White blood cells push cancer cells towards spreading, Cédric Blanpain's team at ULB shows
Neutrophils and macrophages around the tumour each send their own signal; in mice, a drug against one of those substances slowed lung metastases.
Researchers at the Université libre de Bruxelles (ULB) led by Professor Cédric Blanpain have discovered how certain immune cells help cancer cells to spread. Their work appeared in the journal Nature Cancer and was presented on Monday, La Libre and BX1 report. The stakes are high: most cancer deaths are caused not by the original tumour but by metastases to other organs.
To spread, cancer cells detach and become more mobile, a process called epithelial-mesenchymal transition. The researchers found that two types of white blood cells each gather in their own zone around the tumour during this process. Neutrophils secrete oncostatin M, which brings cancer cells into a hybrid intermediate state in which they spread most effectively. Macrophages release TGF-beta 1, which triggers the transition and drives it to its most advanced stage.
In mice, a drug blocking oncostatin M reduced the number of hybrid cancer cells and the number of metastases in the lungs. The researchers also observed the same mechanism around human tumours of the breast, pancreas, lung and bladder. According to ULB, the discovery could open new ways to prevent metastases and make tumour cells more sensitive to treatment. The research was funded by, among others, the FNRS, Télévie, the Fondation contre le Cancer and the European Research Council.