Figure 2. Effects of SL analogues on cell cycle regulation.

A, The cell cycle distribution of HCT116 colon cancer and DU145 prostate cancer cells treated with the indicated doses of strigolactone analogues for 48 hr was analyzed by flow cytometry. Bar graphs represent mean ±SD of at least two experiments. *** P<0.001 as analyzed by Student t-test. B. The percent of treated HCT116 cells in M phase (green boxes and numbers) as assessed by FACS analysis of phospho-Ser10 Histone-H3 (vertical) versus DNA content (horizontal) is shown. The cells were treated with 5.0 or 7.5 ppm of either ST357 (middle panels or MEB55 (lower panels) and harvested after 48 hr. Immunoblot analyses of cell cycle regulatory proteins. DU145 cells were treated with 10 ppm of MEB or vehicle alone for the indicated times and the levels of cyclin B, Cdc25C, Cdk1 and Thr14-Cdk1 were determined. D. qRT-PCR for cyclin B1 mRNA expression in DU145 and HCT116 cells treated with vehicle or 10 ppm of MEB55. The experiment was repeated twice and graphs represent mean ± SD of triplicate wells from each experiment is shown vs. controls. * P<0.05, ** P<0.01 as analyzed by Student t-test. E. Cyclin B1 protein levels following proteasomal inhibition in DU145 cells treated with MEB55 or ST362. The cells were exposed to SLs for 24 hr prior and then treated with 10 mM ALLN for additional 4 (+⁴) or 8 (+⁸) hrs.