A mechanism used by metastasising tumour cells to invade lung tissue and establish secondary tumours is reported online this week in Nature Cell Biology. The research identifies a promising drug target to prevent the spread of cancer.
Primary tumours prepare the lung for invasion by inducing chemokines ? chemical factors normally used to recruit immune cells during infection ? which guide migration of tumour cells to the secondary site. Hiratsuka and colleagues show that primary tumours also induce lung cells to produce an additional factor, serum amyloid A3 (SAA3). SAA3 accelerates the recruitment of primary tumour cells by switching on genes involved in inflammation and boosting the production of chemokines. Importantly, the team show that blocking SAA3 or its receptor strikingly reduces lung metastasis in mice.
Metastasis is difficult to predict and even harder to treat. The new findings offer researchers vital clues for understanding how cancer cells can establish new tumours at sites quite distant from the original tumour.