BT549-TripZ-200c cells were treated with DOX to induce expression of miR-200c, or vehicle control. (A) Relative PD-L1 mRNA levels were determined by qRT-PCR in 24 hours after DOX treatment began, cells were treated with interferon γ (IFNγ, 10 ng/mL) or vehicle. Cells were harvested 72 hours after the commencement of DOX treatment. ****P<0.0001, as determined by one-way ANOVA. (B) Relative PD-L2 mRNA levels were determined by qRT-PCR in BT549 cells expressing a stably transduced, DOX-inducible miR-200c vector were treated with DOX to induce expression of miR-200c, or vehicle control. 24 hours after DOX treatment began, cells were treated with IFNγ (10 ng/mL) or vehicle. Cells were harvested 72 hrs after DOX treatment. ****P<0.0001, as determined by one-way ANOVA. (C) PD-L1 expression was measured by flow cytometry. BT549 cells expressing a stably transduced, DOX-inducible miR-200c vector were treated with DOX to induce expression of miR-200c, or vehicle control. 24 hours after DOX treatment began, cells were treated with IFNγ (10 ng/mL) or vehicle. Cells were harvested 72 hours after the commencement of DOX treatment and stained for PD-L1. n=3 samples, data shown is representative of two independent experiments. *** p<0.001, **** p<0.0001, as determined by unpaired t-test. (D) Model of factors repressed by restoration of miR-200c to TNBC and their published effects on T cells.