LECTURE: Emmanuel Griessinger, Ph.D - “Protective mitochondrial transfer from bone marrow stromal cells to leukemia-initiating cells during chemotherapy“
For the first time, researchers have discovered that some leukemia cells harvest energy resources from normal cells during chemotherapy, helping the cancer cells not only to survive, but actually thrive, after treatment. The study, published online today in Blood, the Journal of the American Society of Hematology (ASH), focuses on acute myeloid leukemia (AML), a cancer of the blood and bone marrow that is the most common type of acute leukemia in adults. Although chemotherapy treatments are often initially successful against this type of cancer, relapse occurs in about two-thirds of treated patients, often resulting in death.
The researchers found that leukemia cells are capable of stealing organelles known as mitochondria from stromal cells, non-cancerous connective tissue cells found in bone marrow and other organs. These stolen mitochondria give an energy boost to the surviving cancer cells that helps fuel the cancer’s rebound, they explain.
“Mitochondria produce the energy that is vital for cell functions,” said Emmanuel Griessinger, PhD, principal investigator of the study. “Through the uptake of mitochondria, chemotherapy- injured acute myeloid leukemia cells recover new energy to survive. It’s like getting new batteries, or refueling during a pit stop.”
The leukemia cells were found to increase their mitochondria mass by an average of 14 percent. This increase in mitochondria led to a 1.5-fold increase in energy production and significantly better survival rates. That is, the leukemia cells that have a high level of mitochondria are also more resistant to the chemotherapy. The researchers observed the phenomenon in several types of leukemia cells, most notably those known as leukemia-initiating cells, which are considered to be responsible for the cancer’s resurgence after treatment. Researchers believe these findings offer new hope for developing better treatments for AML.