Leukemia Stem Cell Research
What does Pten do?Pten is a tumor suppressor that regulates stem cell function. It is one of the body's most powerful tumor suppressors. Scientists have found that the gene for Pten is often turned off or doesn't work properly in all types of cancer.
What is known about Pten from the research?Researchers wanted to know what happens to normal blood-forming stem cells without the Pten tumor suppressor. In a study at U-M, Dr. Morrison and his colleagues deleted the gene in the blood-forming systems of mice. Afterwards, the mice rapidly developed leukemias -- acute myeloid leukemia and acute lymphocytic leukemia. The researchers found that deleting Pten had a different effect on normal blood-forming stem cells than on leukemic stem cells. When they took Pten away, normal blood-forming stem cells were depleted, but leukemic stem cells kept expanding until they killed the mice. The researchers then tested a drug called rapamycin on these mice, because rapamycin inhibits an enzyme called mTOR that is part of the PI(3)K pathway.