Department of Gynaecology and Obstetrics, Zhongnan Hospital of Wuhan University, Wuhan, 430071, Hubei, China.
Department of Cardiothoracic vascular surgery, Zhongnan Hospital of Wuhan University, Wuhan, 430071, Hubei, China.
BMC Cancer. 2019 Sep 5;19(1):878. doi: 10.1186/s12885-019-6087-1.
We aimed to develop inhibitory short peptides that can prevent protein interactions of SOS1/EPS8/ABI1 tri-complex, a key component essential for ovarian cancer metastasis.
Plasmids containing various regions of HA-tagged ABI1 were co-transfected into ovarian cancer cells with Flag-tagged SOS1 or Myc-tagged EPS8. Co-immunoprecipitation and GST-pulldown assay were used to identify the regions of ABI1 responsible for SOS1 and EPS8 binding. Inhibitory short peptides of these binding regions were synthesized and modified with HIV-TAT sequence. The blocking effects of the peptides on ABI1-SOS1 or ABI1-EPS8 interactions in vitro and in vivo were determined by GST-pulldown assay. The capability of these short peptides in inhibiting invasion and metastasis of ovarian cancer cell was tested by Matrigel invasion assay and peritoneal metastatic colonization assay.
The formation of endogenous SOS1/EPS8/ABI1 tri-complex was detected in the event of LPA-induced ovarian cancer cell invasion. In the tri-complex, ABI1 acted as a scaffold protein holding together SOS1 and EPS8. The SH3 and poly-proline+PxxDY regions of ABI1 were responsible for SOS1 and EPS8 binding, respectively. Inhibitory short peptides p + p-8 (ppppppppvdyedee) and SH3-3 (ekvvaiydytkdkddelsfmegaii) could block ABI1-SOS1 and ABI1-EPS8 interaction in vitro. TAT-p + p-8 peptide could disrupt ABI1-EPS8 interaction and suppress the invasion and metastasis of ovarian cancer cells in vivo.
TAT-p + p-8 peptide could efficiently disrupt the ABI1-EPS8 interaction, tri-complex formation, and block the invasion and metastasis of ovarian cancer cells.
我们旨在开发抑制性短肽，以阻止 SOS1/EPS8/ABI1 三聚复合物的蛋白相互作用，该复合物是卵巢癌转移所必需的关键组成部分。
将含有 HA 标签的 ABI1 的各种区域的质粒与 Flag 标签的 SOS1 或 Myc 标签的 EPS8 共转染到卵巢癌细胞中。使用免疫共沉淀和 GST 下拉实验来鉴定负责 SOS1 和 EPS8 结合的 ABI1 区域。合成这些结合区域的抑制性短肽，并修饰 HIV-TAT 序列。通过 GST 下拉实验来确定这些肽在体外和体内对 ABI1-SOS1 或 ABI1-EPS8 相互作用的阻断作用。通过 Matrigel 侵袭实验和腹膜转移定植实验来测试这些短肽抑制卵巢癌细胞侵袭和转移的能力。
在 LPA 诱导的卵巢癌细胞侵袭过程中，检测到内源性 SOS1/EPS8/ABI1 三聚复合物的形成。在三聚复合物中，ABI1 作为一个支架蛋白，将 SOS1 和 EPS8 结合在一起。ABI1 的 SH3 和多脯氨酸+PxxDY 区域分别负责与 SOS1 和 EPS8 结合。抑制性短肽 p + p-8 (ppppppppvdyedee) 和 SH3-3 (ekvvaiydytkdkddelsfmegaii) 可以在体外阻断 ABI1-SOS1 和 ABI1-EPS8 的相互作用。TAT-p + p-8 肽可以破坏 ABI1-EPS8 相互作用，并抑制卵巢癌细胞的侵袭和转移。
TAT-p + p-8 肽可以有效地破坏 ABI1-EPS8 相互作用、三聚复合物的形成，并阻断卵巢癌细胞的侵袭和转移。
