In the complex scenario of cancer, treatment with compounds targeting multiple cell pathways has been emerging. In Glioblastoma Multiforme (GBM), p53 and Translocator Protein (TSPO), both acting as apoptosis inducers, represent two attractive intracellular targets. On this basis, novel indolylglyoxylyldipeptides, rationally designed to activate TSPO and p53, were synthesized and biologically characterized. The new compounds were able to bind TSPO and to reactivate p53 functionality, through the dissociation from its physiological inhibitor, murine double minute 2 (MDM2). In GBM cells, the new molecules caused Δψm dissipation and inhibition of cell viability. These effects resulted significantly higher with respect to those elicited by the single target reference standards applied alone, and coherent with the synergism resulting from the simultaneous activation of TSPO and p53. Taken together, these results suggest that TSPO/MDM2 dual-target ligands could represent a new attractive multi-modal opportunity for anti-cancer strategy in GBM.

Cellular oxidative stress serves as a common denominator in many neurodegenerative disorders, including Parkinson's disease. Here we use in-cell NMR spectroscopy to study the fate of the oxidation-damaged Parkinson's disease protein alpha-synuclein (α-Syn) in non-neuronal and neuronal mammalian cells. Specifically, we deliver methionine-oxidized, isotope-enriched α-Syn into cultured cells and follow intracellular protein repair by endogenous enzymes at atomic resolution. We show that N-terminal α-Syn methionines Met1 and Met5 are processed in a stepwise manner, with Met5 being exclusively repaired before Met1. By contrast, C-terminal methionines Met116 and Met127 remain oxidized and are not targeted by cellular enzymes. In turn, persisting oxidative damage in the C-terminus of α-Syn diminishes phosphorylation of Tyr125 by Fyn kinase, which ablates the necessary priming event for Ser129 modification by CK1. These results establish that oxidative stress can lead to the accumulation of chemically and functionally altered α-Syn in cells.

The urotensin II receptor (UTR) has long been studied mainly for its involvement in the cardiovascular homeostasis both in health and disease state. Two endogenous ligands activate UTR, i.e. urotensin II (U-II) and urotensin II-related peptide (URP). Extensive expression of the two ligands uncovers the diversified pathophysiological effects mediated by the urotensinergic system such as cardiovascular disorders, smooth muscle cell proliferation, renal disease, diabetes, and tumour growth. As newly reported, U-II and URP have distinct effects on transcriptional activity, cell proliferation, and myocardial contractile activities supporting the idea that U-II and URP interact with UTR in a distinct manner (biased agonism). To shed light on the origin of the divergent activities of the two endogenous ligands, we performed a conformational study on URP by solution NMR in sodium dodecyl sulfate micelle solution and compared the obtained NMR structure of URP with that of hU-II previously determined. Finally, we undertook docking studies between URP, hU-II, and an UT receptor model.

Analogues of the previously described spiro[imidazo[1,5-c]thiazole-3,3'-indoline]-2',5,7(6H,7aH)-trione p53 modulators were prepared to explore new structural requirements at the thiazolidine domain for the antiproliferative activity and p53 modulation. In cell, antiproliferative activity was evaluated against two human tumor cell lines. Derivative 5-bromo-3'-(cyclohexane carbonyl)-1-methyl-2-oxospiro[indoline-3,2'-thiazolidine] (4n) emerged as the most potent compound of this series, inhibiting in vitro 30% of p53-MDM2 interaction at 5 μM and the cell growth of different human tumor cells at nanomolar concentrations. Docking studies confirmed the interactions of 4n with the well-known Trp23 and Phe19 clefts, explaining the reasons for its binding affinity for MDM2. 4n at 50 nM is capable of inducing the accumulation of p53 protein, inducing significant apoptotic cell death without affecting the cell cycle progression. Comparative studies using nutlin in the same cellular system confirm the potential of 4n as a tool for increasing understanding of the process involved in the nontranscriptional proapoptotic activities of p53.