Figure 4
From: Stapled BIG3 helical peptide ERAP potentiates anti-tumour activity for breast cancer therapeutics
Stapled ERAP inhibits the E2-dependent growth of tamoxifen-resistant MCF-7 cells. (a) MTT assays evaluating the inhibitory effect of unstapled, original ERAP (left) and stERAP-6 (right) on the growth of tamoxifen-resistant (TAM-R) MCF-7 cells. TAM-R MCF-7 cells were treated with unstapled original ERAP or stERAP-6 in the presence of 10 nM E2 and 1 μM tamoxifen (TAM) at 0 h. The data represent the mean ± s.d. of three independent experiments. (b,c) Immunoblot analysis evaluating the phosphorylation levels of MAPK (b), mTOR, and S6K (c) in TAM-R MCF-7 cells. (d) The combined inhibitory actions of stERAP-6 and tamoxifen (TAM), fuluvestrant (Fulv) or everolimus (Ever) assessed via MTT assays. MCF-7 cells were treated for 24 h and 96 h with 10 nM E2 ± 10 μM stERAP-6, 10 μM unstapled original ERAP, 1 μM TAM, and a combination of stERAP-6 or unstapled original ERAP and 1 μM TAM, 2 μM Fulv or 0.5 μM Ever. The data represent the mean ± s.d. of three independent experiments. **P < 0.01 and ***P < 0.001 via two-sided Student’s t-tests. (e) Flow cytometric analyses evaluating the effect of stERAP-6 treatment on the cell cycle of MCF-7 cells.
