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A diet rich in saturated fatty acids (FAs) has been correlated with metabolic dysfunction and ROS increase in the adipose tissue of obese subjects. Thus, reducing hypertrophy and oxidative stress in adipose tissue can represent a strategy to counteract obesity and obesity-related diseases. In this context, the present study showed how the peel and seed extracts of mango (Mangifera indica L.) reduced lipotoxicity induced by high doses of sodium palmitate (PA) in differentiated 3T3-L1 adipocytes. Mango peel (MPE) and mango seed (MSE) extracts significantly lowered PA-induced fat accumulation by reducing lipid droplet (LDs) and triacylglycerol (TAGs) content in adipocytes. We showed that MPE and MSE activated hormone-sensitive lipase, the key enzyme of TAG degradation. In addition, mango extracts down-regulated the adipogenic transcription factor PPARγ as well as activated AMPK with the consequent inhibition of acetyl-CoA-carboxylase (ACC). Notably, PA increased endoplasmic reticulum (ER) stress markers GRP78, PERK and CHOP, as well as enhanced the reactive oxygen species (ROS) content in adipocytes. These effects were accompanied by a reduction in cell viability and the induction of apoptosis. Interestingly, MPE and MSE counteracted PA-induced lipotoxicity by reducing ER stress markers and ROS production. In addition, MPE and MSE increased the level of the anti-oxidant transcription factor Nrf2 and its targets MnSOD and HO-1. Collectively, these results suggest that the intake of mango extract-enriched foods in association with a correct lifestyle could exert beneficial effects to counteract obesity.

Triple-Negative Breast Cancer (TNBC) is a particularly aggressive subtype among breast cancers (BCs), characterized by anoikis resistance, high invasiveness, and metastatic potential as well as Epithelial–Mesenchymal Transition (EMT) and stemness features. In the last few years, our research focused on the function of MCL1, an antiapoptotic protein frequently deregulated in TNBC. Here, we demonstrate that MCL1 inhibition by A-1210477, a specific BH3-mimetic, promotes anoikis/apoptosis in the MDA-MB-231 cell line, as shown via an increase in proapoptotic markers and caspase activation. Our evidence also shows A-1210477 effects on Focal Adhesions (FAs) impairing the integrin trim and survival signaling pathways, such as FAK, AKT, ERK, NF-κB, and GSK3β-inducing anoikis, thus suggesting a putative role of MCL1 in regulation of FA dynamics. Interestingly, in accordance with these results, we observed a reduction in migratory and invasiveness capabilities as confirmed by a decrease in metalloproteinases (MMPs) levels following A-1210477 treatment. Moreover, MCL1 inhibition promotes a reduction in EMT characteristics as demonstrated by the downregulation of Vimentin, MUC1, DNMT1, and a surprising re-expression of E-Cadherin, suggesting a possible mesenchymal-like phenotype reversion. In addition, we also observed the downregulation of stemness makers such as OCT3/4, SOX2, NANOG, as well as CD133, EpCAM, and CD49f. Our findings support the idea that MCL1 inhibition in MDA-MB-231 could be crucial to reduce anoikis resistance, aggressiveness, and metastatic potential and to minimize EMT and stemness features that distinguish TNBC.

Methyl gallate (MG), which is a gallotannin widely found in plants, is a polyphenol used in traditional Chinese phytotherapy to alleviate several cancer symptoms. Our studies provided evidence that MG is capable of reducing the viability of HCT116 colon cancer cells, while it was found to be ineffective on differentiated Caco-2 cells, which is a model of polarized colon cells. In the first phase of treatment, MG promoted both early ROS generation and endoplasmic reticulum (ER) stress, sustained by elevated PERK, Grp78 and CHOP expression levels, as well as an upregulation in intracellular calcium content. Such events were accompanied by an autophagic process (16–24 h), where prolonging the time (48 h) of MG exposure led to cellular homeostasis collapse and apoptotic cell death with DNA fragmentation and p53 and γH2Ax activation. Our data demonstrated that a crucial role in the MG-induced mechanism is played by p53. Its level, which increased precociously (4 h) in MG-treated cells, was tightly intertwined with oxidative injury. Indeed, the addition of N-acetylcysteine (NAC), which is a ROS scavenger, counteracted the p53 increase, as well as the MG effect on cell viability. Moreover, MG promoted p53 accumulation into the nucleus and its inhibition by pifithrin-α (PFT-α), which is a negative modulator of p53 transcriptional activity, enhanced autophagy, increased the LC3-II level and inhibited apoptotic cell death. These findings provide new clues to the potential action of MG as a possible anti-tumor phytomolecule for colon cancer treatment.

Oncogenic BRAF mutations have been widely described in melanomas and promote tumour progression and chemoresistance. We previously provided evidence that the HDAC inhibitor ITF2357 (Givinostat) targets oncogenic BRAF in SK-MEL-28 and A375 melanoma cells. Here, we show that oncogenic BRAF localises to the nucleus of these cells, and the compound decreases BRAF levels in both the nuclear and cytosolic compartments. Although mutations in the tumour suppressor p53 gene are not equally frequent in melanomas compared to BRAF, the functional impairment of the p53 pathway may also contribute to melanoma development and aggressiveness. To understand whether oncogenic BRAF and p53 may cooperate, a possible interplay was considered in the two cell lines displaying a different p53 status, being p53 mutated into an oncogenic form in SK-MEL-28 and wild-type in A375 cells. Immunoprecipitation revealed that BRAF seems to preferentially interact with oncogenic p53. Interestingly, ITF2357 not only reduced BRAF levels but also oncogenic p53 levels in SK-MEL-28 cells. ITF2357 also targeted BRAF in A375 cells but not wild-type p53, which increased, most likely favouring apoptosis. Silencing experiments confirmed that the response to ITF2357 in BRAF-mutated cells depends on p53 status, thus providing a rationale for melanoma-targeted therapy.

In this work, we extend the concept of 5-fluorouracil/heme oxygenase 1 (5-FU/HO-1) inhibitor hybrid as an effective strategy for enhancing 5-FU-based anticancer therapies. For this purpose, we designed and synthesized new mutual prodrugs, named SI 1/20 and SI 1/22, in which the two active parent drugs (i. e., 5-FU and an imidazole-based HO-1 inhibitor) were connected through an easily cleavable succinic linker. Experimental hydrolysis rate, and in silico ADMET predictions were indicative of good drug-likeness and pharmacokinetic properties. Novel hybrids significantly reduced the viability of prostate DU145 cancer cells compared to the parent compounds 5-FU and HO-1 inhibitor administered alone or in combination. Interestingly, both compounds showed statistically significant lower toxicity, than 5-FU at the same dose, against non-tumorigenic human benign prostatic hyperplasia (BPH-1) cell line. Moreover, the newly synthesized mutual prodrugs inhibited the HO-1 activity both in a cell-free model and in vitro, as well as downregulated the HO-1 expression and increased the reactive oxygen species (ROS) levels.

Organotin(IV) complexes represent promising drugs in medicinal chemistry for their potential use in cancer therapy. We recently reported synthesis and characterization of a new organotin(IV) complex of ferulic acid (FA), tributyltin(IV) ferulate (TBT-F), showing its antitumor action in colon cancer cells. Here we provide evidence that the efficacy of this compound is strongly potentiated by the proteasome inhibitor bortezomib (BTZ). While low concentrations of tributyltin(IV) ferulate alone promoted autophagy without reducing cell viability, combination of the two compounds markedly affected colon cancer cell viability, cell morphology and exasperated endoplasmic reticulum (ER) stress, as revealed by a dramatic increase in Grp78 ER stress marker and consequent unfolded protein response (UPR) pathway components including PERK, eIF2α and downstream transcription factor CHOP. Our data also indicated that ER stress promoted by the TBT-F/BTZ combination leads to apoptosis, as shown by caspase 3 and caspase 7 activation, PARP cleavage, increase in p53 levels, chromatin condensation and prevention of the TBT-F effect by the caspase inhibitor zVAD-fmk.

Currently, cellular stresses as the oxidative, metabolic and genotoxic stress are considered the cause of many different human pathologies as neurodegenerative diseases (e.g.,Alzheimer’s, Parkinson’s, amyotrophic lateral sclerosis), alcoholic liver disease, chronic obstructive pulmonary disease, and also cancer. Although the role of cellular stress has been largely debated in cancer, nowadays some therapies aim to target the intracellular pro-oxidant/anti-oxidant balance triggering the tumor commitment to cell death. Therefore, it has become more necessary an improved understanding of cancer response to cellular stress that could be advantageous to develop cancer tailored therapies. In this scenario, the present study shows how extracts of some fractions of Sicilian mango, a tropical fruit rich in phytochemicals with nutraceutical properties, are able to affect the cell viability of three colon cancer cell lines (HT29, Caco2 and HCT116) inducing cellular stress. By using hydro-alcoholic extracts of three different portions of the fruit (peel, pulp and kernel), we observed that mango peel extract (MPE) is the most effective in reducing cell viability causing a remarkable LDH release and the death of all three cancer cells. The effect was accompanied by mitochondrial injury, dissipation of mitochondrial potential membrane and decrease in the level of proteins localized in the mitochondrial membrane such as voltage-dependent anion-selective channel (VDAC), mitofilin, and some members of Bcl-2 family proteins (Mcl-1, Bcl-2 and Bcl-XL). All these effects were accompanied by redox balance changes and upregulation in MnSOD, a mitochondrial scavenger enzyme able to modulate the cellular response against oxidative damage. The analysis of the effects exerted by the different phytochemicals present in MPE allowed to identify those molecules responsible for the observed anticancer effects sustaining their future employment as chemopreventive or therapeutic agents.

Nuclear factor erythroid 2-related factor 2 (Nrf2) is a well-known transcription factor best recognised as one of the main regulators of the oxidative stress response. Beyond playing a crucial role in cell defence by transactivating cytoprotective genes encoding antioxidant and detoxifying enzymes, Nrf2 is also implicated in a wide network regulating anti-inflammatory response and metabolic reprogramming. Such a broad spectrum of actions renders the factor a key regulator of cell fate and a strategic player in the control of cell transformation and response to viral infections. The Nrf2 protective roles in normal cells account for its anti-tumour and anti-viral functions. However, Nrf2 overstimulation often occurs in tumour cells and a complex correlation of Nrf2 with cancer initiation and progression has been widely described. Therefore, if on one hand, Nrf2 has a dual role in cancer, on the other hand, the factor seems to display a univocal function in preventing inflammation and cytokine storm that occur under viral infections, specifically in coronavirus disease 19 (COVID-19). In such a variegate context, the present review aims to dissect the roles of Nrf2 in both cancer and COVID-19, two widespread diseases that represent a cause of major concern today. In particular, the review describes the molecular aspects of Nrf2 signalling in both pathological situations and the most recent findings about the advantages of Nrf2 inhibition or activation as possible strategies for cancer and COVID-19 treatment respectively.

Today, an improved understanding of cancer cell response to cellular stress has become more necessary. Indeed, targeting the intracellular pro-oxidant/antioxidant balance triggering the tumor commitment to cell demise could represent an advantageous strategy to develop cancer-tailored therapies. In this scenario, the present study shows how the peel extract of mango—a tropical fruit rich in phytochemicals with nutraceutical properties—can affect the cell viability of three colon cancer cell lines (HT29, Caco-2 and HCT116), inducing an imbalance of cellular redox responses. By using hydro-alcoholic mango peel extract (MPE), we observed a consistent decline in thiol group content, which was accompanied by upregulation of MnSOD—a mitochondrial scavenger enzyme that modulates the cellular response against oxidative damage. Such an effect was the consequence of an early production of mitochondrial superoxide anions that appeared after just 30 min of exposure of colon cancer cells to MPE. The effect was accompanied by mitochondrial injury, consisting of the dissipation of mitochondrial membrane potential and a decrease in the level of proteins localized in the mitochondrial membrane—such as voltage-dependent anion-selective channel (VDAC1), mitofilin, and some members of Bcl-2 family proteins (Mcl-1, Bcl-2 and Bcl-XL)—with the mitochondrial release of apoptogenic factors (cytochrome C and AIF). The analysis of the cytotoxic effects exerted by the different constituents of MPE (gallic acid, mangiferin, citric acid, quinic acid, pentagalloyl glucose, and methyl gallate) allowed us to identify those phytochemicals responsible for the observed anticancer effects, sustaining their future employment as chemopreventive or therapeutic agents.

Organotin(IV) compounds have found their place among a class of non-platinum chemotherapeutic metallo-pharmaceuticals exhibiting good antitumor activity. The cytotoxicity induced by the different kinds of organotins has been related to several mechanism. In this review we report our last decade research activity concerning the synthesis and chemical characterization of new organotin(IV) derivatives containing epigenetic modulator ligand by using, FT-IR, Mössbauer spectroscopy, 119Sn{1H} cross polarization magic angle spinning, electrospray ionization mass spectroscopy, UV–Vis, 1H, 13C{1H} and 119Sn{1H} NMR spectroscopy and density functional theory calculations. The first aim of the biological studies was to evaluate the effects exerted by organotin(IV) complexes in comparison with corresponding free ligands on a panel of different cancer cell lines, including human HepG2 hepatoma cells, HCT116 colorectal carcinoma cells and MDA-MB-231 breast cancer cells. We provide evidence that the compounds, generally, exert significant cytotoxic activity in cancer cells even at nanomolar (nM) or micromolar (μM) range concentrations. We also evaluated the biochemical pathways underlining these effects and the epigenetic activity of the compounds in the coordinated form compared to their parental constituents.

A lot of water has passed under the bridge since 1999, when C.J. Jeffery stated in a pioneering review that “the idea of one gene-one protein-one function has become too simple” [...]

Epidemiological studies suggest that chronic alcohol consumption is a lifestyle risk factor strongly associated with colorectal cancer development and progression. The aim of the present study was to examine the effect of ethanol (EtOH) on survival and progression of three different colon cancer cell lines (HCT116, HT29, and Caco-2). Our data showed that EtOH induces oxidative and endoplasmic reticulum (ER) stress, as demonstrated by reactive oxygen species (ROS) and ER stress markers Grp78, ATF6, PERK and, CHOP increase. Moreover, EtOH triggers an autophagic response which is accompanied by the upregulation of beclin, LC3-II, ATG7, and p62 proteins. The addition of the antioxidant N-acetylcysteine significantly prevents autophagy, suggesting that autophagy is triggered by oxidative stress as a prosurvival response. EtOH treatment also upregulates the antioxidant enzymes SOD, catalase, and heme oxygenase (HO-1) and promotes the nuclear translocation of both Nrf2 and HO-1. Interestingly, EtOH also upregulates the levels of matrix metalloproteases (MMP2 and MMP9) and VEGF. Nrf2 silencing or preventing HO-1 nuclear translocation by the protease inhibitor E64d abrogates the EtOH-induced increase in the antioxidant enzyme levels as well as the migration markers. Taken together, our results suggest that EtOH mediates both the activation of Nrf2 and HO-1 to sustain colon cancer cell survival, thus leading to the acquisition of a more aggressive phenotype.

A lifelong adherence to a gluten-free (GF) diet is currently the only treatment for Celiac disease (CD), an autoimmune disorder that arises after gluten ingestion in individuals who are genetically predisposed. The gluten intake exerts toxic effects through several pathways involving gut barrier integrity, intestinal microbiota composition and immune system stimulation. However, despite the great benefit of GF diet for CD patients, its use has been debated. Indeed, individuals who adopt this diet regime may be at risk of nutrient deficiencies. Emerging evidence supports a beneficial effect of a GF diet also for other pathological conditions, including gluten-related disorders (GRD) often associated to CD, such as Non celiac gluten sensitivity (NCGS) and Dermatitis Herpetiforme (DH) as well as Irritable bowel syndrome (IBS) and Diabetes. This suggests a pathogenic role of gluten in these conditions. Despite the growing popularity of GF diet among consumers, to date, there are limited evidences supporting its use for the management of non-celiac diseases. Therefore, in this review, we discuss whether the GF diet could really improve the general quality of life of patients with GRD and non-GRD conditions, keeping in mind its sensorial limitations and nutritional inadequacies. In addition, we discuss the current motivations, leading to the use of a GF diet, despite the inferior quality of GF products respect to those containing gluten.

Celiac Disease (CD) is an immune-mediated disease triggered by the ingestion of wheat gliadin and related prolamins from other cereals, such as barley and rye. Immunity against these cereal-derived proteins is mediated by pro-inflammatory cytokines produced by both innate and adaptive system response in individuals unable to adequately digest them. Peptides generated in this condition are absorbed across the gut barrier, which in these patients is characterized by the deregulation of its permeability. Here, we discuss a possible correlation between CD and Autistic Spectrum Disorder (ASD) pathogenesis. ASD can be induced by an excessive and inappropriate brain opioid activity during the neonatal period. Cereal-derived peptides produced in celiac patients cross the blood–brain barrier and bind to endogenous opioid receptors interfering with neurotransmission and generating deleterious effects on brain maturation, learning and social relations. Moreover, an increase in oxidative stress and a decrease in the antioxidant capacity, as well as an extended mitochondrial impairment in the brain, could represent a possible connection between ASD and CD. Therefore, we critically discuss the proposed relationship between ASD and CD and the possible usefulness of a gluten-free diet in ASD patients.

p62 is a versatile protein involved in the delicate balance between cell death and survival, which is fundamental for cell fate decision in the context of both cancer and neurodegenerative diseases. As an autophagy adaptor, p62 recognizes polyubiquitin chains and interacts with LC3, thereby targeting the selected cargo to the autophagosome with consequent autophagic degradation. Beside this function, p62 behaves as an interactive hub in multiple signalling including those mediated by Nrf2, NF-κB, caspase-8, and mTORC1. The protein is thus crucial for the control of oxidative stress, inflammation and cell survival, apoptosis, and metabolic reprogramming, respectively. As a multifunctional protein, p62 falls into the category of those factors that can exert opposite roles in the cells. Chronic p62 accumulation was found in many types of tumors as well as in stress granules present in different forms of neurodegenerative diseases. However, the protein seems to have a Janus behaviour since it may also serve protective functions against tumorigenesis or neurodegeneration. This review describes the diversified roles of p62 through its multiple domains and interactors and specifically focuses on its oncoJanus and neuroJanus roles.

Organotin compounds represent potential cancer therapeutics due to their pro-apoptotic action. We recently synthesized the novel organotin ferulic acid derivative tributyltin (IV) ferulate (TBT-F) and demonstrated that it displays anti-tumor properties in colon cancer cells related with autophagic cell death. The purpose of the present study was to elucidate the mechanism of TBT-F action in colon cancer cells. We specifically show that TBT-F-dependent autophagy is determined by a rapid generation of reactive oxygen species (ROS) and correlated with endoplasmic reticulum (ER) stress. TBT-F evoked nuclear factor erythroid-2 related factor 2 (Nrf2)-mediated antioxidant response and Nrf2 silencing by RNA interference markedly increased the anti-tumor efficacy of the compound. Moreover, as a consequence of ROS production, TBT-F increased the levels of glucose regulated protein 78 (Grp78) and C/EBP homologous protein (CHOP), two ER stress markers. Interestingly, Grp78 silencing produced significant decreasing effects on the levels of the autophagic proteins p62 and LC3-II, while only p62 decreased in CHOP-silenced cells. Taken together, these results indicate that ROS-dependent ER stress and autophagy play a major role in the TBT-F action mechanism in colon cancer cells and open a new perspective to consider the compound as a potential candidate for colon cancer treatment.

Programmed cell death is fundamental for multicellular organisms either in animal or plant kingdom. Classic apoptosis, which represents the best studied form of cell death, is dependent on caspase protease activity in animals. These proteases are not present in plants, where caspase-like activities, including metacaspases, are involved in the execution of plant cell death. Beyond apoptosis, various non-apoptotic forms of cell death also exist, including autophagy, necroptosis, pyroptosis, and ferroptosis. These types of cell death can be activated independently of apoptosis and sometimes occur when apoptosis is inhibited. Non-apoptotic forms of cell death are best characterized in animals, whereas, in plants, the literature is less extensive, but the molecular executioners of plant cell death are becoming clearer. The aim of this review is to describe different types of cell death and the mechanisms involved in animals and plants, highlighting similarities and differences in the two kingdoms. Moreover, implications of cell death pathways in cancer are discussed.

Litchi chinensis Sonnerat is a tropical tree whose fruits contain significant amounts of bioactive polyphenols. Litchi cultivation has recently spread in Sicily where the climate conditions are particularly favorable for this crop. Recent findings have shown that Litchi extracts display anti-tumor and pro-apoptotic effects in vitro, but the precise underlying mechanisms have not been fully elucidated. In this study, we report for the first time the effects of Sicilian litchi fruit extracts on colon cancer cells. The results indicated that litchi exocarp, mesocarp and endocarp fractions reduce the viability and clonogenic growth of HT29 cells. These effects were due to cell cycle arrest in the G2/M phase followed by caspase-dependent cell death. Interestingly, litchi exocarp and endocarp triggered a precocious autophagic response (16&ndash, 24 h), which was accompanied by an increase in the level of autophagy related 1/autophagy activating kinase 1 (ATG1/ULK1), beclin-1, microtubule associated protein 1 light chain 3 (LC3)-II and p62 proteins. Autophagy inhibition by bafilomycin A1 or beclin-1 silencing increased cell death, thus suggesting that autophagy was initially triggered as a pro-survival response. Significant effects of Litchi extracts were also observed in other colon cancer cells, including HCT116 and Caco-2 cells. On the other hand, differentiated Caco-2 cells, a model of human enterocytes, appeared to be insensitive to the extracts at the same treatment conditions. High-Performance Liquid Chromatography&ndash, Electrospray Ionization-Quadrupole-Time-Of-Flight HPLC/ESI/Q-TOF evidenced the presence of some polyphenolic compounds, specifically in exocarp and endocarp extracts, that can account for the observed biological effects. The results obtained suggest a potential therapeutic efficacy of polyphenolic compounds purified from Sicilian Litchi fractions for the treatment of colon cancer. Moreover, our findings indicate that modulation of autophagy can represent a tool to improve the effectiveness of these agents and potentiate the anti-tumor response of colon cancer cells.

Osteosarcoma is a highly metastatic tumor affecting adolescents, for which there is no second-line chemotherapy. As suggested for most tumors, its capability to overgrow is probably driven by cancer stem cells (CSCs), and finding new targets to kill CSCs may be critical for improving patient survival. TP53 is the most frequently mutated tumor suppressor gene in cancers and mutant p53 protein (mutp53) can acquire gain of function (GOF) strongly contributing to malignancy. Studies thus far have not shown p53-GOF in osteosarcoma. Here, we investigated TP53 gene status/role in 3AB-OS cells-a highly aggressive CSC line previously selected from human osteosarcoma MG63 cells-to evaluate its involvement in promoting proliferation, invasiveness, resistance to apoptosis and stemness. By RT-PCR, methylation-specific PCR, fluorescent in situ hybridization, DNA sequence, western blot and immunofluorescence analyses, we have shown that-in comparison with parental MG63 cells where TP53 gene is hypermethylated, rearranged and in single copy-in 3AB-OS cells, TP53 is unmethylated, rearranged and in multiple copies, and mutp53 (p53-R248W/P72R) is post-translationally modified and with nuclear localization. p53-R248W/P72R-knockdown by short-interfering RNA reduced the growth and replication rate of 3AB-OS cells, markedly increasing cell cycle inhibitor levels and sensitized 3AB-OS cells to TRAIL-induced apoptosis by DR5 up-regulation; moreover, it strongly decreased the levels of stemness and invasiveness genes. We have also found that the ectopic expression of p53-R248W/P72R in MG63 cells promoted cancer stem-like features, as high proliferation rate, sphere formation, clonogenic growth, high migration and invasive ability; furthermore, it strongly increased the levels of stemness proteins. Overall, the findings suggest the involvement of p53-R248W/P72R at the origin of the aberrant characters of the 3AB-OS cells with the hypothesis that its GOF can be at the root of the dedifferentiation of MG63 cells into CSCs.

p62 is a versatile protein involved in the delicate balance between cell death and survival, which is fundamental for cell fate decision in the context of both cancer and neurodegenerative diseases. As an autophagy adaptor, p62 recognizes polyubiquitin chains and interacts with LC3, thereby targeting the selected cargo to the autophagosome with consequent autophagic degradation. Beside this function, p62 behaves as an interactive hub in multiple signalling including those mediated by Nrf2, NF-κB, caspase-8, and mTORC1. The protein is thus crucial for the control of oxidative stress, inflammation and cell survival, apoptosis, and metabolic reprogramming, respectively. As a multifunctional protein, p62 falls into the category of those factors that can exert opposite roles in the cells. Chronic p62 accumulation was found in many types of tumors as well as in stress granules present in different forms of neurodegenerative diseases. However, the protein seems to have a Janus behaviour since it may also serve protective functions against tumorigenesis or neurodegeneration. This review describes the diversified roles of p62 through its multiple domains and interactors and specifically focuses on its oncoJanus and neuroJanus roles.

Litchi is a tasty fruit that is commercially grown for food consumption and nutritional benefits in various parts of the world. Due to its biological activities, the fruit is becoming increasingly known and deserves attention not only for its edible part, the pulp, but also for its peel and seed that contain beneficial substances with antioxidant, cancer preventive, antimicrobial, and anti-inflammatory functions. Although literature demonstrates the biological activity of Litchi components in reducing tumor cell viability in in vitro or in vivo models, data about the biochemical mechanisms responsible for these effects are quite fragmentary. This review specifically describes, in a comprehensive analysis, the antitumor properties of the different parts of Litchi and highlights the main biochemical mechanisms involved.

Breast cancer stem cells seem to play important roles in breast tumor recurrence and endocrine therapy resistance, although the underlying mechanisms have not been well established. Moreover, in some tumor systems the immunosurveillance failure against cancer cells has been related to the presence of the granzyme B inhibitor PI-9. This study explored the status of PI-9 in tumorspheres isolated from estrogen receptor-α positive (ERα+) breast cancer MCF7 cells. Studies were performed in tertiary tumorspheres which possess high levels of stemness markers (Nanog, Oct3/4 and Sox2) and self-renewal ability. The exposure to estrogens (17-β estradiol and genistein) increased the number and sizes of tumorspheres, promoting cell proliferation as demonstrated by the increase in the proliferating cell nuclear antigen (PCNA). The study of the three isoforms (66, 46 and 36 kDa) of ERα disclosed that tertiary tumorspheres exhibit a marked increase in ERα36, while the level of ERα66, which is highly expressed in MCF7 cells, declines. Although it is known that PI-9 is a transcriptional target of ERα66, surprisingly in tertiary tumorspheres, despite the reduced level of ERα66, the protein and mRNA content of PI-9 is higher than in MCF7 cells. Treatment with estrogens further increased PI-9 level while decreased that of ERα66 isoform thus excluding the involvement of this receptor isoform in the event. Moreover, our studies also provided evidence that tertiary tumorspheres express elevated levels of CXCR4 and phospho-p38, suggesting that the high PI-9 content might be ascribed to the activation of the proliferative CXCR4/phospho-p38 axis. Taken together, these events could supply a selective advantage to breast cancer stem cells by interfering with immunosurveillance systems and open up the avenue to new possible targets for breast cancer treatment.

DNA-binding investigations showed that two different derivatives endowed with pyrene and imidazolium moieties, 1 and 2, strongly bind both double-stranded DNA and telomeric sequences in G-quadruplex (G4) conformation. The values of the DNA-binding constants indicate that 1 and 2 show preferential affinity for G4-DNA, of about one and two orders of magnitude, respectively. Moreover, 1 and 2 inhibit short and long-term proliferation of breast cancer cell lines in a time- and dose-dependent fashion. Remarkably, senescence assays indicate that telomeric G4-DNA is a possible biotarget for the cytotoxic activity of 2. Molecular dynamics simulations suggest that the stronger binding of 2 with G4-DNA and the related senescence induction, are a consequence of additional edge-to-face interactions with a base in the TTA loop.

In this article, we demonstrate that the synthetic cannabinoid R-(+)-(2,3-dihydro-5-methyl-3-[(4-morpholinyl)methyl]pyrol[1,2,3-de]-1,4-benzoxazin-6-yl)-(1-naphthalenyl) methanone mesylate (WIN 55,212-2) sensitizes human hepatocellular carcinoma (HCC) cells to apoptosis mediated by tumor necrosis-related apoptosis inducing ligand (TRAIL). The apoptotic mechanism induced by treatment with WIN/TRAIL combination involved the loss of the mitochondrial transmembrane potential and led to the activation of caspases. In HCC cells, WIN treatment induced the up-regulation of TRAIL death receptor DR5, an effect that seemed to be related to the increase in the level of p8 and CHOP, two factors implicated in cellular stress response and apoptosis. This relationship was suggested by the observation that the down-regulation of p8 or CHOP by specific small interfering RNAs attenuated both WIN-mediated DR5 up-regulation and the cytotoxicity induced by WIN/TRAIL cotreatment. Moreover, WIN induced a significant decrease in the levels of some survival factors (survivin, c-inhibitor of apoptosis protein 2, and Bcl-2) and in particular in that of the active phosphorylated form of AKT. This event seemed to be dependent on the transcription factor peroxisome proliferator-activated receptor-gamma whose level significantly increased after WIN treatment. Therefore, both the induction of DR5 via p8 and CHOP and the down-regulation of survival factors seem to be crucial for the marked synergistic effects induced by the two drugs in HCC cells. Taken together, the results reported in this article indicate that WIN/TRAIL combination could represent a novel important tool for the treatment of HCC.

A novel cancer stem-like cell line (3AB-OS), expressing a number of pluripotent stem cell markers, was irreversibly selected from human osteosarcoma MG-63 cells by long-term treatment (100 days) with 3-aminobenzamide (3AB). 3AB-OS cells are a heterogeneous and stable cell population composed by three types of fibroblastoid cells, spindle-shaped, polygonal-shaped, and rounded-shaped. With respect to MG-63 cells, 3AB-OS cells are extremely smaller, possess a much greater capacity to form spheres, a stronger self-renewal ability and much higher levels of cell cycle markers which account for G1-S/G2-M phases progression. Differently from MG-63 cells, 3AB-OS cells can be reseeded unlimitedly without losing their proliferative potential. They show an ATP-binding cassette transporter ABCG2-dependent phenotype with high drug efflux capacity, and a strong positivity for CD133, marker for pluripotent stem cells, which are almost unmeasurable in MG-63 cells. 3AB-OS cells are much less committed to osteogenic and adipogenic differentiation than MG-63 cells and highly express genes required for maintaining stem cell state (Oct3/4, hTERT, nucleostemin, Nanog) and for inhibiting apoptosis (HIF-1alpha, FLIP-L, Bcl-2, XIAP, IAPs, and survivin). 3AB-OS may be a novel tumor cell line useful for investigating the mechanisms by which stem cells enrichment may be induced in a tumor cell line. The identification of a subpopulation of cancer stem cells that drives tumorigenesis and chemoresistance in osteosarcoma may lead to prognosis and optimal therapy determination. Expression patterns of stem cell markers, especially CD133 and ABCG2, may indicate the undifferentiated state of osteosarcoma tumors, and may correlate with unfavorable prognosis in the clinical setting.

The rotational spectrum of 3-hydroxy-pyridine has been investigated by free-jet absorption millimeter-wave spectroscopy. Two conformers ( cis and trans ) related to the orientation of the hydroxyl group with respect to the nitrogen atom, have been observed. The cis form is more stable by 380 (1 0 0) cm −1 .

Secreted protein acidic and rich in cysteine (SPARC) is a multi-functional protein which modulates cell-cell and cell-matrix interactions. In cancer cells, SPARC behaves as a tumor promoter in a number of tumors, but it can also act as a tumor suppressor factor. Our previous results showed that the synthetic cannabinoid WIN55,212-2 (WIN), a potent cannabinoid receptor agonist, is able to sensitize osteosarcoma MG63 cells to TNF-related apoptosis-inducing ligand (TRAIL)-induced apoptosis which is accompanied with endoplasmic reticulum (ER)-stress induction and the increase in autophagic markers. In the present investigation, we studied the role of SPARC in WIN/TRAIL-induced apoptosis demonstrating that WIN increased the level of SPARC protein and mRNA in a time-dependent manner. This event was functional to WIN/TRAIL-dependent apoptosis as demonstrated by RNA interfering analysis which indicated that SPARC-silenced cells were less sensitive to cytotoxic effects induced by the combined treatment. Our experiments also demonstrate that SPARC interacts with caspase-8 thus probably favoring its translocation to plasma membrane and the activation of extrinsic apoptotic pathway. In conclusion, to the best of our knowledge, our results are the first to show that WIN-dependent increase in the level of SPARC plays a critical role in sensitizing osteosarcoma cells to TRAIL action.

The 1:1 molecular complex between oxetane and water has been investigated by using free-jet millimeter-wave spectroscopy. The rotational spectra of five isotopomers (with H(2)O, D(2)O, DOH, HOD and H(2) (18)O) have been assigned. Partial r(0) and r(s) structures of the complex have been derived. The water moiety lies in the plane of symmetry of oxetane, with the "free" hydrogen E with respect to the ring. The oxetane ring appears to be slightly nonplanar, with the C(beta) carbon tilted on the opposite side of the water unity. The three atoms involved in the hydrogen bond adopt a linear arrangement with an O(ring).H distance of about 1.86 A, and the angle between the COC bisector and the O(ring).H bond being congruent with 106 degrees. Additionally, quantum-chemical calculations for the complex were performed and were found to be in agreement with the experimental results.

Little is known of the functions of caspases in mediating the surface changes required for phagocytosis of dying cells. Here we investigate the role played by the effector caspase, caspase-3 in this process using the caspase-3-defective MCF-7 breast carcinoma line and derived caspase-3-expressing transfectants. Our results indicate that, while certain typical features of apoptosis induced by etoposide - namely classical morphological changes and the ability to degrade DNA into oligonucleosomal fragments - are caspase-3-dependent, loss of cell adhesion to plastic and the capacity to interact with, and to be phagocytosed by, human monocyte-derived macrophages - both by CD14-dependent and CD14-independent mechanisms - do not require caspase-3. Furthermore, both etoposide-induced caspase-3-positive and -negative MCF-7 cells suppressed proinflammatory cytokine release by macrophages. These results demonstrate directly that cell surface changes that are sufficient for anti-inflammatory clearance by human macrophages can be regulated independently of stereotypical features of the apoptosis programme that require caspase-3.

The rotational spectra of the ground state and of one vibrational satellite of 2,3-benzofuran have been measured by millimetre-wave absorption free jet spectroscopy in the frequency range 60-78 GHz. The value of the inertial defect (-0.072 uÅ2) shows the molecule to be planar. The shifts of the rotational constants in going from the ground to the excited state indicate that the observed vibrational satellite does not belong to the two lowest energy motions, the butterfly and 1,3-ring-twisting, which undergo relaxation upon the supersonic expansion.

Historically, Mangifera indica L. cultivations have been widely planted in tropical areas of India, Africa, Asia, and Central America. However, at least 20 years ago its spreading allowed the development of some cultivars in Sicily, an island to the south of Italy, where the favourable subtropical climate and adapted soils represent the perfect field to create new sources of production for the Sicilian agricultural supply chain. Currently, cultivations of Kensington Pride, Keitt, Glenn, Maya, and Tommy Atkins varieties are active in Sicily and their products meet the requirements of local and European markets. Mango plants produce fleshy stone fruits rich in phytochemicals with an undisputed nutritional value for its high content of polyphenolics and vitamins. This review provides an overview of the antioxidant, anti-inflammatory, and anticancer properties of mango, a fruit that should be included in everyone’s diet for its multifaceted biochemical actions and health-enhancing properties.

The synthetic cannabinoid WIN 55,212-2 is a potent cannabinoid receptor agonist with anticancer potential. Experiments were performed to determine the effects of WIN on proliferation, cell cycle distribution, and programmed cell death in human osteosarcoma MG63 and Saos-2 cells. Results show that WIN induced G2/M cell cycle arrest, which was associated with the induction of the main markers of ER stress (GRP78, CHOP and TRB3). In treated cells we also observed the conversion of the cytosolic form of the autophagosome marker LC3-I into LC3-II (the lipidated form located on the autophagosome membrane) and the enhanced incorporation of monodansylcadaverine and acridine orange, two markers of the autophagic compartments such as autolysosomes. WIN also induced morphological effects in MG63 cells consisting in an increase in cell size and a marked cytoplasmic vacuolization. However, WIN effects were not associated with a canonical apoptotic pathway, as demonstrated by the absence of specific features, and only the addition of TRAIL to WIN-treated cells led to apoptotic death probably mediated by up-regulation of the tumor suppressor factor PAR-4, whose levels increased after WIN treatment, and by the translocation of GRP78 on cell surface.

Cannabinoids have been reported to possess anti-tumorigenic activity in cancer models although their mechanism of action is not well understood. Here, we show that the synthetic cannabinoid WIN55,212-2 (WIN)-induced apoptosis in colon cancer cell lines is accompanied by endoplasmic reticulum stress induction. The formation of acidic vacuoles and the increase in LC3-II protein indicated the involvement of autophagic process which seemed to play a pro-survival role against the cytotoxic effects of the drug. However, the enhanced lysosomal membrane permeabilization (LMP) blocked the autophagic flux after the formation of autophagosomes as demonstrated by the accumulation of p62 and LC3, two markers of autophagic degradation. Data also provided evidence for a role for nuclear receptor peroxisome proliferator-activated receptor γ (PPARγ) in cannabinoid signalling. PPARγ expression, at both protein and mRNA levels, was significantly down-regulated after WIN treatment and its inhibition, either by specific antagonists or by down-regulation via gene silencing, induced effects on cell viability as well as on ER stress and autophagic markers similar to those obtained in the presence of WIN. Moreover, the observation that the increase in p62 level and the induction of LMP were also modified by PPARγ antagonists seemed to indicate that PPARγ down-regulation was crucial to determinate the block of autophagic flux, thus confirming the critical role of PPARγ in WIN action. In conclusion, at our knowledge, our results are the first to show that the reduction of PPARγ levels contributes to WIN-induced colon carcinoma cell death by blocking the pro-survival autophagic response of cells.

This paper studies the cytotoxic effect induced by the topoisomerase I inhibitor camptothecin in human osteosarcoma Saos-2 cells, which lack p53 and contain a non-functional form of the product of the retinoblastoma gene, pRb. Cytotoxicity induced by camptothecin was dose- and time-dependent; the treatment with 100 nM camptothecin reduced cell viability by 50% at 32 h and by 75% at 72 h of exposure. The cytotoxic effect was caused by apoptosis, as ascertained by morphological evidence, acridine orange-ethidium bromide staining and flow cytometric analysis. Apoptosis was accompanied by both the activation of caspase-3 and the fragmentation of poly(ADP-ribose) polymerase. Treatment with camptothecin caused a threefold increase in the activity of c-Jun N-terminal kinase (JNK) and an eightfold increase in the level of phosphorylated c-Jun. The introduction of the RB gene into Saos-2 cells reduced the rate of cell growth. Moreover, stable clones of transfected cells were resistant to camptothecin. Exposure to 100 nM camptothecin for 72 h reduced the viability of transfected cells by only 10%; moreover, very modest effects were observed on the activity of JNK as well as on the level of phosphorylated c-Jun. The results reported in this paper support the conclusion that the expression of wild-type pRb in Saos-2 cells exerts an anti-apoptotic influence through the control of JNK activity.

The rotational spectrum of 4-hydroxypyridine has been investigated by free jet absorption millimeter-wave spectroscopy. Only the enolic form is observed. All transitions are split into two component lines due to the internal rotation of the hydroxyl group. From the ground state splitting (Δ E = 7.97(4) MHz) the barrier to internal rotation V 2 = 1513(10) cm −1 has been obtained.