Factors that protect HepG2 cells by anandamide-induced cell death

A Deadly Liaison between Oxidative Injury and p53 Drives Methyl-Gallate-Induced Autophagy and Apoptosis in HCT116 Colon Cancer Cells

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 …

Apoptosis induced in HepG2 cells by the synthetic cannabinoid WIN: involvement of the transcription factor PPARgamma.

It has recently been shown that cannabinoids induce growth inhibition and apoptosis in different tumour cell lines. In the current study, the effects of WIN 55,212-2 (WIN), a synthetic and potent cannabinoid receptor agonist, are investigated in hepatoma HepG2 cells and a possible signal transduction pathway is proposed. In these cells, WIN induces a clear apoptotic effect which was accompanied by up-regulation of the death-signalling factors Bax, Bcl-X(S), t-Bid and down-regulation of the survival factors survivin, phospho-AKT, Hsp72 and Bcl-2. Moreover, WIN-induced apoptosis is associated with JNK/p38 MAPK pathway activation and mitochondrial depolarisation demonstrated by a cytofluorimet…

pRb suppresses camptothecin-induced apoptosis in human osteosarcoma Saos-2 cells by inhibiting c-Jun N-terminal kinase

AbstractThis 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 wi…

Role of PPARγ in apoptosis induced by cannabinoids in hepatoma HepG2 cells.

Apoptosis induced by the histone deacetylase inhibitor SAHA in human colon adenocarcinoma cell line HT29

INVOLVEMENT OF ER-STRESS IN SPARC UP-REGULATION INDUCED BY WIN AND IN APOPTOSIS OF MG63 CELLS

ER+-derived breast cancer stem cells reveal a high expression of the serpin protease inhibitor PI-9.

Introduction: Breast cancers (BC) are the major cause of death in women. More than 70% of BCs express high levels of estrogen receptor-α (ERα) and are sustained for their growth by the hormone. Estrogens seem to protect BC cells from apoptosis mediated by immunosurveillance associated with cytotoxic T lymphocytes and NK cells granzyme B release. However, the production of granzyme B inhibitor PI-9 by tumor cells causes a short-circuit in immunosurveillance’s signalling. Although it has been shown the role of PI-9 in BC cells, its presence has not been investigated in tumor stem cells so far. Methods: Cell viability was evaluated by MTT, cell cycle by propidium iodide staining; mRNA and prot…

The synthetic cannabinoid WIN55,212-2 synergizes with the death receptor ligand TRAIL to induce apoptotic effect in HepG2 hepatoma cells.

Different expression of PPARs in WIN-treated cells: the game of roles

Nucleoside phosphotransferase of chick embryo

This paper describes a purification procedure and some properties of a nonspecific nucleoside phosphotransferase of chick embryo, an activity which catalyzes the transfer of chick embryo, an activity which catalyzes the transfer of the phosphate ester from a deoxyribonucleotide or a pyrimidine ribonucleotide to a deoxyribonucleoside acceptor. The enzyme is very unstable to heat, dilution and dialysis and it is almost entirely inactivated by DEAE-cellulose chromatography or gel filtration. A marked enhancement in its stability is caused by numerous nucleotides. In these experiments at least 920-fold purification was obtained by using dTTP (50 microM) as nucleotide protector. The enzyme, puri…

Multifaceted Health Benefits of Mangifera indica L. (Mango): The Inestimable Value of Orchards Recently Planted in Sicilian Rural Areas

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 undispute…

Multifaceted Healthy Benefits of Mangifera Indica L. (Mango): The Inestimable Value of an Orchard Recently Rooted in Sicilian Rural Areas

Historically, Mangifera indica L. cultivations have been widely rooted in tropical areas of India, Africa, Asia and Central America. However, at least 20 years ago its spreading allowed the development of some cultivars, also in Sicily, the South of Italy, where the favorable subtropical climate and adapted soils represent the perfect field to create new sources of production for Sicilian agricultural supply chain. Currently, cultivations of Kensington Pride, Keitt, Klenn, Maya and Tommy Atkins varieties are active in Sicilian island and their products meet the requirements of local and European markets. Mango plants produce fleshy stone fruits rich in phytochemicals with an undisputed nutr…

Role of insulin-like growth factors in autocrine growth of human retinoblastoma Y79 cells.

In this study, we have demonstrated that human retinoblastoma Y79 cells produce insulin-like growth factors (IGFs) type I and type II and release them into the medium. We have also ascertained, by means of competitive studies and cross-linking procedure, that Y79 cells contain the type-I IGF receptor (IGF-IR). Furthermore, surface-bound IGF-I is internalised by the receptor, then degraded to amino acids. Insulin, IGF-I and IGF-II caused down-regulation of IGF-IR; the effect is concentration and time dependant. Scatchard analysis demonstrated that incubation with insulin markedly decreased the binding capacity measured for IGF-I while the apparent Kd value calculated for IGF-I binding was no…

Insulin and IGFs induce apoptosis in chick embryo retinas deprived of L-glutamine

In chick embryo retinas, cultured in serum-free medium lacking L-glutamine, IGF-I, IGF-II and insulin induced apoptotic DNA fragmentation and cell death, IGF-I being the most efficacious compound. The apoptotic effect, which was particularly evident in retinas removed from 7-day-old chick embryos, declined with the age of the embryos and disappeared after day 11. Apoptosis appeared after a time lag of 8 h and then increased with time up to 16 h. Cycloheximide, an inhibitor of protein synthesis, was capable of entirely abolishing apoptotic cell death. The effect induced by IGFs or insulin was suppressed by the addition of glutamine. Cytokine-mediated apoptosis was also observed after withdra…

The proteasome inhibitor bortezomib in programmed cell death and cancer therapy

The 26S proteasome is a ubiquitous enzyme complex which is responsible for degrading proteins that regulate essential cellular functions, such as cell-cycle control, cellular adhesion, proliferation, apoptosis and angiogenesis. The inhibition of proteasome dysregulates these signalling pathways, ultimately leading to cell cycle arrest and apoptosis in many cell types. Importantly, preclinical research has shown that cancer cells seem to be more sensitive to the proapoptotic effects of proteasome inhibition than normal cells. First-generation proteasome inhibitors lacked usefulness because of broad specificity and irreversible binding to the proteasome. However, the peptide boronic acid prot…

Inhibition of DNA synthesis in chick embryo retinas, in vitro, by a factor from fetal bovine serum

Fetal bovine serum inhibited deoxyribonucleic acid (DNA) synthesis in chick embryo retina explants. The inhibitory activity was precipitated from fetal bovine serum by 45% saturated ammonium sulfate and isolated by means of Sephadex G-100 and Bio-Gel P-60 columns as a peak with an apparent molecular weight of 7000 Da. DNA-inhibiting activity was heat- and acid-stable and was destroyed by dithiothreitol and alkaline treatment. The purified factor inhibited similarly both DNA synthesis and thymidine kinase activity; 50% inhibitory effect was found with 160 ng, 17 h after the addition into the incubation medium.

Electrophoretic Mobility Shift Assay (EMSA) or Gel Shift Assay

Apoptosis induced in hepatoblastoma HepG2 cells by the proteasome inhibitor MG132 is associated with hydrogen peroxide production, expression of Bcl-Xs and activation of caspase-3

This report is focused on the apoptotic effect induced by MG132, an inhibitor of 26S proteasome, in human hepatoma HepG2 cells. The results were compared with those obtained with non-transformed human Chang liver cells. MG132 reduced the viability of HepG2 cells in a time- and dose-dependent manner. The effect was in tight connection with the induction of apoptosis, as indicated by fluorescence microscopy and cytometric analysis, and was accompanied by a remarkable increase in the production of H2O2 and a reduction in mitochondrial transmembrane potential (Deltapsim). In addition cell death was prevented by antioxidants such as GSH, N-acetylcysteine or catalase. Western blot analysis showed…

WIN induces apoptotic cell death in human colon cancer cells through a block of autophagic flux dependent on PPARγ down-regulation.

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 ma…

JNK and AP-1 mediate apoptosis induced by bortezomib in HepG2 cells via FasL/caspase-8 and mitochondria-dependent pathways

The proteasome inhibitor bortezomib is an efficacious apoptotic agent in many tumor cells. This paper shows that bortezomib induced apoptosis in human hepatoma HepG2 cells associated with many modifications in the expression of survival or death factors. Although bortezomib increased the level of the protective factors HSP70 and HSP27, the effects of the drug that favour cell death were predominant. These events include accumulation of c-Jun, phospho-c-Jun and p53; increase in FasL level with activation of caspase-8; changes related to members of Bcl-2 family with increase in the level of pro-apoptotic members and decrease in that of anti-apoptotic ones; dissipation of mitochondrial potenti…

WIN modulates osteosarcoma MG63 cell migration by inhibiting MMPs activity and adjusting intra- and extra-cellular SPARC differential expression

Invasion of cancer cells into surrounding tissue is an initial step in tumor metastasis. This event, which requires migration of cancer cells and attachment to extracellular matrix (ECM), is regulated by elements of the local microenvironment, including ECM architecture. After having demonstrated the ability of the synthetic cannabinoid WIN55,512 to induce osteosarcoma MG63 cell death (1), we studied the effects of WIN on MG63 cell migration. Wound healing assay was performed to measure the ability of cells to migrate and fill the gap obtained by physical disruption of cell monolayer (2). We observed a significant delay in wound closure in 5 M WIN treated cells compared to untreated cells …

FT-IR Investigation of the Urea State in AOT Reversed Micelles

Abstract FT-IR spectra of the urea/sodium bis(2-ethylhexyl) sulfosuccinate (AOT)/CCl 4 system as a function of the urea-to-AOT molar ratio ( R urea ) at a fixed AOT concentration ([AOT]=0.1 mol·kg −1 ) have been recorded at 25°C. The experimental data are consistent with the hypothesis that at low R urea values urea is dispersed as monomers among the hydrophilic core of AOT reversed micelles, whereas at R urea >0.13 it is encapsulated as small molecular clusters. These clusters display some departures from the H-bonded structure of the pure solid urea attributable to their small size and to urea–AOT head group interactions. The stretching modes of AOT sulfonate groups are affected by the pr…

The Anti-Cancer Effect of Mangifera indica L. Peel Extract is Associated to γH2AX-mediated Apoptosis in Colon Cancer Cells

Ethanolic extracts from Mangifera indica L. have been proved to possess anti-tumor properties in many cancer systems. However, although most effects have been demonstrated with fruit pulp extract, the underlying molecular mechanisms of mango peel are still unclear. This study was designed to explore the effects of mango peel extract (MPE) on colon cancer cell lines. MPE affected cell viability and inhibited the colony formation trend of tumor cells, while no effects were observed in human dermal fibroblasts used as a non-cancerous cell line model. These events were a consequence of the induction of apoptosis associated to reactive oxygen species (ROS) production, activation of players of th…

Polynuclear complexes of Pt(II) with polypyridyl ligands.II.Synthesis, spectroscopic and structural characterization and cytotoxic activity

Transfer of Some Alkyl Substituted Ferrocenes from Water to Cationic Surfactant Micelles Studied by Kinetic Method

Abstract Binding of ferrocene and its 1,1′-dimethyl and n -butyl derivatives to dodecyl and tetradecyltrimethylammonium nitrate micellar aggregates has been studied at 20.0°C and ionic strength 0.02 tool dm -3 by examining the micellar retarding effects on the rates of iron(III) oxidation of these substrates. Solubilization of the ferrocenes in the cationic micellar phase increases as the substrate hydrophobic character increases and, to a lesser extent, as the surfactant hydrocarbon chain length becomes longer. The critical micelle concentrations of the surfactants used and the incremental free energy of transfer of methylene groups of both the substrate and the surfactant from the aqueous…

SICILIAN MANGO PEEL INDUCES CELLULAR STRESS ACCOMPANIED TO MITOCHONDRIAL DYSFUNCTION IN COLON CANCER CELLS

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…

Stromal SPARC contributes to the detrimental fibrotic changes associated with myeloproliferation whereas its deficiency favors myeloid cell expansion.

Abstract In myeloid malignancies, the neoplastic clone outgrows normal hematopoietic cells toward BM failure. This event is also sustained by detrimental stromal changes, such as BM fibrosis and osteosclerosis, whose occurrence is harbinger of a dismal prognosis. We show that the matricellular protein SPARC contributes to the BM stromal response to myeloproliferation. The degree of SPARC expression in BM stromal elements, including CD146+ mesenchymal stromal cells, correlates with the degree of stromal changes, and the severity of BM failure characterizing the prototypical myeloproliferative neoplasm primary myelofibrosis. Using Sparc−/− mice and BM chimeras, we demonstrate that SPARC contr…

Synthesis, characterization, cellular uptake and interaction with native DNA of a bis(pyridyl)-1,2,4-oxadiazole copper(II) complex

The copper(II) complex of 3,5-bis(2'-pyridyl)-1,2,4-oxadiazole was synthesized and characterized. X-Ray crystallography revealed that the complex consists of a discrete [Cu(3,5-bis(2'-pyridyl)-1,2,4-oxadiazole)(2)(H(2)O)(2)](2+) cation and two ClO(4)(-) anions. The Cu(II) coordination sphere has a distorted octahedral geometry and each ligand chelates the copper ion through the N(4) nitrogen of the oxadiazole ring and the nitrogen of one pyridine moiety. The coordinated water molecules are in cis position and each of them is H-bonded to the 5-pyridyl nitrogen of the oxadiazole ligand and to an oxygen of the perchlorate anion. Biological assays showed that, despite the free ligand not being …

Organotin(IV) and simple fatty acids: preliminary assessments

Our group has a long researching tradition in the field of organotin(IV) complexes, usually proposed and tested as potential anti-tumor drugs. The leitmotif has usually been the modulation of the intrinsic toxicity/cytotoxicity of the organometallic moiety and a modulation of the toxic effect by means of biologically related molecules (synthetic or natural). Such a modulation is usually achieved by two (often overlapping) routes: dampen the damaging effects of the metal core, and serving as a carrier for specific tissue districts. Since a too tight binding on the organotin moiety is not always desirable – a too much stable complex could be a non-active one – carboxylates have always played …

Insulin synthesis in chick embryo retinas during development.

Retinas of chick embryos contain insulin (1) and further, are capable of synthesizing it, as demonstrated by incubating retinas at different ages (7th–18th day) with [3H]leucine. The synthesized radioactive insulin was isolated and assayed by means of a HPLC procedure. The synthesis of insulin was found to be highest in the youngest retinas studied (day 7), afterwards it declined with age except for an increment found at 14–15 day. Explants of chick embryo retinas, cultured in vitro, rapidly degraded insulin. Nevertheless, the content of immunoreactive insulin in retinal explants diminished slowly with the age of culture, so that, after 8 days of incubation, it was about 60% of the content …

Synthesis of insulin and its effects in Y79 human retinoblastoma cells

This paper demonstrates that Y79 human retinoblastoma cells contain immunoreactive insulin (IRI) and release it in the medium. Cells cultured either in suspension or in monolayer showed a similar content of IRI. Moreover, in both conditions, IRI concentration was higher in cells cultured in serum-supplemented medium rather than in serum-free medium. Retinoblastoma cells are capable of synthesizing insulin. This was demonstrated by incubating Y79 cells with [3H]leucine. The synthesized radioactive insulin was separated and assayed by means of a HPLC procedure described in this paper. Both cell growth and [3H]thymidine and [3H]uridine incorporation into acid-insoluble fraction was reduced (-7…

The analysis of estrogen receptor-α positive breast cancer stem-like cells unveils a high expression of the serpin proteinase inhibitor PI-9: Possible regulatory mechanisms

Abstract 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…

Some kinetic properties of the chick embryos nucleoside phosphotransferase

Purification of a fetal bovine serum factor that inhibits DNA synthesis in chick embryo retinas

Anti-adipogenic potential of bio-waste products of Sicilian mango in 3T3-L1 cells

Cannabinoid-associated cell death mechanisms in tumor models

In recent years, cannabinoids (the active compo- nents of Cannabis sativa) and their derivatives have received considerable interest due to findings that they can affect the viability and invasiveness of a variety of different cancer cells. Moreover, in addition to their inhibitory effects on tumor growth and migration, angiogenesis and metastasis, the ability of these compounds to induce different pathways of cell death has been highlighted. Here, we review the most recent results generating interest in the field of death mechanisms induced by cannabinoids in cancer cells. In particular, we analyze the pathways triggered by cannabinoids to induce apoptosis or autophagy and investigate the …

The cannabinoid WIN induces DR5 receptor expression in hepatoma cells sensitizing them to TRAIL signal

Ethanol-Mediated Stress Promotes Autophagic Survival and Aggressiveness of Colon Cancer Cells via Activation of Nrf2/HO-1 Pathway

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-acetyl…

SYNERGISTIC APOPTOTIC INTERACTION BETWEEN THE HDAC INHIBITOR SAHA AND THE PROTEASOME INHIBITOR BORTEZOMIB IN HUMAN HEPATOMA CELLS.

Studio dell'autofagia nella citotossicità indotta dai cannabinoidi in cellule tumorali

Bortezomib induces in HepG2 cells IkappaBalpha degradation mediated by caspase-8.

The present paper demonstrates that the proteasome inhibitor bortezomib, which behaves as an apoptotic agent in hepatoma HepG2 cells, caused in these cells a decrease in IkappaBalpha level and a consequent increase in NF- kappaB activity. The effect already appeared at 4 h of treatment and preceded the onset of apoptosis which was observed at 24 h. Our results demonstrate that bortezomib-induced IkappaBalpha degradation occurred in conjunction with the activation of caspase-8; moreover, the decrease in IkappaBalpha level was prevented in a dose-dependent manner by the addition of z-IETD, a specific inhibitor of caspase-8. Bortezomib caused the same effects in non-tumor Chang liver cells, wh…

The synthetic cannabinoid WIN sensitizes hepatocellular carcinoma cells to TRAIL-induced apoptosis by activating p8/CHOP/DR5 axis.

In this paper we demonstrate that the synthetic cannabinoid WIN sensitizes human hepatocellular carcinoma (HCC) cells to apoptosis mediated by TNF-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 up-regulation of TRAIL death receptor DR5, an effect which 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 siRNAs …

Dibuthyltin(IV) Complexes with Caffeic acid: Apoptotic Effect on human cancer cells

JNK AND AP-1 MEDIATE APOPTOSIS INDUCED BY BORTEZOMIB IN HEPATOMA HEPG2 CELLS.

Role of sparc and MIR-29B1 in molecular effects induced by win in osteosarcoma MG63 cells

SPARC (Secreted protein acidic and rich in cysteine) is considered as a prototype of matricellular protein due to its structure and the function that it displays in regulating cell/extracellular microenvironment interactions during development and in response to injury. Earlier studies underlined pleiotropic effects of intracellular SPARC on cancer growth and, in some cancer cell lines, identified it as a tumor suppressor protein. Objective This study aimed to evaluate the role of SPARC and its related miRNA in the molecular effects induced by the cannabinoid WIN in osteosarcoma MG63 cells. In these cells WIN is not able to induce cell death but sensitizes cells to TRAIL-mediated apoptotic …

DNA content and thymidine incorporation during chick embryo retina development:hydrocortisone effect

Hsp72 and NF-κB protect human hepatoma HepG2 cells in the first phase of treatment with bortezomib

Ornithine decarboxylase activity during chick embryo retina development:hydrocortisone effect

Oxidative stress induced by the novel compound tributyltin(iv) ferulate promotes ER stress and autophagy in colon cancer cells

Synergistic effects induced by combinations of the synthetic cannabinoid WIN55,212-2 and the death receptor ligand TRAIL in hepatoma HepG2 cells.

Cannabinoid-associated cell death mechanisms in tumor models (review)

In recent years, cannabinoids (the active components of Cannabis sativa) and their derivatives have received considerable interest due to findings that they can affect the viability and invasiveness of a variety of different cancer cells. Moreover, in addition to their inhibitory effects on tumor growth and migration, angiogenesis and metastasis, the ability of these compounds to induce different pathways of cell death has been highlighted. Here, we review the most recent results generating interest in the field of death mechanisms induced by cannabinoids in cancer cells. In particular, we analyze the pathways triggered by cannabinoids to induce apoptosis or autophagy and investigate the in…

Uridine enhances the cytotoxic effect of D-glucosamine in rat C6 glioma cells.

This paper studies the influence of uridine on the effects exerted by D-glucosamine in rat C6 glioma cells. 2 mM uridine increased markedly both the cytotoxic effect of the aminosugar and the inhibition of thymidine incorporation into acid-insoluble fraction. Furthermore the complete resumption of the capacity to incorporate either 3H-thymidine or 3H-mannose which was observed after the removal of the aminosugar, was impeded when the cells were treated contemporaneously with D-glucosamine and uridine. An exposure for 4 hr to 20 mM glucosamine alone enhanced about 15-fold the cellular pool of UDP-N-acetylhexosamines; the addition of 2 mM uridine intensified the expansion of this pool, which …

Hsp-72 contrasta l'effetto apoptotico indotto dal bortezomib in cellule di epatoblastoma umano Hep-G2

Sodium phenylbutyrate induces apoptosis in human retinoblastoma Y79 cells: The effect of combined treatment with the topoisomerase I-inhibitor topotecan

Our results demonstrate that sodium phenylbutyrate, a compound with a low degree of toxicity, exerted a cytotoxic effect on human retinoblastoma Y79 cells in a time- and dose-dependent manner. Treatment of Y79 cells for 72 h with phenylbutyrate reduced cell viability by 63% at 2 mM and 90% at 4 mM. Cell death caused by phenylbutyrate exhibited the typical features of apoptosis, as shown by light and fluorescent microscopy. Western blot analysis demonstrated that exposure of Y79 cells to phenylbutyrate decreased the level of the antiapoptotic factor Bcl-2 and induced the activation of caspase-3, a key enzyme in the execution phase of apoptosis. Moreover, treatment with phenylbutyrate markedl…

Parthenolide and Its Soluble Analogues: Multitasking Compounds with Antitumor Properties

Due to its chemical properties and multiple molecular effects on different tumor cell types, the sesquiterpene lactone parthenolide (PN) can be considered an effective drug with significant potential in cancer therapy. PN has been shown to induce either classic apoptosis or alternative caspase-independent forms of cell death in many tumor models. The therapeutical potential of PN has been increased by chemical design and synthesis of more soluble analogues including dimethylaminoparthenolide (DMAPT). This review focuses on the molecular mechanisms of both PN and analogues action in tumor models, highlighting their effects on gene expression, signal transduction and execution of different ty…

Partial purification and some properties of a nucleoside phosphotransferase of chick embryos.

A nucleoside phosphotransferase purified about 40fold from chick embryos utilizes efficiently as phosphate donors deoxyribonucleoside and pyrimidine ribonucleoside monophosphates, whereas the pyrimidine deoxyribonucleoside appear to be the preferred acceptors of phosphate. The enzyme is very unstable to heat, dilution and dialysis. A marked enhancement in the stability is caused by nucleotides and it seems associated with the formation of an aggregated state of the protein.

Synergistic cytotoxic interactions between sodium butyrate, MG132 and camptothecin in human retinoblastoma Y79 cells.

This paper studies the effects caused in human retinoblastoma Y79 cells by treatment with combinations of sodium butyrate, the inhibitor of topoisomerase I camptothecin and the inhibitor of 26S proteasome MG132. The combination of sodium butyrate and camptothecin resulted in a strong synergistic cytotoxicity, as revealed by combination indices of 0.77 and 0.52 calculated at IC(50) and IC(75). Synergistic interactions were also demonstrated for combinations of sodium butyrate and MG132, camptothecin and MG132 and for a combination of all three compounds. The cytotoxic effects observed after the combined treatments can be considered a consequence of apoptosis, as suggested by the appearance o…

Loss of ISWI in Drosophila immaginal discs causes cell cycle defects

Oncogenic BRAF protein as a molecular target of HDAC inhibitors in melanoma cells

Redox Imbalance and Mitochondrial Release of Apoptogenic Factors at the Forefront of the Antitumor Action of Mango Peel Extract

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 a…

Insulin-like growth factors in chick embryo retina during development.

Evidence exists supporting an important role for insulin-like growth factors (IGFs) during fetal growth. In the present report we performed studies to define whether developing chick retina contains IGFs and whether IGFs play a role in the growth of this tissue. We have shown that both IGF-I and IGF-II are present in chick embryo retina throughout development (7th-18th day). The highest values, when expressed as ng/g of tissue, were found in the youngest retinas studied (7th-9th day) and at 16th-18th day of development. During whole development the content of IGF-II was about two to three times higher than that ascertained for IGF-I. The tissue also contains cell-surface binding for IGFs. H…

High-performance liquid chromatographic method for the determination of insulin synthesis in biological systems

Effects of N2, O2'-dibutyril cyclic GMP on the nucleoside phosphotransferase activity of the retina of the chick embryos.

In the retina of the chick embryo, 2 different forms of nucleoside phosphotransferase take part in the phosphorylation of thymidine. One is an unstable form with higher molecular weight. The other with lower m. wt is a stable form. This paper shows that N2, O2′-dibutyril cyclic GMP causes a marked decrement of the activity of the unstable nucleoside phosphotransferase.

Kinetic properties of a nucleoside phosphotransferase of chick embryo

1. A nonspecific nucleoside phosphotransferase (nucleotide : 3'-deoxynucleotide 5'-phosphotransferase, EC 2.7.1.77), purified from chick embryos, catalyzes the transfer of phosphate ester from a nucleotide donor to a nucleoside acceptor. 2. The enzyme exhibits sigmoidal kinetics with respect to nucleoside monophosphate donors, but with respect to nucleoside di- or triphosphate donors and nucleoside acceptors hyperbolic kinetics were obtained. 3. The nucleoside phosphotransferase of chick embryo is unstable to heat and is protected from inactivation by a large number of nucleosides. 4. Nucleoside di- and triphosphates lower both the concentration of nucleoside monophosphates required for hal…

Autophagy and ER-stress participate to cannabinoid-induced apoptosis in colon carcinoma cells

The Beneficial Effects of Essential Oils in Anti-Obesity Treatment

Obesity is a complex disease caused by an excessive amount of body fat. Obesity is a medical problem and represents an important risk factor for the development of serious diseases such as insulin resistance, type 2 diabetes, cardiovascular disease, and some types of cancer. Not to be overlooked are the psychological issues that, in obese subjects, turn into very serious pathologies, such as depression, phobias, anxiety, and lack of self-esteem. In addition to modifying one’s lifestyle, the reduction of body mass can be promoted by different natural compounds such as essential oils (EOs). EOs are mixtures of aromatic substances produced by many plants, particularly in medicinal and aromatic…

A comparison between the role of SPARC in osteogenic differentiation of mesenchymal stem cells and in WIN/TRAIL-induced apoptosis in osteosarcoma cells

Synthesis, structural characterisation and biological studies of new mononuclear platinum(II) complexes with sterically hindered heterocyclic ligands

Abstract Three novel cisplatin analogues were synthesized, designed according to an approach which violates the “classical” structure–activity relationship, by replacing the diamine ligands with a planar N donor heterocycle giving a sterically hindered complex. Moreover, the sterical hindrance of antitumor drug candidates potentially makes them less susceptible to deactivation by sulphur-containing proteins and helping to overcome resistance mechanisms. The resulting mononuclear complexes of sterically hindered polidentate heterocyclic N ligands [PtCl(bbp)]Cl ( 1 ) [bbp = 2,6-bis(2-benzimidazolyl)pyridine], [PtCl 2 (dptdn)](H 2 O) ( 2 ) [dptdn = sodium 5,6-diphenyl-3-(2′-pyridyl)-1,2,4-tria…

Hsp72 controls bortezomib-induced HepG2 cell death via interaction with pro-apoptotic factors.

The proteasome inhibitor bortezomib is an efficacious inducer of apoptosis in the hepatoma HepG2 cell line. This study shows that bortezomib increased in these cells the level of the survival factor Hsp72 in a time- and dose-dependent manner. In a first phase of treatment, Hsp72 rapidly increased so that at 24 h of incubation with 50 nM bortezomib its level was approximately five-fold higher than the control. In this phase Hsp72 seemed to play a role in preventing HepG2 cell death, since it interacted with and sequestered the pro-apoptotic factors p53, AIF, Bax and Apaf-1. During a second day of treatment, although the nuclear levels of Hsp72, p53 and AIF increased, the interaction of Hsp72…

WIN55,212-2-induced expression of Mir-29b1 favours the suppression of osteosarcoma cell migration in a SPARC-independent manner

WIN55,212-2 (WIN) is a synthetic agonist of cannabinoid receptors that displays promising antitumour properties. The aim of this study is to demonstrate that WIN is able to block the migratory ability of osteosarcoma cells and characterize the mechanisms involved. Using wound healing assay and zymography, we showed that WIN affects cell migration and reduces the activity of the metalloproteases MMP2 and MMP9. This effect seemed to be independent of secreted protein acidic and rich in cysteine (SPARC), a matricellular protein involved in tissue remodeling and extracellular matrix deposition. SPARC release was indeed prevented by WIN, and SPARC silencing by RNA interference did not influence …

Hypertrophy and ER Stress Induced by Palmitate Are Counteracted by Mango Peel and Seed Extracts in 3T3-L1 Adipocytes

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 a…

Synthesis, chemical characterization, computational studies and biological activity of new DNA methyltransferases (DNMTs) specific inhibitor. Epigenetic regulation as a new and potential approach to cancer therapy.

This work deals with the synthesis, the chemical characterization of dibutyltin(IV) complex of caffeic acid (Bu2Sn(IV)HCAF, caf1) and its cytotoxic action on tumor cells. The coordination environment at the tin center was investigated by FTIR, (119)Sn{(1)H} cross polarization magic angle spinning, electrospray ionization mass spectroscopy in the solid state and UV-vis, fluorescence and (1)H, (13)C and (119)Sn NMR spectroscopy in solution phases. Density functional theory study confirmed the proposed structures in solution phase and indicated the most probably stable conformation. The effects on viability of breast cancer MDA-MB231, colorectal cancer HCT116, hepatocellular carcinoma HepG2 an…

Synthesis, chemical characterization, computational studies and biological activity of organotin(IV) compounds interacting with enzymes involoved in epigenetic regulation. New and potential methodologies for studying molecular interactions

Our studies deal with the synthesis, the chemical characterization of organotin(IV) complexes of molecules, as caffeic acid, interacting with enzymes involved in epigenetic regulation.

WIN-induced vesiculation cooperates to the inhibition of osteosarcoma cell migration

Introduction. Animal cells release vesicles that mediate the secretion of a variety of factors in the surrounding environment affecting neighboring cells. There is increasing evidence that secreted vesicles play an important role as vehicle of intercellular communication in different biological systems and are able to influence both physiological and pathological processes. Recently, we have reported that the synthetic cannabinoid WIN55,512 is able to induce osteosarcoma MG63 cell death and negatively affect cell migration. Here, we study the effects of WIN on the induction of vesicle secretion and their possible role in WIN-dependent reduction of osteosarcoma cell migratory ability. Method…

Effetti benefici degli oli essenziali nel trattamento anti-obesità

The involvement of the c-Jun/JNK/AP-1 pathway and HSPs in apoptosis induced by the proteasome inhibitor PS-341 (Velcade) in human hepatoma cells.

Degradation of IkBalfa during apoptosis induced by proteasome inhibitors in hepatoma cells.

Notch inhibition restores TRAIL-mediated apoptosis via AP1-dependent upregulation of DR4 and DR5 TRAIL receptors in MDA-MB-231 breast cancer cells.

Notch is a family of transmembrane receptors whose activation through proteolytic cleavage by γ-secretase targets genes which participate in cell development, differentiation and tumorigenesis. Notch signaling is constitutively activated in various cancers, including breast cancer and its upregulation is usually related with poor clinical outcomes. Therefore, targeting Notch signaling with γ-secretase inhibitors (GSIs) is considered a promising strategy for cancer treatment. We report that the γ-secretase inhibitor-I (GSI-I) sensitizes human breast cancer cells to apoptosis mediated by tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). The antiproliferative GSI-I/TRAIL synergi…

The role of oxidative stress in apoptosis induced by the histone deacetylase inhibitor suberoylanilide hydroxamic acid in human colon adenocarcinoma HT-29 cells.

Histone deacetylase inhibitors (HDACIs) activate genes that promote cell cycle arrest and apoptosis in a number of tumor cells. This study showed that suberoylanilide hydroxamic acid (SAHA), a potent and commonly used HDACI, induced apoptosis in human colon adenocarcinoma HT-29 cells in a time- and dose-dependent manner. This effect was accompanied by the induction of oxidative stress, dissipation of mitochondrial transmembrane potential and activation of executioner caspases. Moreover, SAHA increased the levels of phosphorylated active forms of p38 and JNK. The addition of either the antioxidant N-acetylcysteine or the specific inhibitor of NADPH oxidase diphenylene iodonium chloride reduc…

COINVOLGIMENTO DELLO STRESS DEL RETICOLO E DEL PROCESSO AUTOFAGICO NELL’APOPTOSI INDOTTA DAL CANNABINOIDE SINTETICO WIN IN CELLULE DI EPATOMA UMANO IN COLTURA

Studi da noi condotti precedentemente hanno dimostrato la capacità del cannabinoide sintetico WIN di indurre apoptosi in cellule di epatocarcinoma umano HepG2 attraverso un meccanismo, dipendente dal fattore trascrizionale PPARg, che prevede riduzione dei livelli di alcuni fattori di sopravvivenza e attivazione di fattori pro-apoptotici della famiglia Bcl-2 (M. Giuliano et al. Biochimie. 2009). Recentemente è, inoltre, emerso che in cellule di glioma i cannabinoidi possono stimolare l’apoptosi attraverso induzione di stress del reticolo endoplasmatico seguito da autofagia. Scopo L'obiettivo del presente studio è stato quello di valutare il coinvolgimento dell’autofagia nel percorso di morte…

Possible regulatory mechanisms responsible for the high expression of serpin protease inhibitor PI-9 in ER+ -derived breast cancer stem cells.

Breast cancer (BC) is the most common endocrine cancer and the second leading cause of cancer-related death in women. About 75% of BCs expresses high levels of estrogen receptors that sustain the tumor growth. Moreover, in BC estrogens prevent apoptosis induced by granzyme B released by cytotoxic T lymphocytes and NK cells through the production of the granzyme B inhibitor PI-9. As a consequence, cancer cells acquire the ability to escape immune surveillance’s signaling. Although some studies explored the role of PI-9 in BC cells, its presence has not been investigated in cancer stem cells so far. In this research, tertiary tumorspheres were obtained from estrogen receptor-alfa positive (ER…

The histone deacetylase inhibitor ITF2357 targets oncogenic BRAF in human melanoma cells

ITF2357 (Givinostat) is a potent antineoplastic histone deacetylase inhibitor which is currently used in clinical trials for leukemias and myelomas and in the therapy for systemic juvenile idiopathic arthritis. Here evidence is provided that ITF2357 reduces the viability of human melanoma SK-Mel28 cells thereby inducing cell death. This compound was more efficacious than SAHA, another well known HDAC inhibitor belonging to the same class of hydroxamic acids. Moreover, we demonstrated for the first time that ITF2357 determines in SK-Mel28 cells a remarkable reduction in the level of oncogenic B-Raf, the product of the BRAF V600E mutated gene in melanoma. Western blot analysis showed that the…

Involvement of PAR-4 in Cannabinoid-Dependent Sensitization of Osteosarcoma Cells to TRAIL-Induced Apoptosis

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 t…

Anandamide-induced apoptosis in Chang liver cells involves ceramide and JNK/AP-1 pathway

In the present study we demonstrate that anandamide, the most important endogenous cannabinoid, markedly induced apoptosis in Chang liver cells, an immortalized non-tumor cell line derived from normal liver tissue, while it induced only modest effects in a number of hepatoma cell lines. The apoptotic effect was reduced by methyl-beta-cyclodextrin, a membrane cholesterol depletor, suggesting an interaction between anandamide and the membrane microdomains named lipid rafts. Anandamide effects were mediated by the production of ceramide, as demonstrated by experiments performed with the sphingomyelinase inhibitor, desipramine, or with the sphingomyelinase activator, melittin. This conclusion w…

Low doses of paclitaxel potently induce apoptosis in human retinoblastoma Y79 cells by up-regulating E2F1.

Paclitaxel (PTX) is an anticancer drug currently in phase II clinical trials. This study shows for the first time that low doses of PTX (5 nM) potently induce apoptosis in human retinoblastoma Y79 cells. The effect of PTX is accompanied by a potent induction of E2F1 which appears to play a critical role in the effects induced by PTX. PTX induced a dose- and time-dependent effect, with G2/M arrest, cyclines A, E and B1 accumulation and a marked modification in the status of Cdc2-cyclin B1 complex, the major player of the G2/M checkpoint. Apoptosis followed G2/M arrest. An early and prolonged increase in p53 expression with its stabilization by phosphorylation and acetylation and its nuclear …

COMPLESSI POLINUCLEARI DI Pt(II)CON LEGANTI POLIPIRIDINICI. SINTESI, CARATTERIZZAZIONE STRUTTURALE E SPETTROSCOPICA, ATTIVITÀ CITOTOSSICA

WIN55,212-2, a synthetic agonist of cannabinoid receptors, sensitizes tumor cells to TRAIL-induced apoptosis.

Sicilian Litchi Fruit Extracts Induce Autophagy versus Apoptosis Switch in Human Colon Cancer Cells

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 t…

The cannabinoid system and its potential therapeutic applications in cancer.

THE CANNABINOID AGONIST WIN55,212-2 INDUCES APOPTOSIS IN HUMAN HEPATOMA CELLS.

Litchi chinensis as a Functional Food and a Source of Antitumor Compounds: An Overview and a Description of Biochemical Pathways.

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 comprehe…

Induction of apoptosis in human osteosarcoma Saos-2 cells by the proteasome inhibitor MG132 and the protective effect of pRb

Induction of apoptosis in human osteosarcoma Saos-2 cells by the proteasome inhibitor MG132 and the protective effect of pRb

Pattern of polyamines and related monoacetyl-derivatives in chick embryo retina during development

Autophagic cell death induced by Litchi fruit extracts in human colon cancer cells.

Litchi chinensis is a tropical fruit which cultivation has been recently introduced in Sicily. Some findings have shown that Litchi extracts display antitumor effects but the underlying mechanisms have not been elucidated. This study focuses on the effects of Litchi hydro-alcoholic extracts in colorectal cancer cells. The results indicated that Litchi exocarp (peel), mesocarp (pulp) and endocarp (seeds) extracts reduce the viability of HT-29 colon cancer cells in a dose dependent manner. This effect was accompanied with G2/M arrest of the cell cycle followed by cell death. Interestingly, exocarp and endocarp extracts triggered an autophagic response in the first phase of treatment (16-24h) …

Mono- and polynuclear complexes of Pt(II) with polypyridyl ligands. Synthesis, spectroscopic and structural characterization and cytotoxic activity.

Abstract An array of poly- and mononuclear complexes of Pt(II) with polypyridyl ligands is reported. The framework complexes [(PtCl 2 ) 2 (bpp) 2 (μ-PtCl 2 )](H 2 O) 2 [bpp = 2,3-bis(2-pyridyl)pyrazine], [PtCl 2 (μ-tptz)PtClNCPh]Cl [tptz = 2,4,6-tris(2-pyridyl)-1,3,5-triazine], and mononuclear PtCl 2 (NH 2 dpt) [NH 2 dpt = 4-amino-3,5-bis(2-pyridyl)-1,2,4-triazole] have been prepared and structurally characterized. Both neutral and ionic complexes are present, with bifunctional and monofunctional Pt(II) moieties, whose size and shape enable them to behave as novel scaffolds for DNA binding. Pt(II) complexes were tested for their biological activity. Cell viability assay and flow cytometric …

The Double-Edged Sword Profile of Redox Signaling: Oxidative Events As Molecular Switches in the Balance between Cell Physiology and Cancer.

The intracellular redox state in the cell depends on the balance between the level of reactive oxygen species (ROS) and the activity of defensive systems including antioxidant enzymes. This balance is a dynamic process that can change in relation to many factors and/or stimuli induced within the cell. ROS production is derived from physiological metabolic events. For instance, mitochondria represent the major ROS sources during oxidative phosphorylation, but other systems, such as NADPH oxidase or specific enzymes in certain metabolisms, may account for ROS production as well. Whereas high levels of ROS perturb the cell environment, causing oxidative damage to biological macromolecules, low…

Synthetic, structural and biochemical studies of polynuclear platinum(II) complexes with heterocyclic ligands.

"Non-classical" di- and trinuclear Pt(II) complexes with polydentate nitrogen ligands; ionic [(PtCl(2))(2)(tptz)(2)(mu-PtClNCPh)]Cl (1) [tptz =2,4,6-tris(2-pyridyl)-1,3,5-triazine], [(PtCl(2))(2)(bptz)(2)(mu-Pt)]Cl(2) (2) [bptz = 3,6-bis(2-pyridyl)-1,2,4,5-tetrazine] and neutral [(PtCl(2))(2)(tptz)(2)(mu-PtCl(2))](H(2)O)(4) (3), [(PtCl(2))(2)(mu-tppz)](CHCl(3)) (4) [tppz = 2,3,5,6-tetra(2-pyridyl)pyrazine] complexes, have been prepared and structurally characterized. The neutral tptz and tppz complexes present three and two separate PtCl(2) moieties, respectively, in a cis position, presumably acting in a bifunctional mode towards DNA; the cationic tptz and bptz complexes contain monofuncti…

Bio-Waste Products of Mangifera indica L. Reduce Adipogenesis and Exert Antioxidant Effects on 3T3-L1 Cells

Several studies highlighted the beneficial value of natural compounds in the prevention and treatment of obesity. Here, we investigated the anti-obesity effects of extracts of peel and seed of mango (Mangifera indica L.) cultivated in Sicily (Italy) in 3T3-L1 cells. Mango Peel (MPE) and Mango Seed (MSE) extracts at a 100 µg/mL concentration significantly reduced lipid accumulation and triacylglycerol contents during 3T3-L1 adipocyte differentiation without toxicity. HPLC-ESI-MS analysis showed that both the extracts contain some polyphenolic compounds that can account for the observed biological effects. The anti-adipogenic effect of MPE and MSE was the result of down-regulation of th…

Biochemical Aspects of Chick Embryo Retina Development: The Effects of Glucocorticoids

In chick embryo retina during development, DNA synthesis and the activities of DNA polymerase, thymidine kinase, thymidylate synthetase, and ornithine decarboxylase (ODC) declined in parallel from day 7 to 12. The administration in ovo of hydrocortisone reduced significantly, particularly at 8-10 days of incubation, both DNA synthesis and the four enzyme activities tested. The effect was dose dependent, reaching the maximum with 50-100 nmol of hydrocortisone, 8-16 h after treatment. The highest inhibition was found for ODC activity (70%), followed by thymidine kinase activity (62%) and DNA synthesis (45%), whereas activities of DNA polymerase and thymidylate synthetase were reduced only by …

APOPTOTIC EFFECTS INDUCED BY ANANDAMIDE IN HEPATIC CELLS.

New organotin(IV) complexes with L-Arginine,Nα-t-Boc-L-Arginine and L-Alanyl-L-Arginine.Synthesis, structural investigations and cytotoxic activity

Abstract Novel diorganotin(IV) derivatives of l -Arginine (HArg), N α -( tert -Butoxycarbonyl)- l -Arginine (Boc–Arg–OH) and l -Ala- l -Arg (H 2 Ala–Arg), H 2 NC( NH)NH(CH 2 ) 3 CH(NHR′)CO 2 H, where R′ = H in HArg, R′ = C(O)OC(CH 3 ) 3 in Boc–Arg–OH, R′ = H 2 NCH(CH 3 )CO in H 2 Ala–Arg and triorganotin(IV) derivatives of Boc–Arg–OH have been synthesized and structurally characterized. The complexes were investigated by FT-IR and 119 Sn Mossbauer in the solid state and by 1 H, 13 C, 119 Sn and 1 H– 1 H COSY NMR spectroscopy, in solution. The spectroscopic characterization leading to the proposed molecular structures was accomplished on the basis of these experiments. l -Arginine appears to…

The Synthetic Cannabinoid WIN 55,212-2 Sensitizes Hepatocellular Carcinoma Cells to Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand (TRAIL)-Induced Apoptosis by Activating p8/CCAAT/Enhancer Binding Protein Homologous Protein (CHOP)/Death Receptor 5 (DR5) Axis

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 implicat…

Effects of hydrocortisone on chick embryo liver during development

Routes to cell death in animal and plant kingdoms: from classic apoptosis to alternative ways to die—a review

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, …

Brain Opioid Activity and Oxidative Injury: Different Molecular Scenarios Connecting Celiac Disease and Autistic Spectrum Disorder

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 neon…

The secreted protein acidic and rich in cysteine is a critical mediator of cell death program induced by WIN/TRAIL combined treatment in osteosarcoma cells.

Abstract 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 apoptosi…

Identification of Insulin in Chick Embryo Retina During Development and Its Inhibitory Effect on DNA Synthesis

Incubation of chick embryo retinal explants with insulin resulted in a pronounced inhibition of thymidine uptake and incorporation into trichloroacetic acid-insoluble fraction. The inhibitory effect was highest with explants from embryos at day 7 and day 8, and thereafter it declined markedly with the age of embryos until day 11. A time-course study of the effect revealed that the inhibition occurred after a lag time; both thymidine uptake and incorporation were not altered significantly after 2-6 h of incubation with insulin, but began to decrease thereafter, reaching the maximum after 16 h. The effect was also dose dependent. After 16 h of incubation, the maximal inhibition (65%) was foun…

The transcription factor CHOP is critical for WIN-mediated DR5 up-regulation in apoptosis induced by WIN/TRAIL co-treatment in hepatoma cells

Pattern of polyamines and related monoacetyl derivatives in chick embryo retina during development.

Polyamines and related monoacetyl derivatives were studied in chick embryo retina during development (6th-19th day). Putrescine, which is high in the first phase of retinogenesis, is necessary to sustain both tissue proliferation and via N-acetylputrescine, gamma-aminobutyric acid synthesis. A later increase in spermidine and particularly spermine may play a role in the last phase of development when the retina reaches maturation. The presence of N1-acetylspermidine already at the 8th day indicates that in chick embryo retina, putrescine synthesis can depend on two separate pathways. The first involves ornithine decarboxylase activity; the second, spermidine/spermine N1-acetyltransferase an…

ROS-Dependent ER Stress and Autophagy Mediate the Anti-Tumor Effects of Tributyltin (IV) Ferulate in Colon Cancer Cells

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 silenc…

Gluten Free Diet for the Management of Non Celiac Diseases: The Two Sides of the Coin

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 as…

A factor derived from chick embryo retina which inhibits DNA synthesis of retina itself.

Chick embryo retinas contain a peptide factor that inhibits DNA synthesis in explants of chick embryo retina. The inhibitory factor, obtained by acid/ethanol extraction from 15-day-old chick embryo retinas, was partially purified by affinity chromatography on heparin-sepharose CL-6B and gel filtration on Sephadex G-100. The inhibitor reduced DNA synthesis with maximal effects observed in retinal explants from 7 to 8-day-old chick embryos. The inhibitory effect became apparent after 10 h of incubation and reached the maximum levels after 16 h. DNA-inhibiting activity was heat and acid-stable and was destroyed by trypsin and alkaline treatments. The inhibitory effect was observed in retinal e…