CD47 is More Highly Expressed on AML LSC Compared to Their Normal Counterparts
A. Relative CD47 expression on normal bone marrow HSC (Lin−CD34+CD38−CD90+) and MPP (Lin−CD34+CD38−CD90−CD45RA−), as well as LSC (Lin−CD34+CD38−CD90−) and bulk leukemia cells from human AML samples, was determined by flow cytometry. Mean fluorescence intensity was normalized for cell size and against lineage positive cells to account for analysis on different days. The same sample of normal bone marrow (red, n=3) or AML (blue, n=13) is indicated by the same symbol in the different populations. Normalized mean expression (and range) for each population was: HSC 30.6 (28.8–33.4), MPP 31.8 (30.0–33.4), LSC 59.8 (21.6–104.7), and bulk AML 56.3 (22.1–85.1). The differences between the mean expression of HSC with LSC (p=0.003), HSC with bulk leukemia (p=0.001), MPP with LSC (p=0.004), and MPP with bulk leukemia (p=0.002) were statistically significant using a 2-sided Student’s t-test. The difference between the mean expression of AML LSC compared to bulk AML was not statistically significant with p=0.50 using a paired 2-sided Student’s t-test.
B. Clinical and molecular characteristics of primary human AML samples manipulated in vitro and/or in vivo.