Fig. 5

Blockage of ERK pathway significantly attenuating osteolysis in metastatic bone of CRC. A–C Histochemistry analysis and TRAP staining showed the bone resorption in tibias at 21 days post injection of MC-38 cells after administration of Ravoxertinib in the presence of IL-4 (Scale bar = 100 μm) (A) and the quantification of trabecular area (B) and the quantification of area of OCs (C). (n = 6) D–E μCT analysis showed the bone resorption in tibias at 21 days post injection of MC-38 cells after administration of Ravoxertinib in the presence of IL-4 (D) and compared the bone mineral density (BMD) of tibias at 21 days post injection of MC-38 cells after administration of Ravoxertinib in the presence of IL-4 (E). (n = 3) F, G Quantification of trabecular bone volume fraction (BV/TV) (F), trabecular thickness (Tb.Th), trabecular number (Tb. N) and trabecular separation (Tb. Sp) (G) of tibias at 21 days post injection of MC-38 cells after administration of Ravoxertinib in the presence of IL-4. (n = 3) (H–I) Histochemistry analysis showed the bone resorption in tibias at 21 DPI after injection of CT-26 cells in IL-4 treated mice with/without treatment of Ravoxertinib (Scale bar = 100 μm) (H) and quantification of trabecular area (I). (n = 8) (J–K) TRAP staining showed the area of OCs at 21 days post injection of CT-26 cells  (Scale bar = 100 μm) (J) and the quantification of OC area in bone surface  (K). (n = 8) *p < 0.05, **p < 0.01