The proline-specific serine protease fibroblast activation protein (FAP) can participate in the progression of malignant tumors and represents a potential diagnostic and therapeutic target. Recently, we demonstrated an increased expression of FAP in glioblastomas, particularly those of the mesenchymal subtype. Factors controlling FAP expression in glioblastomas are unknown, but evidence suggests that transforming growth factor beta (TGFbeta) can trigger mesenchymal changes in these tumors. Here, we investigated whether TGFbeta promotes FAP expression in transformed and stromal cells constituting the glioblastoma microenvironment. We found that both FAP and TGFbeta-1 are upregulated in glioblastomas and display a significant positive correlation. We detected TGFbeta-1 immunopositivity broadly in glioblastoma tissues, including tumor parenchyma regions in the immediate vicinity of FAP-immunopositive perivascular stromal cells. Wedemonstrate for the first time that TGFbeta-1 induces expression of FAP in non-stem glioma cells, pericytes, and glioblastoma-derived endothelial and FAP+ mesenchymal cells, but not in glioma stem-like cells. In glioma cells, this effect is mediated by the TGFbeta type I receptor and canonical Smad signaling and involves activation of FAP gene transcription. We further present evidence of FAP regulation by TGFbeta-1 secreted by glioma cells. Our results provide insight into the previously unrecognized regulation of FAP expression by autocrine and paracrine TGFbeta-1 signaling in a broad spectrum of cell types present in the glioblastoma microenvironment.

• Klíčová slova
• Smad2, fibroblast activation protein, glioblastoma, regulation of expression, seprase, signaling, transforming growth factor beta, tumor microenvironment,
• MeSH
• endopeptidasy genetika   metabolismus   MeSH
• fluorescenční protilátková technika MeSH
• fosforylace MeSH
• glioblastom etiologie   metabolismus   patologie   MeSH
• imunohistochemie MeSH
• kultivované buňky MeSH
• lidé MeSH
• membránové proteiny genetika   metabolismus   MeSH
• nádorové buněčné linie MeSH
• nádorové mikroprostředí účinky léků   genetika   MeSH
• regulace genové exprese u nádorů * účinky léků   MeSH
• transformující růstový faktor beta1 metabolismus   farmakologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• endopeptidasy MeSH
• fibroblast activation protein alpha MeSH Prohlížeč
• membránové proteiny MeSH
• TGFB1 protein, human MeSH Prohlížeč
• transformující růstový faktor beta1 MeSH