The vast majority of cancer deaths–90 percent–are the result of metastasis. Dr. Jing Yang’s lab produced findings that suggest that a process known as epithelial-to-mesenchymal transition or EMT is a key factor in the metastasis of carcinomas and tumors in human beings.

EMT is a process seen in developing embryo cells which transforms stationary cells into mobile cells so that they can move to other places in the body and develop into different organs. Ten years ago a researcher named Jean Paul Thiery, hypothesized that tumor cells might be able to exploit the embryonic process of EMT and use it to metastasize.

He proposed that cancer cells may have a way to activate this metamorphic process, change their structure and become mobile. Where afterwards they could join into the bloodstream, plant themselves elsewhere in the body, revert back to their original form and develop into new carcinomas.

The publication of the results of Yang’s lab resolves the debate that arose with Thiery’s initial claim ten years ago. Thiery’s proposal was met with disagreement and remained controversial because no one had been able to find enough supporting evidence or produce results with experiments that used cancer cells.

That was until Jeff Tsai, a postdoctoral fellow in Yang’s lab and first author of the study, used a cancer from a mouse to show that a gene called Twist1 is capable of activating the process that allows cancer cells to change form and move through the body. According to Yang, even with this breakthrough, there is still much to be learned about metastasis. The study has shown that carcinoma cells need some way to turn off EMT, the process that changes their structure and lends them mobility, in order to metastasize efficiently. The next step is to understand how this happens, which is crucial to creating a therapy to prevent metastasis.

“It suggests that EMT reversion could be a critical step to wake up tumor cells from dormancy, a phenomenon in which cancer patients develop metastasis years after the initial primary tumor diagnosis and removal,” Yang said.