Embryonic development protein active in cancer growth

A team of scientists at the University of California, San Diego have identified a novel protein expressed by breast cancer cells that could provide a new target for future anti-cancer drugs and treatments. They have found that the tumor cells of patients with breast cancer frequently express the Receptor-tyrosine-kinase-like Orphan Receptor 1, or ROR1, and that silencing expression of ROR1 impaired the growth and survival of human breast cancer cells. ROR1 was first identified in the early 1990s and labeled an orphan receptor because its purpose was unknown. Subsequent work found that ROR1 is expressed at high levels during embryogenesis, when it plays an important role in regulating embryonic muscle and skeletal development. The most aggressive cancers were the ones more likely to express ROR1. The discovery of ROR1's role in both blood and breast cancers suggests it might have a similar function in other forms of cancer.