Figure 4. Cucurbitacin B treatments in the parental MCF-7 and MDA-MB-231 (endogenously expressed wt-BRCA1), BRCA1 knocked-down counterparts and shRNA scrambled controls.

(A) and (B), Western blot analysis for p21, p27 and survivin proteins after the cells were cultured either in control medium or in the medium containing 15 µg/ml cucurbitacin B for 48 h. GAPDH was used as loading control. (C), The degrees of significantly cytotoxic responses (indicating as percent killed) to paclitaxel and cucurbitacin B in wt-BRCA1 parental and BRCA1 knocked-down MCF-7 and MDA-MB-231 cells are shown, (* p<0.01).