Figure 4.

ING1 regulates rDNA transcription during stress. (A and B) A431 cells expressing control or shING1 constructs were treated with 20 nM rapamycin (24 h) or cultured in medium lacking glucose (24 h). Cells were assayed for relative levels of 47S and 18S rRNA by qRT-PCR. Values were normalized to actin (P < 0.05). (C) Levels of 47S rRNA were assayed in HS68 cells transfected with siING1 or siControl that were subjected to rapamycin treatment or glucose deprivation (P < 0.04). (D) Nuclei from cells treated as above were digested with MNase and subjected to PCR using primers for the 47S core promoter. PCR amplicons of MNase digested samples were normalized to undigested controls (P < 0.04).