SLPU
Wednesday October 13, 2:59 pm Eastern Time
E. coli toxin used to cleanse cancer cells
WASHINGTON, Oct 13 (Reuters) - Canadian scientists said on Wednesday they used a
toxin produced by the sometimes deadly strain of E. coli bacteria to cleanse cancer cells
from bone marrow.
They said they hoped their technique could lead to ways to make transplants of bone
marrow and of stem cells -- which, like bone marrow, generate new blood cells -- more effective.
''Our group has seized an opportunity to use a deadly bacterial toxin responsible for hamburger disease to treat a variety of
cancer patients,'' Dr. Jean Gariepy of Princess Margaret Hospital's Ontario Cancer Institute in Toronto said in a statement.
Bone marrow and stem cell transplants are commonly used to treat people for diseases such as leukemia and non-Hodgkin's
lymphoma -- both cancers of blood cells.
The strong chemical and radiation therapy used to destroy the cancer can also kill off the bone marrow. Transplants are done
after a course of treatment to rescue the bone marrow, which is the source of both red and white blood cells.
In one approach, doctors harvest some bone marrow or stem cells from the patient, then grow them in culture to reinfuse into
the patient after chemotherapy or radiation treatment.
They try to filter those cells to ensure no cancer remains, but are not always successful.
Gariepy and colleagues at the University of Alberta used a toxin called SLT-1 from E. coli to cleanse the cells.
Writing in Friday's issue of the journal Blood, they said the toxin recognized a receptor -- a kind of cellular doorway -- on the
surface of the cancerous cells. It ignored healthy cells, they said.
It worked against a range of cancer cells, including breast, lymphoma and multiple myeloma cells, they said.
''We've shown that myeloma cells are effectively purged by SLT-1 ... and that the normal stem cells survive. This means it is
potentially safe to use as a purging agent for the graft before reinfusing it into the patient,'' University of Alberta oncology
professor Linda Pilarski said in a statement.
''There is a lot more work to be done to refine the technique and to ensure safety, but this could prove to be an important
advance for myeloma patients and perhaps other patients treated with autologous transplants (transplants from the patient rather
than from a donor) such as lymphoma and breast cancer patients.''
Multiple myeloma, a cancer that affects immune cells that are generated in the bone marrow, has no cure. Patients survive on
average only three to four years.
The SLT technology is licensed by Select Therapeutics Inc. (OTC BB:SLPU.OB - news).
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