BRCA mutated TNBC cell lines express high levels of PARP1 and are sensitive to PARP inhibition.

<p>(A) Cells were treated with increasing concentrations of ABT-888 over a 5 day incubation period. MTT assays were used to assess cell viability. The fraction of surviving cells was used to calculate the IC₅₀ values for ABT-888 for each cell line by sigmoidal dose response curve analyses (GraphPad Prism). IC₅₀ values calculated from three independent experiments performed in triplicate were graphed for each cell line. (B) PARP1 protein expression levels were evaluated from cell lysates collected from cells growing in log phase. Equal protein was separated by SDS-PAGE, transferred to PVDF, and immunoblotted using anti-PARP1 antibodies. β-actin protein levels were used as a loading control.