%0 Journal Article %T Cyclin E1 and Rb modulation as common events at time of resistance to palbociclib in hormone receptor-positive breast cancer %A Angelo Di Leo %A C. Kent Osborne %A Carmine De Angelis %A Chiara Biagioni %A Cristina Guarducci %A Dario Romagnoli %A Giulia Boccalini %A Ilenia Migliaccio %A Luca Malorni %A Martina Bonechi %A Matteo Benelli %A Rachel Schiff %A Roberto Verardo %J Archive of "NPJ Breast Cancer". %D 2018 %R 10.1038/s41523-018-0092-4 %X Functional characterization of PDR and PDS BC cell lines. a Proliferation of PDS models treated with palbociclib 1£¿¦ÌM, palbociclib STC or 0.01% DMS0 (vehicle). b Proliferation of PDR models treated with palbociclib 1£¿¦ÌM or 0.01% DMS0 (vehicle). Growth rate was assessed at day 6 by methylene blue assay. Growth fold changes were computed as ratio, dividing growth rate of treated cells by their controls treated with drug vehicle. Mean value of growth fold change of three independent experiments ¡Àstandard error of the mean (SEM) was plotted (*P-values£¿<£¿0.05, two¨Cway ANOVA with Sidak¡¯s multiple comparisons test). c ¦Â-galactosidase activity of PDS and PDR models treated with palbociclib 1£¿¦ÌM or 0.01% DMS0 (vehicle). Positive and negative cells were counted in six randomly selected 20X fields and the percentage of positive cells was calculated. Mean percentage value of ¦Â-galactosidase positive cells of three independent experiments ¡ÀSEM was plotted (*P-values£¿<£¿0.05, by Student¡¯s t test %U https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6261939/