Gene activity may explain how exercise lowers prostate Ca progression risk

A recent study has identified nearly 200 genes that may help explain how physical activity improves survival in men with low-grade prostate cancer.

The study, which was presented at the recent Genitourinary Cancers Symposium in San Francisco, compared the activity of some 20,000 genes in healthy prostate tissue biopsied from several dozen patients.

The finding builds on two previous studies that showed brisk walking or vigorous exercise, such as jogging for 3 or more hours a week, was linked to a lowered risk of prostate cancer progression and death after diagnosis. Those earlier studies, however, offered no explanation as to why.

In the current study, researchers from the University of California, San Francisco teased out a molecular profile of 184 genes whose expression in the prostate gland is linked to vigorous exercise.

Understanding how the activity of these genes is impacted by vigorous exercise and how this might translate to a lowered risk of prostate cancer progression may help reveal new ways to manage the disease, said senior author June Chan, ScD.

"Vigorous physical activity may provide clinical benefits for men diagnosed with earlier stage prostate cancer," Dr. Chan said. "The finding suggests some interesting leads on mechanisms by which physical activity may protect against prostate cancer progression."

The analysis involved examining the levels of expression of the same 20,000 genes in 70 men. This information was correlated with the exercise patterns the men reported on questionnaires.

The study revealed 109 genes were up-regulated and 75 were down-regulated among the men who exercised vigorously for at least 3 hours per week compared with those who exercised less. Among the genes that exhibited greater expression were a number that already are thought to help thwart cancer progression, including the tumor suppressor genes BRCA1 and BRCA2, as well as genes involved in cell cycle and DNA repair.

The authors are continuing to analyze the data, including investigating pathways that were down-regulated by vigorous physical activity.

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