Stamping Bar Codes on Cells to Solve Medical Mysteries
The New York Times
By tracking every cell in an organism, scientists are working out why certain cancer treatments fail, which could lead to improved medicine.
No one really knew why some patients with a white blood cell cancer called chronic lymphocytic leukemia, or CLL, relapsed after treatment and got a second cancer. Were some cancer cells just resistant?
An unexpected answer to this mystery has been found using a new technique that researchers call bar coding: The treatment does not always target the right cells.
Scientists discovered that the cancer does not always originate in the mature bone marrow cells where it is found and where textbooks say it originates. Instead, for some patients, the mother lode of the cancer can be primitive bone marrow cells, the stem cells, that give rise to all of the body’s white and red blood cells. Those cells, not affected by the chemotherapy treatment, can spawn new cancer cells, causing a relapse.
