FICZ by itself had no effect on these markers. Co administered with RA, FICZ enhanced the induced expression of these markers compared to RA alone. Cells were untreated or treated with 1 uM RA with or without 100 nM FICZ. Expression of the CD38 and selleck Vorinostat CD11b cell surface differentiation markers, the respiratory burst and the percentage of cells with G0 G1 DNA were measured by flow cytometry. CD38 is an early cell sur face differentiation marker. At 6 h, FICZ alone did not induce CD38 expression. Likewise, FICZ did not affect RA induced CD38 expression at this early time. CD11b is the alpha subunit of the integrin receptor and is a differentiation marker that typically appears with slower kinetics than CD38 in RA treated cells.

For CD11b expres sion, the percentage of cells that were positive was higher for cells treated with RA plus FICZ compared to RA alone, namely 26% versus 21%, p 0. 012 after 24 h, 62% versus 50%, p 0. 042, after 48 h and 84% versus 57%, p 0. 0029, after 72 h. The flow cytometry raw data and mean fluorescence Inhibitors,Modulators,Libraries index for a representative experiment are presented in Additional file 1, Figure S1. Cells treated with FICZ alone showed no CD11b Inhibitors,Modulators,Libraries expression like untreated controls. Inducible oxidative metabolism is a functional marker of further differentiation that is characteristic of mature cells. This mature functional differentiation marker was also enhanced in cells treated with FICZ plus RA com pared to RA alone. At 48 h, FICZ plus RA treated cells were 57% positive compared to 39% for cells treated with RA alone with a p 0.

08, and by 72 h 84% of FICZ plus RA treated cells were positive versus 63% of RA treated cells with a p 0. 001. G0 G1 cell cycle arrest Inhibitors,Modulators,Libraries is a characteristic of differenti ation. RA caused an increase in the relative number of G0 G1 cells and an associated Inhibitors,Modulators,Libraries reduction in S phase cells. Addition of FICZ with RA enhanced this effect, consistent with the enhanced phenotypic shift. At 48h, 48% cells were in G0 G1 phase for un treated cells, and 56% for RA treated cells, p 0. 0001. At 72 h, the proportions were 56% and 72% for untreated and RA treated respectively. FICZ alone had a slightly lower proportion of cells in G0 G1 compared to untreated cells. For cells treated Inhibitors,Modulators,Libraries with FICZ plus RA compared to RA alone, the percentage of cells with G0 G1 DNA was 66% compared to 56%, p 0. 0001, after 48 h, and 85% versus 72%, p 0. 0001, www.selleckchem.com/products/z-vad-fmk.html after 72 h. Growth curves were consistent with the cell cycle phase distribution changes. FICZ alone did not significantly affect, although slightly increased, the cell density compared with control. FICZ in combination with RA lowered the cell densities compared to RA alone consistent with the G0 G1 data.