Interaction of VO-hydrazonates with lysozyme.

Vanadium compounds (VCs) exhibit a broad range of pharmacological properties, with their most significant medical applications being in the treatment of cancer and diabetes. The therapeutic effects and mode of action of VCs may be associated with their ability to bind proteins and, consequently, understanding the VC-protein interaction is of paramount importance. Among the promising VCs, the VO complex with the aroylhydrazone furan-2-carboxylic acid ((3-ethoxy-2-hydroxybenzylidene)hydrazide, hereafter denoted as VC1), deserves attention, since it exhibits cytotoxicity against various cancer cell lines, including HeLa.

Selective delivery of G-quadruplex ligand in glioma cell lines: the power of cyclic-RGD peptide.

Compounds targeting non-canonical secondary structures of nucleic acids, known as G-quadruplexes, are highly cytotoxic, both for cancer and healthy cells, because of their action mechanism's lack of appropriate selectivity. The targeted delivery of cytotoxic molecules to cancer cells is a valuable strategy to expand the repertoire of potential drugs, especially for cancer types for which new therapeutic tools are urgently needed, like glioblastoma. In this work, we conjugated a cyclic arginyl-glycyl-aspartic acid peptide to a naphthalene diimide, previously described as a highly performing stabilizing ligand for DNA G-quadruplexes, to specifically target glioma cells overexpressing RGD-binding integrin receptors.

Protein-Protein Stabilization in VO/8-Hydroxyquinoline-Lysozyme Adducts.

The binding of the potential drug [VO(8-HQ)], where 8-HQ is 8-hydroxyquinolinato, with hen egg white lysozyme (HEWL) was evaluated through spectroscopic (electron paramagnetic resonance, EPR, and UV-visible), spectrometric (electrospray ionization-mass spectrometry, ESI-MS), crystallographic (X-ray diffraction, XRD), and computational (DFT and docking) studies. ESI-MS indicates the interaction of [VO(8-HQ)(HO)] and [VO(8-HQ)(HO)] species with HEWL. Room temperature EPR spectra suggest both covalent and non-covalent binding of the two different V-containing fragments.

Small Molecules against Metastatic Tumors: Concrete Perspectives and Shattered Dreams.

Metastasis is the main cause of anti-cancer therapy failure, leading to unfavorable prognosis for patients. The true challenge to increase cancer patient life expectancy by making cancer a chronic disease with periodic but manageable relapses relies on the development of efficient therapeutic strategies specifically directed against key targets in the metastatic process. Traditional chemotherapy with classical alkylating agents, microtubule inhibitors, and antimetabolites has demonstrated its limited efficacy against metastatic cells due to their capacity to select chemo-resistant cell populations that undergo epithelial-to-mesenchymal transition (EMT), thus promoting the colonization of distant sites that, in turn, sustain the initial metastatic process.

Implications of Protein Interaction in the Speciation of Potential VO-Pyridinone Drugs.

Vanadium complexes (VCs) are promising agents for the treatment, among others, of diabetes and cancer. The development of vanadium-based drugs is mainly limited by a scarce knowledge of the active species in the target organs, which is often determined by the interaction of VCs with biological macromolecules like proteins. Here, we have studied the binding of [VO(empp)] (where Hempp is 1-methyl-2-ethyl-3-hydroxy-4(1)-pyridinone), an antidiabetic and anticancer VC, with the model protein hen egg white lysozyme (HEWL) by electrospray ionization-mass spectrometry (ESI-MS), electron paramagnetic resonance (EPR), and X-ray crystallography.

cRGD-Functionalized Silk Fibroin Nanoparticles: A Strategy for Cancer Treatment with a Potent Unselective Naphthalene Diimide Derivative.

Developing drug delivery systems to target cytotoxic drugs directly into tumor cells is still a compelling need with regard to reducing side effects and improving the efficacy of cancer chemotherapy. In this work, silk fibroin nanoparticles (SFNs) have been designed to load a previously described cytotoxic compound (NDI-1) that disrupts the cell cycle by specifically interacting with non-canonical secondary structures of DNA. SFNs were then functionalized on their surface with cyclic pentapeptides incorporating the Arg-Gly-Asp sequence (RGDs) to provide active targeting toward glioma cell lines that abundantly express ανβ3 and ανβ5 integrin receptors.

RGD Cyclopeptide Equipped with a Lysine-Engaging Salicylaldehyde Showing Enhanced Integrin Affinity and Cell Detachment Potency.

Salicylaldehyde (SA) derivatives are emerging as useful fragments to obtain reversible-covalent inhibitors interacting with the lysine residues of the target protein. Here the SA installation at the C terminus of an integrin-binding cyclopeptide, leading to enhanced ligand affinity for the receptor as well as stronger biological activity in cultured glioblastoma cells is reported.

Effect of the simulated digestion process on the chlorogenic acid trapping activity against methylglyoxal.

Chlorogenic acids are hydroxycinnamic derivatives widespread in food or food by-products, known for their antioxidant effects and ability to interfere with the formation of advanced glycation end products (AGEs). AGEs are potential glycotoxins involved in age-related disorders, such as diabetes, cardiovascular diseases, and neurological disorders. The ability of chlorogenic acids to inhibit AGE formation under physiological conditions needs further investigation other than the assays.

Multiple and Variable Binding of Pharmacologically Active Bis(maltolato)oxidovanadium(IV) to Lysozyme.

The interaction with proteins of metal-based drugs plays a crucial role in their transport, mechanism, and activity. For an active ML complex, where L is the organic carrier, various binding modes (covalent and non-covalent, single or multiple) may occur and several metal moieties (M, ML, ML, etc.) may interact with proteins.

Berberine Photo-Activation Potentiates Cytotoxicity in Human Astrocytoma Cells through Apoptosis Induction.

Photodynamic therapy (PDT) has recently attracted interest as an innovative and adjuvant treatment for different cancers including malignant gliomas. Among these, Glioblastoma (GBM) is the most prevalent neoplasm in the central nervous system. Despite conventional therapeutic approaches that include surgical removal, radiation, and chemotherapy, GBM is characterized by an extremely poor prognosis and a high rate of recurrence.

Fostering "Education": Do Extracellular Vesicles Exploit Their Own Delivery Code?

Extracellular vesicles (EVs), comprising large microvesicles (MVs) and exosomes (EXs), play a key role in intercellular communication, both in physiological and in a wide variety of pathological conditions. However, the education of EV target cells has so far mainly been investigated as a function of EX cargo, while few studies have focused on the characterization of EV surface membrane molecules and the mechanisms that mediate the addressability of specific EVs to different cell types and tissues. Identifying these mechanisms will help fulfill the diagnostic, prognostic, and therapeutic promises fueled by our growing knowledge of EVs.

In Vitro Glioblastoma Models: A Journey into the Third Dimension.

Glioblastoma multiforme (GBM) is the most lethal primary brain tumor in adults, with an average survival time of about one year from initial diagnosis. In the attempt to overcome the complexity and drawbacks associated with in vivo GBM models, together with the need of developing systems dedicated to screen new potential drugs, considerable efforts have been devoted to the implementation of reliable and affordable in vitro GBM models. Recent findings on GBM molecular features, revealing a high heterogeneity between GBM cells and also between other non-tumor cells belonging to the tumoral niche, have stressed the limitations of the classical 2D cell culture systems.

Silk Fibroin Nanoparticle Functionalization with Arg-Gly-Asp Cyclopentapeptide Promotes Active Targeting for Tumor Site-Specific Delivery.

Arg-Gly-Asp (RGD)-based cyclopentapeptides (cRGDs) have a high affinity towards integrin αvβ3 and αvβ5, which are overexpressed by many tumor cells. Here, curcumin-loaded silk fibroin nanoparticles (SFNs) have been functionalized on the surface with cRGD to provide active targeting towards tumor cells; a "click reaction" between the RGD-based cyclopentapeptide carrying an azide group and triple-bond-functionalized nanoparticles has been exploited. Both naked and functionalized SFNs were less than 200 nm in diameter and showed a round-shaped morphology but, after functionalization, SFNs increased in size and protein molecular weight.

Integrin-Targeting Dye-Doped PEG-Shell/Silica-Core Nanoparticles Mimicking the Proapoptotic Smac/DIABLO Protein.

Cancer cells demonstrate elevated expression levels of the inhibitor of apoptosis proteins (IAPs), contributing to tumor cell survival, disease progression, chemo-resistance, and poor prognosis. Smac/DIABLO is a mitochondrial protein that promotes apoptosis by neutralizing members of the IAP family. Herein, we describe the preparation and in vitro validation of a synthetic mimic of Smac/DIABLO, based on fluorescent polyethylene glycol (PEG)-coated silica-core nanoparticles (NPs) carrying a Smac/DIABLO-derived pro-apoptotic peptide and a tumor-homing integrin peptide ligand.

Stem-Like Cancer Cells in a Dynamic 3D Culture System: A Model to Study Metastatic Cell Adhesion and Anti-Cancer Drugs.

Metastatic spread is mainly sustained by cancer stem cells (CSC), a subpopulation of cancer cells that displays stemness features. CSC are thought to be derived from cancer cells that undergo epithelial to mesenchymal transition (EMT), thus acquiring resistance to anoikis and anti-cancer drugs. After detachment from the primary tumor mass, CSC reach the blood and lymphatic flow, and disseminate to the target tissue.

Extracellular Matrix Alterations in Metastatic Processes.

The extracellular matrix (ECM) is a complex network of extracellular-secreted macromolecules, such as collagen, enzymes and glycoproteins, whose main functions deal with structural scaffolding and biochemical support of cells and tissues. ECM homeostasis is essential for organ development and functioning under physiological conditions, while its sustained modification or dysregulation can result in pathological conditions. During cancer progression, epithelial tumor cells may undergo epithelial-to-mesenchymal transition (EMT), a morphological and functional remodeling, that deeply alters tumor cell features, leading to loss of epithelial markers (i.

A dimeric bicyclic RGD ligand displays enhanced integrin binding affinity and strong biological effects on U-373 MG glioblastoma cells.

A C-symmetric bicyclic peptide bearing two RGD motifs was developed as a dimeric ligand, and it displayed enhanced inhibition of ECM protein binding to purified integrin receptors as compared to monomeric RGD analogues. Moreover, the dimeric bicyclic ligand induced cell detachment and inhibited FAK phosphorylation in U-373 MG glioblastoma cells.

A new millifluidic-based gastrointestinal platform to evaluate the effect of simulated dietary methylglyoxal intakes.

The search for new in vitro modular bioreactors to simulate flow-mediated transport and absorption of chemical substances is a very important issue in toxicology and in drug and bioactive delivery research. The possibility of setting up a dynamic microenvironment leads to experimental conditions that may more closely resemble the in vivo model, especially to measure acute or chronic intake of compounds. We propose a novel millifluidic-based gastrointestinal model as an evolution of the common in vitro methods, to evaluate the exposure to exogenous methylglyoxal (MGO), a highly reactive α-oxoaldehyde responsible for the formation of advanced glycation end products involved in a number of chronic diseases.

The Importance of Detail: How Differences in Ligand Structures Determine Distinct Functional Responses in Integrin α β.

Ligand-based control of protein functional motions can provide novel opportunities in the study of fundamental biological mechanisms and in the development of novel therapeutics. In this work we addressed the ligand-based modulation of integrin functions. Inhibitors of integrin α β are interesting anticancer agents but their molecular mechanisms are still unclear: Peptides and peptidomimetics characterized by the Arg-Gly-Asp (RGD) or isoAsp-Gly-Arg (isoDGR) binding motifs have shown controversial agonist/antagonist effects.

An RGD small-molecule integrin antagonist induces detachment-mediated anoikis in glioma cancer stem cells.

The malignancy of glioblastoma (GB) is primarily due to the ability of glioma cancer stem cells (GSC) to disseminate into surrounding brain tissues, despite surgery and chemotherapy, and to form new tumoral masses. Members of the RGD-binding integrin family, which recognize the arginine-glycine-aspartic acid (RGD) sequence present in components of the extracellular matrix, and which serve a crucial function in the dissemination of GCS, are overexpressed in GB. Small-molecule integrin antagonists (SMIAs) designed to recognize RGD-integrins may therefore be an effective tool for decreasing GB infiltration and recurrence.

Identification of dual Sigma1 receptor modulators/acetylcholinesterase inhibitors with antioxidant and neurotrophic properties, as neuroprotective agents.

In this manuscript we report on the design, synthesis and evaluation of dual Sigma 1 Receptor (S1R) modulators/Acetylcholinesterase (AChE) inhibitors endowed with antioxidant and neurotrophic properties, potentially able to counteract neurodegeneration. The compounds based on arylalkylaminoketone scaffold integrate the pharmacophoric elements of RRC-33, a S1R modulator developed by us, donepezil, a well-known AChE inhibitor, and curcumin, a natural antioxidant compound with neuroprotective properties. A small library of compounds was synthesized and preliminary in vitro screening performed.

cGMP Imaging in Brain Slices Reveals Brain Region-Specific Activity of NO-Sensitive Guanylyl Cyclases (NO-GCs) and NO-GC Stimulators.

Impaired NO-cGMP signaling has been linked to several neurological disorders. NO-sensitive guanylyl cyclase (NO-GC), of which two isoforms-NO-GC1 and NO-GC2-are known, represents a promising drug target to increase cGMP in the brain. Drug-like small molecules have been discovered that work synergistically with NO to stimulate NO-GC activity.

Real-Time Imaging Reveals Augmentation of Glutamate-Induced Ca Transients by the NO-cGMP Pathway in Cerebellar Granule Neurons.

Dysfunctions of NO-cGMP signaling have been implicated in various neurological disorders. We have studied the potential crosstalk of cGMP and Ca signaling in cerebellar granule neurons (CGNs) by simultaneous real-time imaging of these second messengers in living cells. The NO donor DEA/NO evoked cGMP signals in the granule cell layer of acute cerebellar slices from transgenic mice expressing a cGMP sensor protein.

Sigma Receptors as Endoplasmic Reticulum Stress "Gatekeepers" and their Modulators as Emerging New Weapons in the Fight Against Cancer.

Despite the interest aroused by sigma receptors (SRs) in the area of oncology, their role in tumor biology remains enigmatic. The predominant subcellular localization and main site of activity of SRs are the endoplasmic reticulum (ER). Current literature data, including recent findings on the sigma 2 receptor subtype (S2R) identity, suggest that SRs may play a role as ER stress gatekeepers.