1. Identification of a possible tumor suppressor microRNA in leukemia Kara A. Scheibner, PhD Center for Stem Cell Biology and Regenerative Medicine October 2, 2009 Experimental Therapeutics Retreat
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4. MicroRNA regulation (and deregulation) of hematopoiesis miR-17-92 cluster: expression decreases during monocyte development; highly expressed in pre B and T precursor cells and decreases after maturation miR-146: drives naïve T cells to become T1 helper cells over Th2 cells miR-223: expressed specifically in the granulocyte lineage; decreases as cells move from MEPs to erythrocytes miR-221/222: downregulated during erythropoiesis (Modified from Baltimore et al, 2008)
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7. Low expression levels of miR-27a in leukemia cells compared to HSPCs…….a hint? miRNA microarray data qRT-PCR data Does the fact that miR-27a expression is low or absent in multiple leukemia cell lines and patient samples mean anything in the etiology of the disease? 0 0.2 0.4 0.6 0.8 1 1.2 1.4 RQ value (normalized to CD34+ cells) CD34+ K562 TF-1 KOPN8 HEK293T ALL #1 ALL #2 miR-23a miR-23b miR-27a miR-27b 34,913 TF1 47,337 REH 38,099 K562 113,257 CD34+ (HSPCs) miR-27a expression Cell type
8. miR-27a as a tumor suppressor miRNA Decreased cell growth Increased death by apoptosis Increased cell death Altered cell cycle profile 0 50000 100000 150000 200000 250000 300000 350000 400000 450000 0 1 2 3 4 5 6 7 Days Cell number K562 FUGW miR-27 #1 miR-27 #5 miR-27 #6 miR-27 #11 0 5 10 15 20 25 30 35 40 Control #9 miR-27a #3 % total cell death Experiment 1 Experiment 2 0 5 10 15 20 25 30 35 % annexinV+/7AAD- GFP- Control #10 miR-27a #3 mirR-27a #4 miR-27a #7 0 10 20 30 40 50 60 70 80 G1 S G2 % cells GFP- miR-27a #1 miR-27a #2 miR-27a #3 miR-27a #4 miR-27a #5 miR-27a #6
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