Figure 4: CD24 reduces levels of p53 and p21 and promotes tumour cell proliferation.

(a) Heat-map depiction of alterations in gene expression in DU145 cells following CD24 gene silencing. RNA isolated from five independent cultures of Scr, three cultures of Sh1 and three cultures of Sh2 were compared using Affymeatrix Human U133 Plus 2.0 microarrays. Only those genes that met the statistical threshold of P<0.001 and mean alterations that reached the cutoff of >150% or<66% of Scr levels are displayed. The genes are listed in Supplementary Data set and the pathway analysis summary of affected genes is provided in Supplementary Table 1. (b) CD24 silencing increases p21/CDKN1A mRNA. Error bars, s.d. n=3. The data have been reproduced three times. (c) CD24 silencing increased levels of p53 and p21 proteins, but not p27 protein. Representative images of western blots are shown and the data have been reproduced three times. (d) CD24 silencing reduces cell cycle re-entry after starvation. Scr, Sh1 and Sh2 clones were starved for 48 h in serum-free medium and then shifted into serum containing medium. The cells were harvested and analysed for cell cycle progression based on DNA content. These data have been reproduced three times. (e) Ectopic expression of CD24 in LNCaP cell line decreases levels of p53 and p21, but not p27. Representative images of western blots are shown and the data have been reproduced two times. (f) CD24 transduction increases proliferation of LNCaP cells. Data shown are triplicate means and s.d. of triplicates and have been reproduced twice. LSD, least significant difference.