Fibronectin induces epithelial-mesenchymal transition in human breast cancer MCF-7 cells via activation of calpain

Abstract

Abstract. Fibronectin (FN) is a primary component of the mammary mesenchymal compartment and undergoes dramatic changes during breast cancer development. Increased FN expression is associated with an invasive and metastatic breast cancer phenotype. The present study demonstrated that FN causes an epithelial-mesenchymal transition (EMT)-like morphological change in MCF-7 breast cancer cells. FN stimulation caused the downregulation of epithelial markers E-cadherin and tight junction protein ZO-1, and the upregulation of mesenchymal markers N-cadherin and vimentin. Additionally, FN promoted cell migration and invasion in MCF-7 cells, with increased expression of calpain-2 and proteolysis of focal adhesion kinase 1 (FAK), indicating calpain activation. Notably, the FN induced changes in morphology and EMT markers were reversed with the treatment of calpain-specific inhibitors, calpain inhibitor I (N-acetyl-L-leucyl-L-leucyl-L-norleucinal), calpeptin and calpain inhibitor IV. Meanwhile, the effects of FN on cell migration and invasion, as well as FAK proteolysis were markedly suppressed by calpain inhibitors. Taken together, the results of the present study indicate that calpain plays an essential role in FN-induced EMT response, and that targeting calpain signaling may be a potential strategy to reduce breast cancer metastasis.

Pharmacological Inhibition of CA-IX Impairs Tumor Cell Proliferation, Migration and Invasiveness

“…According to the increased E-Cadherin level, a decrease of Vimentin expression, the mesenchymal marker, is measured in both tumor cells lines, especially in MDA-MB-231. Fibronectin, a mesenchymal component of mammary tissues, is reported to cause the downregulation of E-Cadherin and the EMT process in breast cancer development [38,39]. However, in our experiments we did not observe a statistical significative reduction of mesenchymal marker Fibronectin.…”

Integrin α6and EGFR Signaling Converge at Mechanosensitive Calpain 2

“…Together, these data suggest that EGFR phosphorylation could be a stronger activator of calpain 2 than stiffness. Previous work has shown that calpain 2 has a significant correlation with an epithelial-to-mesenchymal transition [76] and lymphatic or vascular invasion, where patients with basal-like tumors and high calpain 2 expression had a significantly worse prognosis [77].…”

Quantitative trait loci mapped for TCF21 binding, chromatin accessibility and chromosomal looping in coronary artery smooth muscle cells reveal molecular mechanisms of coronary disease loci

“…These genes, ARNTL, CCBE1, CDH13, EMP1 and FN1 have been reported as CADassociated, or related to vascular development or function [2,18,28]. In addition, they are involved in epithelial-mesenchymal transition (EMT) processes, which are prominent in vascular disease [29][30][31][32]. We validated the QTLs in CDH13 and FN1 loci with multiple approaches.…”