ASH News Daily - Monday, December 12, 2011 - (Page A-8)

Page A–8 ® ASH NEWS DAILY Monday, December 12, 2011 Marie Arturi, recipient of the 2011 ASH Award for Outstanding Service, shares a laugh with Dr. George Weiner after speaking at Sunday’s Grassroots Network Breakfast. Stem Cells «« From Page A-5 potentially provide a stable supply of platelets. Dr. Mortimer Poncz introduced the talk and discussed the clinical importance of using hematopoietic progenitor cells as opposed to induced pluripotent stem cells in generating mature megakaryocytes; in the latter, the yield of platelets from megakaryocytes is inefficient, producing hundreds of non-directed cells. By using hematopoietic progenitor cells, Dr. Takayama and colleagues are able to generate a sufficient number of functional platelets. CiRA previously showed that the pattern of c-Myc reactivation influences the generation of platelets derived from hiPSCs. Specifically, sustained excessive c-Myc expression induces senescence and apoptosis, diminishing the production of functional platelets, whereas an increase in expression of c-Myc followed by a decline is associated with efficient platelet generation. To explore this further, the group created different protocols containing hematopoietic progenitor cells using various candidate genes. They found that turning off gene cassette overexpression of c-Myc and BMI1 led to the development of non-polyploid megakaryocytes. Based on this finding, using de- High School senior William Qu discusses his poster, “Effects of Enhanced Physical Exercise of Hematopoietic Stem Cell Cell Aging,” with Dr. Ivo Touw, Rotterland, The Netherlands. fined culture conditions and gene manipulation techniques, they were able to establish immortalized megakaryocytic progenitor cells (iMKPCs) that produced “functional” platelets. They went on to transfuse platelets derived from their iMKPCs into mice, which showed normal distribution within the circulatory system using in vivo posttransfusion kinetic studies. They also demonstrated in vivo functionality by showing that the platelets contributed to thrombus formation in injured vessels in living mice. Dr. Takayama’s abstract raises several important questions, including the mechanism(s) by which hematopoietic cells derived from hiPSCs are able to survive and retain their functional abilities in the recipient. According to supervisor Dr. Koji Eto, the next phase of research for Dr. Takayama and colleagues will be preclinical in vivo and ex vivo studies focused on the length of time iMKPCs could be established prior to transfusion, while retaining their functionality. Dr. Takayama’s presentation was met with enthusiasm, as we learned more about the use of hiPSCs as a powerful research tool, with the potential of novel targeted therapeutics for hematopoietic disorders. Drs. Garcia and Ghanny indicated no relevant conflicts of interest. The halls of the San Diego Convention Center are a swarm of activity with ASH members coming and going to meetings. Dr. Craig Morrell delivers his presentation during the session titled “Transfusion Medicine I: Adverse Complications of Stored Blood.”

Table of Contents for the Digital Edition of ASH News Daily - Monday, December 12, 2011

ASH News Daily - Monday, December 12, 2011

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