Detection of increased icb-1 transcript levels in maturing HL-60 cells: a novel marker for granulocytic and monocytic in vitro differentiation

Abstract 

Human gene icb-1 was initially described as a gene with increased expression in endometrial tumor cells differentiated in vitro by culture on a reconstituted basement membrane. We provide evidence for a more general involvement of icb-1 gene function in cellular differentiation processes. We report the up-regulation of icb-1 transcript levels in HL-60 promyelocytic leukemia cells during their in vitro differentiation induced by all-trans retinoic acid, vitamin D₃ or DMSO. Increased icb-1 mRNA levels could be observed both in monocytic and granulocytic differentiation. We also report the identification of the novel icb-1 splice variants icb-1β and γ, and the spleen-specific isoform icb-1δ. Expression of icb-1 can be used as a novel marker for in vitro differentiation processes of HL-60 cells.

bp, base pair(s), kb, kilo base pair(s), knt, kilo nucleotides, ATRA, all-trans retinoic acid, 1,25(OH)₂D₃, 1,25-dihydroxyvitamin D₃, DMSO, dimethylsulfoxide, NS, normal serum, FCS, fetal calf serum, SFM, serum-free medium, DD, differential display

HL-60 cell, Retinoic acid, Vitamin D₃, icb-1, Monocytic maturation, Granulocytic maturation