A group of researchers has identified a specific protein that is critical for the expansion of blood stem cells. Their discovery, which has been published in Cell Reports, may lead to new methods for growing large quantities of these stem cells, both inside and outside of the human body.

Although hematopoietic stem cells (HSCs) have enormous potential in treating incurable cancers, autoimmune diseases and inherited blood disorders, only one in 2500 cells in the blood marrow are HSCs.

Within their study, the authors used an algorithm termed ‘VIPER’ to identify proteins capable of reprogramming other blood stem cells. Using this algorithm, the investigators were able to identify one candidate – a gene known as BAZ2B – that was able to significantly expand the number of HSCs in blood from the umbilical cord.

BAZ2B was able to reprogram blood stem cells to an HSC-like state by rearranging their chromatin, opening up unique regions in the genome that were previously inaccessible. These resulting cells were successfully transplanted into the bone marrow of immunocompromised mice, renewing the growth of the tissue.

“The scarcity of HSCs is one of the biggest barriers to development of new and improved treatments. Our findings are exciting because we have found a way of boosting their numbers after activating just one factor,” commented study author, Pia Cosma (Center for Genomic Regulation, Barcelona, Spain). “Yielding more of these [life]-saving stem cells will benefit a variety of different patients in the long-run.”

“It is really exciting to see that the methodologies we have developed to discover the proteins that implement and maintain the malignant state of cancer cells can also be used to identify key players in normal human physiology, including proteins that can help fight other diseases,” concluded study author, Andea Califano (Columbia University Medical Center, NY, USA).

“Remarkably, the proteins that are best suited to the VIPER methodology are exactly those that control human developmental processes, such as blood differentiation and regeneration, thus opening up new exciting avenues in regenerative medicine.”