Cell viability of cucurbitacin B treated BRCA1 knocked-down breast cancer cells.

<p>(A) and (B), BRCA1 expressions were knocked down in MCF-7 cells and MDA-MB-231 cells, respectively. Lanes 1 and 2, parental and transfected control cells. Lanes 3, shRNA-BRCA1 transfected cells. GAPDH expression represents internal control. All the densitometric values were normalized to loading controls (GAPDH), and the fold change relative to the parental control are indicated numerically above the blots. (C), Cells were treated with 1, 10, 20, 40, 60, 80 and 100 µg/ml cucurbitacin B for 48 h. Three repetitive experiments were done and each was run in triplicate. (D), The results from the experiment shown in (C) are compared in each group at the specified concentration of 20 µg/ml cucurbitacin B. Knocked-down BRCA1 breast cancer cells showed significant higher sensitivity to cucurbitacin B when compared to the parental cells, (* <i>p</i><0.01).