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…

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

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

Nuove tecniche di dosaggio: la Cloned Enzyme Donor Immuno Assay (CEDIA)

Electrophoretic Mobility Shift Assay (EMSA) or Gel Shift Assay

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…

140 p8 (Candidate Of Metastasis 1) drives ER-stress/autophagy/apoptosis axis induced by the synthetic cannabinoid WIN in HCC cells

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

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 …

Production and purification of His-tagged recombinant proteins.

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

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…

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

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

Complessi di Organostagno(IV) con amminoacidi e dipeptidi: sintesi, caratterizzazione e attività biologica in vitro.

Scopo della ricerca è la sintesi, caratterizzazione strutturale ed attività biologica di complessi di organostagno(IV) e amminoacidi quali L-arginina (Arg), N-Boc-L-arginina (Boc-Arg), L-ornitina (L-Orn) ed un dipeptide contenente L-arginina, Alanil-Arginina (Ala-Arg). I complessi di diorganostagno(IV) sono noti possedere attività antitumorale [1], antimicrobica [2] e antiinfiammatoria. I complessi di triorganostagno(IV) inibiscono la funzione mitocondriale almeno in tre modi: 1) reagendo con le membrane cellulari; 2) alterando lo scambio Cl-/OH- attraverso la membrana; 3) inibendo la fosforilazione ossidativa o l’idrolisi di ATP [3].L’arginina (Arg) è un amminoacido essenziale con un grup…

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

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

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…

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…

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…

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.

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

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 …

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…

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…

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

Sintesi, caratterizzazione e studio dell'attività biologica di nuovi complessi mononucleari di PT(II) con leganti eterociclici

Sono stati precedentemente sintetizzati complessi mono- e polinucleari di Pt(II) [1, 2] che hanno mostrato attività citotossica maggiore del cisplatino. Tre nuovi complessi mononucleari di Pt(II) analoghi del cisplatino sono stati quindi in seguito preparati usando leganti eterociclici quali: 5,6-difenil-3-(2-piridil)-1,2,4-triazina-4’,4’’-disulfonato sodico (dptdn), 5,6-difenil-3-(2-piridil)-1,2,4-triazina (dpt) e 2,6-bis(2-benzimidazolil)piridina (bbp). I risultanti tre complessi [PtCl(bbp)]Cl (1), [PtCl2(dptdn)](H2O) (2) e [(dptdn)(dpt)Pt]Cl2(H2O) (3), ionici (1) e (3) e neutro (2), sono stati sintetizzati e strutturalmente caratterizzati tramite spettroscopia IR e NMR 1D e 2D 1H e 13C. …