Levels and activity of c-myc are increased in a series of stably transfected DAOY and UW228 medulloblastoma cell lines. Levels and activity of c-myc are increased in a series of stably transfected DAOY and UW228 medulloblastoma cell lines. A, c-myc mRNA levels, determined by quantitative reverse transcription-PCR (RT-PCR), are increased 10- to 30-fold in c-myc–transfected cell lines (DAOYM2, DAOYM14, and UWM13-15) compared with parent (DAOY and UW228) or vector-transfected (DAOYV11 and UWV1) cells. Columns, averages of more than three independent determinations, normalized to β-actin levels; bars, SE. B, Western blots of protein extracts, with glyceraldehyde-3-phosphate dehydrogenase (GAPDH) included as a loading control, document similar increases in c-Myc protein levels. C, c-Myc transcriptional activity was measured using a transient transfection assay with the pLDHluc plasmid positively regulated by c-Myc. Results of two experiments run in triplicate. Bars, SE. Duncan Stearns et al. Cancer Res 2006;66:673-681 ©2006 by American Association for Cancer Research