Abstract A031: The role of nuclear epidermal growth factor receptor in cell migration and wound healing

Abstract

Abstract In breast cancer cells, epidermal growth factor receptor (EGFR) can retrotranslocate to the nucleus where it acts as a transcription cofactor and activates pro-oncogenic pathways such as stemness and migration. This retrotranslocation can occur through interaction with the BAR domain-containing protein Sorting Nexin 1 (SNX1). Upon retrotranslocation, EGFR is removed from the membrane via the Sec61 translocon, where the now soluble EGFR can interact with heat shock proteins and nuclear importins via its conserved nuclear localization sequence (NLS). Presence of the NLS in all wildtype EGFR indicates nuclear EGFR (nEGFR) also plays a role in non-cancerous tissue. EGFR is a known contributor to wound-healing, migration, and mammary gland development but the role of nEGFR in these processes has yet to be elucidated. Our lab has created cSNX1.3, a peptide-based therapeutic that recapitulates the BAR domain of Sorting Nexin 1. CSNX1.3 competitively binds to EGFR to prevent nuclear trafficking, and this treatment is effective at killing cancer cells that express EGFR, while leaving non-cancerous cells alive. In addition, cSNX1.3 is a potent inhibitor of EGF-dependent cell migration in Triple Negative Breast Cancer cell lines. Based on this data, we hypothesize that, in response to a wound, nEGFR activates cell migration pathways to promote wound healing. To better understand the role of nEGFR in wound healing and migration of non-cancer cell types, we have utilized CRISPR/Cas9 to insert mScarlet or mVenus, improved fluorescent proteins, onto the C-terminus of endogenous EGFR in immortalized MCF10A cells. Using a live cell imaging platform, we discovered that cells on the leading edge of a wound have increased levels of nEGFR. Furthermore, treatment with cSNX1.3 inhibits the migration of MCF10As and reduces levels of nEGFR. This data implies a role for nEGFR in the migration of MCF10As during wound healing. Future studies will delve deeper into the triggers of EGFR retrotranslocation to the nucleus and investigate the specific proteins nEGFR interacts with to affect cell migration. By elucidating the intrinsic role of nuclear EGFR in non-cancerous tissue types, we can better understand how cancer takes advantage of these molecular pathways and possibly its role in the cell migration essential to metastatic progression. Citation Format: Danielle M DiFranco, Joyce Schroeder. The role of nuclear epidermal growth factor receptor in cell migration and wound healing [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Breast Cancer Research; 2023 Oct 19-22; San Diego, California. Philadelphia (PA): AACR; Cancer Res 2024;84(3 Suppl_1):Abstract nr A031.