Figure 2

Retinoblastoma (Rb) protein expression and activity. HGUE-C-1 and HT-29, SW620, SW480 and HCT-15 colorectal carcinoma cells were grown, lysed and subjected to Western blot analyses to detect levels of Rb or β-actin, using specific antibodies. β-actin was used as a loading control (2A). Densitometric values of Rb bands were normalized to β-actin bands and represented as the average of at least three experiments. Error bars are the S.E.M. (2B). Retinoblastoma activity was determined on HT-29 and HGUE-C-1 cell lines by transient transfection assays with Rb and E2F reporter genes and represented as the average of at least four experiments. Error bars are the S.E.M. (2C).