复发与转移是骨肉瘤患者死亡的主要原因，循环肿瘤细胞（CTCs）在其中发挥了极为重要的作用。最近的研究表明，CTCs 能够由身体其它器官回到原发灶并继续发展，这个过程被定义为肿瘤的自我种植。该现象已在包括乳腺癌在内的多个肿瘤中得到印证，而其在骨肉瘤进展中的作用及机制仍不明了。本课题拟通过移植绿色与红色荧光蛋白示踪标记的骨肉瘤细胞系，建立一个肿瘤细胞的自我种植模型，从而验证骨肉瘤自我种植现象的存在，并探讨CTCs自我种植在骨肉瘤发展中可能发挥的作用；进一步采用流式细胞分选法 (FACS) 分选种植于受体肿瘤的转移细胞，研究其原位种植能力；利用基因芯片表达谱和细胞因子抗体芯片筛选参与CTCs细胞浸润原位肿瘤的相关差异基因以及参与吸引CTCs的细胞调节因子。该项目的完成将进一步揭示骨肉瘤复发转移之谜，为预防和治疗转移癌症提供新的策略。

Recurrence and metastases remain the leading cause of death among osteosarcoma patients,during which circulating tumor cells（CTCs） play an important role. Recent researches propose a new twist on metastasis, showing that CTCs can return to the primary tumor from other organs and proceed, a process termed tumor self-seeding.This phenomenon was found in several kinds of tumors, such as breast cancer. However, the role of CTCs in osteosarcoma and its related mechanisms are still unknown. The purpose of this project is to set up a tumor self-seeding model in mice and confirm the exsistence of tumor self-seeding in osteosarcoma via inoculations of green and red fluorescent protein labeled osteosarcoma cells,and investigate the role of CTCs in osteosarcoma progression;to separate the metastatic tumor cells in receptor tumor tissue with fluorescence-activated cell sorting(FACS), and subsequently study their in situ self-seeding capacity; to identify differentially expressed genes that may participate in the infiltration of CTCs using gene expression profile analysis and screen the cytokines that are involved in the attraction of CTCs using cytokine antibody array. The successful reveal of local recurrence and distant metastases in osteosarcoma will surely offer new opportunities for successful prevention and cure of metastatic osteosarcoma.