Figure 3

miR-155 enhanced E2 stimulated proliferation is mediated through altered mTOR signaling in vivo and in vitro . (A) Crystal violet assay for proliferation of MCF-7-vector and MCF-7-miR-155 cells treated with E2. Cells were grown in 5% CS phenol free DMEM for 48 hours prior to treatment with E2 (1nM) or vehicle control (DMSO). Each cell line was normalized to the respective vehicle control, n = 4. (B) Tumor volume for ovariectomized CB-17 SCID female mice injected bilaterally with 5X10^{^6} MCF-7-vector cells or MCF-7-miR-155 cells, n = 5 animals/group. All animals were implanted with an E2 pellet (0.72 mg) at day of cell injection. Points represent average tumor volume ± SEM. (C) MCF-7-vector and –miR-155 cells were harvested for total RNA extraction and PCR was performed for PgR following treatment with E2 (1nM), RAD001 (20nM) + E2, or vehicle control (DMSO), normalized to MCF-7-vector treated with E2 (1nM). Bars represent fold change ± SEM, n ≥ 3. * Significantly different from MCF-7-vector + E2 p < 0.05. (D) Tumor volume for ovariectomized CB-17 SCID female mice injected bilaterally with 5X10^{^6} MCF-7-miR-155 cells + E2 + RAD001 vs. MCF-7-miR-155 + E2 given placebo, n = 7. Points represent normalized tumor volume ± SEM. * p < 0.05, ** p < 0.01.