The BRCA1 protein has a role in the repression of the K18 promoter in NT cells. (A) SW613-3 (T) or SW613-B3 (NT) cells were transfected with plasmid pK18(80)luc alone (none) or in the presence of 24 μg of plasmids pCBRCA1C (BRCA1wt), pcDNA3-BRCA1(Y1853→STOP) or pcDNA3-BRCT, as indicated. Results are presented as in figure 3. Error bars represent standard deviation of the mean of three experiments. (B) and (C) Expression level of the BRCA1 constructs. SW613-3 (3) or SW613-B3 (B3) cells were untransfected (mock) or transfected with plasmid pCBRCA1C (wt), pcDNA3-BRCA1(Y1853→STOP) (mut) or pcDNA3-BRCT, as indicated. Cellular extracts were analyzed by Western blotting with an anti-HA antibody.