Stopping the flow of cancer cells promotes the spread of tumours

Metastasis is the cause of more than 90% of cancer deaths. The cancer cells break away from the original tumour and spread through the body anchoring to other organs and forming new tumours called metastases. For a focus of cancer to spread to other organs, its cells undergo a process known as epithelial-mesenchymal transition (EMT) which makes them mobile and invasive, and they begin to travel through the bloodstream. However, to re-anchor to a new organ or tissue they must first recover their initial characteristics, i.e. lose mobility.

The Institute of Neurosciences, a joint centre of the Universidad Miguel Hernández of Elche and the National Research Council (CSIC), has found that the transition from mobile to stationary cancer cell involves the loss of its component Prrx1. The researcher Ángela Nieto, who led the study, explains that "although this component is one of the factors favouring the initial spread of cancer cells and their arrival to other organs, it has to be turned off for these cells to group together to form other tumours."

Tumours with high amounts of Prrx1 have therefore better prognosis as they can not form metastases. The researcher Óscar Ocaña believes that "the therapeutic strategy of blocking the EMT to prevent the spread of tumours would only be effective if done before the first cancer cells detach from the primary tumour, which usually occurs in very early stages of the disease and usually before receiving the diagnosis." In fact, Nieto adds, "blocking the EMT in these conditions favours the appearance of new tumours." However, the research also shows that a strategy aimed at attacking other properties of cancer cells would work against metastasis.

The results have been obtained by studying various animal models: chicken, zebrafish and mouse, and by analysing patient samples. Other participants in the project include researchers from the Institute of Biomedical Research "Alberto Sols" in Madrid, the Bellvitge Biomedical Research Institute and the MD Anderson International Foundation.