Aberrent gene behavior links aging and prostate cancer

Researchers at the University of Wisconsin School of Medicine and Public Health in Madison have pinpointed a gene behavior that could mark susceptibility to prostate cancer.

Senior author David Jarrard, MD, said the findings may provide a window into preventing prostate cancer in aging men, as well as a mechanism to diagnose the disease in its early stages.

In the first phase of the research, Dr. Jarrard and his team found an erosion of normal gene regulation in mice that encourages a cancer promoter linked to the development of prostate cancer. Researchers then examined normal-appearing prostate tissues in aging men and found that this same alteration occurred more commonly in men who later developed associated cancer, as reported in Cancer Research (2008; 68:6797-802).

“We are setting up a trial to look at this gene change as a marker for men who develop cancer in a broader group of patients, both within and outside UW,” Dr. Jarrad said.

In a related study, scientists at Seattle’s Fred Hutchinson Cancer Research Center have discovered that microRNAs are released by cancer cells and circulate in the blood, which gives them the potential to become a new class of biomarkers for detecting cancer at its earliest stages. The study, led by Muneesh Tewari, MD, PhD, is published in the Proceedings of the National Academy of Sciences (2008; 105:10513-8).

For the study, Dr. Tewari and colleagues tested blood from mice and humans with advanced prostate cancers, as well as that from healthy controls. They measured microRNAs made by the tumors in both cases and controls, and they could distinguish which individuals had cancer based on blood microRNA measurement.

“This research shows that microRNAs, which weren’t previously thought of as markers of cancer in the blood, are a worthwhile class of molecules to study for the purpose of early cancer detection,” Dr. Tewari said.

“Current technology for developing tests to measure microRNAs in clinical samples is quite advanced, whereas the bottleneck for developing protein-based biomarkers is the slow process of generating assays for measuring specific proteins.”

The next steps are to identify specific microRNAs that can signal the presence of a variety of solid-tumor cancers at an early stage and to further develop the technology to detect minute quantities of microRNAs.