Herpes to the Rescue: A New Form of Cancer Treatment that Utilizes Viruses

For most of us getting sick with a virus is not something we hope for. However, for some cancer patients contracting a virus may be their key to recovery. Viral therapy is an up and coming form of cancer treatment that aims to kill cancerous tumors using viruses. Doctors at Nationwide Children's Hospital in Columbus, Ohio are pioneering this new approach for the treatment of pediatric cancers. The idea behind viral therapy is relatively simple. Viruses infect healthy tissues in the body. By modifying viruses to be directly inserted into solid cancer tumors the virus can cause the tumor to "shrink and disappear".

Viral therapy research comes at an especially crucial time in cancer treatment. Cancer is the second leading cause of death for children in the U.S. according to the American Cancer Society. This year alone approximately 12,000 children under the age of 15 will be diagnosed with cancer. Even though research has been conducted on viral therapy's use in adults, very limited studies have been done on its use in children. Dr.Timothy Cripe, a pediatric oncologist at Nationwide Children's Hospital, decided to break the trend and focus on viral therapy's potential to cure childhood cancer.

There are several different kinds of cancer treatments in existence, chemotherapy being the most recognizable. In healthy cells there are specialized genes that regulate the cell's growth. Cancer cells' growth pattern differs from normal cells. In cancer cells the genes that stimulate growth are abnormal which causes uncontrollable, abnormal cellular growth. The rapidly growing cancer cells form into cancerous tumors. Like current treatments, the goal of viral therapy is to slow and eventually stop the spread of harmful cancerous cells. During their research Dr. Cripe and his team tested the effects of two types of viruses on inhibiting cancer growth. One virus was "weakened" so as to not sicken the patient but strong enough to still "infiltrate the tumor and direct the immune system to attack it." New genes, such as immune stimulating ones and ones that damage cancer blood vessels, were added to the other virus in a lab to enhance its fighting capabilities. You'd probably be surprised to learn that Herpes simplex virus, the one that causes cold sores, is one of the viruses being studied at Nationwide Children's Hospital.

Dr. Cripe has not tested viral therapy on humans yet. Research has been done on animals though and appears promising. When the animals were injected with viruses, their bodies' worked to fight against the infection. Ordinarily, the immune system does not recognize the presence of cancer cells as foreign. Dr. Cripe found that when tumors are injected with viruses the immune system does register the tumors and begins to attack them.

One of the advantages of viral treatment is that the virus does not impair healthy cells and tissues in the body even though the tumor is affected. For this reason, viral therapy exhibits very few side effects unlike traditional chemotherapy. Chemotherapy, on the other hand, can damage healthy cells and in some cases trigger unpleasant side effects such as hair loss, nausea, and weight gain or loss. The only known effects spurred by viral therapy are fever, chills, and aches. These symptoms are merely short lived and characteristic of the effects of an infection. Dr. Cripe believes that viral therapy could "make a world of difference for pediatric cancer patients who would otherwise be treated with chemotherapy."

The doctors at Nationwide are also studying ways to inject an altered virus intravenously into the blood system. Cancer cells can spreadTreating Pediatric Cancer with Viruses throughout the body. It is hypothesized that an intravenously injected virus could target cancer cells anywhere in the body. Currently, when the doctor tells you that your cancer has spread the options for treatment are limited. A treatment that could kill cancer anywhere in the body and not just at the primary tumor site could save hundreds of lives.

Dr. Cripe and his team are pleased with the results from their research on animals and are now moving into phase I clinical trials focusing on the safety of viral therapy for kids. They also plan to study whether viral therapy works most efficiently in tandem with other treatments or by itself. Their research will focus on treatments for cancers like neuroblastoma and sarcoma. Dr. Cripe hopes that his research will not only improve the lives of kids battling cancer but also save them. It's great to see that viruses are being utilized to potentially save lives!

References:

Cripe, T. "The cold sore virus may help kids fight cancer." Live Science. October 10, 2013.

Science Daily. "Doctors look at treating specific types of pediatric cancer with viral therapy." Science Daily. September 9, 2013.

University of Southern California, Department of Surgery. What is Cancer (2002).

Videos:

Both from Nationwide Children's Hospital (via Youtube).