Lyn, a member of the Src family of kinases, is a key factor in the dysregulation of survival and apoptotic pathways of malignant B cells in chronic lymphocytic leukemia. One of the effects of Lyn's action is spatial and functional segregation of the tyrosine phosphatase SHP-1 into two pools, one beneath the plasma membrane in an active state promoting pro-survival signals, the other in the cytosol in an inhibited conformation and unable to counter the elevated level of cytosolic tyrosine phosphorylation. We herein show that SHP-1 activity can be elicited directly by nintedanib, an agent also known as a triple angiokinase inhibitor, circumventing the phospho-S591-dependent inhibition of the phosphatase, leading to the dephosphorylation of pro-apoptotic players such as procaspase-8 and serine/threonine phosphatase 2A, eventually triggering apoptosis.
View Article and Find Full Text PDFMalignant gliomas are aggressive and life-threatening tumours that still show a poor prognosis: the current therapeutic approach based on surgical resection and chemotherapy combined with radiotherapy does not provide a satisfactory chance of long-term survival to patients. Natural bioactive compounds represent a precious source of molecules with antiproliferative activity, potentially effective also against glioma cells. Among these, Juglone is a known allelopathic compound extracted from the eastern black walnut (Juglans nigra) whose antimitotic effect has been extensively described in mammalian cells.
View Article and Find Full Text PDFNatural (iso)flavonoids have been recently reported to inhibit cyclic nucleotide phosphodiesterases (PDEs) and induce vasorelaxation, albeit the results described in the literature are discordant. The cGMP-selective isoform PDE-5A, in particular, represents the target of sildenafil and its analogues in the treatment of erectile dysfunction (ED) and pulmonary hypertension by promoting relaxation in vascular smooth muscle through the activation of the NO/cGMP pathway. We undertook this study to verify if osajin and pomiferin, two natural prenylated isoflavones and major constituents of Maclura pomifera extracts previously investigated for their anticancer, antibacterial and antidiabetic properties, show inhibitory activity on PDE-5A.
View Article and Find Full Text PDFArch Pharm (Weinheim)
September 2015
The interest toward sex-related diseases keeps growing through the years. In this review, we focus our attention on erectile dysfunction (ED), a condition that caught much attention especially after the introduction on the market of phosphodiesterase 5 inhibitors such as the well-known sildenafil. Here, we briefly describe both the etiology of ED and the available treatments, examining then extensively some natural derivatives that, coming from traditional medicine, could represent promising starting points for the development of alternative remedies.
View Article and Find Full Text PDFAberrant protein kinase activities, and the consequent dramatic increase of Ser/Thr and -Tyr phosphorylation, promote the deregulation of the survival pathways in chronic lymphocytic leukemia (CLL), which is crucial to the pathogenesis and progression of the disease. In this study, we show that the tumor suppressor protein phosphatase 2A (PP2A), one of the major Ser/Thr phosphatases, is in an inhibited form because of the synergistic contribution of 2 events, the interaction with its physiologic inhibitor SET and the phosphorylation of Y307 of the catalytic subunit of PP2A. The latter event is mediated by Lyn, a Src family kinase previously found to be overexpressed, delocalized, and constitutively active in CLL cells.
View Article and Find Full Text PDFThis work was aimed to the development of a set of new naphtoquinone derivatives that can act against glioma. The compounds were tested in order to find out their ability to inhibit the growth of glioma cells, and the results of these assays were correlated with electrochemical analysis and NMR-based reoxidation kinetic studies, suggesting that a redox mechanism underlies and may explain the observed biological behavior. In addition to a full description of the synthetic pathways, electrochemistry, NMR and single crystal X-ray diffraction data are provided.
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