骨转移是膀胱癌晚期常见的转移方式之一，预后极差。破骨细胞作为目前已知的唯一具有骨吸收功能的细胞，在肿瘤骨转移中发挥了关键作用。靶向抑制破骨细胞功能是目前防治膀胱癌骨转移的治疗新方向。LncRNA与肿瘤的发生发展密切相关，在肿瘤转移过程中起重要调控作用。本课题组的已发表研究证实lncRNA XIST可与miRNA互作促进膀胱癌侵袭转移。进一步的预实验结果以及各大数据库和在线工具预测结果支持本项目的科学假说：lncRNA XIST可通过与miR-124-3p和miR-34a-5p互作靶向作用RANKL通路的多个关键因子调节破骨细胞分化与功能。因此，本项目拟从原代破骨细胞分离诱导开始，辅以膀胱癌骨转移动物模型的体内实验，以及结合多种分子生物学技术阐明lncRNA XIST调节膀胱癌骨转移的作用机制。本课题将为膀胱癌骨转移的防治提供新的切入点。

Bone metastasis is a common type of metastatic bladder cancer in the late stages, with a very poor prognosis. Osteoclasts, the only known bone resorption cell, play a key role in bone metastasis. Targeted inhibition of osteoclast function is currently a new therapeutic approach to prevent and treat bone metastases in bladder cancer. LncRNA is closely related to the occurrence and development of tumors and plays an important role in regulating tumor metastasis. In our previous studies, it was confirmed that lncRNA XIST can interact with miRNAs to promote the invasion and metastasis of bladder cancer. Further, based on online database analysis, online tools prediction and pre-test results, the following hypothesis was proposed: lncRNA XIST can regulate multiple key factors in the RANKL pathway through interactions with miR-124-3p and miR-34a-5p, thus modulating differentiation and function of osteoclasts. Starting from primary osteoclast isolation induction, the present study is attempted to investigate the mechanism by which lncRNA XIST regulates bone metastasis of bladder cancer using in vivo bladder cancer bone metastasis animal models and a variety of molecular biological techniques. The present study provides a new pointcut for the prevention and treatment of bone metastases in bladder cancer.