Fig. 2: EZH2 in myeloma cells enhances bone resorption and inhibits bone formation in the mouse model.

6–7 weeks old female NSG mice were intrafemorally injected with myeloma cell lines RPMI8226 [nontargeted shRNA (shCtrl), and EZH2 shRNA (shEZH2)] or MM.1S [control vector (Vec), and EZH2 cDNA (EZH2)]. The mice not receiving myeloma cells (No MM) served as controls. After six weeks of cells injection, shown are the representative x-ray images of lytic lesions (a) (n = 5 mice/group). Yellow arrow, bone lesion. Scale bar, 1 mm. Another batch of NSG mice were intrafemorally injected with the same combination of myeloma cell lines. After four weeks of injections, shown are the representative images of bioluminescent signals (b) and microcomputed tomography images (c), concentrations of PINP (d) or CTX-1 (e) in mouse sera, percentages of BV/TV (f), ES/BS (g), Oc.S/BS (h), OS/BS (i), and Ob.S/BS (j). Scale bar, 1 mm. k, l Bone formation rate (BFR/BS) was measured by calcein injection, and the bone sections were imaged and analyzed. Shown are representative images and summarized data of bone formation in mouse femurs (n = 5 mice/group). Scale bar: 20 μm. m Schematic diagram showing primary patient-derived mouse model generation and analyzes performed. n ELISA analysis shown the concentrations of human λ chains in mouse serum. o After the mice were euthanized, myeloma cells were isolated from the bone marrow of PDX mice using anti-CD138 antibody-coated magnetic beads. EZH2 mRNA levels were compared between P1 and P2 groups (n = 5 mice/group). p Shown are the representative microcomputed tomography images in PDX mouse model. Scale bar, 0.5 mm. Shown are the percentages of BV/TV (q), ES/BS (r), and OS/BS (s) in PDX mouse model. The P1 and P2 cells used here are from the same source as those in Fig. 1b. d–k, q–s: p values were determined using one-way ANOVA with Tukey’s test; (n, o): p values were determined by unpaired two-tailed t test. Data are means ± SD. Source data are provided as a Source data file.