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 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.
Dipartimento di Scienze Biochimiche, Università degli Studi di Palermo, Palermo, Italy.
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Pellerito
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Calvaruso
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Portanova
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De Blasio
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Santulli
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Vento
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Tesoriere
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Giuliano
D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D048588:Benzoxazines / Q000494:pharmacology*; D002186:Cannabinoids / Q000494:pharmacology*; D006528:Carcinoma, Hepatocellular / Q000378:metabolism* / Q000473:pathology; D045744:Cell Line, Tumor / Q000187:drug effects / Q000502:physiology; D017931:DNA Primers; D018076:DNA, Complementary / Q000187:drug effects / Q000235:genetics; D004273:DNA, Neoplasm / Q000187:drug effects / Q000235:genetics; D005434:Flow Cytometry; D005784:Gene Amplification; D006801:Humans; D008113:Liver Neoplasms / Q000378:metabolism*; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D051336:Mitochondrial Membranes / Q000187:drug effects / Q000502:physiology; D009025:Morpholines / Q000494:pharmacology*; D009281:Naphthalenes / Q000494:pharmacology*; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand / Q000187:drug effects / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D053221:TNF-Related Apoptosis-Inducing Ligand / Q000494:pharmacology*; D051742:Transcription Factor CHOP / Q000187:drug effects / Q000502:physiology*
D048588:Benzoxazines; D002186:Cannabinoids; C497249:DDIT3 protein, human; D017931:DNA Primers; D018076:DNA, Complementary; D004273:DNA, Neoplasm; D009025:Morpholines; D009281:Naphthalenes; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D053221:TNF-Related Apoptosis-Inducing Ligand; C505653:TNFSF10 protein, human; D051742:Transcription Factor CHOP; C070417:(3R)-((2,3-dihydro-5-methyl-3-((4-morpholinyl)methyl)pyrrolo-(1,2,3-de)-1,4-benzoxazin-6-yl)(1-naphthalenyl))methanone