A fascinating study from researchers at the University of Basel has revealed a method that forces malignant breast cancer cells to turn into fat cells. The research, currently only demonstrated in mice, suggests the process could stop tumors from metastasizing and potentially make the cancer more susceptible to conventional chemotherapy.

One of the tricks cancer cells exploit to spread to other organs is a process called epithelial–mesenchymal transition (EMT). This process traditionally occurs during embryonic development as cells shift from one type into another.

Cancer cells hijack this plasticity process in order to leave a primary site, enter the bloodstream and move to a secondary site. The reverse of EMT is a process called mesenchymal-epithelial transition (MET). So essentially, EMT initiates the metastatic process, while MET completes it, optimizing tumor growth at the newly seeded secondary site.

This cellular plasticity is vital to the way cancer can avoid conventional therapies and spread around the human body. However, a team of Swiss researchers may have discovered a way of turning cancer's plasticity against itself, and forcing the cells to become other, more harmless, cell types.

The study found, using two preexisting drugs, breast cancer cells can be forced into becoming harmless fat cells. The experiments so far have only been performed on mice, and have some key limitations. At this stage the technique does not convert all breast cancer cells into fat cells. Only the proliferating cells that have left the primary cancer site seem to be affected by the forced transition. This suggests that the treatment only catches the cancer cells as they enter into the EMT process and begin to metastasize.

A great deal of experimental work is still needed before this research translates into human treatments, but the discovery is incredibly promising. It reveals that the plasticity of cancer cells can be effectively exploited and since this technique is triggered through the administration of two already FDA-approved drugs it hopefully can rapidly transition into clinical applications.

The ultimate goal is not to generate a treatment that magically turns cancer cells into harmless fat cells, but harness this process to stop malignant tumors from spreading and amplify the effects of current chemotherapy treatments.

"In future, this innovative therapeutic approach could be used in combination with conventional chemotherapy to suppress both primary tumor growth and the formation of deadly metastases," explains Gerhard Christofori, senior author on the new study.

The new study was published in the journal Cancer Cell.