miR-183抑制骨肉瘤转移的作用及机制研究

Pulmonary metastases are the main cause of death in patients with osteosarcoma, however, the molecular mechanisms of metastasis are not well understood. Our previous study showed that down-regulation of miR-183 promotes migration and invasion of Osteosarcoma by targeting Ezrin in vitro. The expression levels of miR-183 significantly correlated with lung metastasis as well as with local recurrence of osteosarcoma. Whether miR-183 could inhibit the metastasis of osteosarcoma in vivo? What is the mechanism of miR-183 inhibiting metastasis of osteosarcoma in vivo? Results of our preliminary experiments indicated that miR-183 could impede local invasion of the invasion-metastasis cascade of osteosarcoma in vivo. This project is planned to establish stable expression of green fluorescence protein and a doxycycline (dox)-inducible miR-183 expression in osteosarcoma cell model, which could express miR-183 in a temporally controlled manner, and further establish the animal model of osteosarcoma with lung metastasis with the above stable cell line. By using this cell and animal model, continous expression of green fluorescent protein and temporally controlled miR-183 expression at different time points of experimental could provide us with reliable evidence in the miR-183 play in different steps of the invasion-metastasis cascade of osteosarcoma. The project will be expected to reveal the mechanism of miR-183 inhibiting pulmonary metastasis of osteosarcoma and provide scientific basis for miR-183 as a new target in treatment of osteosarcoma.

肺转移是临床骨肉瘤患者死亡的主要原因，但机制尚不清楚。申请人以往研究表明：miR-183能够靶向作用于Ezrin蛋白抑制体外骨肉瘤细胞的迁移和侵袭；miR-183的表达与骨肉瘤的肺转移以及局部复发显著相关。那么，miR-183能否抑制体内骨肉瘤的转移及机制如何？初期预实验提示miR-183能在裸鼠体内抑制骨肉瘤的局部浸润。本课题拟建立同时稳定表达绿色荧光且受四环素调控表达miR-183的骨肉瘤细胞模型，并进一步建立皮下及尾静脉注射骨肉瘤肺转移裸鼠模型，利用绿色荧光便于观察的特点以及四环素调控系统对miR-183表达的精确调控方式，研究miR-183在体内对骨肉瘤侵袭-转移不同阶段的影响及其机制，皆在获得miR-183在骨肉瘤肺转移过程中发挥作用的可靠证据。本项目将有望揭示miR-183对骨肉瘤肺转移的调控作用和机制、为确立miR-183作为骨肉瘤治疗的新靶点提供更充分的科学依据。

Mir183在对骨肉瘤的转移增殖起到一定作用。与此同时，我们发现TEM8在骨肉瘤细胞系及组织中广泛表达；我们进一步研究了其与骨肉瘤复发分期、转移等临床恶性生物学参数的关系，明确了TEM8骨肉瘤患者的预后呈负相关；瞬时干扰TEM8表达后发现骨肉瘤细胞的增殖受到明显抑制，并发现这种现象与MAPK通路相关。在本研究中，我们明确了TEM8与MAPK通路及增值相关蛋白的关系，并在裸鼠体内成瘤进一步观察TEM8在增殖方面的作用，发现TEM8可以通过MAPK通路调节骨肉瘤的增殖。该研究对骨肉瘤发病的分子机制提供新的理论基础。.关键词(不超过5个，用分号分开): 骨肿瘤 ;骨肉瘤 ;肿瘤转移 ;miR-183