... alone didnot increase the extent of staining. However, in cells thathad been cocultured with CDO and a cytotoxic drug,staining was significantly increased, indicating the presence of senescence. ... therefore interferes with cAMP-induced gene transcription. We have examined theeffect of this CDO alone and in combination with a range of common chemotherapeutic agents in colorectal cancer celllines. ... an increase in p21waf1expression,loss of CDK function, and the generation of cells with senescence characteristics. In the first part of the investigation, we determined theeffect of continuous...