Genome-wide screening of target genes of BRONJ

Objective. RANKL抑制剂，地诺单抗最近可用于替代双膦酸盐（BP）。然而，地那单抗治疗患者中颌骨骨坏死（ONJ）的出现频率与BP大致相同。这一证据表明RANKL介导的破骨细胞生成的抑制可能与ONJ的爆发密切相关。根据这一假设，本研究旨在评估唑来膦酸盐对RANKL介导的破骨细胞生成的影响，并研究唑来膦酸盐在RANKL诱导基因中的分子靶点。方法.使用RANKL和M-CSF刺激的破骨细胞前体细胞的体外培养系统研究唑来膦酸盐对破骨细胞分化的直接作用。通过基因组筛选分析唑来膦酸盐在RANKL信号通路中的分子靶点以及与破骨细胞生成相关的其他因素。结果唑来膦酸盐减少RANKL处理诱导的TRAP阳性多核细胞的形成。微阵列分析发现，2个基因，活化T细胞核因子c1（NFATc 1）和碳酸酐酶2（Car 2），沉默在唑来膦酸盐处理的细胞中RANKL诱导的基因和其他因素。两个基因，NFATc 1和Car 2显着沉默唑来膦酸治疗。结论唑来膦酸盐抑制RANKL介导的破骨细胞生成。此外，唑来膦酸盐强烈抑制NFATc 1和Car 2的表达。我们的结果表明，这些基因可能是唑来膦酸盐在RANKL介导的破骨细胞生成中的靶点。

Objective. RANKL inhibitors, denosmab is recently available for use replace to bisphosphonates (BPs). However, the appearance frequency of osteonecrosis of jaw (ONJ) in denosmab treated patients is about the same as BPs. This evidence suggests that the inhibition of RANKL-mediated osteoclastogenesis may have close relationship with the outbreak of ONJ. According to this hypothesis, this study was designed to evaluate the effect of zoledronate on RANKL-mediated osteoclastogenesis and to investigate the molecular targets of zoledronate in RANKL-inducible genes. Methods. The direct effect of zoledronate on osteoclast differentiation was investigated using an in vitro culture system of osteoclast precursor cells stimulated with RANKL and M-CSF. The molecular targets of zoledronate in RANKL signal pathway and additional factors associated with osteoclastogenesis were analyzed by genome-widescreening. Results. Zoledronate reduced the formation of TRAP-positive multi-nucleated cells induced by RANKL treatment. Microarray analysis identified that 2 genes, nuclearfactor of activated T cells c1 (NFATc1) and carbonic anhydrase 2 (Car2), were silenced in zoledronate treated cells among RANKL-inducible genes and additional factors. Two genes, NFATc1 and Car2 were significantly silenced by zoledronate treatment. Conclusion. Zoledronate inhibited RANKL-mediated osteoclastogenesis. In addition, the expression of NFATc1 and Car2 is strongly suppressed by zoledronate. Our result suggests that these genes are possible targets of zolodronate in RANKL-mediated osteoclastogenesis