Abstract 6439: ROME, a novel membrane protein in vertebrates, is a key modulator of embryonal development and cancer metastasis

Despite many advances in cancer treatment, metastasis remains the major cause of mortality: over 90% of cancer-related deaths are due to metastasis. We chose Ewing sarcoma (ES) as a model to study cancer metastasis since less than 25% of ES patients with metastatic disease live beyond five years and there are no effective therapies available to specifically target metastatic disease. Through an in vivo genome-wide CRISPR/Cas9 transcriptional activation screen using human ES cells as xenografts, we identified the human INAFM2 gene as a strong driver of metastasis and therefore named the vertebrate gene and its protein product, ROME (Regulator of Metastasis). Up until now, INAFM2 has not been studied in-depth and INAFM2 protein expression profile or function is not known. We characterized aspects of ROME expression and function in vertebrate development, physiology, and pathology. Blocking ROME expression in zebrafish embryos resulted in severe developmental defects and early mortality. Single cell RNA sequencing of zebrafish embryos with rome knockdown and RNA sequencing of cancer cell lines with ROME modulation revealed that ROME negatively regulates calcium and canonical Wnt pathways. We also discovered that ROME directly interacts with CAV1, FLOT1, and Vimentin proteins. ROME overexpression increased metastasis of ES xenografts in zebrafish and immunodeficient mice while ROME knockout in ES xenografts reduced metastasis. Human tumor RNA sequencing data revealed a negative correlation between ROME expression and patient survival. In summary, we discovered a previously unstudied human glycoprotein located on the plasma membrane that can regulate cell motility and invasion, is essential for normal development in vertebrates, and increases the metastatic phenotype of human tumor cells. Citation Format: Anna Molotkova, Emre Deniz, Matthew Swift, Eric Glasgow, Jeffrey Toretsky, Aykut Üren. ROME, a novel membrane protein in vertebrates, is a key modulator of embryonal development and cancer metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 6439.