Cellular switch biomarker predicts prostate cancer's spread

Once a patient is treated for prostate cancer, close medical monitoring offers an imperfect way to catch potential recurrence or spread of the disease. A team of U.S. and Canadian researchers believe they've found an easier way to get the job done: a biomarker for a cellular switch. 

Scientists from Vanderbilt University Medical Center, the University of Alberta in Canada and others came up with the new finding. The journal Cancer Research published their study details online.

The protein CD151 is what is generating all the attention. Researchers found that patients faced early recurrence and a spread of their prostate cancer if they tested positive for CD151free, a version of the protein minus its adhesion partner integrin that has essentially changed its molecular state. But patients without detectable CD151free didn't face the same early bad news. Those found to have CD151free often faced prostate cancer metastasis up to a decade sooner than patients who lacked the protein mutation, according to the research team. CD151 is typically found in other cancers, helping those cells to migrate.

"What's so novel about this discovery is we're not talking about changing protein expression, which is what we traditionally see," co-investigator Andries Zijlstra, a Vanderbilt assistant professor, said in a statement. "We're talking about a protein that changes its molecular state and detection of that molecular state is an indication of disease progression... That information ultimately determines the type of care given to a cancer patient." 

Enabling the research: samples from 137 patients treated for prostate cancer in Canada over the previous 12 years.

More work needs to be done and scientists must validate these results on a larger scale. But the finding takes a significant step toward giving scientists a new tool to identify whether patients expect to face a metastasis of their prostate cancers. The team is also working hard to develop an antibody test based on the new biomarker. Earlier identification of CD151free offers great potential to facilitate quicker treatment, something that's vital in battling cancer, especially if it returns.

The finding continues a streak in recent weeks of promising prostate cancer biomarker research. Earlier this fall, for example, folks at the Herbert Irving Comprehensive Cancer Center at Columbia University Medical Center identified three genes that can help predict whether prostate cancer will remain slow-growing or become aggressive. Researchers at the Albert Einstein College of Medicine of Yeshiva University determined earlier this summer that nerve density could serve as a biomarker to predict the development and spread of prostate tumors.

- read the research
- here's the journal abstract