Figure 4.

XRK3F2 reverses GFI1 occupancy and reverses loss of H3K9ac at Runx2 in MM-exposed preOB. (A) MC4 cells were cultured as depicted and described in 3A, with XRK3F2 added only after MM cells were removed. Shown are ChIP data for (A) GFI1 occupancy and (B) H3K9ac at the Runx2-P1 promoter obtained from MC4 cells harvested after culture (48 h) in proliferation media in the absence or presence of 5TMG1 cells in direct co-culture (d0, d0+MM) or continued in the absence of MM cells in osteogenic media (d4, d4+MM) or continued in osteogenic media with 5 μM XRK3F2 (d4+MM+XRK3F2). (C) MC4 preOB were co-cultured with MM1.S (direct contact) for 72 h in proliferation media, MM cells were removed and remaining preOB were subjected to osteogenic differentiation for 5 days +/– XRK3F2 (2.5, 5 μM). (D) MC4 preOB were co-cultured with MM1.S (in transwells) for 72 h in proliferation media +/– 5 μM XRK3F2 (during), then the MM cells were removed and the preOB were subjected to osteogenic differentiation for 5 days +/– 5 μM XRK3F2 (after). MC4 were treated with XRK3F2 either during MM exposure or afterwards, but not both. (C,D) Alkaline phosphatase staining with quantitation measurements is shown as a representative of 2 independent experiments. SEM for 3 experimental wells and representative of 2 biological replicates is indicated. ^*p ≤ 0.05; ^**p ≤ 0.01.