body conditions" the success rate shot up to nearly 100 percent.
