When cancer cells break off from their initial tumour they can spread throughout the body and invade other organs to form new tumours, in a process known as metastasis. Although metastatic tumours cause 90% of deaths in cancer patients, the underlying mechanisms are not well understood. However, a new study revealed that the expression of a ‘sticky protein’ could be the key to allowing breast cancer metastasis.

The study aimed to investigate the role of the protein E-cadherin during metastasis. The protein is an adhesive that allows cells to stick together and can be used to hold cancer cells together within tumours. As cells break away from the bulk primary tumour during metastasis, it was previously thought that cancer cells would have to stop expressing E-cadherin to enable successful metastasis. However, in the most common type of breast cancer, ductal carcinoma, E-cadherin is still expressed, and sometimes even over expressed, during metastasis.

The study tested across three subtypes of breast cancer; luminal, basal, and triple negative breast cancer. The three subtypes show differences in gene expression and patient outcomes. Losing the E-caderin gene significantly hindered cancer cells ability to invade healthy tissues across all three subtypes. Tumours expressing the E-caderin protein only invaded 6% of their tumour borders, while those without E-cadherin invaded 82% of their borders.

However, loss of E-caderin prevented effective cell migration away from the tumour in both lab and mouse models. The cells without E-caderin got lost during migration and died in large numbers after leaving the primary tumour. Cells that were able to migrate to a suitable location to form another tumour were rarely able to proliferate enough to do so.

It appears that E-caderin protein is vital to allow the metastasis of ductal carcinoma breast cancer and represents an intriguing treatment avenue to improve patient survival.

Front Line Genomics are delighted to launch the World Metastasis Summit, an event which aims to create conversation between the oncology community and drive research forward. Tackling metastatic cancer is the greatest opportunity to improve the lives of most cancer patients. The Metastasis Summit will move beyond basic research and focus on the development of new therapies that tackle cancer where it hits hardest.