Fig. 5.

TLE1 is required for Runx2-mediated rRNA genes suppression. (A) Real-time qPCR shows that pre-rRNA levels are increased when TLE1 is depleted from cells. Western blots demonstrate specific down-regulation of TLE1 by three different siRNA oligonucleotides (1, 2, and 3). (B) Expression of Runx2 in the presence of a TLE1-specific siRNA does not alter pre-rRNA levels as assessed by qPCR. Western blot shows the knockdown of TLE1 protein in the presence and absence of Runx2 expression. (C) Western blot shows specific down-regulation of TLE1 alone or TLE1 with Runx2 by using siRNA oligonucleotides. (D) Chromatin immunoprecipitation assay demonstrates an increase in active histone modifications on rDNA repeats by knocking down either TLE1 alone or in combination with Runx2. (E) Line graphs represent cell count when either TLE1 or both Runx2 and TLE1 are down-regulated by specific siRNA oligonucleotides. Results indicate that the absence of TLE1 or TLE1 and Runx2 increases cell number. (F) Radioactive metabolic labeling with [³⁵S] methionine shows TLE1 and Runx2 negatively regulate the rate of protein synthesis. Line scan was performed on individual lanes to show the difference in protein synthesis rate. Coomassie stain shows that equal protein samples were loaded in each lane.