Engineering Viruses to Target Resistant Breast Cancer


It has long been said that imitation is the sincerest form of flattery. At City of Hope, researchers are implementing this concept of imitation—of making one thing similar to another—in a leading-edge approach to treating difficult cancers.

City of Hope’s new chief of surgery and an enthusiastic researcher, Yuman Fong, M.D., has been developing a therapy that essentially makes resistant breast cancer respond like thyroid cancer, which is cured in 90 percent of patients.

Triple-negative breast cancer—named for its lack of three important receptors that can be targeted with common, effective therapies—remains a challenge for women, as well as for the oncologists who care for them. Fong is energized by this challenge and the promise of discovery. “If we can find something that can kill [these types of] cancer cells, it would be a big breakthrough for the field,” he says.

Fong has been developing a new approach to treating triple-negative breast cancer by starting with what he knows and loves: viral therapy. He has long studied how viruses can kill cancer. Happily, his expertise in viruses and affinity to the challenge of treatment-resistant cancers is a good fit.

“Many of the reasons these cancer cells are highly resistant to chemotherapy and radiation are reasons they should support the growth of viruses,” Fong explains. Cells become resistant to treatment when they turn off the normal “shut down and die” response to toxins such as chemotherapy and radiation. With this response turned off, cancer cells can support and spread a viral infection.

To further enhance viral therapies, Fong is engineering viruses with genes that induce cell death. He recently published a study that showed that viruses can be engineered to cut off the blood supply to cancer cells, and to stimulate surrounding immune cells to recognize and kill cancer. These engineered viruses are currently in clinical trials for resistant head and neck cancers and for mesothelioma, a deadly type of cancer that grows in the lining of the lungs.

Fong is now engineering viruses to produce a protein called hNIS, which carries iodine into thyroid cells. Using these engineered viruses, physicians can deliver the same treatment to breast cancer patients as they would to patients fighting thyroid cancer: radioactive iodine. When the iodine is introduced into breast cancer cells by the virus engineered with hNIS, it kills cells in a radius of 3mm around the infected cell.

Already proven effective in early studies, this viral treatment is nearly ready for human clinical trials.

Fong hopes to start these studies at City of Hope by next year—and to find that, with this new therapy, resistant breast cancer will have the same successful cure rate as thyroid cancer.

Become a member of NAWRB today! LEARN MORE

Leave a Reply

Your email address will not be published. Required fields are marked *