Enzymes Guide Ovarian Cancer Research

June 15, 2017

A new imaging test holds special promise for ovarian cancer patients. The test is designed to identify a key enzyme that cancer cells need in order to survive. Researchers at the University of Pennsylvania’s Perelman School of Medicine will present their findings at the American Association for Cancer Research Annual Meeting in Washington, D.C. this year.

PARP-1 is an enzyme that helps damaged cancer cells repair their DNA. Drugs that block that enzyme, researchers discovered, have an equal or even greater impact on treatment than restoring the BRCA1 mutation, a genetic mutation that makes cells more likely to divide and therefore increases the risk of, in particular, ovarian and breast cancer. By using a PARP inhibitor, doctors trap the enzyme on cancer DNA, causing the cell to form poisonous lesions and die. The radiotracer technology is being used as a “biomarker” for PARP-1 in order to select patients who could most benefit from PARP inhibitor therapy.

In addition to the work in the lab, researchers used clinical PET scans to measure PARP-1 in patients who had epithelial ovarian cancer. The multidisciplinary approach used at the University of Pennsylvania involved physicists, chemist, biologists, and imaging technicians.

Researchers at MIT have also studied how enzymes might be used to combat ovarian cancer. Using principles similar to the PARP-1 detector research, the MIT studies measured the activity of protein-cutting enzymes called endoproteases that are made by tumors to help invade surrounding tissue. Researchers developed a synthetic biomarker that interacts with tumor proteins to release fragments detectable in a patient’s urine sample, translating to detection of ovarian cancer five months earlier than with existing blood tests.

Enzyme research, so far, looks promising. Since the survival rate for ovarian cancer decreases dramatically if it is diagnosed too late, the research out of MIT may help diagnose women earlier and improve their prognosis. And the research out of University of Pennsylvania may develop into new ways of combating the disease in patients.