Engineered Virus in Triple-Negative Breast Cancer Shows Treatment Potential

February 10, 2014

Scientists have discovered that the injection of an engineered virus into triple-negative breast cancer cells may allow the cancers to be treated with therapeutic radioiodine, a treatment traditionally used to treat thyroid cancers.

Scientists have discovered that the injection of an engineered virus into triple-negative breast cancer cells may allow the cancers to be treated with therapeutic radioiodine, a treatment traditionally used to treat thyroid cancers. In laboratory experiments, the virus was able to get triple-negative breast cancer cells to produce the protein human sodium-iodide symporter (hNIS), which makes these cells susceptible to radioactive iodine.

“We employed a virus that has been designed to specifically infect, replicate within, and kill cancers,” study author Yuman Fong, MD, a researcher from the department of surgery at Memorial Sloan-Kettering Cancer Center, told Cancer Network. “These data indicate that this highly novel strategy may be promising in the treatment of this deadly disease.”

Triple-negative breast cancer lacks effective therapies because the disease lacks hormonal targets for treatment and is resistant to chemotherapy. Previous research has shown that hNIS is endogenously expressed in lactating mammary glands and has a low level presence in a majority of breast cancers.

To determine if hNIS expression could be increased in order to use it as a target for treatment, Fong and colleagues infected and killed triple-negative breast cancer cells using an engineered vaccinia virus, GLV-1h153, previously used by the World Health Organization to help eradicate small pox. In this study, the researchers investigated the therapeutic efficacy of the virus in combination with radioiodine in mouse models of triple-negative breast cancer.

“Cells expressing hNIS allowed influx of radioactive iodine,” Fong said. “This study showed that not only did the virus directly kill cancer, virally induced hNIS expression allowed radioactive iodine to further kill triple-negative breast cancers in animal models.”

Data from the study showed that cells injected with the virus had a 178-fold increase in radioiodine uptake compared with the control cells. Additionally, cells infected with the virus and given iodine had a sixfold increase in tumor regression compared with virus-only treated cells (P < .05).

“Our results support the continued investigation of this novel engineered vaccinia virus as a potentially important, readily translatable therapy and imaging tool for triple-negative breast cancer,” the researchers wrote.

The results of the study were published in the FASEB Journal.