In a ray of hope for leukemia patients, a protein critical to hematopoietic stem cell function - that give rise to all other blood cells - and blood formation has been identified.
The finding has potential as a new target for treating leukemia because cancer stem cells rely upon the same protein to regulate and sustain their growth, said researchers at University of California, San Diego School of Medicine.
"A protein called Lis1 fundamentally regulates asymmetric division of hematopoietic stem cells, assuring that the stem cells correctly differentiate to provide an adequate, sustained supply of new blood cells," said principal investigator Tannishtha Reya from department of pharmacology.
Asymmetric division occurs when a stem cell divides into two daughter cells of unequal inheritance.
When researchers deleted Lis1 from mouse hematopoietic stem cells, differentiation was radically altered.
Asymmetric division increased and accelerated differentiation, resulting in an oversupply of specialised cells and an ever-diminishing reserve of undifferentiated stem cells, which eventually resulted in a bloodless mouse.
"What we found was that a large part of the defect in blood formation was due to a failure of stem cells to expand," said Reya.
Instead of undergoing symmetric divisions to generate two stem cell daughters, they predominantly underwent asymmetric division to generate more specialized cells.
As a result, the mice were unable to generate enough stem cells to sustain blood cell production.
Reya said the findings shed new light on the fundamental regulators of cell growth both in normal development and in cancer.
"Our work shows that elimination of Lis1 potently inhibits cancer growth, and identifies Lis1 and other regulators of protein inheritance as a new class of molecules that could be targeted in cancer therapy," he explained.
The findings appeared in the journal Nature Genetics.
