SK-MEL-2 melanoma cells were treated with vehicle (DMSO) or the designated concentrations of compounds E-26, 22, or 7 for 6 hours. Following RNA extraction and reverse transcription, cDNA was amplified by PCR using primers for MDM2 and the intronless gene ubiquitin. Due to the presence of endogenous, transcriptionally inactive, mutant p53 in the SK-MEL-2 cell line, basal levels of MDM2 are low-to-undetectable in the untreated cells.35,36 The asterisk (*) denotes the size of properly spliced MDM2; arrows indicate splice variants of MDM2.