Transition of cleaved Notch1 and gene expression changes in myeloblastic leukemia cells stimulated with notch ligands.
BACKGROUND
Notch activation by ligand stimulation regulates the growth of acute myeloid leukemia (AML) cells. However, the molecular mechanisms underlying this have not been fully elucidated.


METHODS
Two AML cell lines, THP-1 and TMD7, and three Notch ligands, Jagged1, Dll1 and Dll4, were used. The effects of the ligands on cell growth, cleavage of Notch1, and the expression of various genes were examined by cell culture, immunoblotting, and quantitative RT-PCR, respectively.


RESULTS
Ligand stimulation suppressed the growth of the THP-1 cells but promoted that of the TMD7 cells. Immunoblots showed two cleaved Notch1 bands, which became intense with different peak time from the start of stimulation. Ligand stimulation changed the expression levels of various genes related to cell proliferation. Some genes changed in opposite directions in the two cell lines. The three ligands had similar effects on gene expression.


CONCLUSIONS
The time course for Notch1 cleavage following ligand stimulation and the effects of stimulation on gene expression are shown.
Department of Laboratory Medicine, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-Ku, Tokyo 113-8519, Japan.
Lu
L
Fu
Ken-ichi
K
Katsube
Shuji
S
Tohda
D000818:Animals; D016466:CHO Cells; D002135:Calcium-Binding Proteins / Q000494:pharmacology*; D048708:Cell Growth Processes / Q000187:drug effects; D045744:Cell Line, Tumor; D006224:Cricetinae; D003412:Cricetulus; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D015151:Immunoblotting; D036341:Intercellular Signaling Peptides and Proteins / Q000494:pharmacology*; D047908:Intracellular Signaling Peptides and Proteins; D000072100:Jagged-1 Protein; D015470:Leukemia, Myeloid, Acute / Q000235:genetics / Q000378:metabolism*; D008024:Ligands; D008565:Membrane Proteins / Q000494:pharmacology*; D051881:Receptor, Notch1 / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000494:pharmacology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000072099:Serrate-Jagged Proteins
D002135:Calcium-Binding Proteins; C512925:Dlk1 protein, mouse; D036341:Intercellular Signaling Peptides and Proteins; D047908:Intracellular Signaling Peptides and Proteins; C000606273:JAG1 protein, human; C000606274:Jag1 protein, mouse; D000072100:Jagged-1 Protein; D008024:Ligands; D008565:Membrane Proteins; C497761:NOTCH1 protein, human; D051881:Receptor, Notch1; D011994:Recombinant Proteins; D000072099:Serrate-Jagged Proteins; C064045:delta protein