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

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

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…

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 …

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

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

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

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

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…

Ruolo citotossico del cannabinoide sintetico WIN55,212-2 in cellule di osteosarcoma MG63: coinvolgimento della proteina SPARC.

Il cannabinoide sintetico WIN 55,212-2 è un potente agonista sintetico del recettore per i cannabinoidi con spiccate potenzialità antitumorali. Gli esperimenti riportati in questa tesi sono stati condotti per delineare gli effetti indotti dal WIN sulla proliferazione, la migrazione e la sensibilizzazione alla morte indotta dalla citochina TRAIL in cellule di osteosarcoma umano MG63. I risultati ottenuti mostrano che il WIN induce un blocco del ciclo cellulare in fase G2/M che è associato all’induzione dei principali markers di ER stress (GRP78, CHOP e TRB3). Nelle cellule trattate abbiamo inoltre osservato la conversione della forma citosolica del marker autofagosomale LC3-I in LC3-II (la f…

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…

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…

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…