Overexpression of MTA1 inhibits the metastatic ability of ZR-75-30 cells in vitro by promoting MTA2 degradation
Overexpression of MTA1 inhibits the metastatic ability of ZR-75-30 cells in vitro by promoting MTA2 degradation
复制标题
MTA1过表达通过促进MTA2降解抑制ZR-75-30细胞的体外转移能力
DOI：
10.1186/s12964-019-0318-6
复制
发表时间：
2019-01-14
影响因子：
8.4
通讯作者：
Hu，Weiguo
中科院分区：
文献类型：
--
作者：
Zhang，Long;Wang，Qi;Hu，Weiguo
研究背景作为转移相关蛋白（MTA）家族的第一个成员，MTA 1和MTA家族的另一个成员MTA 2均被报道促进乳腺癌的进展和转移。方法采用Transwell法研究MTA 1和MTA 2在ZR-75-30 luminal B乳腺癌细胞体外转移中的作用。使用免疫印迹和qRT-PCR来评估MTA 1过表达对MTA 2的影响。使用在线网络服务器预测切割MTA 2的蛋白酶。中性粒细胞弹性蛋白酶（NE）在MTA 1过表达诱导的MTA 2下调中的作用通过特异性抑制剂处理、敲低、过表达和免疫细胞化学证实，MTA 2中的NE切割位点通过MTA 2截短和突变证实。结果MTA 1过表达可抑制ZR-75-30细胞的体外转移，而MTA 2过表达可促进ZR-75-30细胞的体外转移。MTA 1过表达下调MTA 2的表达在蛋白水平，而不是mRNA水平。预计NE切割MTA 2，并负责MTA 1过表达诱导的MTA 2降解。发现NE在486、497、542、583和621位点的C-末端切割MTA 2。结论MTA 1和MTA 2在ZR-75-30 luminal B乳腺癌细胞的体外转移过程中起相反的作用。MTA 1通过表观遗传学抑制弹力蛋白的表达并释放对中性粒细胞弹性蛋白酶的抑制而在蛋白质水平下调MTA 2，中性粒细胞弹性蛋白酶在多个特异性位点切割MTA 2的C末端。
BackgroundAs the first member of the metastasis-associated protein (MTA) family, MTA1 and another MTA family member, MTA2, have both been reported to promote breast cancer progression and metastasis. However, the difference and relationship between MTA1 and MTA2 have not been fully elucidated.MethodsTranswell assays were used to assess the roles of MTA1 and MTA2 in the metastasis of ZR-75-30 luminal B breast cancer cells in vitro. Immunoblotting and qRT-PCR were used to evaluate the effect of MTA1 overexpression on MTA2. Proteases that cleave MTA2 were predicted using an online web server. The role of neutrophil elastase (NE) in MTA1 overexpression-induced MTA2 downregulation was confirmed by specific inhibitor treatment, knockdown, overexpression and immunocytochemistry, and NE cleavage sites in MTA2 were confirmed by MTA2 truncation and mutation. The effect of MTA1 overexpression on the intrinsic inhibitor of NE, elafin, was detected by qRT-PCR, immunoblotting and treatment with inhibitors.ResultsMTA1 overexpression inhibited, while MTA2 promoted the metastasis of ZR-75-30 cells in vitro. MTA1 overexpression downregulated MTA2 expression at the protein level rather than the mRNA level. NE was predicted to cleave MTA2 and was responsible for MTA1 overexpression-induced MTA2 degradation. NE was found to cleave MTA2 in the C-terminus at the 486, 497, 542, 583 and 621 sites. MTA1 overexpression activated NE by downregulating elafin in a histone deacetylase- and DNA methyltransferase-dependent manner.ConclusionsMTA1 and MTA2 play opposing roles in the metastasis of ZR-75-30 luminal B breast cancer cells in vitro. MTA1 downregulates MTA2 at the protein level by epigenetically repressing the expression of elafin and releasing the inhibition of neutrophil elastase, which cleaves MTA2 in the C-terminus at multiple specific sites.