Fibulin-4 promotes osteosarcoma invasion and metastasis by inducing epithelial to mesenchymal transition via the PI3K/Akt/mTOR pathway.
Fibulin-4 promotes osteosarcoma invasion and metastasis by inducing epithelial to mesenchymal transition via the PI3K/Akt/mTOR pathway.
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DOI：
10.3892/ijo.2017.3921
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发表时间：
2017-05
影响因子：
5.2
通讯作者：
Chen Y
中科院分区：
文献类型：
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作者：
Zhang D;Wang S;Chen J;Liu H;Lu J;Jiang H;Huang A;Chen Y
本研究探讨了纤维蛋白-4在骨肉瘤进展中的作用及其可能的信号通路。采用免疫组织化学（IHC）、免疫细胞化学（ICC）和实时逆转录聚合酶链反应（real-time qRT-PCR）技术检测正常组织、良性纤维发育不良、骨肉瘤、骨肉瘤细胞系、正常成骨细胞系hFOB和不同侵袭性亚克隆中Fibulin-4 mRNA和蛋白的表达。通过体外功能测定，我们分析了具有不同侵袭潜力的不同骨肉瘤细胞系和亚克隆的侵袭和增殖能力。为了研究纤维蛋白-4在骨肉瘤细胞侵袭转移中的作用，构建了含有纤维蛋白-4小发夹RNA （shRNA）和plvx -纤维蛋白-4的慢病毒载体，分别感染高侵袭性、低侵袭性亚克隆和骨肉瘤细胞系。通过体外和体内功能实验研究了纤维蛋白-4下调和上调对骨肉瘤细胞生物学行为的影响。结果显示，纤维蛋白-4在骨肉瘤中表达上调，与骨肉瘤低分化、淋巴结转移、预后不良呈正相关。Fibulin-4也被发现在高侵袭性细胞系和高侵袭性亚克隆中过度表达。Fibulin-4通过PI3K/AKT/mTOR通路诱导EMT，促进骨肉瘤细胞侵袭转移。总之，我们的研究结果表明，纤维蛋白-4是骨肉瘤发展和进展的促进剂，并为未来的研究提供了新的治疗靶点。
This study explored the role of fibulin-4 in osteosarcoma progression and the possible signaling pathway involved. Fibulin-4 mRNA and protein expression in normal tissue, benign fibrous dysplasia, osteosarcoma, osteosarcoma cell lines, the normal osteoblastic cell line hFOB, and different invasive subclones were evaluated by immunohistochemistry (IHC) or immunocytochemistry (ICC) and real-time reverse transcriptase-polymerase chain reaction (real-time qRT-PCR). Using in vitro functional assays, we analyzed the invasive and proliferative abilities of different osteosarcoma cell lines and subclones with differing invasive potential. To assess the role of fibulin-4 in the invasion and metastasis of osteosarcoma cells, lentiviral vectors with fibulin-4 small hairpin RNA (shRNA) and pLVX-fibulin-4 were constructed and used to infect the highly invasive and low invasive subclones and osteosarcoma cell lines. The effects of fibulin-4 knockdown and upregulation on the biological behavior of osteosarcoma cells were investigated by functional in vitro and in vivo assays. The results revealed that fibulin-4 expression was upregulated in osteosarcoma, and was positively correlated with low differentiation, lymph node metastasis, and poor prognosis. Fibulin-4 was also found to be over-expressed in highly invasive cell lines and in the highly invasive subclones. Fibulin-4 could promote osteosarcoma cell invasion and metastasis by inducing EMT via the PI3K/AKT/mTOR pathway. Collectively, our findings demonstrate that fibulin-4 is a promoter of osteosarcoma development and progression, and suggest a novel therapeutic target for future studies.