Proteomic landscapes of 3D and 2D models of High-Grade Serous Ovarian Carcinoma: Implications for Carboplatin Response

High-Grade Serous Ovarian Carcinoma (HGSOC) is is the most common form of ovarian cancer and finding new treatments remains an unmet need. While drug discovery is typically performed in two-dimensional (2D) monolayers, three-dimensional (3D) culture systems better mimic in vivo conditions. However, a comprehensive comparison of 3D vs 2D ovarian cancer models is lacking. Here, we quantitatively compared the whole cell proteomic signatures of 4 ovarian cell lines—PEO1, PEO4, UWB1.289, and UWB1.289+BRCA1— with different status of BRCA genes grown, in 2D and in 3D. Using isobaric labeling proteomics, we quantified 6,668 proteins and identified 412 significantly altered proteins between 2D and 3D. Proteins upregulated in 3D were enriched for transmembrane transport and oxidoreductase activity, while energy metabolism and cell growth pathways also showed dimensionality-dependent changes. Notably, membrane-associated proteins such as EGFR were downregulated in spheroids, particularly in PEO1 and PEO4. Furthermore, 3D culture modulated the response to carboplatin, with increased expression of drug resistance-associated proteins, including NDUF family members and ATP6V0A2, in all spheroid models. These findings underscore how culture dimensionality influences both the molecular landscape and chemotherapeutic response of HGSOC cells and highlight candidate targets for overcoming carboplatin resistance.