Institute of Biostructures and Bioimaging (IBB), CNR, via Mezzocannone 16, 80134, Naples, Italy.
Department of Pharmacy, Research Centre on Bioactive Peptides (CIRPeB), University of Naples "Federico II", Via Mezzocannone 16, 80134, Naples, Italy.
Sci Rep. 2017 Dec 12;7(1):17474. doi: 10.1038/s41598-017-17684-5.
The lipid phosphatase Ship2 represents a drug discovery target for the treatment of different diseases, including cancer. Its C-terminal sterile alpha motif domain (Ship2-Sam) associates with the Sam domain from the EphA2 receptor (EphA2-Sam). This interaction is expected to mainly induce pro-oncogenic effects in cells therefore, inhibition of the Ship2-Sam/EphA2-Sam complex may represent an innovative route to discover anti-cancer therapeutics. In the present work, we designed and analyzed several peptide sequences encompassing the interaction interface of EphA2-Sam for Ship2-Sam. Peptide conformational analyses and interaction assays with Ship2-Sam conducted through diverse techniques (CD, NMR, SPR and MST), identified a positively charged penta-amino acid native motif in EphA2-Sam, that once repeated three times in tandem, binds Ship2-Sam. NMR experiments show that the peptide targets the negatively charged binding site of Ship2-Sam for EphA2-Sam. Preliminary in vitro cell-based assays indicate that -at 50 µM concentration- it induces necrosis of PC-3 prostate cancer cells with more cytotoxic effect on cancer cells than on normal dermal fibroblasts. This work represents a pioneering study that opens further opportunities for the development of inhibitors of the Ship2-Sam/EphA2-Sam complex for therapeutic applications.
脂质磷酸酶 Ship2 是一种药物发现靶点，可用于治疗多种疾病，包括癌症。它的 C 端无菌α基序结构域（Ship2-Sam）与 EphA2 受体的 Sam 结构域（EphA2-Sam）结合。这种相互作用预计主要会在细胞中诱导致癌作用，因此，抑制 Ship2-Sam/EphA2-Sam 复合物可能代表发现抗癌治疗药物的一种创新途径。在本工作中，我们设计并分析了几个包含 EphA2-Sam 与 Ship2-Sam 相互作用界面的肽序列。通过多种技术（CD、NMR、SPR 和 MST）进行的肽构象分析和与 Ship2-Sam 的相互作用实验，确定了 EphA2-Sam 中的一个带正电荷的五肽基序，该基序重复三次串联，与 Ship2-Sam 结合。NMR 实验表明，该肽靶向 EphA2-Sam 中 Ship2-Sam 的带负电荷的结合位点。初步的基于细胞的体外测定表明，在 50μM 浓度下，它诱导 PC-3 前列腺癌细胞坏死，对癌细胞的细胞毒性作用比对正常真皮成纤维细胞更强。这项工作是一项开拓性的研究，为开发 Ship2-Sam/EphA2-Sam 复合物抑制剂用于治疗应用开辟了更多机会。
