Fig. 1

TBX3 represses p21 promoter activity. a Total protein and RNA were extracted from ATDC5 and SW1353 control and TBX3 knock down cells. Upper panels lysates were subjected to western blot analysis with antibodies specific to TBX3 and p21. p38 was used as a loading control. Lower panels quantitative real-time PCR was performed on reverse transcribed RNA using primers specific to TBX3 and p21 and mRNA levels were normalised against GUSB levels. b ATDC5 and SW1353 cells were co-transfected with the p21 promoter luciferase reporter construct and varying amounts of the TBX3 expression construct pCMV-TBX3. Total amount of plasmid DNA transfected was held constant using the corresponding empty vector, pCMV. The plasmid pRL-TK containing the Renilla luciferase reporter gene was also introduced to normalize transfection efficiency. Thirty hours following transfection cells were lysed and relative luciferase activity measured. Data were normalised against renilla values and fold repression was obtained by comparing the results to that of the empty pCMV vector transfection. Lower panels western blotting shows expression of HA-tagged TBX3 protein using a HA antibody. a, b The values in the graphs indicate the mean of three independent experiments ± SEM (*p < 0.05; **p < 0.01; ***p < 0.001)