Figure 3 Treatment with E2 enhanced the growth of T47D cells and fulvestrant inhibited its growth. (A, B) Influence of E2 or fulvestrant on the cell cycle status of T47D cells. (A) Cells were treated with E2 for 16 hours www.selleckchem.com/products/gs-9973.html before being analyzed by flow cytometry. (B) Cells were treated with E2 for 12 days. Fulvestrant was added to the medium 12 hours before E2 treatment. (C) The growth curve of E2 or fulvestrant
treated T47D cells and control cells were plotted for 6 days of cell culture. ERα transfected Bcap37 cells (BC-ER cells) exhibited much higher resistance to chemotherapeutic agents than cells transfected with empty vector (BC-V cells) in the presence of Selleck CHIR98014 E2. The stable transformants of the Bcap37 cells were established after transfection with either ERα expression vector (BC-ER cells) or empty vector (BC-V cells). The difference in chemosensitivity between BC-ER cells and BC-V cells was determined by MTT assays and PI dye exclusion tests. This process was completed after the cells were exposed to chemotherapeutic agents for 72 hours with or without preincubation of 10 nM E2 Topoisomerase inhibitor for either 16 hours or 12 days. In the absence of E2, BC-ER and BC-V cells exhibited similar
cell viability. However, in the presence of E2, cell viability after treatment using chemotherapeutic agents was much higher in BC-ER cells than in BC-V cells (P < 0.05; see Figure 4A and 4B). Pretreatment with E2 for 16 hours or 12 days increased the cell viability of BC-ER cells after exposure to chemotherapeutic agents.
Figure 4 BC-ER cells exhibited much higher resistance than BC-V cells in the presence of E2. (A, B) The viability of BC-ER and BC-V cells after being exposed to four chemotherapeutic agents was determined by MTT assays. (A) Cells were pretreated with or without E2 for 16 hours before being exposed to chemotherapeutic agents. (B) Cells were pretreated with or without E2 for 12 days. The chemotherapeutic agents used in the MTT assays were paclitaxel, epirubicin, fluorouracil, and vinorelbine. Three concentrations were tested for each chemotherapeutic agent. (C, D) Cell death why induced by chemotherapeutic agents was determined by PI dye exclusion assays. (C) Cells were pretreated with or without E2 for 16 hours before being exposed to chemotherapeutic agents. (D) Cells were pretreated with or without E2 for 12 days. The chemotherapeutic agents used in the PI dye exclusion assays were paclitaxel, fluorouracil, and vinorelbine. One concentration was tested for each anticancer drug. Results of PI dye exclusion tests showed that in the absence of E2, BC-ER and BC-V cells had similar levels of cell death after treatment with chemotherapeutic agents. However, in the presence of E2, the percentage values of PI-stained dead cells were significantly lower in BC-ER than in BC-V cells.