Stress, Exercise Could Help Deadly Cancer Cells Survive Treatment

Here's a recent story from Aol Health that Dr. Asa Andrew discussed on his radio show "Dr. Asa on Call"

Cancer patients who subject themselves to psychological or physical stress, even in the form of intense exercise, a day or two before treatment might be canceling out its effects without even realizing it.

New research shows that significant stress in the body, including that caused by a rigorous workout, may activate a protein that will help deadly cancer cells survive chemotherapy and radiation.

Scientists at The Ohio State University say the findings suggest that cancer cells have found a way to use the stress-sensitive protein to stave off treatment.

"One of the known inducers of this factor is exercise. I am not against exercise, but the timing is critical," study lead author Govindasamy Ilangovan, an associate professor of internal medicine at Ohio State, said in a statement. "It looks like any intense or prolonged physical activity a couple of days before the start of cancer therapy is highly risky, and has potential to reduce the benefits of the treatment."

The study, published in the journal Molecular Cancer Research, relied on several experiments on breast cancer cell cultures. The team linked the ability of cancer cells to resist treatment to the presence of a common protein called heat shock factor-1, known to be induced by stress.

Researchers initially saw that the protein protected heart tissue from toxins, and set about proving whether it could also stop cancer cells from being zapped by radiation or chemo.

They found that another protein activated by heat shock factor-1, called Hsp27, stopped cancer cells from being killed by radiation and chemo medication, even after the cells' DNA was damaged.

The team wants to create a drug that will block heat shock factor-1 in patients undergoing cancer therapy so their treatment isn't compromised. But for now, they advise those with cancer to avoid any kind of stress a few days before they go in for radiation or chemo.

Researchers tested the findings by suppressing Hsp27 using a molecule called siRNA, which interferes with the protein's ability to function. When Hsp27 was blocked, more cancer cells died during therapy -- at least 60 percent of them in one of the trials.

"We clearly showed that a reduction in the level of the Hsp27 protein made the cancer cells more susceptible to both treatments," Ilangovan said.

The experiments showed that Hsp27 levels peaked within 48 hours after a stressful event like vigorous exercise that triggers heat shock factor-1, which they believe means the protein is especially active in the two days after the body is exposed to stress.

"The process that sets these activities in motion takes a couple of days," Ilangovan said. "It is not proven in a clinical setting, but our hypothesis leads us to strongly caution cancer patients about avoiding stress because that stress might trigger recurrence of cancer cell growth."

The research was funded by grants from the American Heart Association and the National Institutes of Health.

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