Panoply™ Human FGFR2 Knockdown Stable Cell Line

In recent years, fibroblast growth factor receptor 2 (FGFR2), as an important mediator of paracrine and autocrine signaling, has been extensively studied in breast morphogenesis and breast cancer. Here, researchers investigated the behavior of a non-tumor model of FGFR2-dependent breast epithelial cells. In vitro analysis showed that FGFR2 regulates communication between epithelial cells and extracellular matrix (ECM) proteins. Silencing of FGFR2 significantly altered the phenotype of cell colonies in three-dimensional culture, reduced protein levels of integrins α2, α5, and β1, and affected integrin-driven processes such as cell adhesion and migration. Further analysis revealed that FGFR2 knockdown induces proteasomal degradation of integrin β1. RNA-seq database analysis showed significantly reduced levels of FGFR2 and ITGB1 mRNA in breast tumor samples compared to non-transformed tissues. Furthermore, gene expression profiles related to FGFR2 and integrin signaling pathways, cell adhesion/migration, and extracellular matrix (ECM) remodeling were also disrupted in high-risk healthy individuals. These findings strongly suggest that the loss of FGFR2 and the associated degradation of integrin β1 are the cause of dysregulation of epithelial cell-ECM interactions, and that this process may play an important role in the initiation of mammary gland epithelial tumorigenesis.

To investigate the functional role of FGFR2 in integrin-dependent processes, researchers conducted adhesion and migration experiments on HB2 and FGFR2 knockdown HB2 cells. Adhesion experiments showed that, compared to wild-type cells, FGFR2 knockdown HB2 cells exhibited a significant reduction in adherent cells, with similar reductions in type I collagen and fibronectin (44% and 46%, respectively), while adhesion to the Matrigel matrix showed a more significant difference (76% lower than wild-type cells) (Figure 1a). Furthermore, to analyze cell adhesion to these matrices in more detail, cell spreading experiments were performed. Quantitative analysis of cell area after 90 minutes of adhesion revealed similar reductions in spreading area on type I collagen and the Matrigel matrix (31% and 32%, respectively), while spreading ability on fibronectin was significantly reduced (53% reduction per cell) (Figure 1b). Interestingly, knockdown of FGFR2 in HB2 cells not only affected cell spreading itself but also the formation of cell processes and the organization of the actin cytoskeleton (Figure 1c). Furthermore, transwell cell migration assay revealed significantly decreased migratory abilities of FGFR2 knockdown HB2 cells towards all tested substrates in a pattern similar to that observed in adhesion assay (Figure 1d-e). These results confirm a functional link between FGFR2 and integrin-dependent mammary epithelial cell behavior.

Figure 1. FGFR2 regulates HB2 cell adhesion and migration towards specific ECM proteins. (Mieczkowski K, et al., 2023)