Phosphorylation independent eIF4E translational reprogramming of selective mRNAs determines tamoxifen resistance in breast cancer

摘要

Comparing the protein expression of a panel of translation regulators between tamoxifen sensitive (MCF-7 and ZR-75) and resistant cells (LCC2 and AK-47). Western blotting was used to determine the expression of the indicated protein candidates. Tubulin was used as the loading control. Overexpression of in MCF-7 and ZR-75 breast cancer cells could induce distinctive molecular alterations in polysomes. The cells were transfected with for 72 h. RNA sequencing was performed to determine the effect of eIF4E overexpression on mRNA profile in the polysome. Heatmap was used to show the profiles of the molecular features. Top 10 molecular pathways being enriched by overexpression of eIF4E. KEGG pathway analysis was performed to identify pathways which were potentially enriched in eIF4E overexpressing breast cancer cells. The effect of eIF4E overexpression on the mRNA levels of eIF4E, ERα and FOXM1 in MCF-7, ZR-75, LCC2 and AK-47 cells. qPCR was performed to determine the levels of the corresponding mRNAs. Actin was used as the internal control. Results were expressed as mean ± s.d. from three independent experiments. Student test was employed. *** represents  e The effect of eIF4E overexpression on the protein levels of eIF4E, ERα and FOXM1 in MCF-7, ZR-75, LCC2 and AK-47 cells. The cells were transfected with 2 µg of (eIF4E O/E) or (Ctrl O/E). Whole cell lysates were harvested after 72 h posttransfection. Western blot was performed. Tubulin was used as the loading control.