Figure 7
Proposed model for the critical roles of miR-320a in the mediation of tamoxifen sensitivity.
P4 or E2 specifically promotes or represses miR-320a expression via c-Myc to modulate the expression of ARPP-19, ERRγ and their downstreams c-Myc, Cyclin D1, which are also directly regulated by E2. MiR-320a further directly downregulates ARPP-19 and ERRγ, which in turn represses c-Myc expression and subsequently re-sensitizes tamoxifen-resistant breast cancer cells to tamoxifen. A positive feedback loop is proposed as indicated between c-Myc and miR-320a to regulate tamoxifen resistance in breast cancer.
