Researchers at the University of Southern California (USC) developed a vaccine that stimulates immune response against prostate stem cell antigen (PSCA), a protein whose over-expression indicates a developing prostate cancer. The vaccine proved successful in arresting the growth of a prostate cancer in mice that were genetically modified to develop the disease.
The vaccine is administered twice, the second shot given two weeks after the first vaccination. The first shot produces PSCA to activate the immune system and the second shot "used a modified horse virus to deliver the PSCA gene" and boost the immune system.
Dr. W. Martin Kast, a professor of Molecular Microbiology and Immunology and Obstetrics & Gynecology at the Norris Comprehensive Cancer Center, led the USC researchers in developing the prostate cancer vaccine, which still needs testing on humans.
Currently, vaccines to treat prostate cancer are not administered when PSCA is present. Patients have to wait for the tumor to appear before getting the shot.
Meanwhile, researchers at the University of Michigan (UM) developed a urine test that detects four different RNA molecules associated with the cancer. The presence of the molecules called GOLPH2, SPINK1, PCA3 and TMPRSS2:ERG in the urine of 234 men with rising prostate specific antigen (PSA), a protein produced by the prostate gland, means they have prostate cancer. The accuracy of the test was confirmed as the biopsy results of the men showed they have the cancer.
Currently, prostate cancer is detected through a blood test that quantifies the level of PSA. But the test also identifies men with enlarged prostate glands that do not develop into cancer. Another screening method called PCA3 test is less accurate according to researchers.
The leader of the UM researchers, Dr. Arul Chinnaiyan, director of UM's Michigan Center for Translational Pathology, said the urine test is the best test and it doesn't require a biopsy to rule out cancer, according to Newswise.
The findings of the USC and UM researchers were published in the Feb. 1 issue of the "Cancer Research," a journal of the American Association for Cancer Research.
