Eisenberger: Mystery in advanced cancer
Prostate cancer is notorious for playing the race card. In fact, for scientists who study the minute hormonal and molecular differences among men of various races, prostate cancer has multiple manifestations: There’s the kind of prostate cancer that white men get, the kind that Asian men get, and the kind that affects black men. And in general, American men of African descent seem to have it the worst: “Prostate cancers diagnosed in African American men are more likely to progress to an advanced stage even after definitive treatment,” says Jun Luo, Ph.D., the Carolyn and Bill Stutt Scholar, “and these men are most likely to die of prostate cancer.” Luo is interested in pinpointing and characterizing the tiny differences in the molecular makeup of men of different ancestries. “This line of research,” he believes, “may help us uncover the biological processes that affect the development of cancer, and determine how severe that disease will be. Most importantly, it may help us find new ways to save lives from prostate cancer.”
He has discovered an important new contender in the interplay between race and cancer — an enzyme called PLA 2G7, which fights inflammation. In recent years, investigators at Hopkins have demonstrated that inflammation is involved in cancer’s very earliest stages; inflammation is thought to progress to precancerous changes, which ultimately become cancerous. Lower-than-normal levels of this anti-inflammatory enzyme are known to be a factor in cardiovascular disease. In exploratory studies, Luo found that it’s a worse culprit than scientists suspected: “PLA 2G7 is linked to prostate cancer progression in African American men.”
Here are some other key facts Luo has discovered about this enzyme:
- In blood and tissue samples of men with prostate cancer, PLA 2G7 levels are generally lower in African American men than in men of European descent;
- Lower production of PLA2G7 is more likely to be found in men with advanced prostate cancer; and
- African American men are more likely than others to inherit a particular variant of the PLA 2G7 gene that is linked to a recurrence in cancer after prostatectomy.
Luo believes the connection between PLA 2G7, these genetic variants and cancer — and worse, aggressive cancer — is so strong, that his studies may lead to new markers for aggressive cancer, and even to race-specific tests. “We are looking to see whether PLA 2G7 can differentiate between aggressive and non-aggressive prostate cancer,” he says, “and whether we can pinpoint the genetic variants of PLA 2G7 that make cancer more likely to progress, with the goal of better, earlier detection and treatment of potentially lethal prostate cancer.” Also, what he learns about PLA 2G7 could lead to new avenues of treatment — for example, drugs that boost this enzyme, fight inflammation, and slow or prevent the progression of prostate cancer.
African American men are most likely to develop aggressive prostate cancer, and to die from it. Luo has discovered that the loss of an enzyme, called PLA 2G7, is largely to blame. His findings are so conclusive that they may lead to new, race-specific tests for potentially lethal cancer.