RT Journal Article SR Electronic T1 γ-Secretase Inhibitors Induce Erythroid Differentiation in Erythroid Leukemia Cell Lines JF Anticancer Research JO Anticancer Res FD International Institute of Anticancer Research SP 4071 OP 4074 VO 30 IS 10 A1 OKUHASHI, YUKI A1 ITOH, MAI A1 ARAI, AYAKO A1 NARA, NOBUO A1 TOHDA, SHUJI YR 2010 UL http://ar.iiarjournals.org/content/30/10/4071.abstract AB Background: Notch signaling regulates the fate of hematopoietic stem cells and leukemia cells. However, the role of Notch in erythroid differentiation remains unclear. Materials and Methods: We examined the effects of three γ-secretase inhibitors (GSI-IX, GSI-XII and GSI-XXI) that inhibit Notch signaling on the in vitro growth and differentiation of HEL and AA erythroid leukemia cell lines. Results: GSI treatment induced morphologic erythroid differentiation and promoted hemoglobin production. GSI treatment suppressed short-term growth and colony formation, while treatment with GSI-XXI promoted the growth of AA cells. The degree of differentiation induced by each GSI roughly correlated with the reduction in HES1 mRNA expression. Conclusion: GSIs have potential uses in differentiation induction therapy for erythroid leukemia in the future. Before clinical use, in vitro sensitivity tests should be performed because the effects of GSIs are diverse depending upon the combination of leukemia cells and GSIs.