Stress causes cells to turn into cancerous tumors
Researchers from Yale have discovered that stress sends out signals that can turn cells into cancerous tumors. The findings could lead to novel ways to attack back. The scientists also found that stress signals that lead to tumors and cancer can be blocked.
Until now researchers believed that several gene mutations inside a single cell is necessary for tumors associated with cancer to develop. The new study shows that cells can work together to promote cancer by signaling each other through a process called JNK. Environmental stress conditions activate JNK.
The study that stress can trigger cancer was conducted by Tian Xu, professor and vice chairman of genetics and a Howard Hughes Medical Institute Investigator and colleagues. "The bad news is that it is much easier for a tissue to accumulate mutations in different cells than in the same cell," said Tian, contradicting previous beliefs about the way cancer begins. "A lot of different conditions can trigger stress signaling: physical stress, emotional stress, infections, inflammation - all these things. Another bad news for cancer”, Xu said.
The researchers studied the activity of two genes in fruits flies: RAS that is responsible for 30 percent of cancers and a gene called scribble that thwarts cancer, but promotes it if it becomes mutated. Neither gene when mutated or defective can singly produce tumors. Previous studies by the same scientists showed that if both genes go awry within the same cell it can lead to cancer. The scientists now discover that stress can cause cells to signal each other and they work together to promote tumor growth.
In the new study Yale researchers discovered that RAS and scribble do not have to co-exist in the same cell to cause cancer. A scribble gene in one cell can work with a mutated RAS gene in another cell. They also found that stress can also trigger cancer – such as a wound infection that sets the JNK signaling process into motion.
Now that researchers understand that environmental stress can trigger cancer they can find new ways to block the signals between cells that make them turn into tumors. "Better understanding of the underlying mechanism causing cancer always offers new tools to battle the disease," Xu said. Stress sends signals to nearby cells with either mutated RAS or defective scribble genes, in turn triggering cancerous tumors.