Leukemia May Start in Marrow

Certain blood cancers may be caused by the surrounding bone marrow in which blood is produced, according to recent findings from researchers at Harvard’s Stem Cell and Regenerative Biology department.

Led by principal investigator Dr. David T. Scadden of the Harvard Stem Cell Institute, the team of researchers has succeeded in refuting the common notion that cancer emerges from the mutations of a single cell.

“Cancer is thought to be a process by which a cell accumulates a series of genetic injuries in a multi-step process,” Scadden said. “Our model says that one of those steps can occur in a neighboring cell.”

By specifically altering genes in the progenitive bone cells of mice, the researchers were able to observe a profound disruption of blood formation.

The lead researcher, Dr. Marc Raaijmakers of Massachusetts General Hospital, noted the significance of such a disturbance.

“As a hematologist, [the disruption] reminded me of a disease seen in humans called myelodysplastic syndrome (MDS), which tends to evolve into the blood cancer leukemia,” Raaijmakers said.

This discovery demonstrates that instead of arising through mutations primarily in the blood cells, as previously thought, cancer may be formed in support cells—the bone marrow.

“Stem cells maintain our tissues and get their signals from their environment,” Scadden said. “We just happened upon this finding that in fact abnormal signals can not just prevent stem cells from functioning normally, but can change the whole system.”

According to Raaijmakers, the medical community hopes that this research will help bring new therapies for those suffering from leukemia.

He also said that the results have the potential to be applied to other types of cancer.

The research team will now have to investigate the exact signals that occur between the bone and blood cells in order to figure out which are pertinent to the formation of leukemia.

Raaijmakers said that once these signals are known, they can be targeted and ideally prevented from coming to completion.

Researchers are already conducting follow-up research to continue and build upon this discovery. Because the model was conducted on mice, and thus has not yet been proven on humans, Scadden said the team of researchers is now “examining the cellular setting of patients with these human blood cancers.”