When prostate cancer, one of the most lethal cancers, spreads in the body, it most often targets bone. Difficult to treat, such metastasis is implicated in over 70% of prostate cancer deaths. A new therapy crosses bone barriers.
Prof. Zelig Eshhar, Head of the Immunology Department at the Weizmann Institute of Science, previously developed prostate-cancer-fighting cells, dubbed T bodies, which are modified immune system cells customized to be highly effective in identifying and destroying cancer cells. However, T bodies were unable to effectively penetrate bone. The Weizmann team, which included Dr. Jehonathan Pinthus of Sheba Medical Center, Tel Hashomer, implemented a pre-treatment consisting of either low doses of radiation or a specific chemotherapy drug, followed by T body injections. The pre-treatments caused some disruption in the bone marrow, the intended target of the T bodies, which responded with a chemical distress signal that alerted the immune cells, aided them in locating the problem area and enabled them to pass through barriers into the bone marrow tissue.
Mice treated with either therapy showed a significant drop in the tumor marker PSA (an indicator of cancer levels), a reduction in the tumor load and prolonged survival. This method holds promise for treating disseminated cancers that are resistant to other forms of therapy.
Prof. Zelig Eshhar’s research is supported by the M.D. Moross Institute for Cancer Research; the Crown Endowment Fund for Immunological Research; the Estate of Irene Kuhn and Lotte Stern, UK; and the Harry and Jeanette Weinberg Fund for the Molecular Genetics of Cancer. Prof. Eshhar is the incumbent of the Marshall and Renette Ezralow Professorial Chair of Chemical and Cellular Immunology.