A Blessing in Disguise: Fighting Cancer With Herpes

Rebekah Hwang/Guardian

UCSD researchers have discovered how to use an STD to treat skin cancer.

A team of scientists led by Dr. Gregory Daniels, assistant clinical professor of oncology at the Moores Cancer Center, has engineered the herpes virus to kill melanoma, or skin cancer, tumors.

When a foreign substance, such as a virus, is introduced to the body, the immune system detects the change and begins to fight the entire area, killing the cancer present as well. The cancerous cells are not usually detected because they are integrated with the body’s cells.

According to Daniels, surgeons have been using viruses to stimulate immune response to cancerous tumors since the 1880s.

“You can inject anything into cancer and kill it,” he said. “People inject weird stuff, and as long as it has toxicity, it works.”

However, this treatment has been dangerous because some of the viruses made matters worse by spreading through the body, or causing cancer themselves. Now, the herpes virus can be engineered so that it is elicits the immune response while still being harmless for non-cancerous cells.

Daniels’ team of researchers used recombinant DNA technology to delete the genes in the herpes virus that cause the disease and the genes that program the virus to spread, making it harmless to noncancerous cells while simultaneously eliciting an immune response.

“We engineered the virus to delete harmful genes until we had a less robust version of herpes,” Daniels said.

The herpes virus was then injected with the protein GM-CSF, which initiates the inflammatory immune system.

“This causes a one-two response,” Daniels said. “The presence of the virus itself causes the immune system to be heightened, and by engineering it to carry the protein, we ensure that GM-CSF also creates a response.”

Daniels conducted a clinical study in which 50 patients with melanoma were injected with the virus twice weekly.

“We saw over 80-percent success [rates] in the tumors,” Daniels said. “They just went away.”

In addition, Daniels said the virus elicited such a strong immune response throughout the entire body, that 20 percent of the patients saw melanoma tumors disappear from parts of their bodies not directly injected.

This type of gene therapy can be used for other cancers as well.

“The therapy can also be used for head and neck cancers too, or any cancer that starts from the skin,” Daniels said.

The next step is for the Food and Drug Administration to review Daniels’ study and decide whether this is a safe treatment for skin cancers.

Readers can contact Angela Chen at shchen@ucsd.edu.

References : http://www.ucsdguardian.org/news/science-and-technology/a-blessing-in-disguise-fighting-cancer-with-herpes/