Researchers Target How and Why Tumors Form

Researchers at the University of Iowa recently discovered how and why tumors are able to form.

During 2 studies using 3-D technology, investigators were able to watch the movements of cancerous cells in human breast tissue. This is the first time cancerous cells were continually tracked while forming of tumors.

The results of a study published in the American Journal of Cancer Research showed that cancerous cells actively recruit healthy cells by extending a “cable” to grab both cancerous and healthy cells, bringing them back in together, according to the study. Tumors are able to form with as little as 5% of cancerous cells.

"It's not like things sticking to each other," said study author David Soll. "It's that these cells go out and actively recruit. It's complicated stuff, and it's not passive. No one had a clue that there were specialized cells in this process, and that it's a small number that pulls all the rest in."

In another paper published last spring in PLOS One, researchers showed that it was only cancerous cells that were actively a part of grabbing cells for the tumor formation. The cancerous cells extend out to reach for cells to pull in. This forms a larger mass that continues as more cells are drawn in.

"There's nothing but tumorigenic cells in the bridge (between cells), and that's the discovery,” Soll said. “The tumorigenic cells know what they're doing. They make tumors."

Researchers sought to determine how these cells knew what to do, so they compared cell activity in human breast tissue (MoVi-10’) with a weakly tumorigenic, parental breast cancer cell line (MCF-7).

Over a 50 hour period, investigators discovered that MoVi-10' cells grew more in density than MCF-7. Regardless of the ratio of MCF-7 to MoVi-10’ cells in the cluster, only MoVi-10’ cells probed around to draw in other cells, both cancerous and healthy.

"The results here extend our original observation that tumorigenic cell lines and fresh tumor cells possess the unique capacity to undergo coalescence through the active formation of cellular cables," the authors wrote.

The most important take away from the study was that MoVi-10’ cells move at 92 microns per hour, and at about twice the speed of healthy cells. This helps them and other scientists have a better understanding on how quickly tumors can be created.