New Breast Cancer Research Upends Long Notions: Stanford Study

PALO ALTO, CA — Mutations and other changes in DNA lead a cell to replicate uncontrollably. A tumor forms, then metastasizes.

However, recent science is upending this notion by showing that the surrounding microenvironment plays a major role in "tumorigenesis." For example, something so seemingly innocuous as the stiffening of surrounding tissue, which is commonly observed in breast cancer, plays a key role in driving breast cancer progression, the Stanford News Service reported.

Now, researchers at Stanford University say they can explain why. In experiments, they introduced mammary cells into what they term “high-stiffness environments” and showed that even healthy cells begin to proliferate and migrate when stiffness increases, the news service added.

Unchecked growth and movement to other parts of the body are two key characteristics of malignancies. Their findings appear in the journal Nature Biomedical Engineering.
While not dismissing genetics as a pathway to cancer, Ovijit Chaudhuri, an assistant professor of mechanical engineering and senior author of the study, says some forms of breast cancer respond to physical as well as chemical cues.

“It’s not just what’s inside the cell that matters,” he said. “The neighborhood plays a key role, too.”

The researchers believe that the mechanical stiffness of the microenvironment changes the cell’s “epigenome.” The epigenome is a catch-all term for the complex processes and biochemical changes that regulate genetic expression — the turning on and off of genes to produce or impede important biochemicals, the report dictates.

This hypothesis would explain how an otherwise normal cell without genetic changes can behave like a cancer: In any given cell, every strand of DNA must fold upon itself again and again in a highly organized manner merely to fit inside the cell’s nucleus. Cells, meanwhile, are continuously tugging and teasing against their surrounding materials, which changes how the DNA folds.

In this process of exposing or hiding genes, stiffness can cause a cell to produce new and different chemicals that change how the cell behaves.

“That’s how a healthy cell begins to act like a cancer cell,” Chaudhuri said.

With this knowledge in hand, the question then turns to how scientists might use this new information to better understand how cancers form and, eventually, to find new ways to fight cancer.