The role of FGF-2/HGF and fibronectin matrix on pleomorphic adenoma myoepithelial cell morphology and immunophenotype: an in vitro study

Fibronectin Mediates Endothelial-to-Mesenchymal Transition in Retina Angiogenesis

Purpose

The purpose of this study was to investigate the role of endothelial-mesenchymal transition (EndoMT) in pathological retinal angiogenesis and identify key molecular mediators in retina angiogenesis.

Methods

RNA sequencing (RNA-seq) was performed on retinal tissue from an oxygen-induced retinopathy (OIR) mouse model to analyze gene expression patterns. The Gene Set Enrichment Analysis was used to examine the correlation between epithelial-mesenchymal transition (EMT) and angiogenesis gene sets. Fibronectin (FN1) expression was evaluated in endothelial cells, and its function was assessed through siRNA-mediated knockdown in both in vitro angiogenesis assays and the OIR model.

Results

EndoMT occurred early in retinal angiogenesis development, with significant correlation between EMT and angiogenesis gene sets. FN1 was identified as the most significantly upregulated EMT-related gene in endothelial cells. The siRNA-mediated inhibition of fibronectin effectively prevented VEGF-induced angiogenesis in vitro and reduced pathological angiogenesis in the OIR model.

Conclusions

EndoMT is a crucial early event in pathological retinal angiogenesis, with fibronectin serving as a key mediator. Targeting fibronectin may provide a novel therapeutic strategy that could synergize with anti-VEGF treatments to more effectively treat pathological angiogenesis in diabetic retinopathy (DR) and retinopathy of prematurity (ROP), particularly in cases of poor response to anti-VEGF therapy alone.

Two sides of the same coin: Insights into the myoepithelial cells in carcinoma ex pleomorphic adenoma development

The myoepithelial cell seems to play an important role as a tumor suppressor in the development of carcinoma ex pleomorphic adenoma. Nevertheless, interesting aspects concerning the other side of the coin, i.e., the contribution of the myoepithelial cell to cell proliferation, were brought to light. Here we highlighted the studies in which myoepithelial cells were presented as tumor suppressors and promoters in the context of PA malignant transformation. In conclusion, even if in a paracrine way, divergent signals can alter the suppressor role of the myoepithelial cell and induce it to compose a microenvironment propitious to the tumor progression of the malignant cells. This would cause myoepithelial cells to succumb and malignant epithelial cells to initiate progression beyond the basal membrane.