Dissection of Wnt5a-Ror2 Signaling Leading to Matrix Metalloproteinase (MMP-13) Expression
Dissection of Wnt5a-Ror2 Signaling Leading to Matrix Metalloproteinase (MMP-13) Expression
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DOI：
10.1074/jbc.m111.315127
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发表时间：
2012-01-06
影响因子：
4.8
通讯作者：
Minami, Yasuhiro
中科院分区：
文献类型：
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作者：
Yamagata, Kaoru;Li, Xin;Minami, Yasuhiro
研究表明，在骨肉瘤细胞系中，组成型激活的Wnt 5a-Ror 2信号在诱导基质金属蛋白酶-13（MMP-13）的表达中起着至关重要的作用，而MMP-13的表达是骨肉瘤细胞侵袭性的必需条件;然而，Wnt 5a-Ror 2信号诱导MMP-13基因表达的分子基础仍不清楚。在此，我们通过报告基因分析表明，激活蛋白1（AP 1）（MMP-13基因启动子区的结合位点）主要负责骨肉瘤细胞系SaOS-2和U2 OS中Wnt 5a-Ror 2信号转导对其转录激活。染色质免疫沉淀分析显示，c-Jun和ATF 2是在SaOS-2细胞中Wnt 5a-Ror 2信号传导过程中招募到MMP-13基因启动子中的AP 1结合位点的关键转录因子。使用siRNA介导的抑制或特异性抑制剂，我们还表明Dishevelled 2（Dvl 2）和c-Jun N-末端激酶是MMP-13基因诱导所需的，推测是通过在SaOS-2细胞中Wnt 5a-Ror 2信号传导期间c-Jun和ATF 2的磷酸化。有趣的是，MMP-13在SaOS-2细胞中的表达需要Dvl 2和Rac 1，而不是Dvl 3，而其在U2 OS细胞中的表达需要Dvl 3，而不是Dvl 2和Rac 1，这表明在不同的骨肉瘤细胞系中存在导致相同基因（在这种情况下为MMP-13基因）表达的不同细胞内信号传导机制。此外，我们提供的证据表明，Wnt 5a-Ror 2信号也可能需要在软骨组织的发育过程中表达MMP-13基因。
It has been shown that constitutively active Wnt5a-Ror2 signaling in osteosarcoma cell lines plays crucial roles in induced expression of matrix metalloproteinase-13 (MMP-13), required for their invasiveness; however, it remains largely unclear about the molecular basis of MMP-13 gene induction by Wnt5a-Ror2 signaling. Here we show by reporter assay that the activator protein 1 (AP1) (binding site in the promoter region of MMP-13 gene is primarily responsible for its transcriptional activation by Wnt5a-Ror2 signaling in osteosarcoma cell lines SaOS-2 and U2OS. Chromatin immunoprecipitation assays revealed that c-Jun and ATF2 are crucial transcription factors recruited to the AP1-binding site in the MMP-13 gene promoter during Wnt5a-Ror2 signaling in SaOS-2 cells. Using siRNA-mediated suppression or specific inhibitors, we also show that Dishevelled2 (Dvl2) and c-Jun N-terminal kinase are required for MMP-13 gene induction presumably via phosphorylation of c-Jun and ATF2 during Wnt5a-Ror2 signaling in SaOS-2 cells. Interestingly, Dvl2 and Rac1, but not Dvl3, are required for MMP-13 expression in SaOS-2 cells, whereas Dvl3, but not Dvl2 and Rac1, is required for its expression in U2OS cells, indicating the presence of distinct intracellular signaling machineries leading to expression of the same gene, in this case MMP-13 gene in different osteosarcoma cell lines. Moreover, we provide evidence suggesting that Wnt5a-Ror2 signaling might also be required for expression of MMP-13 gene during the development of the cartilaginous tissue.