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Green tea polyphenols have been identified as molecules responsible for the beneficial effects showed by the green tea against oxidative stress and cancer risk. We investigated the effects of green tea polyphenol extracts (GTPs) on oxidative stress and cell invasiveness in human gastric MKN-28 cancer cells. The pre-treatment with 10–4 M catechin equivalents of GTPs exerts a protective effect on xanthine-xanthine oxidase induced cell cytotoxicity, thus confirming the anti-oxidant properties of GTPs. The effect of GTPs was also extended on the cell migration and invasive ability induced by TNF-alpha or LPS. Results demonstrated that GTPs exposure (10–6 M) prevents the increase in cell invasiveness induced by the inflammatory agents. In addition, the treatment with GTPs prevented the TNF-alpha or LPS induced Matrix Metalloproteinases (MMP)-9/2 up-regulation. Our results demonstrated that GTPs reduced the oxidative stress and the invasive potential of gastric MKN-28 cancer cells thus confirming the protective role of these polyphenols against the metastatic process in gastric cancer., Archives of ISANH: Vienna Polyphenols 2017

Green tea polyphenols have been identified as molecules responsible for the beneficial effects showed by the green tea against oxidative stress and cancer risk. We investigated the effects of green tea polyphenol extracts (GTPs) on oxidative stress and cell invasiveness in human gastric MKN-28 cancer cells. The pre-treatment with 10-4 M catechin equivalents of GTPs exerts a protective effect on xanthine-xanthine oxidase induced cell cytotoxicity, thus confirming the anti-oxidant properties of GTPs. The effect of GTPs was also extended on the cell invasive ability induced by TNF-?lpha or LPS. Results demonstrated that demonstrated that GTPs exposure (10-6 M) prevents the increase in cell invasiveness induced by the inflammatory agents. In addition, the treatment with GTPs prevented the TNF-?lpha or LPS induced Matrix Metalloproteinases (MMP)-9/2 up-regulation. In conclusion, our results demonstrated that GTPs reduced the oxidative stress and the invasive potential of gastric MKN-28 cancer cells thus confirming the protective role of these polyphenols against the metastatic process in gastric cancer.

Cutaneous melanoma (CM) remains one of the leading causes of tumor mortality due to its high metastatic spread. CM growth is influenced by inflammation regulated by prostaglandins (PGs) whose synthesis is catalyzed by cyclooxygenases (COXs). COX inhibitors, including non-steroidal anti-inflammatory drugs (NSAIDs), can inhibit tumor development and growth. In particular, in vitro experiments have shown that celecoxib, a NSAID, inhibits the growth of some tumor cell lines. However, two-dimensional (2D) cell cultures, used in traditional in vitro anticancer assays, often show poor efficacy due to a lack of an in vivo like cellular environment. Three-dimensional (3D) cell cultures, such as spheroids, are better models because they can mimic the common features displayed by human solid tumors. Hence, in this study, we evaluated the anti-neoplastic potential of celecoxib, in both 2D and 3D cell cultures of A2058 and SAN melanoma cell lines. In particular, celecoxib reduced the cell viability and migratory capability and triggered the apoptosis of melanoma cells grown as 2D cultures. When celecoxib was tested on 3D melanoma cell cultures, the drug exerted an inhibitory effect on cell outgrowth from spheroids and reduced the invasiveness of melanoma cell spheroids into the hydrogel matrix. This work suggests that celecoxib could represent a new potential therapeutic approach in melanoma therapy.

The microaerophile Streptococcus mutans, the main microaerophile responsible for the development of dental plaque, has a single cambialistic superoxide dismutase (SmSOD) for its protection against reactive oxygen species. In order to discover novel inhibitors of SmSOD, possibly interfering with the biofilm formation by this pathogen, a virtual screening study was realised using the available 3D-structure of SmSOD. Among the selected molecules, compound ALS-31 was capable of inhibiting SmSOD with an IC50 value of 159 µM. Its inhibition power was affected by the Fe/Mn ratio in the active site of SmSOD. Furthermore, ALS-31 also inhibited the activity of other SODs. Gel-filtration of SmSOD in the presence of ALS-31 showed that the compound provoked the dissociation of the SmSOD homodimer in two monomers, thus compromising the catalytic activity of the enzyme. A docking model, showing the binding mode of ALS-31 at the dimer interface of SmSOD, is presented. Cell viability of the fibroblast cell line BJ5-ta was not affected up to 100 µM ALS-31. A preliminary lead optimization program allowed the identification of one derivative, ALS-31-9, endowed with a 2.5-fold improved inhibition power. Interestingly, below this concentration, planktonic growth and biofilm formation of S. mutans cultures were inhibited by ALS-31, and even more by its derivative, thus opening the perspective of future drug design studies to fight against dental caries.

Background Alzheimer's disease (AD) is one of the most common causes of dementia in old people. Neuronal deficits such as loss of memory, language and problem-solving are severely compromised in affected patients. The molecular features of AD are Aβ deposits in plaques or in oligomeric structures and neurofibrillary tau tangles in brain. However, the challenge is that Aβ is only one piece of the puzzle, and recent findings continue to support the hypothesis that their presence is not sufficient to predict decline along the AD outcome. In this regard, metabolomic-based techniques are acquiring a growing interest for either the early diagnosis of diseases or the therapy monitoring. Mass spectrometry is one the most common analytical platforms used for detection, quantification, and characterization of metabolic biomarkers. In the past years, both targeted and untargeted strategies have been applied to identify possible interesting compounds. Aim of review The overall goal of this review is to guide the reader through the most recent studies in which LC–MS-based metabolomics has been proposed as a powerful tool for the identification of new diagnostic biomarkers in AD. To this aim, herein studies spanning the period 2009–2020 have been reported. Advantages and disadvantages of targeted vs untargeted metabolomic approaches have been outlined and critically discussed.

CDC25 phosphatases play a critical role in the regulation of the cell cycle and thus represent attractive cancer therapeutic targets. We previously discovered the 4-(2-carboxybenzoyl)phthalic acid (NSC28620) as a new CDC25 inhibitor endowed with promising anticancer activity in breast, prostate and leukemia cells. Herein, we report a structure-based optimization of NSC28620, leading to the identification of a series of novel naphthylphenylketone (NPK) and naphthylphenylamine (NPA) derivatives as CDC25B inhibitors. Compounds 7j, 7i, 6e, 7f and 3 showed higher inhibitory activity than the initial lead, with Ki values in the low micromolar range. Kinetic analysis, intrinsic fluorescence studies and induced fit docking simulations provided a mechanistic understanding of the activity of these derivatives. All compounds were tested in the highly aggressive human melanoma cell lines A2058 and A375. Compound 4a potently inhibited cell proliferation and colony formation, causing an increase of the G2/M phase and a reduction of G0/G1 phase of the cell cycle in both cell lines.

This study investigates on the presence of toxic proteins in quinoa seeds. To this aim, a plethora of biochemical approaches were adopted for the purification and characterization of quinoin, a type 1 ribosome-inactivating protein (RIP) contained in quinoa seeds. We determined its melting temperature (68.2±0.6°C) and thermostability (loss of activity after 10-min incubation at 70°C). Considering that quinoa seeds are used as a food, we found that quinoin is cytotoxic against BJ-5ta (human fibroblasts) and HaCaT (human keratinocytes) in a dose- and time-dependent manner. Moreover, in an in vitro digestive pepsin-trypsin treatment, 30% of quinoin is resistant to enzymatic cleavage. This toxin was found in seeds (0.23mg/g of seeds) and in sprouted seeds obtained after 24-h (0.12mg/g of sprout) and 48-h (0.09mg/g of sprout). We suggest a thermal treatment of quinoa seeds before consumption in order to inactivate the toxin, particularly in sprouts, generally consumed raw.

Fyn is a non-receptor or cytoplasmatic tyrosine kinase (TK) belonging to the Src family kinases (SFKs) involved in multiple transduction pathways in the central nervous system (CNS) including synaptic transmission, myelination, axon guidance, and oligodendrocyte formation. Almost one hundred years after the original description of Fyn, this protein continues to attract extreme interest because of its multiplicity of actions in the molecular signaling pathways underlying neurodevelopmental as well as neuropathologic events. This review highlights and summarizes the most relevant recent findings pertinent to the role that Fyn exerts in the brain, emphasizing aspects related to neurodevelopment and synaptic plasticity. Fyn is a common factor in healthy and diseased brains that targets different proteins and shapes different transduction signals according to the neurological conditions. We will primarily focus on Fyn-mediated signaling pathways involved in neuronal differentiation and plasticity that have been subjected to considerable attention lately, opening the fascinating scenario to target Fyn TK for the development of potential therapeutic interventions for the treatment of CNS injuries and certain neurodegenerative disorders like Alzheimer’s disease.

Ageritin is the first reported ribotoxin-like protein from basidiomycetes fungi. It can induce ribosomal integrity damage and translation block, and interferes with mitochondrial redox activity of some glioma and neuroblastoma cell lines. Herein, Ageritin has been investigated as a valuable neurotoxin towards either undifferentiated or retinoic acid (RA)-differentiated SH-SY5Y neuroblastoma cells showing a selective cell toxicity against undifferentiated cells. MTT and sulforhodamine B (SRB) assays highlighted that Ageritin markedly decreases the mitochondrial redox activity and viability of undifferentiated cells, meanwhile inducing evident morphological changes eliciting neuronal-like appearance in these cells. Data from lactate dehydrogenase release assay, cytofluorimetric analysis and caspase-3 enzymatic activity measurement suggest that Ageritin promotes cell death through a caspase-dependent apoptotic pathway. The Z-VAD-FMK caspase inhibitor was able to prevent this apoptotic pathway activation. Based on the interesting behaviour of Ageritin vs. SH-SY5Y cells, the development of a scale-up procedure to obtain the purified protein in larger amounts (yield 2.5 mg per 100 g) has been optimized.

Melanoma is one of the most aggressive solid tumors and includes a stromal microenvironment that regulates cancer growth and progression. The components of stromal microenvironment such as fibroblasts, fibroblast aggregates and cancer-associated fibroblasts (CAFs) can differently influence the melanoma growth during its distinct stages. In this work, we have developed and studied a stromal microenvironment model, represented by fibroblasts, proto-myofibroblasts, myofibroblasts and aggregates of inactivated myofibroblasts, such as spheroids. In particular, we have generated proto-myofibroblasts from primary cutaneous myofibroblasts. The phenotype of proto-myofibroblasts is characterized by a dramatic reduction of &alpha, smooth muscle actin (&alpha, SMA) and cyclooxygenase-2 (COX-2) protein levels, as well as an enhancement of cell viability and migratory capability compared with myofibroblasts. Furthermore, proto-myofibroblasts display the mesenchymal marker vimentin and less developed stress fibers, with respect to myofibroblasts. The analysis of crosstalk between the stromal microenvironment and A375 or A2058 melanoma cells has shown that the conditioned medium of proto-myofibroblasts is cytotoxic, mainly for A2058 cells, and dramatically reduces the migratory capability of both cell lines compared with the melanoma-control conditioned medium. An array analysis of proto-myofibroblast and melanoma cell-conditioned media suggests that lower levels of some cytokines and growth factors in the conditioned medium of proto-myofibroblasts could be associated with their anti-tumor activity. Conversely, the conditioned media of melanoma cells do not influence the cell viability, outgrowth, and migration of proto-myofibroblasts from spheroids. Interestingly, the conditioned medium of proto-myofibroblasts does not alter the cell viability of both BJ-5ta fibroblast cells and myofibroblasts. Hence, proto-myofibroblasts could be useful in the study of new therapeutic strategies targeting melanoma.

Breast cancer is the most common cancer in women, which incidence has increased in recent years. It is constituted by very heterogeneous tissue characterized by an abnormal microenvironment regulating tumor progression and providing evasion from cancer therapies. Breast cancer-associated fibroblasts (BCAFs) are the main cell type of breast cancer microenvironment and can represent up to 80% of the tumor mass. In particular, BCAFs induce cancer initiation, proliferation, invasion and metastasis by undergoing an activation process associated with the secretion of growth factors, cytokines, and paracrine interactions. Therapy resistance is the main cause of poor therapeutic results or even failure in breast cancer patients. Despite recent advances in breast cancer management, there is a need for new prognostic markers and novel agents for targeting key signalling pathways to either improve the efficacy of the current therapies, or reduce toxicity. In this view, BCAFs represent markers useful to clinical diagnosis, therapy, and prognosis of breast cancer. This review focuses on the role of BCAFs in cancer, and describes the processes of endocrine/chemotherapy resistance linked to BCAFs action. Moreover, it points to molecules and pathways regulating therapy resistance induced by BCAFs. Finally, potential therapeutic strategies targeting BCAFs and offering new tools in breast cancer therapy are highlighted.

The dual phosphatases cell division cycle 25 (CDC25) are crucial regulators of cell cycle progression, also involved in cell response to DNA damage. Their overexpression was detected in many tumors, including melanoma [1]. The characterization of molecules with an inhibitory potency on CDC25 activity, such as compound 19 (NSC 28620) [2], contributes to the research of novel anti-cancer drugs. The structure of this lead compound was engineered to produce more potent inhibitors. The most active compounds synthesized had Ki values in the 0.79 – 10.0 μM interval. Kinetic studies identified two different mechanisms of inhibition, related to specific functional groups possessed by the inhibitors. Information on positioning/interaction of the inhibitors was also obtained by intrinsic fluorescence measurements of CDC25B. The possible cytotoxicity of the most active compounds on melanoma cell lines was analysed. Data from MTT assay indicated that at a low concentration, i.e. 10 μM, essentially one compound (cpd 21) significantly reduced the cell growth of melanoma cells in a time dependent manner. The effect of cpd 21 on cell viability was further confirmed by the colony-forming assay, that showed a similar trend in the ability to inhibit the clonogenicity of melanoma cells. Moreover, cpd 21 provoked an early increase of pCdk1 protein level and an arrest of melanoma cells in G2/M of cell cycle, followed by the activation of a caspase-mediated apoptotic program. Conversely, cpd 21 didn’t show cytotoxic effect on BJ-5ta, a nonmalignant fibroblast cell line. 85 Finally, a reduction of pAkt and an increase of p53 protein level could mediate the cytotoxic effect of cpd 21 on melanoma cells. References 1) Boutros et al. Nat Rev Cancer (2007),7,495-507. 2) Lavecchia et al. J. Med. Chem. (2012), 55, 4142-4158.