Cells that help to create bone also promote lung tumours in mice.
Mikael Pittet of Massachusetts General Hospital in Boston and his colleagues discovered that mice with lung cancer had high numbers of bone-forming cells called osteoblasts, which are found in the bone marrow. The researchers showed that reducing levels of a subset of osteoblasts known as Ocn+ cells in mice led to slower growth of lung tumours.
The team traced the Ocn+ cells’ effect to white blood cells called neutrophils. Previous studies had shown that neutrophils can invade lung tumours, and people with various cancers who have high neutrophil levels fare poorly. In this case, the researchers showed that Ocn+ osteoblasts spur the production of a particular type of neutrophil whose gene activity is linked to the formation and growth of tumours.