Disruption of SND1–MTDH Interaction by a High Affinity Peptide Results in SND1 Degradation and Cytotoxicity to Breast Cancer Cells <i>In Vitro</i> and <i>In Vivo</i>

Abstract Staphylococcal nuclease domain-containing protein 1 (SND1) is a multifunctional oncoprotein overexpressed in breast cancer. Binding of metadherin (MTDH) to SND1 results the stabilization and important initiation progression Disruption such interaction potential therapeutic for SN1/2 domain was used as bait phage display screening identify 12-amino acid peptide 4-2. The activity 4-2 evaluated by ELISA, coimmunoprecipitation, MTS, Western blot analysis, xenograft mouse model. Peptide could disrupt SND1–MTDH interaction. Cell penetrating derivative 4–2 (CPP-4–2) penetrate kill cancer cells disrupting degrading SND1. Tryptophan 10 (W10) essential mediating cytotoxicity, interaction, disruption, degradation. CPP-4-2 inhibit growth SND1-interacting both vitro vivo interacting with SND1, inducing W10 an amino