Signals Blog

Last month, Signals re-posted a blog entry of mine from The Black Hole where I lamented the lack of teamwork in the life sciences. There are, however, always exceptions and I want to highlight one such exception that took the field of blood stem cell expansion by storm last month. It was also presented yesterday at the 2014 Till and McCulloch Meetings by senior author Guy Sauvageau.

Guy set the stage by showing a graph he made from data obtained from Hema Quebec. Shockingly, just 6% of the banked cord blood samples in their reserves were of sufficient cell number to treat a 70kg (154 lbs) adult. A much larger 47% are able to treat smaller adults and children, but could be used in more patients if one could achieve modest expansion of stem cells outside the body. He emphasized the substantial clinical need to achieve this and it has been a longstanding goal of the field that has met with limited success.

Nearly five years ago, the first splash was made using a small molecule to help blood stem cells grow in culture. The report, Boitano et al., also appeared in Science magazine and reported modest expansion of blood stem cell numbers by modulating the aryl hydrocarbon receptor. The Sauvagaeu lab (Fares et al., 2014,) built directly on this approach and identified several new compounds that out-performed the Boitano method, but most importantly they appeared to target more primitive cells. The paper shows for the first time a substantial expansion of a population of human hematopoietic stem cells that showed robust activity in long term functional stem cell assays.

A big story no doubt – but the reason I’m writing about it today is its strong illustration of the benefits of long term collaborative projects between scientists. Guy Sauvageau trained in Keith Humphries’ lab many moons ago and published what would be the first in a string of papers aimed at expanding blood stem cells outside the body. Funnily enough, Peter Zandstra was in the Terry Fox Lab at the same time under the tutelage of Connie Eaves, applying bioengineering principles to blood stem cell expansion. This relationship between scientists at the Terry Fox lab would continue through the years to include many co-publications from these groups and other members of the Canadian stem cell community. These most recent exploits feature all four of Sauvageau, Zandstra Humphries, and Eaves – a testament to the value of co-operation. The Canadian Stem Cell Network (SCN) funded much of this project and it represents the significant value of a network encouraging collaboration across multiple universities. This particular project represents a collaboration of top groups in Canada (Montreal, Toronto, Vancouver), involved biologists, chemists, clinicians and bioengineers, and has been beneficial for all involved.

Science can move effectively and quickly when done in teams and I wish more resources were put in place to encourage such long term collaborative networks – it is a pity that the SCN is in its final year, but hopefully it has forged relationships amongst its younger members that will last well beyond the network’s completion.


The following two tabs change content below.
David Kent

David Kent

Principal Investigator at University of Cambridge
Dr. David Kent is a Principal Investigator at the University of Cambridge in the Cambridge Stem Cell Institute ( His laboratory's research focuses on fate choice in single blood stem cells and how changes in their regulation lead to cancers. David is currently the Stem Cell Institute’s Public Engagement Champion and has a long history of public engagement and outreach including the creation of The Black Hole in 2009. He has been writing for Signals since 2010.