Three-dimensional (3D) systems provide a suitable environment for cells cultured in vitro since they reproduce the physiological conditions that traditional cell culture supports lack. Electrospinning is a cost-effective technology useful to manufacture scaffolds with nanofibers that resemble the extracellular matrix that surround cells in the organism. Poly(lactic acid) (PLA) is a synthetic polymer suitable for biomedical applications. The main objective of this study is to evaluate electrospun (ES)-PLA scaffolds to be used for culturing cancer cells. Triple-negative breast cancer (TNBC) is the most aggressive breast cancer subtype with no validated targeted therapy and a high relapse rate. MDA-MB-231 TNBC cells were grown in scaffolds from two different PLA concentrations (12% and 15% w/v). The appropriateness of ES-PLA scaffolds was evaluated using a cell proliferation assay. EGFR and STAT3 gene expression and protein levels were compared in cells grown in 2D versus in 3D cultures. An increase in STAT3 activation was shown, which is related to self-renewal of cancer stem cells (CSCs). Therefore, the enrichment of the breast CSC (BCSC) population was tested using a mammosphere-forming assay and gene expression of BCSC-related stemness and epithelial-to-mesenchymal transition markers. Based on the results obtained, ES-PLA scaffolds are useful for 3D cultures in short culture periods with no BCSC-enrichment.
Keywords: EGFR; STAT3; breast cancer; poly(lactic acid); three-dimensional cell culture; triple-negative breast cancer.