Figure 1.CYP19A1 expression promotes the sensitivity of ER positive breast cancer cells to Letrozole. (A) mRNA expression level of CYP19A1 in plasma of breast cancer patients was detected by RT-QPCR and analyzed by Mann Whitney test.**P<0.01. (B) Western Blot Analysis of endogenous protein expression levels of CYP19A1 in 5 breast cancer cell lines, using GAPDH as an internal reference, and 3 experiments were repeated. ***P<0.001, ****P<0.0001. (C) RT-QPCR was used to detect the endogenous mRNA expression level of CYP19A1 in 5 breast cancer cell lines. β-actin was used as an internal reference, and 3 replicates were carried out each time. *P<0.05, **P<0.01, ***P<0.001, ****P<0.0001. (D) BT-474 cells in 4 groups were treated with 8 concentrations of Letrozole, and CCK-8 was added 48 hours later to detect cell activity. Cells in each group had 3 repeated Wells. **P<0.01. (E) Graphpad Prism calculated the IC50 of four groups of BT-474 cells against Letrozole. ****P<0.0001.
