RKIP Inhibits Local Breast Cancer Invasion by Antagonizing the Transcriptional Activation of MMP13.
RKIP Inhibits Local Breast Cancer Invasion by Antagonizing the Transcriptional Activation of MMP13.
复制标题
DOI：
10.1371/journal.pone.0134494
复制
发表时间：
2015
期刊：
影响因子：
3.7
通讯作者：
Yeung KC
中科院分区：
文献类型：
--
作者：
Datar I;Feng J;Qiu X;Lewandowski J;Yeung M;Ren G;Aras S;Al-Mulla F;Cui H;Trumbly R;Arudra SK;De Las Casas LE;de la Serna I;Bitar MS;Yeung KC
Raf激酶抑制蛋白或RKIP最初使用酵母双杂交筛选鉴定为Raf-1结合蛋白。RKIP通过竞争性抑制MEK与Raf-1的结合来抑制Raf-1对MEK的活化磷酸化，从而对Raf-MEK-Erk途径发挥抑制作用。RKIP已被鉴定为转移抑制基因。RKIP在癌转移灶中的表达较低。虽然原发性肿瘤生长保持不受影响，但RKIP的再表达抑制癌症转移。在机制上，RKIP通过抑制血管生成、局部侵袭、内渗和定殖来限制转移。RKIP如何抑制这些单个步骤的分子机制仍不清楚。在本研究中，使用基于无偏PCR的筛选和通过分析DNA微阵列表达数据集，我们观察到多种金属蛋白酶（MMPs）包括MMP 1、MMP 3、MMP 10和MMP 13的表达与乳腺癌细胞系和临床样品中的RKIP表达呈负相关。由于癌细胞表达MMPs对癌转移很重要，我们推测RKIP可能通过抑制多种MMPs介导乳腺癌转移的抑制。我们发现RKIP和MMPs的表达特征比单个基因更能预测高转移风险。使用功能丧失和获得方法的组合，我们发现MMP 13是RKIP介导的局部癌症侵袭抑制的原因。有趣的是，MMP 13的单独表达不足以逆转由于RKIP的表达而导致的乳腺癌细胞向肺转移的抑制。我们发现RKIP通过Erk 2信号通路负调控MMP 13，并且RKIP对MMP 13的抑制不依赖于转录因子AP-1。总之，我们的研究结果表明，RKIP抑制癌细胞侵袭，部分是通过抑制MMP 13。这些数据还暗示RKIP参与MMP转录的调节，表明RKIP抑制肿瘤进展和转移的潜在机制。
Raf Kinase Inhibitory Protein or RKIP was initially identified as a Raf-1 binding protein using the yeast 2-hybrid screen. RKIP inhibits the activation phosphorylation of MEK by Raf-1 by competitively inhibiting the binding of MEK to Raf-1 and thus exerting an inhibitory effect on the Raf-MEK-Erk pathway. RKIP has been identified as a metastasis suppressor gene. Expression of RKIP is low in cancer metastases. Although primary tumor growth remains unaffected, re- expression of RKIP inhibits cancer metastasis. Mechanistically, RKIP constrains metastasis by inhibiting angiogenesis, local invasion, intravasation, and colonization. The molecular mechanism of how RKIP inhibits these individual steps remains undefined. In our present study, using an unbiased PCR based screening and by analyzing DNA microarray expression datasets we observe that the expression of multiple metalloproteases (MMPs) including MMP1, MMP3, MMP10 and MMP13 are negatively correlated with RKIP expression in breast cancer cell lines and clinical samples. Since expression of MMPs by cancer cells is important for cancer metastasis, we hypothesize that RKIP may mediate suppression of breast cancer metastasis by inhibiting multiple MMPs. We show that the expression signature of RKIP and MMPs is better at predicting high metastatic risk than the individual gene. Using a combination of loss- and gain-of-function approaches, we find that MMP13 is the cause of RKIP-mediated inhibition of local cancer invasion. Interestingly expression of MMP13 alone is not sufficient to reverse the inhibition of breast cancer cell metastasis to the lung due to the expression of RKIP. We find that RKIP negatively regulates MMP13 through the Erk2 signaling pathway and the repression of MMP13 by RKIP is transcription factor AP-1 independent. Together, our findings indicate that RKIP inhibits cancer cell invasion, in part, via MMP13 inhibition. These data also implicate RKIP in the regulation of MMP transcription, suggesting a potential mechanism by which RKIP inhibits tumor progression and metastasis.