‘Trojan horses’ deliver blows to tumors

U. SHEFFIELD (UK) — White blood cells that act as Trojan horses releasing a tumor-busting virus could stop the spread of cancer after therapy.

Researchers from the University of Sheffield have discovered white blood cells, called macrophages, surge into tumors after frontline therapies, like chemotherapy or radiotherapy, and are now exploiting this to deliver a second potent blow to stop tumors from growing back.

They are injecting macrophages carrying a tumor-destroying virus into the bloodstream at the exact moment when this surge occurs so that the therapeutic macrophages can surf this wave and get swept up into the tumor in large numbers.

Each macrophage then releases large amounts of virus inside the tumor.


Using the blood cells as Trojan-horses ensures that the virus is delivered to where it is needed most after initial therapies: deep into the heart of the remaining tumor.

The virus then kills the cancer residue from within, preventing regrowth or further spread of the cancer to other parts of the body.

“Our Trojan-horse can convert a patient’s own white blood cells into tiny tumor-killing machines which fight to prevent tumor regrowth after the end of chemo or radio therapy treatment,” says Claire Lewis, a professor in the oncology department at Sheffield, who co-led the project.

“This is very empowering for patients who have been undergoing rounds and rounds of chemotherapy or radiotherapy because treatment means it is their own white blood cells doing the work and blasting the cancer.”

“This breakthrough means that we may now have developed a way of preventing cancer coming back after frontline treatments—many patients unfortunately die because of tumor regrowth or the spread of cancer so this is a ground-breaking discovery which could impact on thousands of lives.”

Study co-leader Munitta Muthana, from the infection and immunity department, says the new therapy has been developed to treat prostate cancer, “however, it has the potential to be used to treat patients with any form of cancer.”

The research, reported in the journal Cancer Research, shows that the therapy completely eradicates primary and metastic prostate tumors after chemo or radiotherapy. Researchers hope clinical trials in prostate cancer patients could begin as early as next year.

Source: University of Sheffield