PAXILLIN INCREASES AS RETINOIC ACID OR VITAMIN D3 INDUCE HL-60 CELL DIFFERENTIATION

摘要

HL-60 is an established granulocyte/monocyte precursor (GM) cell line that has retained the ability to differentiate along both the gran-ulocytic and monocytic lineages in response to retinoic acid and vitamin D3 treatment, respectively. Retinoic acid-induced HL-60 differentiation is known to coincide with changes in cellular morphology and elevated levels of the cytoskeletal proteins alpha-actinin, vinculin, and talin. We have found that the level of paxillin, a protein known to bind to vinculin, also increases during the granulocytic and monocytic differentiation of HL-60 cells. Paxillin protein expression increased after 12 h of retinoic acid treatment and occurred before any changes in morphology, functional differentiation, or G_1/G_0 growth arrest. In contrast, the increased level of paxillin protein expression in the vitamin D3-treated cells coincided with cellular differentiation. These data identify paxillin as a new marker of myelo-monocytic HL-60 differentiation and as a protein with anearly response to retinoic acid.