New Data Shows Most Breast Cancers are Growth Hormone-Releasing Hormone-Receptor Positive
Researchers have presented data that supports the cancer fighting potential of growth hormone-releasing hormone technology developed by two Miller School of Medicine scientists. The work was featured in a September 5 presentation at the American Society of Clinical Oncology’s (ASCO) Breast Cancer Symposium 2014, by Norman Block, M.D., L. Austin Weeks Family Professor of Urologic Research and Clinical Director of the Endocrine, Polypeptide and Cancer Institute at the Miami VA Healthcare System.
Block is Medical Director of Biscayne Pharmaceuticals, which is developing novel drugs for cancer and other diseases based on the analogs of GHRH discovered by Nobel laureate Andrew V. Schally, Ph.D., M.D.h.c., D.Sc.h.c., Distinguished Medical Research Scientist of the Department of Veterans Affairs, and Distinguished Professor of Pathology at the Miller School.
Scientists have long known that GHRH, which is made in the brain, releases growth hormone to manage growth and tissue repair in nearby cells. Schally discovered that other cells throughout the body, including cancer cells, also have receptors for GHRH. Cancer cells contain GHRH receptors and also produce the GHRH hormone, thereby fueling their own growth. Biscayne Pharmaceuticals has licensed the rights to Schally’s GHRH discoveries and is developing GHRH antagonists that inhibit tumor growth by binding to and blocking the activity of the GHRH receptors on cancer cells.
Much of the earlier work on GHRH and cancer has been conducted in preclinical models. In the Breast Cancer Symposium 2014 poster presentation, Block and his colleagues presented data on GHRH using specimens from breast cancer patients. They conclude that the majority of breast cancers, including both primary and metastatic tumors, are GHRH-receptor positive, confirming the validity of GHRH as a potential therapeutic target for new breast cancer drugs.
Block, who conducts research in collaboration with Schally, said, “Extensive studies in preclinical models gave us confidence that GHRH is an important driver of tumor growth and that antagonists of GHRH might have potential as effective anti-cancer agents. This new study using tumor samples from breast cancer patients further confirms the potential relevance of those findings to human disease and supports our goal of rapidly advancing our lead GHRH antagonist into human clinical trials.”
In animal studies, these antagonists have shown promising anti-tumor activity. Block writes that based on the presence of GHRH receptors in most breast cancers, a clinical trial with GHRH receptor antagonists is warranted.