"Scientists at the Penn State College of Medicine have discovered that a virus that is harmless to humans will kill triple-negative breast cancer cells and tumour cells in mice when applied to cancers.
Breast cancer is the leading cause of cancer death in women in the world, and triple-negative breast cancer is the hardest type of breast cancer to treat.
Some types of tumours contain protein receptors that are activated by one of three proteins – namely the human epidermal growth factor receptor 2 (HER2), the hormone oestrogen or the hormone progesterone.
Chemotherapies usually target one of these three receptors, but since triple-negative cancers do not express these genes, doctors have to treat them with a combination of therapies.
"Treatment of breast cancer remains difficult because there are multiple signalling pathways that promote tumour growth and develop resistance to treatment," said Craig Meyers, a professor of Microbiology and Immunology at Penn State.
"There is an urgent and ongoing need for the development of novel therapies which efficiently target triple-negative breast cancers."