Proteomic Analysis Reveals Cadherin, Actin, and Focal Adhesion Molecule-Mediated Formation of Cervical Cancer Spheroids

Cancer spheroids are spherical, three-dimensional (3D), in vitro assemblies of cancer cells, which are gaining importance as a useful model in cancer behavior studies. Designed to simulate key features of the in vivo tumor microenvironment, spheroids offer reliable insights for drug screening and testing applications. We observed contrasting phenotypes in 3D cervical cancer (CC) cultures. Thus, in this study, we compared the proteomes of 3D and traditional two-dimensional (2D) cultures of CC cell lines, HeLa, SiHa, and C33A. When cultured in in-house poly-(2-hydroxyethyl methacrylate)-coated plates under conditions suitable for 3D spheroid formation, these CC cell lines yielded spheroids exhibiting different features. Proteomic analysis of cells cultured in 2D and 3D cultures revealed similar protein profiles but remarkable differences in the expression levels of some proteins. In SiHa and C33A cells, the upregulation of key proteins required for spheroid formation was insufficient for the formation of compact spheroids. In contrast, HeLa cells could form compact spheroids because they upregulated the proteins, including cadherin-binding, cytoskeleton, and adhesion proteins, necessary for spheroid formation during the remodeling process. Overall, this study unravels the mechanisms underlying the formation of spheroids in the commonly used CC cell lines.