Figure 5.

MCF7 cells do not require p21 or p27 for palbociclib-mediated cell cycle arrest. (a) MCF7 cells were transfected with the indicated siRNAs, NTC, sip21 and/or sip27 48 h before treatment with 1 µM palbociclib. Cells were pulse labelled for 30 min with 10 µM EdU and fixed 48 h following palbociclib addition. (b) MCF7 cells were treated with palbociclib for 18 h before transfection with the indicated siRNAs. Cells were fixed 48 h following palbociclib addition, after 30 min pulse labelling with 10 µM EdU. (a,b) Data plotted as SuperPlots; dots represent replicate wells; colour coded by experimental repeat. Triangles represent mean values for n = 3 (n = 2 for (a), ii) repeats with mean and s.e.m. shown. Scale bar = 100 µm. One-way ANOVA with Sidak's multiple comparisons test was performed between mean values of palbociclib-treated samples in comparison to WT siNTC palbociclib, all differences were non-significant. (c) MCF7 cells were treated with DMSO for 72 h or palbociclib for 24, 48 or 72 h and (i) p21 and (ii) p27 levels quantified by immunofluorescence. Representative frequency distributions of measured intensities from one experimental repeat (from n = 3) shown.