Figure 1.

PPM1, but not PPM2 or PPM3, is selectively cytotoxic to breast cancer cells. (a) Structures and three-dimensional electrostatic potential models of compounds PPM1, PPM2, and PPM3. The negatively charged regions are red and the positively charged regions are blue. PPM1 (violet carbon sticks), PPM2 (orange carbon sticks), and PPM3 (grey carbon sticks) (bromine, red; chlorine, light green; hydrogen atoms omitted for clarity). (b) MDA-MB-231 cells were treated with the marine-derived synthetic polyhalogenated monoterpene analogues for the indicated times. Cell viability was analyzed by a XTT cell viability assay. (c) MDA-MB-231 cells were treated with different concentrations of doxorubicin or paclitaxel for 24 h and analyzed as in (b). (d) Different cancer cell lines were treated with PPM1 for 24 h and analyzed as in (b). NSCLC, non-small cell lung cancer; PPM1₁₀ shows number of viable cells after treatment with 10 µM PPM1 for 24 h. (e) Normal human primary mammary epithelial HME-1 cells are relatively resistant to PPM1. Cells were treated for 48 h and analyzed as in (b). Statistical analysis was performed by using the Newman-Keuls test. Data are mean ± SEM, n = 3, ** p < 0.01. All data are mean ± SEM, n = 3.