"This is good news in an area where our ability to diagnose and predict has previously been less than stellar," said Krishna Donkena, Ph.D., Mayo Clinic urologic researcher. "Our only tool is the PSA test, which has little predictive value. These findings move us much closer to a more accurate test."
The search to identify biomarkers that can be translated into affordable and effective medical tests can be complicated. Prostate cancer causes differential expression of hundreds of different genes, each potentially an indicator of whether a man may get the disease, or already has it. They also may be used to provide information on the development of the cancer, without the need for a painful tumor biopsy.
When seeking to narrow their search to a manageable level, the researchers analyzed 32 cancerous and eight benign patient-tissue samples using genome microarrays representing 33,000 human genes. The information they gleaned from this analysis allowed them to identify 624 differentially-expressed genes between cancerous and benign tissue. They validated these findings in the original 40 tissue samples as well as in 32 additional samples (20 cancerous, 12 benign). The results showed eight genes with significant under-expression and three with significant over-expression, strongly implicating them in prostate cancer development and progression.
Over the years, research has shown that DNA methylation is commonly linked to the development and progression of cancers. This epi-genetic alteration results in silencing or seriously inhibiting gene expression, which in turn lessens the body’s ability to defend against cancer. Current research has not done enough to discover ways to convert this information into a useful medical test, in large part due to the limited number of genes that have been thoroughly studied, and their insufficient sensitivity and specificity (probability of getting a true positive or true negative) for prostate cancer detection.
Dr. Donkena’s team looked at 62 cancerous and 36 benign tissue samples to assess the degree of methylation in the three previously identified under-expressed genes, comparing two known methylated genes. They determined that one gene, PDLIM4, had hypermethylation that could serve as an effective sensitivity marker, accurately detecting prostate cancer 95 percent of the time. The researchers further determined that the combined measurement of a previously known gene, GSTP1, and PDLIM4 improved the detection rate to 98 percent.
Prostate cancer is the second leading cause of cancer death for men in the United States, exceeded only by lung cancer. The sooner a cancer can be diagnosed, the better treatment outcomes will be, so Dr. Donkena and her colleagues are constantly looking for ways to predict who will get prostate cancer, as well as to find better ways to diagnose early or even prevent this disabling and often fatal disease. "We hope that in addition to being a valuable diagnostic and prognostic tool, our discoveries about these genes will help us develop new treatments for prostate cancer," she said.
Other Mayo researchers involved in this study include Karla Ballman, Ph.D.; Bruce Morlan; John Cheville, M.D.; Roxann Neumann; Michael Lieber, M.D.; Donald Tindall, Ph.D.; and Charles Young, Ph.D.
Elizabeth Zimmermann | EurekAlert!
Repairing damaged hearts with self-healing heart cells
22.08.2017 | National University Health System
Biochemical 'fingerprints' reveal diabetes progression
22.08.2017 | Umea University
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
22.08.2017 | Health and Medicine
22.08.2017 | Materials Sciences
22.08.2017 | Life Sciences