The following tips are on abstracts or posters to be presented at the American Urological Association Annual Meeting 2009, April 25-30, or the concurrent Engineering & Urology Society Annual Meeting 2009, April 25, Chicago, Ill.
GIVING PROSTATE CANCER THE COLD SHOULDER
--"Cold shock" proteins could be new target in cancer fight
AUA Meeting, April 27, 8:00 10:00 A.M., Moderated Poster Session 25, #727, W183 B @ McCormick Place West
Johns Hopkins scientists have discovered a new Achilles heel in the battle against prostate cancer: a family of "cold shock" proteins that, when turned down through genetic techniques, weaken cancer cells and make them more vulnerable to chemotherapy.
The team of scientists, led by Robert H. Getzenberg, Ph.D., and postdoctoral fellow Yu Zeng, M.D., Ph.D., in the Department of Urology at the Johns Hopkins University School of Medicine, were inspired to pursue this new target by recent studies on testicular cancer showing that heat substantially weakens these cells and makes them easier to kill. Researchers have speculated that this vulnerability may be responsible for the high cure rates observed in men with testicular cancer, even when this cancer has metastasized throughout the body.
Wondering whether heat has a similar effect on prostate cancer cells, Zeng and his colleagues warmed cells sampled from patients and monitored the activity of thousands of genes. The scientists found an increase in the expression of genes that control production of heat shock proteins, but they also discovered a decrease in the expression of genes that control production of cold shock proteins. These proteins are normally produced in response to extreme cold to protect the cell against damage.
Using a genetic technique to reduce the activity of the cold shock genes in prostate cancer cells without changing the cells' temperature, the researchers found that these cells grew only half as quickly as cells with normal cold shock gene activity. Additionally, 30 percent to 50 percent more cells with altered cold shock gene activity died when treated with common chemotherapy drugs, compared to the normal prostate cancer cells treated with the same drugs.
"We hope that these cold shock proteins represent a new weakness we can exploit to fight prostate cancer in the future," Zeng says.
BONING UP THE CANCER FIGHT
-- Bone density may give clues to prostate cancer risk
AUA Meeting, April 26, 1:00 3:00 P.M., Podium Session 12, #474, W474 AB @ McCormick Place West
Men with denser bones may be more likely to develop prostate cancer, a new study by Johns Hopkins researchers suggests.
Recent research at other institutions has suggested that women with high bone mineral density are at an increased risk of aggressive breast cancer. These findings prompted resident Stacy Loeb, M.D., in the Department of Urology at the Johns Hopkins University School of Medicine, and her colleagues from the Baltimore Longitudinal Study of Aging (BLSA) to wonder whether higher bone density was associated with an increased risk of developing prostate cancer.
To investigate this idea, the team gathered data from the BLSA, a long-term study that has tracked health-related information for hundreds of Baltimore-area men and women since 1958. The researchers collected data on the bone mineral density of 519 men, measured from 1973 to 1984. They then looked at BLSA data again to see which men were eventually diagnosed with prostate cancer. When they analyzed their results, Loeb and her colleagues found that the 76 men who went on to develop prostate cancer had bone density that remained significantly higher as they aged compared to those who remained cancer free.
Though the reasons for this phenomenon are unclear, Loeb speculates that growth factors in bone may contribute to prostate cancer growth. Additionally, bone density may reflect sex hormone levels in men, which can also affect prostate cancer development.
"We don't have an explanation yet, but we're hoping that these findings stimulate further study," says Loeb.
KIDS WITH KIDNEY STONES HAVE ADULT HEALTH PROBLEMS
--Pediatric kidney stones often accompanied by diabetes and high blood pressure
AUA Meeting, April 27, 1:00 3:00 PM, Podium Session 28, #1063, W474 AB @ McCormick Place West
Recent studies have shown that adults who develop kidney stones often have a host of accompanying health problems, including diabetes and high blood pressure. Now, Johns Hopkins researchers have found that these same health problems may also plague kids who develop kidney stones.
While obesity and kidney stones have both been on the rise in children, it's been unclear if these conditions are linked, says Anthony Schaeffer, M.D., assistant resident in the Johns Hopkins Children's Center. To investigate, he and his colleagues pulled information from a public database of nearly three million pediatric patients to see whether the same adult comorbidities accompanied kidney stones in kids.
Comparing health data from the nearly 7,000 patients in the database who were diagnosed with kidney stones to others who were not, the researchers confirmed other studies that suggest that age remains the strongest predictor of stones, with teenagers having a 2.5 times higher risk than younger children. Interestingly, though, Schaeffer and his colleagues found that when children younger than 6 years of age have high blood pressure or diabetes, they have a tenfold higher risk of stones compared to those older than 6 years.
The findings show that children aren't shielded from the same comorbidities that affect adult kidney stone patients, Schaeffer says. "We're suggesting that if a child develops a kidney stone, his or her physician might want to consider the possibility that the stone could be a marker for these other conditions."
TWO ROBOTS BETTER THAN ONE FOR PROSTATE SURGERY
--Additional robot can help surgeon spot nerve bundle necessary to preserve potency
EUS Meeting, April 25, 1:00 2:30 P.M., Poster Session 1A, #11, Palmer House Hilton, Grant Park Palmer Room
Johns Hopkins researchers have developed a new technique that may improve robotic prostate surgery by using a second robot for taking three-dimensional ultrasound images of the prostate and surrounding structures during the procedure. These images can potentially help surgeons avoid damage to the neurovascular bundle (NVB), a collection of blood vessels and nerves necessary for achieving erection, the researchers say.
Overlying connective tissue or blood can obscure the NVB during radical prostatectomy, increasing the chance that surgeons will inadvertently damage it. Researchers at other institutions have sought to image the prostate during nonrobotic laparoscopic prostatectomy, with a radiologist performing a transrectal ultrasound to better identify the NVB while a surgeon operates. However, this separation of duties can make it cumbersome for surgeons to get the precise images they need. Additionally, this technique can't be done during robotic surgeries, which don't afford enough space for radiologists to maneuver.
To solve these problems, Hopkins engineers led by Dan Stoianovici, Ph.D., from the Urology Robotics Laboratory developed a compact robot that holds and moves the ultrasound probe remotely, allowing a surgeon to precisely control its position with a joystick. A pilot study of three patients who underwent robotic radical prostatectomy showed that the second robot provides surgeons real-time images that incorporate the position of the surgical robot and could allow them to better avoid the NVB. Using the second robot proved safe, producing no complications in these patients, and showed that three-dimensional imaging of the prostate and NVB was possible.
Misop Han, M.D., an associate professor in the Department of Urology at the Johns Hopkins University School of Medicine and the study leader, says he and his colleagues plan to test this technology in a larger group of prostatectomy patients. "We're hoping to continue to refine the images we generate during surgery to ultimately better preserve sexual function," Han says.
|Contact: Christen Brownlee|
Johns Hopkins Medical Institutions