Researchers at the University of Southern California (USC) have found that inactivating a specific biomarker for aggressive prostate cancer blocks the development of prostate cancer in animal models.
Researchers say the upcoming study in the Proceedings of the National Academy of Sciences - now available online - may lead to a novel cancer therapy for humans.
"This research has far-reaching implications in a wide range for human cancers," says Amy Lee, Ph.D., the study's principal investigator and the associate director for basic research and holder of the Freeman Cosmetics Chair at the USC/Norris Comprehensive Cancer Center, and professor of biochemistry and molecular biology at the Keck School of Medicine of USC. "It is a breakthrough study."
Prostate cancer is the most common cancer in men and develops through successive stages. The glucose-regulated protein GRP78 has been identified as a crucial entity in the development of prostate cancer by promoting cancer cell proliferation, mediating oncogenic signaling and protecting cancer cells against cell death resulting from the stress of tumor development, Lee explains.
By suppressing GRP78 expression or activity, the USC researchers found that they could block prostate cancer activation and development resulting from the loss of PTEN, a powerful tumor suppressor gene for a number of human cancers.
Researchers spent more than three years monitoring prostate cancer development in animal models that had been genetically engineered to have both the GRP78 and PTEN tumor suppressor genes inactivated. The research was conducted by Yong Fu, a Ph.D. candidate at the Keck School of Medicine of USC and the first author on the study, in collaboration with Ph.D candidates Shiuan Wey, Miao Wang, Risheng Ye and Chun-Peng Liao and Pradip Roy-Burman, M.D., professor of pathology, biochemistry and molecular biology at the Keck School.
Future research should test the role of GRP78 in other types of cancer and isolate drugs that inhibit GRP78, Lee says.