Development, Functional Characterization, and Matrix Effectors Dynamics in 3D Spheroids of Triple-Negative Breast Cancer Cells

Breast cancer (BC) remains a leading cause of cancer-related mortality in women. Extracellular matrix (ECM) remodeling is a critical modulator of tumor invasion and metastasis. Three-dimensional (3D) cell culture models have been proposed as advanced systems better mimicking the tumor microenvironment (TME), potentially offering enhanced insights into underlying mechanisms compared to conventional two-dimensional (2D) cultures. This study highlights how BC cells develop metastatic potential and tumor progression independently from ECM contact using advanced 3D spheroid culture models compared to traditional 2D cultures in triple-negative breast cancer (TNBC) cell lines. Spheroids were formed using ultra-low adhesion plates, and their morphological and functional properties were assessed via phase-contrast and scanning electron microscopy (SEM), along with functional assays. Both cell lines formed compact spheroids exhibiting mesenchymal-to-epithelial transition (MET) characteristics. Functional assays showed enhanced cell migration and dissemination of spheroid-derived cancer cells. Gene expression profiling revealed increased expression of ECM remodeling enzymes, cell surface receptors, and adhesion molecules in 3D cultures compared to 2D. MicroRNA analysis highlighted distinct regulatory patterns specifically associated with metastasis and epithelial-to-mesenchymal transition (EMT). These findings demonstrate that 3D spheroid models effectively recapitulate the complexity of TNBC, providing valuable insights into ECM dynamics, epigenetic regulation, and metastatic behavior and potentially guiding improved therapeutic strategies.