Eparanasi come regolatore della transazione epitelio-mesenchimale nel cancro al seno

In the last decades the breast cancer (BC) arising as one of the most prevalent tumors in the world among women, according to the World Health Organization (WHO). Noteworthy, BC patients do not die for the primary tumor mass per se, but for the widespread metastasis. A well-described cellular plasticity mechanism, the Epithelial to Mesenchymal Transition (EMT), is correlated with cancer progression and metastatic dissemination. Epithelial cells gradually lose their epithelial phenotype acquiring migration and invasion characteristics related to mesenchymal behaviour. Recent study pointed out that heparanase (HPSE), the only endo-β-glycosidase in mammals, is overexpressed not only in BC, but also in all the solid tumors in human. Its enzymatic activity promotes the cleavage of Heparan Sulfate (HS) chains, actively participates in the remodelling of extracellular matrix (ECM) as well as allows the release of many HS-linked pro-tumoral molecules, such as TGF-β, bFGF, VEGF. These molecules induce a reciprocal crosstalk between cancer cells and the surrounded environment promoting inflammation and angiogenesis that sustain tumor growth and progression. First, we characterize two breast cancer cell lines, MCF-7 and MDA-MB-231, notably for their different metastatic potential. We analysed the expression of fibronectin (FN) and vimentin (VIM) as mesenchymal- and E-Cadherin (E-CAD) as epithelial-marker. The differential expression of EMT markers confirming the cell phenotypes but particularly that the MDA-MB-231 showed a two-fold increase of HPSE expression. In addition, the MCF-7 showed more E-Cad compare to MDA-MB-231, that on the other hand, express higher FN, VIM and especially HPSE. Moreover, the two cell lines response in a different way at the treatment with FGF-2 and TGF-β, two well-known EMT activator. Gene and protein expression analyses of EMT-associated markers confirm that FGF-2 or TGF-β treatment were able to increase the expression of Vim, FN and EMT-associated transcription factors Snail and Slug, while E-Cad expression was reduced. HPSE inhibition with SST0001, a specific HPSE inhibitor, alone or in combination with the two EMT inducer, was able to interfere with the impairing of the EMT markers. In addition, HPSE overexpression was able to increase the EMT marker in gene and protein expression in the case of MCF-7 cell line, but not in MDA-MB-231. The enzymatic inhibition with SST0001 simulate the same slight reduction compared to the basal condition. Therefore, the downregulation of HPSE and the enzymatic inhibition upon the MDA-MB-231 seems to not affect the EMT markers expression both in gene and protein expression. Moreover, cell migration is higher in MCF-7 overexpressing cells compare to the control, while MDA-MB-231 showed no significant change in overexpressing or silenced cell lines. SST0001 was able to reduce the cell migration just at the basal level but also in overexpressing HPSE cell types. The current literature highlights that HPSE can be involved in EMT regulation, both in tumor and non-tumor models, influencing different cellular pathways. Due the correlation with HPSE levels and EMT process, this enzyme could be an important regulatory factor for BC progression and metastases.