Hematopoietic colony formation from human growth factor-dependent TF1 cells and human cord blood myeloid progenitor cells depends on SHP2 phosphatase function.
The protein tyrosine phosphatase, SHP2, is widely expressed; however, previous studies demonstrated that hematopoietic cell development more stringently requires Shp2 expression compared to other tissues. Furthermore, somatic gain-of-function SHP2 mutants are commonly found in human myeloid leukemias. Given that pharmacologic inhibitors to SHP2 phosphatase activity are currently in development as putative antileukemic agents, we conducted a series of experiments examining the necessity of SHP2 phosphatase activity for human hematopoiesis. Anti-sense oligonucleotides to human SHP2 coding sequences reduced human cord blood- and human cell line, TF1-derived colony formation. Expression of truncated SHP2 bearing its Src homology 2 (SH2) domains, but lacking the phosphatase domain similarly reduced human cord blood- and TF1-derived colony formation. Mechanistically, expression of truncated SHP2 reduced the interaction between endogenous, full-length SHP2 with the adapter protein, Grb2. To verify the role of SHP2 phosphatase function in human hematopoietic cell development, human cord blood CD34+ cells were transduced with a leukemia-associated phosphatase gain-of-function SHP2 mutant or with a phosphatase dead SHP2 mutant, which indicated that increased phosphatase function enhanced, while decreased SHP2 phosphatase function reduced, human cord blood-derived colonies. Collectively, these findings indicate that SHP2 phosphatase function regulates human hematopoietic cell development and imply that the phosphatase component of SHP2 may serve as a pharmacologic target in human leukemias bearing increased SHP2 phosphatase activity.
Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN 46202-5181, USA. hbroxmey@iupui.edu
Hal E
HE
Broxmeyer
Maryse
M
Etienne-Julan
Akihiko
A
Gotoh
Stephen E
SE
Braun
Li
L
Lu
Scott
S
Cooper
Gen-Sheng
GS
Feng
Xing Jun
XJ
Li
Rebecca J
RJ
Chan
D018952:Antigens, CD34 / Q000378:metabolism; D002460:Cell Line; D049109:Cell Proliferation; D002478:Cells, Cultured; D005312:Fetal Blood / Q000166:cytology; D051380:GRB2 Adaptor Protein / Q000378:metabolism; D006410:Hematopoiesis; D006801:Humans; D023461:Myeloid Progenitor Cells / Q000201:enzymology*; D010446:Peptide Fragments / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D011485:Protein Binding; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11 / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D059010:Single-Cell Analysis
D018952:Antigens, CD34; D051380:GRB2 Adaptor Protein; C495948:GRB2 protein, human; D010446:Peptide Fragments; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11