Lu Fu1, Ken-ichi Katsube, Shuji Tohda. 1. Department of Laboratory Medicine, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-Ku, Tokyo 113-8519, Japan.
Abstract
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. MATERIALS AND 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. CONCLUSION: The time course for Notch1 cleavage following ligand stimulation and the effects of stimulation on gene expression are shown.
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. MATERIALS AND 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. CONCLUSION: The time course for Notch1 cleavage following ligand stimulation and the effects of stimulation on gene expression are shown.