Figure 3.

Impact of RANK over-expression in osteosarcoma cells on bone structure (A) and bone parameters (B,C). Whatever tumor cell-line or host mouse strain was considered, representative three dimension images did not make it possible to observe any difference concerning bone resorption and osteoid tissue formation in relationship with RANK over-expression (A). As expected, IK22-5 RANKL blocking antibody injections made it possible to protect the bone from resorption (A). The bone parameters BS/TV, BS/BV and BV/TV were measured on 450 sections whose positions are presented in (B). The results showed no difference between the cells over-expressing or not RANK, whatever parameter was considered (C). The IK22-5 RANKL blocking antibody made it possible to significantly reduce the BS/TV and BS/BV parameters, with no impact on the BV/TV parameter. A significant difference was observed concerning the BV/TV parameter only in C57BL/6 mice when comparing contra-lateral control tibias (CT) and tibias with tumors independently of RANK over-expression by tumor cells. The data in (C) are shown as the mean ± SD. Data analyses were performed using the Kruskal Wallis test. ns: no significant. *: p < 0.05. **: p < 0.01. ***: p < 0.001.