Silymarin is the standardized extract from the fruits of Silybum marianum (L.) Gaertn., a well-known hepatoprotectant and antioxidant. Recently, bioactive compounds of silymarin, i.e., silybins and their 2,3-dehydro derivatives, have been shown to exert anticancer activities, yet with unclear mechanisms. This study combines in silico and in vitro methods to reveal the potential interactions of optically pure silybins and dehydrosilybins with novel protein targets. The shape and chemical similarity with approved drugs were evaluated in silico, and the potential for interaction with the Hedgehog pathway receptor Smoothened (SMO) and BRAF kinase was confirmed by molecular docking. In vitro studies on SMO and BRAF V600E kinase activity and in BRAF V600E A-375 human melanoma cell lines were further performed to examine their effects on these proteins and cancer cell lines and to corroborate computational predictions. Our in silico results direct to new potential targets of silymarin constituents as dual inhibitors of BRAF and SMO, two major targets in anticancer therapy. The experimental studies confirm that BRAF kinase and SMO may be involved in mechanisms of anticancer activities, demonstrating dose-dependent profiles, with dehydrosilybins showing stronger effects than silybins. The results of this work outline the dual SMO/BRAF effect of flavonolignans from Silybum marianum with potential clinical significance. Our approach can be applied to other natural products to reveal their potential targets and mechanism of action.

• Klíčová slova
• BRAF kinase, Smoothened, cytotoxicity, in silico methods, silybins,
• Publikační typ
• časopisecké články MeSH

Vertebrate primary cilium is a Hedgehog signaling center but the extent of its involvement in other signaling systems is less well understood. This report delineates a mechanism by which fibroblast growth factor (FGF) controls primary cilia. Employing proteomic approaches to characterize proteins associated with the FGF-receptor, FGFR3, we identified the serine/threonine kinase intestinal cell kinase (ICK) as an FGFR interactor. ICK is involved in ciliogenesis and participates in control of ciliary length. FGF signaling partially abolished ICK's kinase activity, through FGFR-mediated ICK phosphorylation at conserved residue Tyr15, which interfered with optimal ATP binding. Activation of the FGF signaling pathway affected both primary cilia length and function in a manner consistent with cilia effects caused by inhibition of ICK activity. Moreover, knockdown and knockout of ICK rescued the FGF-mediated effect on cilia. We provide conclusive evidence that FGF signaling controls cilia via interaction with ICK.

• Klíčová slova
• FGFR, ICK, cilia length, fibroblast growth factor, intestinal cell kinase,
• MeSH
• buňky NIH 3T3 MeSH
• cilie metabolismus   MeSH
• CRISPR-Cas systémy MeSH
• fibroblastové růstové faktory metabolismus   MeSH
• fosforylace MeSH
• HEK293 buňky MeSH
• interakční proteinové domény a motivy MeSH
• lidé MeSH
• modely u zvířat MeSH
• myši knockoutované MeSH
• myši MeSH
• protein-serin-threoninkinasy genetika   metabolismus   MeSH
• proteiny hedgehog metabolismus   MeSH
• proteomika MeSH
• receptor fibroblastových růstových faktorů, typ 1 metabolismus   MeSH
• receptor fibroblastových růstových faktorů, typ 3 genetika   metabolismus   MeSH
• receptor fibroblastových růstových faktorů, typ 4 metabolismus   MeSH
• receptory fibroblastových růstových faktorů genetika   metabolismus   MeSH
• signální transdukce MeSH
• simulace molekulového dockingu MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• CILK1 protein, human MeSH Prohlížeč
• Cilk1 protein, mouse MeSH Prohlížeč
• FGFR1 protein, human MeSH Prohlížeč
• FGFR3 protein, human MeSH Prohlížeč
• FGFR4 protein, human MeSH Prohlížeč
• fibroblastové růstové faktory MeSH
• protein-serin-threoninkinasy MeSH
• proteiny hedgehog MeSH
• receptor fibroblastových růstových faktorů, typ 1 MeSH
• receptor fibroblastových růstových faktorů, typ 3 MeSH
• receptor fibroblastových růstových faktorů, typ 4 MeSH
• receptory fibroblastových růstových faktorů MeSH