Could physical and psychological stress be sabotaging your cancer treatment?

Limit your exercise in the days before cancer treatment, say researchers.

A study conducted at Ohio State University and published by Genetic Engineering & Biotechnology News online states that both psychological and physical stress, including strenuous exercise, could inhibit the effectiveness of their cancer treatment.

Researchers say that certain stressors one or two days before receiving cancer treatment can activate a “stress-sensitive protein” that somehow safeguards cancer cells from chemo and radiation, resulting in a less effective round of anticancer therapy for the patient. The survival of cancer cells is attributed to something called “heat shock factor-1,” a protein which is linked to stress and is known for helping delicate tissues in the pericardium, or lining of the heart, survive exposure to environmental toxins. The same occurrence that protects the heart tissue from stress may be “protecting” cancerous cells from chemo and other cancer treatments.

Professor Govindasamy Ilangovan, who teaches internal medicine and led the study at Ohio State, says that exercise is one of the top stressors that apparently hinder the effectiveness of cancer treatments.

“I am not against exercise, but the timing is critical,” he says. “It looks like any prolonged physical activity a couple of days before the start of cancer therapy is highly risky.”

Exercise and other factors may “reduce the benefits of treatment,” Ilangovan reports.

A number of tests involving breast cancer cells reveal that another protein known as Hsp27 is activated by heat shock factor-1 and essentially blocks cancer treatments like chemo from killing cancer cells, even after the cells have been damaged by radiation – findings that may change the way that a cancer patient must behave during a round of cancer-killing treatments. Ohio State researchers say that limiting physical and mental stress in the days leading up to a patient’s cancer treatment may be crucial.

Ilangovan, who has long been a researcher at the university’s Davis Heart and Lung Research Institute, believes that heat shock factor-1 probably blocks cancer treatments like chemo from harming cells of other forms of cancer – not just breast cancer – but especially adenocarcinoma cells [cancer cells that form in the glands].

Another protein called p21 allows cancerous cells to “pause,” then repair themselves and continue multiplying, say Ohio State scientists. While cancer treatments like radiation should prevent this from happening, when Hsp27 is present, p21 aids in the survival of harmful cells.

Hsp27, the protein activated by heat shock factor-1, is found in a person who has a decreased level of cancer-killing proteins, like siRNA. siRNA, when introduced to Hsp27, restored the ability of cancer treatments to kill off bad cells – known as the “death mechanism.”

“A reduction in the level of the Hsp27 protein made the cancer cells more susceptible” to treatments like chemo, said Ilangovan. This seems to suggest that new cancer drugs should contain ingredients like siRNA, which stop Hsp27 from preventing the effectiveness of cancer treatments. Unfortunately, siRNA is not suitable for patient use, researchers say, but a drug with a similar effect could be a huge development for the cancer community: siRNA increased the effectiveness of cancer therapies and led to the death of over half of cancer cells that had previously been exposed to radiation but had yet to be destroyed completely.

Ilangovan’s study leads him and other researchers say that oncologists should be warning their patients about the potential risks associated with extreme stress in the days leading up to a round of chemo or radiation.


Molecular Cancer Research

Genetic Engineering & Biotechnology News

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