 |
 |
>>> BIOTECHNOLOGY ------------------------------- Canadian Scientists Use Deadly E.Coli Bacteria to Kill Cancer Cells October 12, 1999 / CAMBRIDGE, Mass. / A toxin produced by the deadly E. coli bacteria most commonly linked to illness caused by undercooked meat has been used to rid bone marrow of cancer cells for the first time by a research team led by scientists at Princess Margaret Hospital's Ontario Cancer Institute, the Cross Cancer Institute and the University of Alberta. The researchers are using a toxin called SLT-1 to clean blood cells of cancer cells by using a receptor on the surface of the cancer cells recognized by the toxin. The toxin is then removed from blood cells prior to re-infusing the stem cells back into cancer patients. The researchers found that while the toxin kills a broad range of cancer cells, particularly breast, lymphoma and multiple myeloma cells, it does not kill healthy blood stem cells. University of Alberta Oncology Professor Linda Pilarski and colleagues in Edmonton and Toronto have studied the use of this ``purging agent'' to kill the malignant cells in multiple myeloma patients and leaving the normal stem cells intact. ``We've shown that myeloma cells are effectively purged by SLT-1 -- a ribosome inactivating toxin -- and that the normal stem cells survive. This means it is potentially safe to use as a purging agent for the graft before re-infusing it into the patient,'' Dr. Pilarski says. The results of the study will be published in the October 15 issue of the journal, Blood. SELECT Therapeutics, which has the license to this new technology, is focused on the interaction of mammalian cells with a bacterial toxin, verotoxin (VT or SLT). Research in this area has lead to a number of defined opportunities in potential therapeutic uses for the toxin such as purging of stem cells in autologous transplants and direct intratumor injection as well as the discovery of a route for antigen presentation to dendritic cells which it believes may be key to development of therapeutic vaccines for cancers and a number of infectious diseases. The technologies have been demonstrated in animal models and are now moving to clinical investigations. Success in clinical settings could lead to rapid and low cost development of therapeutic products.