Cell-cell signaling through NOTCH regulates human embryonic stem cell proliferation.
Unlike pluripotent mouse embryonic stem (ES) cells, human ES cells and their malignant equivalents, embryonal carcinoma (EC) cells, require close cell-cell contact for efficient growth. Signaling through the NOTCH receptor, initiated by interaction with ligands of the DELTA/JAGGED family expressed on neighboring cells, plays a role in regulating the self-renewal of several stem cell systems. Members of the NOTCH and DELTA/JAGGED families are expressed by human EC and ES cells, and we have therefore investigated the possible role of NOTCH in the maintenance of these cells. Cleavage of both NOTCH1 and NOTCH2 to yield the intracellular domain responsible for the canonical signaling pathway of NOTCH was detected in several human EC and ES cell lines, suggesting that NOTCH signaling is active. Furthermore, the proliferation of human EC cells, as well as the expression of several downstream NOTCH target genes, was markedly reduced after small interfering RNA knockdown of NOTCH1, NOTCH2, and the canonical effector CBF-1 or after blocking NOTCH signaling with the gamma-secretase inhibitor L-685,458. The inhibitor also caused a reduction in the growth of human ES cells, although without evidence of differentiation. The results indicate that cell-cell signaling through the NOTCH system provides a critical cue for the proliferation of human EC and ES cell in vitro.
Fox
Victoria
V
Centre for Stem Cell Biology, Department of Biomedical Science, University of Sheffield, Western Bank, Sheffield S10 2TN, United Kingdom.
Gokhale
Paul J
PJ
Walsh
James R
JR
Matin
Maryam
M
Jones
Mark
M
Andrews
Peter W
PW
D000818:Animals; D000911:Antibodies, Monoclonal; D000954:Antigens, Surface / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects; D018236:Carcinoma, Embryonal / Q000378:metabolism / Q000473:pathology; D002450:Cell Communication / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D053595:Embryonic Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D051379:Mice; D039904:Pluripotent Stem Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D011499:Protein Processing, Post-Translational / Q000187:drug effects; D017434:Protein Structure, Tertiary; D021381:Protein Transport / Q000187:drug effects; D051880:Receptors, Notch / Q000737:chemistry / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects
D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D004791:Enzyme Inhibitors; D051880:Receptors, Notch