Protein Linked to Aggressive Recurring Prostate Cancer

The reduction of a specific protein is correlated with the aggressiveness of prostate cancer, acting as a warning sign to indicate an increased risk of cancer recurrence.

A gene called secreted protein, acidic and rich in cysteine-like 1 (SPARCL1) appears to be critically important for cell migration during prostate development in the embryo and apparently becomes active again during cancer progression.

Urologists at Johns Hopkins University (Baltimore, MD, USA) collaborating with others, used a variety of cellular and molecular biology assays including ribonucleic acid (RNA) isolation, reverse transcription polymerase chain reaction (RT-PCR), in vitro organ culture, antibodies, immunoblotting, immunofluorescence (IF), cell culture, cell growth, cell cycle, apoptosis, adhesion, migration, and invasion.

Normally, both benign and malignant prostate cancer cells express high levels of SPARCL1, and reduce these levels when they want to migrate. The team correlated this reduction or down regulation of SPARCL1 with aggressiveness of prostate cancer. The scientists also found that SPARCL1 seems to play a role in predicting tumor recurrence in a number of other diseases including bladder, breast, colon, rectum, tongue, lung, skin, and ovarian cancers.

Edward Schaeffer, MD, PhD, the senior author of the study and an associate professor of urology, oncology and pathology, said "Our findings should allow physicians to not only pinpoint those patients whose cancers are destined to return after surgery, but could also reveal a potential new option for treatment. While many of our patients are initially cured with surgery, some inexplicably have their cancers return. We are working to identify patients at higher risk of recurrence and our ultimate goal is to develop new treatments that would prevent the return of the cancer."

The team is now working to decipher the specific mechanism that controls the gene in hopes of developing a treatment that can reset SPARCL1 to normal levels and potentially prevent a patient’s cancer from recurring. Paula Hurley, PhD, a lead author of the study, is currently investigating novel genes that are not only prognostic of lethal prostate cancer but also contribute to prostate cancer progression to metastasis. The study was published on August 27, 2012, in the Proceedings of the National Academy of Sciences of the United States of America (PNAS).

Related Links:
Johns Hopkins University