For xenograft assays 5-6-weeks old female CrTac:NCr-
Foxn1nu and NOD.Cg-
Prkdcscid Il2rgtm1Sug/JicTac mice were purchased from Taconic. Tumors were induced by bilateral orthotopic mammary fat pad injection of 1×10
6 cells in 50%
Matrigel (BD Biosciences) in DMEM/F12 or Medium 171 (except for IDC50-X cells, which were injected with 3% FBS and 4 mg/ml collagen gel in Medium 171). Animal experiments were conducted following protocol 11-023 approved by the Dana-Farber Cancer Institute Animal Care and Use Committee. For all the xenograft studies, the sample size of each group (5-10 mice) is indicated in the figures. We performed pilot experiments using a few (5-10) mice/group followed by larger studies if needed to reach statistical significance and repeated experiments to ensure reproducibility. Due to the nature of the performed experiments, no randomization and no blinding was used as it was deemed unfeasible. However, the resulting tumors were analyzed in a blinded manner. Mice were administered JQ1 (50mg/kg, daily), vehicle only (control) for 14 days beginning at day 14 (SUM159), or doxycycline at day 21 (SUM159-shBRD4) after injection. Mice were euthanized and tumors evaluated 28 and 60 days after injection of parental and TET-inducible shBRD4-expressing SUM159 cells into mammary fat pads.
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