Only a short 10 km  from the European Commission’s headquarters in Brussels, EU budget funds are bearing fruit as researchers at the Université Libre de Bruxelles are taking a major step forward in cancer research, defining for the first time the tumor transition states that occur during cancer progression and are now identifying the tumor cell populations responsible for metastasis.

The research team, led by Professor Cédric Blanpain, suggested in a study published in nature science journal that cancer cell metastasis is not a binary process. The discovery was made and evaluated in two of the most common cancer forms, skin squamous cell carcinoma and breast cancer. Researcher Yevgenia Pastushenko and her colleagues used state of the art genetic models of skin and breast cancers that undergo spontaneous epithelial to mesenchymal transition (EMT), a process in which epithelial tumour cells lose their adhesion and acquire mesenchymal migratory properties that are associated with metastasis and resistance to therapy.

The team screened hundreds of monoclonal antibodies recognising cell surface molecules and performing single-cell RNA sequencing, finding at least 7 different tumour subpopulations in skin and breast tumours that represent different EMT states that ranged from completely epithelial on the outer layer of a body’s surface to mesenchymal or undifferentiated states in the tissues of the lymphatic and circulatory systems, as well as the musculoskeletal system.

The team concluded that not all cancer cells are functionally equivalent and equally metastatic and proved that cells with shared EMT characteristics were the ones responsible for lung metastasis. “The identification of these different tumour transition states present different functional characteristics such as proliferation, invasion, and metastatic potential across a wide range of mice and human cancers has important implications for developing new strategies to halt tumour progression and metastasis.

It is likely that these different tumour transition states are also important for the response of cancerous cells to chemotherapy and radiotherapy”, said Blanpain.

The EU’s Commissioner for Research, Science and Innovation Carlos Moedas stressed that once again, “European Research Council researchers have found a way to solve a – let me call it – research mystery. The fight against cancer is a paramount mission of the scientific community. This discovery underlines the importance of curiosity-driven research and how much it contributes to our society.”

Apart from the ERC, the cutting-edge research is currently funded by the TELEVIE, WELBIO, the Fondation Contre le Cancer, the ULB fondation, Fonds Erasme, Worldwide Cancer Research and the foundation Baillet Latour, in collaboration with different groups that include Belgian teams led by Thierry Voet from the research institute KU Leuven and Isabelle Salmon of Hôpital Erasme.