If a tumor is like a seed, the soil around it plays a significant role in its growth, according to a study which finds that the microenvironment of a tumor cell has significant impact on cancer metastasis. This discovery by Siyuan Zhang at the University of Notre Dame and a team at the University of Texas MD Anderson Cancer Center has focused attention on fighting cancer in the tumor cell's microenvironment.
When PTEN, a known tumor-inhibiting protein, is artificially deleted in a tumor cell, sometimes there is even less metastasis in the brain, but PTEN was also reduced in tumor cells when they arrive in brain tissue. That suggested critical importance of the tissue environment, what
Siyuan Zhang at the University of Notre Dame
calls the "seed and soil" model: Tumors that grow in one kind of tissue won't grow in another easily. They need to adapt to the new "soil."
"By changing the soil, we potentially can suppress metastasis," he says. "The microenvironment has tremendous impact on how the gene is expressed, what type of gene will be expressed. It's definitely not due to genetic mutation. The point of this paper is we should not overlook the huge influence of the tissue architecture, the tissue environment, the tissue composition. It's a dynamic process."
The team now seeks to understand the mechanisms of the tissue-environment influence, opening the possibility that the environment could be altered in a way that fights cancer by preventing tumor cell growth.
Published in Nature.