Genetic Ablation and Multi-Omics Profiling Reveal CEP55 as a Key Driver of Tumorigenesis in Diverse Cancer Models

Background – CEP55 is a centrosomal protein with emerging oncogenic roles. It is overexpressed in many cancers, where it drives genomic instability, phenocopies PTEN loss and hyperactivates the PI3K/AKT pathway, thereby promoting aggressive and therapy-resistant tumors. Methods – We developed an inducible Cep55 knockout (KO) mouse model as well as generated primary, immortalized (SV40), and transformed (E1A/Ras) mouse embryonic fibroblasts (MEFs) for functional and proteomic assays. Tumorigenesis was studied using E1A/Ras MEF transplantation and a Pten- deficient genetically engineered mouse model (GEMM). Multi-omics apparatus including proteomics, and spatial transcriptomics, histopathology, immunobloting and functional assays were employed to elucidate underlying mechanisms. Findings were cross-validated using human cancer datasets. Results – Cep55 ablation remodeled the extracellular matrix (ECM), disrupted integrin and oncogenic signaling, reduced AKT/ERK activation, and induced stress pathways. Cep55 knockouts (KO) cells showed impaired proliferation, migration, invasion, and adhesion. In vivo , unlike the embryonic lethality observed in constitutive KOs, the inducible Cep55 deletion was well-tolerated in adult mice. Strikingly, tumors derived from Cep55 -null EIA/RAS-transformed MEFs exhibited delayed onset and progression. In the genetically engineered cancer-prone mouse model, Cep55 deletion on a Pten -deficient background led to a greater than seven-fold increase in median survival. Spatial transcriptomics on cancerous tissues revealed that CEP55 regulates ECM remodeling, integrin expression, trafficking, and cell adhesion, supporting its critical role in tumor progression to metastasis. Conclusion – CEP55 is dispensable for adult homeostasis but essential for tumorigenesis, especially with PTEN loss. Its deletion suppresses transformation, delays tumor growth, and prolongs survival, supporting CEP55 as a therapeutic target in PTEN-deficient cancers.